An autosomal dominant defect of cardiac conduction that is characterized by an abnormal ST-segment in leads V1-V3 on the ELECTROCARDIOGRAM resembling a right BUNDLE-BRANCH BLOCK; high risk of VENTRICULAR TACHYCARDIA; or VENTRICULAR FIBRILLATION; SYNCOPAL EPISODE; and possible sudden death. This syndrome is linked to mutations of gene encoding the cardiac SODIUM CHANNEL alpha subunit.
A characteristic symptom complex.
A voltage-gated sodium channel subtype that mediates the sodium ion PERMEABILITY of CARDIOMYOCYTES. Defects in the SCN5A gene, which codes for the alpha subunit of this sodium channel, are associated with a variety of CARDIAC DISEASES that result from loss of sodium channel function.
An alkaloid found in the root of RAUWOLFIA SERPENTINA, among other plant sources. It is a class Ia antiarrhythmic agent that apparently acts by changing the shape and threshold of cardiac action potentials.
A form of heart block in which the electrical stimulation of HEART VENTRICLES is interrupted at either one of the branches of BUNDLE OF HIS thus preventing the simultaneous depolarization of the two ventricles.
A potentially lethal cardiac arrhythmia that is characterized by uncoordinated extremely rapid firing of electrical impulses (400-600/min) in HEART VENTRICLES. Such asynchronous ventricular quivering or fibrillation prevents any effective cardiac output and results in unconsciousness (SYNCOPE). It is one of the major electrocardiographic patterns seen with CARDIAC ARREST.
Recording of the moment-to-moment electromotive forces of the HEART as projected onto various sites on the body's surface, delineated as a scalar function of time. The recording is monitored by a tracing on slow moving chart paper or by observing it on a cardioscope, which is a CATHODE RAY TUBE DISPLAY.
Ion channels that specifically allow the passage of SODIUM ions. A variety of specific sodium channel subtypes are involved in serving specialized functions such as neuronal signaling, CARDIAC MUSCLE contraction, and KIDNEY function.
Unexpected rapid natural death due to cardiovascular collapse within one hour of initial symptoms. It is usually caused by the worsening of existing heart diseases. The sudden onset of symptoms, such as CHEST PAIN and CARDIAC ARRHYTHMIAS, particularly VENTRICULAR TACHYCARDIA, can lead to the loss of consciousness and cardiac arrest followed by biological death. (from Braunwald's Heart Disease: A Textbook of Cardiovascular Medicine, 7th ed., 2005)
An impulse-conducting system composed of modified cardiac muscle, having the power of spontaneous rhythmicity and conduction more highly developed than the rest of the heart.
A transient loss of consciousness and postural tone caused by diminished blood flow to the brain (i.e., BRAIN ISCHEMIA). Presyncope refers to the sensation of lightheadedness and loss of strength that precedes a syncopal event or accompanies an incomplete syncope. (From Adams et al., Principles of Neurology, 6th ed, pp367-9)
A potent anti-arrhythmia agent, effective in a wide range of ventricular and atrial ARRHYTHMIAS and TACHYCARDIAS.
Methods to induce and measure electrical activities at specific sites in the heart to diagnose and treat problems with the heart's electrical system.
Agents used for the treatment or prevention of cardiac arrhythmias. They may affect the polarization-repolarization phase of the action potential, its excitability or refractoriness, or impulse conduction or membrane responsiveness within cardiac fibers. Anti-arrhythmia agents are often classed into four main groups according to their mechanism of action: sodium channel blockade, beta-adrenergic blockade, repolarization prolongation, or calcium channel blockade.
Any disturbances of the normal rhythmic beating of the heart or MYOCARDIAL CONTRACTION. Cardiac arrhythmias can be classified by the abnormalities in HEART RATE, disorders of electrical impulse generation, or impulse conduction.
An abnormally rapid ventricular rhythm usually in excess of 150 beats per minute. It is generated within the ventricle below the BUNDLE OF HIS, either as autonomic impulse formation or reentrant impulse conduction. Depending on the etiology, onset of ventricular tachycardia can be paroxysmal (sudden) or nonparoxysmal, its wide QRS complexes can be uniform or polymorphic, and the ventricular beating may be independent of the atrial beating (AV dissociation).
Implantable devices which continuously monitor the electrical activity of the heart and automatically detect and terminate ventricular tachycardia (TACHYCARDIA, VENTRICULAR) and VENTRICULAR FIBRILLATION. They consist of an impulse generator, batteries, and electrodes.
A condition that is characterized by episodes of fainting (SYNCOPE) and varying degree of ventricular arrhythmia as indicated by the prolonged QT interval. The inherited forms are caused by mutation of genes encoding cardiac ion channel proteins. The two major forms are ROMANO-WARD SYNDROME and JERVELL-LANGE NIELSEN SYNDROME.
An optical isomer of quinine, extracted from the bark of the CHINCHONA tree and similar plant species. This alkaloid dampens the excitability of cardiac and skeletal muscles by blocking sodium and potassium currents across cellular membranes. It prolongs cellular ACTION POTENTIALS, and decreases automaticity. Quinidine also blocks muscarinic and alpha-adrenergic neurotransmission.
A voltage-gated sodium channel beta subunit abundantly expressed in SKELETAL MUSCLE; HEART; and BRAIN. It non-covalently associates with voltage-gated alpha subunits. Defects in the SCN1B gene, which codes for this beta subunit, are associated with generalized epilepsy with febrile seizures plus, type 1, and Brugada syndrome 5.
A class of drugs that act by inhibition of sodium influx through cell membranes. Blockade of sodium channels slows the rate and amplitude of initial rapid depolarization, reduces cell excitability, and reduces conduction velocity.
A class Ia antiarrhythmic drug that is structurally-related to PROCAINE.
The protein constituents of muscle, the major ones being ACTINS and MYOSINS. More than a dozen accessory proteins exist including TROPONIN; TROPOMYOSIN; and DYSTROPHIN.
A mutation in which a codon is mutated to one directing the incorporation of a different amino acid. This substitution may result in an inactive or unstable product. (From A Dictionary of Genetics, King & Stansfield, 5th ed)
A voltage-gated sodium channel beta subunit subtype that non-covalently associates with voltage-gated alpha subunits. Defects in the SCN3B gene which codes for this beta subunit are associated with Brugada syndrome 7.
A congenital cardiomyopathy that is characterized by infiltration of adipose and fibrous tissue into the RIGHT VENTRICLE wall and loss of myocardial cells. Primary injuries usually are at the free wall of right ventricular and right atria resulting in ventricular and supraventricular arrhythmias.
Any detectable and heritable change in the genetic material that causes a change in the GENOTYPE and which is transmitted to daughter cells and to succeeding generations.
An ethanolamine derivative that is an adrenergic alpha-1 agonist. It is used as a vasoconstrictor agent in the treatment of HYPOTENSION.
The record of descent or ancestry, particularly of a particular condition or trait, indicating individual family members, their relationships, and their status with respect to the trait or condition.
A condition caused by dysfunctions related to the SINOATRIAL NODE including impulse generation (CARDIAC SINUS ARREST) and impulse conduction (SINOATRIAL EXIT BLOCK). It is characterized by persistent BRADYCARDIA, chronic ATRIAL FIBRILLATION, and failure to resume sinus rhythm following CARDIOVERSION. This syndrome can be congenital or acquired, particularly after surgical correction for heart defects.
A selective histamine H1-receptor antagonist devoid of central nervous system depressant activity. The drug was used for ALLERGY but withdrawn due to causing LONG QT SYNDROME.
Biochemical identification of mutational changes in a nucleotide sequence.
The innermost layer of the heart, comprised of endothelial cells.
The transmission of traits encoded in GENES from parent to offspring.
Antiarrhythmic agent pharmacologically similar to LIDOCAINE. It may have some anticonvulsant properties.
A chromosome disorder associated either with an extra chromosome 21 or an effective trisomy for chromosome 21. Clinical manifestations include hypotonia, short stature, brachycephaly, upslanting palpebral fissures, epicanthus, Brushfield spots on the iris, protruding tongue, small ears, short, broad hands, fifth finger clinodactyly, Simian crease, and moderate to severe INTELLECTUAL DISABILITY. Cardiac and gastrointestinal malformations, a marked increase in the incidence of LEUKEMIA, and the early onset of ALZHEIMER DISEASE are also associated with this condition. Pathologic features include the development of NEUROFIBRILLARY TANGLES in neurons and the deposition of AMYLOID BETA-PROTEIN, similar to the pathology of ALZHEIMER DISEASE. (Menkes, Textbook of Child Neurology, 5th ed, p213)
Abrupt changes in the membrane potential that sweep along the CELL MEMBRANE of excitable cells in response to excitation stimuli.
A conical fibro-serous sac surrounding the HEART and the roots of the great vessels (AORTA; VENAE CAVAE; PULMONARY ARTERY). Pericardium consists of two sacs: the outer fibrous pericardium and the inner serous pericardium. The latter consists of an outer parietal layer facing the fibrous pericardium, and an inner visceral layer (epicardium) resting next to the heart, and a pericardial cavity between these two layers.
The study of the electrical activity and characteristics of the HEART; MYOCARDIUM; and CARDIOMYOCYTES.
A cluster of metabolic risk factors for CARDIOVASCULAR DISEASES and TYPE 2 DIABETES MELLITUS. The major components of metabolic syndrome X include excess ABDOMINAL FAT; atherogenic DYSLIPIDEMIA; HYPERTENSION; HYPERGLYCEMIA; INSULIN RESISTANCE; a proinflammatory state; and a prothrombotic (THROMBOSIS) state. (from AHA/NHLBI/ADA Conference Proceedings, Circulation 2004; 109:551-556)
A group of conditions in which HEART VENTRICLE activation by the atrial impulse is faster than the normal impulse conduction from the SINOATRIAL NODE. In these pre-excitation syndromes, atrial impulses often bypass the ATRIOVENTRICULAR NODE delay and travel via ACCESSORY CONDUCTING PATHWAYS connecting the atrium directly to the BUNDLE OF HIS.
The abrupt cessation of all vital bodily functions, manifested by the permanent loss of total cerebral, respiratory, and cardiovascular functions.
A local anesthetic and cardiac depressant used as an antiarrhythmia agent. Its actions are more intense and its effects more prolonged than those of PROCAINE but its duration of action is shorter than that of BUPIVACAINE or PRILOCAINE.
The outward appearance of the individual. It is the product of interactions between genes, and between the GENOTYPE and the environment.
Diseases of the parasympathetic or sympathetic divisions of the AUTONOMIC NERVOUS SYSTEM; which has components located in the CENTRAL NERVOUS SYSTEM and PERIPHERAL NERVOUS SYSTEM. Autonomic dysfunction may be associated with HYPOTHALAMIC DISEASES; BRAIN STEM disorders; SPINAL CORD DISEASES; and PERIPHERAL NERVOUS SYSTEM DISEASES. Manifestations include impairments of vegetative functions including the maintenance of BLOOD PRESSURE; HEART RATE; pupil function; SWEATING; REPRODUCTIVE AND URINARY PHYSIOLOGY; and DIGESTION.
Recording of regional electrophysiological information by analysis of surface potentials to give a complete picture of the effects of the currents from the heart on the body surface. It has been applied to the diagnosis of old inferior myocardial infarction, localization of the bypass pathway in Wolff-Parkinson-White syndrome, recognition of ventricular hypertrophy, estimation of the size of a myocardial infarct, and the effects of different interventions designed to reduce infarct size. The limiting factor at present is the complexity of the recording and analysis, which requires 100 or more electrodes, sophisticated instrumentation, and dedicated personnel. (Braunwald, Heart Disease, 4th ed)
Software application for retrieving, presenting and traversing information resources on the World Wide Web.
The lower right and left chambers of the heart. The right ventricle pumps venous BLOOD into the LUNGS and the left ventricle pumps oxygenated blood into the systemic arterial circulation.
Cessation of heart beat or MYOCARDIAL CONTRACTION. If it is treated within a few minutes, heart arrest can be reversed in most cases to normal cardiac rhythm and effective circulation.
A variety of neuromuscular conditions resulting from MUTATIONS in ION CHANNELS manifesting as episodes of EPILEPSY; HEADACHE DISORDERS; and DYSKINESIAS.
An electrical current applied to the HEART to terminate a disturbance of its rhythm, ARRHYTHMIAS, CARDIAC. (Stedman, 25th ed)
Method in which prolonged electrocardiographic recordings are made on a portable tape recorder (Holter-type system) or solid-state device ("real-time" system), while the patient undergoes normal daily activities. It is useful in the diagnosis and management of intermittent cardiac arrhythmias and transient myocardial ischemia.
Detection of a MUTATION; GENOTYPE; KARYOTYPE; or specific ALLELES associated with genetic traits, heritable diseases, or predisposition to a disease, or that may lead to the disease in descendants. It includes prenatal genetic testing.
Identification of genetic carriers for a given trait.
An electrophysiologic technique for studying cells, cell membranes, and occasionally isolated organelles. All patch-clamp methods rely on a very high-resistance seal between a micropipette and a membrane; the seal is usually attained by gentle suction. The four most common variants include on-cell patch, inside-out patch, outside-out patch, and whole-cell clamp. Patch-clamp methods are commonly used to voltage clamp, that is control the voltage across the membrane and measure current flow, but current-clamp methods, in which the current is controlled and the voltage is measured, are also used.
A class I anti-arrhythmic agent (one that interferes directly with the depolarization of the cardiac membrane and thus serves as a membrane-stabilizing agent) with a depressant action on the heart similar to that of guanidine. It also possesses some anticholinergic and local anesthetic properties.
A guanidine that opens POTASSIUM CHANNELS producing direct peripheral vasodilatation of the ARTERIOLES. It reduces BLOOD PRESSURE and peripheral resistance and produces fluid retention. (Martindale The Extra Pharmacopoeia, 31st ed)
An antiarrhythmia agent that is particularly effective in ventricular arrhythmias. It also has weak beta-blocking activity.
Computer-assisted processing of electric, ultrasonic, or electronic signals to interpret function and activity.
A condition characterized by severe PROTEINURIA, greater than 3.5 g/day in an average adult. The substantial loss of protein in the urine results in complications such as HYPOPROTEINEMIA; generalized EDEMA; HYPERTENSION; and HYPERLIPIDEMIAS. Diseases associated with nephrotic syndrome generally cause chronic kidney dysfunction.
A latent susceptibility to disease at the genetic level, which may be activated under certain conditions.
Chronic inflammatory and autoimmune disease in which the salivary and lacrimal glands undergo progressive destruction by lymphocytes and plasma cells resulting in decreased production of saliva and tears. The primary form, often called sicca syndrome, involves both KERATOCONJUNCTIVITIS SICCA and XEROSTOMIA. The secondary form includes, in addition, the presence of a connective tissue disease, usually rheumatoid arthritis.
Studies in which individuals or populations are followed to assess the outcome of exposures, procedures, or effects of a characteristic, e.g., occurrence of disease.

A novel SCN5A mutation, F1344S, identified in a patient with Brugada syndrome and fever-induced ventricular fibrillation. (1/287)

OBJECTIVE: Brugada syndrome (BS) is an inherited electrical cardiac disorder characterized by right bundle branch block pattern and ST segment elevation in leads V1 to V3 on surface electrocardiogram that can potentially lead to malignant ventricular tachycardia and sudden cardiac death. About 20% of patients have mutations in the only so far identified gene, SCN5A, which encodes the alpha-subunit of the human cardiac voltage-dependent sodium channel (hNa(v)1.5). Fever has been shown to unmask or trigger the BS phenotype, but the associated molecular and the biophysical mechanisms are still poorly understood. We report on the identification and biophysical characterization of a novel heterozygous missense mutation in SCN5A, F1344S, in a 42-year-old male patient showing the BS phenotype leading to ventricular fibrillation during fever. METHODS: The mutation was reproduced in vitro using site-directed mutagenesis and characterized using the patch clamp technique in the whole-cell configuration. RESULTS: The biophysical characterization of the channels carrying the F1344S mutation revealed a 10 mV mid-point shift of the G/V curve toward more positive voltages during activation. Raising the temperature to 40.5 degrees C further shifted the mid-point activation by 18 mV and significantly changed the slope factor in Na(v)1.5/F1344S mutant channels from -6.49 to -10.27 mV. CONCLUSIONS: Our findings indicate for the first time that the shift in activation and change in the slope factor at a higher temperature mimicking fever could reduce sodium currents' amplitude and trigger the manifestation of the BS phenotype.  (+info)

Low-dose isoproterenol for repetitive ventricular arrhythmia in patients with Brugada syndrome. (2/287)

AIMS: Arrhythmic storm or repetitive ventricular arrhythmia (VA) has been occasionally observed in Brugada syndrome (BS). A beta-adrenergic stimulator [isoproterenol (ISP)] has been reported to suppress this arrhythmic storm in sporadic cases. Accordingly, we investigated the antiarrhythmic effects of ISP infusion in consecutive BS patients with arrhythmic storm or repetitive VA. METHODS AND RESULTS: Seven BS patients with arrhythmic storm were studied. Intravenous ISP was administered as a bolus injection (1-2 microg), followed by continuous infusion (0.15 microg/min). Arrhythmic storm or repetitive VA was suppressed immediately after the bolus administration of ISP, which was followed by continuous infusion of low-dose ISP for 1-3 days. In all patients, ST-elevation decreased in right precordial leads. In six of the seven patients, VA subsided after the discontinuance of ISP. RR interval was shortened and ST-elevation in right precordial leads was decreased after ISP bolus injection. ST-elevation in right precordial leads remained decreased during continuous ISP infusion, whereas the RR interval returned to the control level. CONCLUSION: Continuous administration of low-dose ISP may be effective for the suppression of repetitive VA occurrence in patients with BS.  (+info)

Sodium channel kinetic changes that produce Brugada syndrome or progressive cardiac conduction system disease. (3/287)

Some mutations of the sodium channel gene Na(V1.5) are multifunctional, causing combinations of LQTS, Brugada syndrome and progressive cardiac conduction system disease (PCCD). The combination of Brugada syndrome and PCCD is uncommon, although they both result from a reduction in the sodium current. We hypothesize that slow conduction is sufficient to cause S-T segment elevation and undertook a combined experimental and theoretical study to determine whether conduction slowing alone can produce the Brugada phenotype. Deletion of lysine 1479 in one of two positively charged clusters in the III/IV inter-domain linker causes both syndromes. We have examined the functional effects of this mutation using heterologous expression of the wild-type and mutant sodium channel in HEK-293-EBNA cells. We show that DeltaK1479 shifts the potential of half-activation, V(1/2m), to more positive potentials (V(1/2m) = -36.8 +/- 0.8 and -24.5 +/- 1.3 mV for the wild-type and DeltaK1479 mutant respectively, n = 11, 10). The depolarizing shift increases the extent of depolarization required for activation. The potential of half-inactivation, V(1/2h), is also shifted to more positive potentials (V(1/2h) = -85 +/- 1.1 and -79.4 +/- 1.2 mV for wild-type and DeltaK1479 mutant respectively), increasing the fraction of channels available for activation. These shifts are quantitatively the same as a mutation that produces PCCD only, G514C. We incorporated experimentally derived parameters into a model of the cardiac action potential and its propagation in a one dimensional cable (simulating endo-, mid-myocardial and epicardial regions). The simulations show that action potential and ECG changes consistent with Brugada syndrome may result from conduction slowing alone; marked repolarization heterogeneity is not required. The findings also suggest how Brugada syndrome and PCCD which both result from loss of sodium channel function are sometimes present alone and at other times in combination.  (+info)

Negative flecainide test in Brugada syndrome patients with previous positive response. (4/287)

Class I antiarrhythmic drug infusion has been established as the standard test to unmask Brugada syndrome. This report presents two patients with Brugada syndrome with positive flecainide response which was not reproducible in a subsequent test.  (+info)

A prospective study on spontaneous fluctuations between diagnostic and non-diagnostic ECGs in Brugada syndrome: implications for correct phenotyping and risk stratification. (5/287)

AIMS: Fluctuations between the diagnostic ECG pattern and non-diagnostic ECGs in patients with Brugada syndrome are known, but systematic studies are lacking. The purpose of this study was to prospectively evaluate the spontaneous ECG changes between diagnostic and non-diagnostic ECG patterns in patients diagnosed with Brugada syndrome. METHODS AND RESULTS: In 43 patients with Brugada syndrome (27 males; mean age 45+/-11 years), 310 resting ECGs were obtained during a median follow-up of 17.7 months. The ECGs were analysed for the presence of coved type, saddle-back type or no, respectively unspecific, changes. A coved-type ECG pattern with more than 2 mm ST-segment elevation in at least two right precordial leads was defined as diagnostic. The patients were compared for different clinical characteristics with respect to the pattern of fluctuations. Out of a total of 310 ECGs, 102 (33%) revealed a coved type, 91 (29%) a saddle-back type, and 117 (38%) a normal ECG. Fifteen patients (35%) initially presented with a diagnostic coved-type ECG. Fourteen patients (33%) with an initially coved-type ECG exhibited intermittently non-diagnostic ECGs during follow-up. Only one patient (2%) presented constantly with a coved-type ECG. Out of 28 patients (65%) with an initially non-diagnostic ECG, eight (19%) patients developed a diagnostic coved-type ECG during follow-up. Twenty patients (47%) revealed a coved-type ECG during ajmaline challenge, but never had a baseline coved-type ECG recorded. No significant differences were found in gender and clinical characteristics among patients with or without fluctuations between diagnostic and non-diagnostic basal ECGs. The rate of inducible ventricular fibrillation was significantly higher in patients with more than 50% coved-type ECGs than in patients with less than 50% diagnostic ECGs. CONCLUSION: The prevalence of fluctuations between diagnostic and non-diagnostic ECGs in patients with Brugada syndrome is high and may have an implication on the correct phenotyping and on the risk stratification in patients with Brugada syndrome without aborted sudden cardiac death. For correct phenotyping and risk stratification, repetitive ECG recordings seem to be mandatory.  (+info)

Frequency of Brugada-type ECG pattern (Brugada sign) in Southern Turkey. (6/287)

The frequency of Brugada sign was found to differ among ethnic groups. Yet, there is no data regarding the prevalence of Brugada syndrome and sign in our country. The aim of this study was to determine the frequency of a Brugada-type electrocardiogram (ECG) pattern in southern Turkey. A total of 1,238 subjects (males, 671, females, 567) were included in the study. The previously archived ECGs of 807 subjects without any evidence of structural heart disease were chosen randomly and evaluated. In addition, prospective analysis of the ECGs of 431 subjects (males, 293, females, 138) randomly chosen from healthy university students were also included. The mean age was 38.9 +/- 17.6 years. Six subjects (0.48%) had a Brugada-type ECG pattern. One (0.08%) of them had the coved-type and 5 (0.40%) had the saddleback-type. All subjects were asymptomatic. A Brugada-type ECG pattern was obtained in 1 (0.17%) female and in 5 (0.74%) males (OR: 4.2 CI: 0.5-36.4, P = 0.2). The Brugada-type ECG pattern frequency was 0.12% in subjects >or= 25 years old and 1.16% in subjects between 17-24 years old (OR: 9.4 CI: 1.1-81.2, P = 0.02). Young males between 17-24 years had the highest (1.70%) frequency. The results indicate that the frequency of the Brugada-type ECG pattern was 0.48% in the general population, being more prevalent in young males in our region. These results are similar to the findings of studies performed in other countries.  (+info)

Brugada syndrome. (7/287)

A novel clinical entity characterized by ST segment elevation in right precordial leads (V1 to V3), incomplete or complete right bundle branch block, and susceptibility to ventricular tachyarrhythmia and sudden cardiac death has been described by Brugada et al. in 1992. This disease is now frequently called "Brugada syndrome" (BrS). The prevalence of BrS in the general population is unknown. The suggested prevalence ranges from 5/1,000 (Caucasians) to 14/1,000 (Japanese). Syncope, typically occurring at rest or during sleep (in individuals in their third or fourth decades of life) is a common presentation of BrS. In some cases, tachycardia does not terminate spontaneously and it may degenerate into ventricular fibrillation and lead to sudden death. Both sporadic and familial cases have been reported and pedigree analysis suggests an autosomal dominant pattern of inheritance. In approximately 20% of the cases BrS is caused by mutations in the SCN5A gene on chromosome 3p21-23, encoding the cardiac sodium channel, a protein involved in the control of myocardial excitability. Since the use of the implantable cardioverter defibrillator (ICD) is the only therapeutic option of proven efficacy for primary and secondary prophylaxis of cardiac arrest, the identification of high-risk subjects is one of the major goals in the clinical decision-making process. Quinidine may be regarded as an adjunctive therapy for patients at higher risk and may reduce the number of cases of ICD shock in patients with multiple recurrences.  (+info)

Brugada syndrome. (8/287)

First introduced as a new clinical entity in 1992, the Brugada syndrome is associated with a relatively high risk of sudden death in young adults, and occasionally in children and infants. Recent years have witnessed a striking proliferation of papers dealing with the clinical and basic aspects of the disease. Characterized by a coved-type ST-segment elevation in the right precordial leads of the electrocardiogram (ECG), the Brugada syndrome has a genetic basis that thus far has been linked only to mutations in SCN5A, the gene that encodes the alpha-subunit of the sodium channel. The Brugada ECG is often concealed, but can be unmasked or modulated by a number of drugs and pathophysiological states including sodium channel blockers, a febrile state, vagotonic agents, tricyclic antidepressants, as well as cocaine and propranolol intoxication. Average age at the time of initial diagnosis or sudden death is 40 +/- 22, with the youngest patient diagnosed at 2 days of age and the oldest at 84 years. This review provides an overview of the clinical, genetic, molecular, and cellular aspects of the Brugada syndrome, incorporating the results of two recent consensus conferences. Controversies with regard to risk stratification and newly proposed pharmacologic strategies are discussed.  (+info)

Brugada Syndrome is a genetic disorder characterized by abnormal electrocardiogram (ECG) findings and an increased risk of sudden cardiac death. It is typically caused by a mutation in the SCN5A gene, which encodes for a sodium channel protein in the heart. This mutation can lead to abnormal ion transport in the heart cells, causing changes in the electrical activity of the heart that can trigger dangerous arrhythmias.

The ECG findings associated with Brugada Syndrome include a distinct pattern of ST-segment elevation in the right precordial leads (V1-V3), which can appear spontaneously or be induced by certain medications. The syndrome is often classified into two types based on the presence or absence of symptoms:

* Type 1 Brugada Syndrome: This type is characterized by a coved-type ST-segment elevation of at least 2 mm in height in at least one right precordial lead, with a negative T wave. This pattern must be present to make the diagnosis, and it should not be transient or induced by any medication or condition. Type 1 Brugada Syndrome is associated with a higher risk of sudden cardiac death.
* Type 2 Brugada Syndrome: This type is characterized by a saddleback-type ST-segment elevation of at least 2 mm in height in at least one right precordial lead, with a positive or biphasic T wave. The ST segment should return to the baseline level or below within 0.08 seconds after the J point (the junction between the QRS complex and the ST segment). Type 2 Brugada Syndrome is associated with a lower risk of sudden cardiac death compared to Type 1, but it can still pose a significant risk in some individuals.

Brugada Syndrome can affect people of any age, gender, or ethnicity, although it is more commonly diagnosed in middle-aged men of Asian descent. The syndrome can be inherited in an autosomal dominant manner, meaning that a child has a 50% chance of inheriting the mutation from a parent who carries the gene. However, not all individuals with the genetic mutation will develop symptoms or have abnormal ECG findings.

Treatment for Brugada Syndrome typically involves implanting a cardioverter-defibrillator (ICD) to prevent sudden cardiac death. Medications such as quinidine or isoproterenol may also be used to reduce the risk of arrhythmias. Lifestyle modifications, such as avoiding alcohol and certain medications that can trigger arrhythmias, may also be recommended.

A syndrome, in medical terms, is a set of symptoms that collectively indicate or characterize a disease, disorder, or underlying pathological process. It's essentially a collection of signs and/or symptoms that frequently occur together and can suggest a particular cause or condition, even though the exact physiological mechanisms might not be fully understood.

For example, Down syndrome is characterized by specific physical features, cognitive delays, and other developmental issues resulting from an extra copy of chromosome 21. Similarly, metabolic syndromes like diabetes mellitus type 2 involve a group of risk factors such as obesity, high blood pressure, high blood sugar, and abnormal cholesterol or triglyceride levels that collectively increase the risk of heart disease, stroke, and diabetes.

It's important to note that a syndrome is not a specific diagnosis; rather, it's a pattern of symptoms that can help guide further diagnostic evaluation and management.

NAV1.5, also known as SCN5A, is a specific type of voltage-gated sodium channel found in the heart muscle cells (cardiomyocytes). These channels play a crucial role in the generation and transmission of electrical signals that coordinate the contraction of the heart.

More specifically, NAV1.5 channels are responsible for the rapid influx of sodium ions into cardiomyocytes during the initial phase of the action potential, which is the electrical excitation of the cell. This rapid influx of sodium ions helps to initiate and propagate the action potential throughout the heart muscle, allowing for coordinated contraction and proper heart function.

Mutations in the SCN5A gene, which encodes the NAV1.5 channel, have been associated with various cardiac arrhythmias, including long QT syndrome, Brugada syndrome, and familial atrial fibrillation, among others. These genetic disorders can lead to abnormal heart rhythms, syncope, and in some cases, sudden cardiac death.

Ajmaline is a type of medication known as a Class I antiarrhythmic agent, which is used to treat certain types of abnormal heart rhythms. It works by blocking the sodium channels in the heart muscle, which helps to slow down the conduction of electrical signals within the heart and can help to restore a normal heart rhythm.

Ajmaline is typically administered intravenously (through a vein) in a hospital setting, as it acts quickly and its effects can be closely monitored by healthcare professionals. It may be used to diagnose certain types of heart rhythm disturbances or to treat acute episodes of arrhythmias that are not responding to other treatments.

Like all medications, ajmaline can have side effects, including dizziness, headache, nausea, and chest pain. It is important for patients to be closely monitored while taking this medication and to report any unusual symptoms to their healthcare provider. Ajmaline should only be used under the close supervision of a qualified healthcare professional.

Bundle-branch block (BBB) is a type of conduction delay or block in the heart's electrical system that affects the way electrical impulses travel through the ventricles (the lower chambers of the heart). In BBB, one of the two main bundle branches that conduct electrical impulses to the ventricles is partially or completely blocked, causing a delay in the contraction of one of the ventricles.

There are two types of bundle-branch block: right bundle-branch block (RBBB) and left bundle-branch block (LBBB). In RBBB, the right bundle branch is affected, while in LBBB, the left bundle branch is affected. The symptoms and severity of BBB can vary depending on the underlying cause and the presence of other heart conditions.

In some cases, BBB may not cause any noticeable symptoms and may only be detected during a routine electrocardiogram (ECG). However, if BBB occurs along with other heart conditions such as coronary artery disease, heart failure, or cardiomyopathy, it can increase the risk of serious complications such as arrhythmias, syncope, and even sudden cardiac death.

Treatment for bundle-branch block depends on the underlying cause and the severity of the condition. In some cases, no treatment may be necessary, while in others, medications, pacemakers, or other treatments may be recommended to manage symptoms and prevent complications.

Ventricular Fibrillation (VF) is a type of cardiac arrhythmia, which is an abnormal heart rhythm. In VF, the ventricles, which are the lower chambers of the heart, beat in a rapid and unorganized manner. This results in the heart being unable to pump blood effectively to the rest of the body, leading to immediate circulatory collapse and cardiac arrest if not treated promptly. It is often caused by underlying heart conditions such as coronary artery disease, structural heart problems, or electrolyte imbalances. VF is a medical emergency that requires immediate defibrillation to restore a normal heart rhythm.

Electrocardiography (ECG or EKG) is a medical procedure that records the electrical activity of the heart. It provides a graphic representation of the electrical changes that occur during each heartbeat. The resulting tracing, called an electrocardiogram, can reveal information about the heart's rate and rhythm, as well as any damage to its cells or abnormalities in its conduction system.

During an ECG, small electrodes are placed on the skin of the chest, arms, and legs. These electrodes detect the electrical signals produced by the heart and transmit them to a machine that amplifies and records them. The procedure is non-invasive, painless, and quick, usually taking only a few minutes.

ECGs are commonly used to diagnose and monitor various heart conditions, including arrhythmias, coronary artery disease, heart attacks, and electrolyte imbalances. They can also be used to evaluate the effectiveness of certain medications or treatments.

Sodium channels are specialized protein structures that are embedded in the membranes of excitable cells, such as nerve and muscle cells. They play a crucial role in the generation and transmission of electrical signals in these cells. Sodium channels are responsible for the rapid influx of sodium ions into the cell during the initial phase of an action potential, which is the electrical signal that travels along the membrane of a neuron or muscle fiber. This sudden influx of sodium ions causes the membrane potential to rapidly reverse, leading to the depolarization of the cell. After the action potential, the sodium channels close and become inactivated, preventing further entry of sodium ions and helping to restore the resting membrane potential.

Sodium channels are composed of a large alpha subunit and one or two smaller beta subunits. The alpha subunit forms the ion-conducting pore, while the beta subunits play a role in modulating the function and stability of the channel. Mutations in sodium channel genes have been associated with various inherited diseases, including certain forms of epilepsy, cardiac arrhythmias, and muscle disorders.

Sudden cardiac death (SCD) is a sudden, unexpected natural death caused by the cessation of cardiac activity. It is often caused by cardiac arrhythmias, particularly ventricular fibrillation, and is often associated with underlying heart disease, although it can occur in people with no known heart condition. SCD is typically defined as a natural death due to cardiac causes that occurs within one hour of the onset of symptoms, or if the individual was last seen alive in a normal state of health, it can be defined as occurring within 24 hours.

It's important to note that sudden cardiac arrest (SCA) is different from SCD, although they are related. SCA refers to the sudden cessation of cardiac activity, which if not treated immediately can lead to SCD.

The heart conduction system is a group of specialized cardiac muscle cells that generate and conduct electrical impulses to coordinate the contraction of the heart chambers. The main components of the heart conduction system include:

1. Sinoatrial (SA) node: Also known as the sinus node, it is located in the right atrium near the entrance of the superior vena cava and functions as the primary pacemaker of the heart. It sets the heart rate by generating electrical impulses at regular intervals.
2. Atrioventricular (AV) node: Located in the interatrial septum, near the opening of the coronary sinus, it serves as a relay station for electrical signals between the atria and ventricles. The AV node delays the transmission of impulses to allow the atria to contract before the ventricles.
3. Bundle of His: A bundle of specialized cardiac muscle fibers that conducts electrical impulses from the AV node to the ventricles. It divides into two main branches, the right and left bundle branches, which further divide into smaller Purkinje fibers.
4. Right and left bundle branches: These are extensions of the Bundle of His that transmit electrical impulses to the respective right and left ventricular myocardium. They consist of specialized conducting tissue with large diameters and minimal resistance, allowing for rapid conduction of electrical signals.
5. Purkinje fibers: Fine, branching fibers that arise from the bundle branches and spread throughout the ventricular myocardium. They are responsible for transmitting electrical impulses to the working cardiac muscle cells, triggering coordinated ventricular contraction.

In summary, the heart conduction system is a complex network of specialized muscle cells responsible for generating and conducting electrical signals that coordinate the contraction of the atria and ventricles, ensuring efficient blood flow throughout the body.

Syncope is a medical term defined as a transient, temporary loss of consciousness and postural tone due to reduced blood flow to the brain. It's often caused by a drop in blood pressure, which can be brought on by various factors such as dehydration, emotional stress, prolonged standing, or certain medical conditions like heart diseases, arrhythmias, or neurological disorders.

During a syncope episode, an individual may experience warning signs such as lightheadedness, dizziness, blurred vision, or nausea before losing consciousness. These episodes usually last only a few minutes and are followed by a rapid, full recovery. However, if left untreated or undiagnosed, recurrent syncope can lead to severe injuries from falls or even life-threatening conditions related to the underlying cause.

Flecainide is an antiarrhythmic medication used to regularize abnormal heart rhythms, specifically certain types of irregular heartbeats called ventricular arrhythmias and paroxysmal atrial tachycardia/atrial fibrillation. It works by blocking sodium channels in the heart, which helps to slow down the conduction of electrical signals and reduces the likelihood of erratic heart rhythms.

Flecainide is available in oral forms such as tablets or capsules and is typically prescribed under the supervision of a healthcare professional experienced in managing heart rhythm disorders. It's important to note that flecainide can have serious side effects, including increasing the risk of dangerous arrhythmias in some patients, so it should only be used under close medical monitoring.

This definition is for informational purposes only and should not be considered a substitute for professional medical advice, diagnosis, or treatment. If you have any questions about your medications or health conditions, please consult with your healthcare provider.

Electrophysiologic techniques, cardiac, refer to medical procedures used to study the electrical activities and conduction systems of the heart. These techniques involve the insertion of electrode catheters into the heart through blood vessels under fluoroscopic guidance to record and stimulate electrical signals. The information obtained from these studies can help diagnose and evaluate various cardiac arrhythmias, determine the optimal treatment strategy, and assess the effectiveness of therapies such as ablation or implantable devices.

The electrophysiologic study (EPS) is a type of cardiac electrophysiologic technique that involves the measurement of electrical signals from different regions of the heart to evaluate its conduction system's function. The procedure can help identify the location of abnormal electrical pathways responsible for arrhythmias and determine the optimal treatment strategy, such as catheter ablation or medication therapy.

Cardiac electrophysiologic techniques are also used in device implantation procedures, such as pacemaker or defibrillator implantation, to ensure proper placement and function of the devices. These techniques can help program and test the devices to optimize their settings for each patient's needs.

In summary, cardiac electrophysiologic techniques are medical procedures used to study and manipulate the electrical activities of the heart, helping diagnose and treat various arrhythmias and other cardiac conditions.

Anti-arrhythmia agents are a class of medications used to treat abnormal heart rhythms or arrhythmias. These drugs work by modifying the electrical activity of the heart to restore and maintain a normal heart rhythm. There are several types of anti-arrhythmia agents, including:

1. Sodium channel blockers: These drugs slow down the conduction of electrical signals in the heart, which helps to reduce rapid or irregular heartbeats. Examples include flecainide, propafenone, and quinidine.
2. Beta-blockers: These medications work by blocking the effects of adrenaline on the heart, which helps to slow down the heart rate and reduce the force of heart contractions. Examples include metoprolol, atenolol, and esmolol.
3. Calcium channel blockers: These drugs block the entry of calcium into heart muscle cells, which helps to slow down the heart rate and reduce the force of heart contractions. Examples include verapamil and diltiazem.
4. Potassium channel blockers: These medications work by prolonging the duration of the heart's electrical cycle, which helps to prevent abnormal rhythms. Examples include amiodarone and sotalol.
5. Digoxin: This drug increases the force of heart contractions and slows down the heart rate, which can help to restore a normal rhythm in certain types of arrhythmias.

It's important to note that anti-arrhythmia agents can have significant side effects and should only be prescribed by a healthcare professional who has experience in managing arrhythmias. Close monitoring is necessary to ensure the medication is working effectively and not causing any adverse effects.

Cardiac arrhythmias are abnormal heart rhythms that result from disturbances in the electrical conduction system of the heart. The heart's normal rhythm is controlled by an electrical signal that originates in the sinoatrial (SA) node, located in the right atrium. This signal travels through the atrioventricular (AV) node and into the ventricles, causing them to contract and pump blood throughout the body.

An arrhythmia occurs when there is a disruption in this electrical pathway or when the heart's natural pacemaker produces an abnormal rhythm. This can cause the heart to beat too fast (tachycardia), too slow (bradycardia), or irregularly.

There are several types of cardiac arrhythmias, including:

1. Atrial fibrillation: A rapid and irregular heartbeat that starts in the atria (the upper chambers of the heart).
2. Atrial flutter: A rapid but regular heartbeat that starts in the atria.
3. Supraventricular tachycardia (SVT): A rapid heartbeat that starts above the ventricles, usually in the atria or AV node.
4. Ventricular tachycardia: A rapid and potentially life-threatening heart rhythm that originates in the ventricles.
5. Ventricular fibrillation: A chaotic and disorganized electrical activity in the ventricles, which can be fatal if not treated immediately.
6. Heart block: A delay or interruption in the conduction of electrical signals from the atria to the ventricles.

Cardiac arrhythmias can cause various symptoms, such as palpitations, dizziness, shortness of breath, chest pain, and fatigue. In some cases, they may not cause any symptoms and go unnoticed. However, if left untreated, certain types of arrhythmias can lead to serious complications, including stroke, heart failure, or even sudden cardiac death.

Treatment for cardiac arrhythmias depends on the type, severity, and underlying causes. Options may include lifestyle changes, medications, cardioversion (electrical shock therapy), catheter ablation, implantable devices such as pacemakers or defibrillators, and surgery. It is essential to consult a healthcare professional for proper evaluation and management of cardiac arrhythmias.

Ventricular Tachycardia (VT) is a rapid heart rhythm that originates from the ventricles, the lower chambers of the heart. It is defined as three or more consecutive ventricular beats at a rate of 120 beats per minute or greater in a resting adult. This abnormal heart rhythm can cause the heart to pump less effectively, leading to inadequate blood flow to the body and potentially life-threatening conditions such as hypotension, shock, or cardiac arrest.

VT can be classified into three types based on its duration, hemodynamic stability, and response to treatment:

1. Non-sustained VT (NSVT): It lasts for less than 30 seconds and is usually well tolerated without causing significant symptoms or hemodynamic instability.
2. Sustained VT (SVT): It lasts for more than 30 seconds, causes symptoms such as palpitations, dizziness, shortness of breath, or chest pain, and may lead to hemodynamic instability.
3. Pulseless VT: It is a type of sustained VT that does not produce a pulse, blood pressure, or adequate cardiac output, requiring immediate electrical cardioversion or defibrillation to restore a normal heart rhythm.

VT can occur in people with various underlying heart conditions such as coronary artery disease, cardiomyopathy, valvular heart disease, congenital heart defects, and electrolyte imbalances. It can also be triggered by certain medications, substance abuse, or electrical abnormalities in the heart. Prompt diagnosis and treatment of VT are crucial to prevent complications and improve outcomes.

An implantable defibrillator is a medical device that is surgically placed inside the chest to continuously monitor the heart's rhythm and deliver electrical shocks to restore a normal heartbeat when it detects a life-threatening arrhythmia, such as ventricular fibrillation or ventricular tachycardia.

The device consists of a small generator that is implanted in the upper chest, along with one or more electrode leads that are threaded through veins and positioned in the heart's chambers. The generator contains a battery and a microcomputer that constantly monitors the heart's electrical activity and detects any abnormal rhythms.

When an arrhythmia is detected, the defibrillator delivers an electrical shock to the heart to restore a normal rhythm. This can be done automatically by the device or manually by a healthcare provider using an external programmer.

Implantable defibrillators are typically recommended for people who have a high risk of sudden cardiac death due to a history of heart attacks, heart failure, or inherited heart conditions that affect the heart's electrical system. They can significantly reduce the risk of sudden cardiac death and improve quality of life for those at risk.

Long QT syndrome (LQTS) is a cardiac electrical disorder characterized by a prolonged QT interval on the electrocardiogram (ECG), which can potentially trigger rapid, chaotic heartbeats known as ventricular tachyarrhythmias, such as torsades de pointes. These arrhythmias can be life-threatening and lead to syncope (fainting) or sudden cardiac death. LQTS is often congenital but may also be acquired due to certain medications, medical conditions, or electrolyte imbalances. It's essential to identify and manage LQTS promptly to reduce the risk of severe complications.

Quinidine is a Class IA antiarrhythmic medication that is primarily used to treat and prevent various types of cardiac arrhythmias (abnormal heart rhythms). It works by blocking the rapid sodium channels in the heart, which helps to slow down the conduction of electrical signals within the heart and stabilize its rhythm.

Quinidine is derived from the bark of the Cinchona tree and has been used for centuries as a treatment for malaria. However, its antiarrhythmic properties were discovered later, and it became an important medication in cardiology.

In addition to its use in treating arrhythmias, quinidine may also be used off-label for other indications such as the treatment of nocturnal leg cramps or myasthenia gravis. It is available in various forms, including tablets and injectable solutions.

It's important to note that quinidine has a narrow therapeutic index, meaning that there is only a small difference between an effective dose and a toxic one. Therefore, it must be carefully monitored to ensure that the patient is receiving a safe and effective dose. Common side effects of quinidine include gastrointestinal symptoms such as nausea, vomiting, and diarrhea, as well as visual disturbances, headache, and dizziness. More serious side effects can include QT prolongation, which can lead to dangerous arrhythmias, and hypersensitivity reactions.

The voltage-gated sodium channel (Nav) beta-1 subunit, also known as SCN1B, is a regulatory protein that associates with the pore-forming alpha subunit of voltage-gated sodium channels. It is a transmembrane protein consisting of an extracellular domain, a single transmembrane segment, and a short intracellular domain.

The beta-1 subunit plays a crucial role in modulating the kinetic properties and expression levels of Nav channels. Specifically, it affects the activation, inactivation, and recovery from inactivation of sodium currents. The beta-1 subunit also functions as an adhesion molecule and interacts with extracellular matrix proteins, which helps to anchor Nav channels to the cytoskeleton and regulate their clustering at nodes of Ranvier in myelinated neurons.

Mutations in the SCN1B gene have been associated with various neurological disorders, including generalized epilepsy with febrile seizures plus (GEFS+), severe myoclonic epilepsy of infancy (SMEI), and Dravet syndrome, which is a severe form of childhood epilepsy. These mutations can affect the function and expression of Nav channels, leading to abnormal neuronal excitability and synchronization, and ultimately to seizures and other neurological symptoms.

Sodium channel blockers are a class of medications that work by blocking sodium channels in the heart, which prevents the rapid influx of sodium ions into the cells during depolarization. This action slows down the rate of impulse generation and propagation in the heart, which in turn decreases the heart rate and prolongs the refractory period.

Sodium channel blockers are primarily used to treat cardiac arrhythmias, including atrial fibrillation, atrial flutter, and ventricular tachycardia. They may also be used to treat certain types of neuropathic pain. Examples of sodium channel blockers include Class I antiarrhythmics such as flecainide, propafenone, lidocaine, and mexiletine.

It's important to note that sodium channel blockers can have potential side effects, including proarrhythmia (i.e., the development of new arrhythmias or worsening of existing ones), negative inotropy (decreased contractility of the heart muscle), and cardiac conduction abnormalities. Therefore, these medications should be used with caution and under the close supervision of a healthcare provider.

Procainamide is an antiarrhythmic medication used to treat various types of irregular heart rhythms (arrhythmias), such as atrial fibrillation, atrial flutter, and ventricular tachycardia. It works by prolonging the duration of the cardiac action potential and decreasing the slope of the phase 0 depolarization, which helps to stabilize the heart's electrical activity and restore a normal rhythm.

Procainamide is classified as a Class Ia antiarrhythmic drug, according to the Vaughan Williams classification system. It primarily affects the fast sodium channels in the heart muscle cells, reducing their availability during depolarization. This results in a decreased rate of impulse generation and conduction velocity, which can help to suppress abnormal rhythms.

The medication is available as an oral formulation (procainamide hydrochloride) and as an injectable solution for intravenous use. Common side effects of procainamide include nausea, vomiting, diarrhea, headache, and dizziness. Procainamide can also cause a lupus-like syndrome, characterized by joint pain, skin rashes, and other autoimmune symptoms, in some patients who take the medication for an extended period.

It is essential to monitor procainamide levels in the blood during treatment to ensure that the drug is within the therapeutic range and to minimize the risk of adverse effects. Healthcare providers should also regularly assess patients' renal function, as procainamide and its active metabolite, N-acetylprocainamide (NAPA), are primarily excreted by the kidneys.

Muscle proteins are a type of protein that are found in muscle tissue and are responsible for providing structure, strength, and functionality to muscles. The two major types of muscle proteins are:

1. Contractile proteins: These include actin and myosin, which are responsible for the contraction and relaxation of muscles. They work together to cause muscle movement by sliding along each other and shortening the muscle fibers.
2. Structural proteins: These include titin, nebulin, and desmin, which provide structural support and stability to muscle fibers. Titin is the largest protein in the human body and acts as a molecular spring that helps maintain the integrity of the sarcomere (the basic unit of muscle contraction). Nebulin helps regulate the length of the sarcomere, while desmin forms a network of filaments that connects adjacent muscle fibers together.

Overall, muscle proteins play a critical role in maintaining muscle health and function, and their dysregulation can lead to various muscle-related disorders such as muscular dystrophy, myopathies, and sarcopenia.

A missense mutation is a type of point mutation in which a single nucleotide change results in the substitution of a different amino acid in the protein that is encoded by the affected gene. This occurs when the altered codon (a sequence of three nucleotides that corresponds to a specific amino acid) specifies a different amino acid than the original one. The function and/or stability of the resulting protein may be affected, depending on the type and location of the missense mutation. Missense mutations can have various effects, ranging from benign to severe, depending on the importance of the changed amino acid for the protein's structure or function.

The voltage-gated sodium channel β-3 subunit, also known as SCN3B or NaVβ4, is a regulatory protein that associates with the pore-forming α-subunit of voltage-gated sodium channels. This subunit is encoded by the SCN3B gene in humans.

The β-3 subunit is a member of the immunoglobulin superfamily and contains an extracellular immunoglobulin domain, a transmembrane region, and a short intracellular tail. It plays a role in modulating the biophysical properties and expression levels of sodium channels, which are crucial for the initiation and propagation of action potentials in excitable cells such as neurons and cardiomyocytes.

Mutations in the SCN3B gene have been associated with various neurological disorders, including epilepsy and developmental delay. Proper functioning of voltage-gated sodium channels is essential for normal nervous system function, and disruptions to these channels can lead to a range of clinical manifestations.

Arrhythmogenic Right Ventricular Dysplasia (ARVD) is a rare cardiac condition characterized by the replacement of the normal heart muscle tissue in the right ventricle with fatty and fibrous tissues. This can lead to abnormal heart rhythms (arrhythmias), particularly during exercise or emotional stress.

The condition can be inherited and is often associated with genetic mutations that affect the desmosomes, which are protein structures that help connect heart muscle cells together. These mutations can weaken the heart muscle and make it more prone to arrhythmias and heart failure over time.

Symptoms of ARVD may include palpitations, chest pain, shortness of breath, dizziness, or fainting, especially during exercise. In some cases, the condition may not cause any symptoms and may only be discovered during a routine medical exam or evaluation for another condition.

Diagnosis of ARVD typically involves a combination of clinical evaluation, imaging tests such as echocardiography or magnetic resonance imaging (MRI), and electrophysiological testing to assess heart rhythm abnormalities. Treatment may include medications to control arrhythmias, implantable devices such as pacemakers or defibrillators, and lifestyle modifications such as avoiding strenuous exercise. In severe cases, a heart transplant may be necessary.

A mutation is a permanent change in the DNA sequence of an organism's genome. Mutations can occur spontaneously or be caused by environmental factors such as exposure to radiation, chemicals, or viruses. They may have various effects on the organism, ranging from benign to harmful, depending on where they occur and whether they alter the function of essential proteins. In some cases, mutations can increase an individual's susceptibility to certain diseases or disorders, while in others, they may confer a survival advantage. Mutations are the driving force behind evolution, as they introduce new genetic variability into populations, which can then be acted upon by natural selection.

Midodrine is a medication that belongs to a class of drugs called vasoconstrictors. It works by narrowing the blood vessels and increasing blood pressure. The medical definition of Midodrine is:

A synthetic derivative of the imidazole compound, adrenergic agonist, which is used in the treatment of orthostatic hypotension. Midodrine is a prodrug that is rapidly metabolized to its active form, desglymidodrine, after oral administration. It selectively binds to and activates alpha-1 adrenergic receptors, causing vasoconstriction and an increase in blood pressure. The drug's effects are most pronounced on the venous side of the circulation, leading to increased venous return and cardiac output. Midodrine is typically administered orally in divided doses throughout the day, and its use is usually reserved for patients who have not responded to other treatments for orthostatic hypotension.

I must clarify that the term "pedigree" is not typically used in medical definitions. Instead, it is often employed in genetics and breeding, where it refers to the recorded ancestry of an individual or a family, tracing the inheritance of specific traits or diseases. In human genetics, a pedigree can help illustrate the pattern of genetic inheritance in families over multiple generations. However, it is not a medical term with a specific clinical definition.

Sick Sinus Syndrome (SSS) is a term used to describe a group of abnormal heart rhythm disturbances that originates in the sinoatrial node (the natural pacemaker of the heart). This syndrome is characterized by impaired functioning of the sinoatrial node, resulting in various abnormalities such as sinus bradycardia (abnormally slow heart rate), sinus arrest (complete cessation of sinus node activity), and/or sinoatrial exit block (failure of the electrical impulse to leave the sinus node and spread to the atria).

People with SSS may experience symptoms such as palpitations, dizziness, fatigue, shortness of breath, or syncope (fainting) due to inadequate blood supply to the brain caused by slow heart rate. The diagnosis of SSS is typically made based on the patient's symptoms and the results of an electrocardiogram (ECG), Holter monitoring, or event recorder that shows evidence of abnormal sinus node function. Treatment options for SSS may include lifestyle modifications, medications, or implantation of a pacemaker to regulate the heart rate.

Terfenadine is an antihistamine medication that has been used to treat symptoms of allergies such as hay fever, hives, and other allergic reactions. It works by blocking the action of histamine, a substance in the body that causes allergic symptoms. Terfenadine was first approved for use in the United States in 1985, but it is no longer available in many countries due to concerns about rare but serious side effects related to heart rhythm disturbances. It has been replaced by other antihistamines that are considered safer and more effective.

DNA Mutational Analysis is a laboratory test used to identify genetic variations or changes (mutations) in the DNA sequence of a gene. This type of analysis can be used to diagnose genetic disorders, predict the risk of developing certain diseases, determine the most effective treatment for cancer, or assess the likelihood of passing on an inherited condition to offspring.

The test involves extracting DNA from a patient's sample (such as blood, saliva, or tissue), amplifying specific regions of interest using polymerase chain reaction (PCR), and then sequencing those regions to determine the precise order of nucleotide bases in the DNA molecule. The resulting sequence is then compared to reference sequences to identify any variations or mutations that may be present.

DNA Mutational Analysis can detect a wide range of genetic changes, including single-nucleotide polymorphisms (SNPs), insertions, deletions, duplications, and rearrangements. The test is often used in conjunction with other diagnostic tests and clinical evaluations to provide a comprehensive assessment of a patient's genetic profile.

It is important to note that not all mutations are pathogenic or associated with disease, and the interpretation of DNA Mutational Analysis results requires careful consideration of the patient's medical history, family history, and other relevant factors.

The endocardium is the innermost layer of tissue that lines the chambers of the heart and the valves between them. It is a thin, smooth membrane that is in contact with the blood within the heart. This layer helps to maintain the heart's internal environment, facilitates the smooth movement of blood through the heart, and provides a protective barrier against infection and other harmful substances. The endocardium is composed of simple squamous epithelial cells called endothelial cells, which are supported by a thin layer of connective tissue.

Heredity, in medical terms, refers to the passing on of genetic characteristics from parents to their offspring through the transmission of genes. These genes carry the information that determines many traits, such as eye color, hair color, height, and certain health conditions. Heredity plays a significant role in understanding the causes of various diseases and disorders, as some are strongly influenced by genetic factors. However, it's important to note that environmental factors can also interact with genetic predispositions to influence the expression of these traits.

Mexiletine is defined as an antiarrhythmic agent, classified as a Class IB medication. It works by blocking sodium channels in the heart, which helps to stabilize cardiac membranes and reduces the rate of firing of cardiac cells. This makes it useful for treating certain types of irregular heart rhythms (ventricular arrhythmias).

Mexiletine is also known to have analgesic properties and is sometimes used off-label for the treatment of neuropathic pain. It is available in oral form, and its use should be under the close supervision of a healthcare provider due to its potential side effects, which can include gastrointestinal symptoms, dizziness, tremors, and cardiac arrhythmias.

Down syndrome is a genetic disorder caused by the presence of all or part of a third copy of chromosome 21. It is characterized by intellectual and developmental disabilities, distinctive facial features, and sometimes physical growth delays and health problems. The condition affects approximately one in every 700 babies born in the United States.

Individuals with Down syndrome have varying degrees of cognitive impairment, ranging from mild to moderate or severe. They may also have delayed development, including late walking and talking, and may require additional support and education services throughout their lives.

People with Down syndrome are at increased risk for certain health conditions, such as congenital heart defects, respiratory infections, hearing loss, vision problems, gastrointestinal issues, and thyroid disorders. However, many individuals with Down syndrome live healthy and fulfilling lives with appropriate medical care and support.

The condition is named after John Langdon Down, an English physician who first described the syndrome in 1866.

An action potential is a brief electrical signal that travels along the membrane of a nerve cell (neuron) or muscle cell. It is initiated by a rapid, localized change in the permeability of the cell membrane to specific ions, such as sodium and potassium, resulting in a rapid influx of sodium ions and a subsequent efflux of potassium ions. This ion movement causes a brief reversal of the electrical potential across the membrane, which is known as depolarization. The action potential then propagates along the cell membrane as a wave, allowing the electrical signal to be transmitted over long distances within the body. Action potentials play a crucial role in the communication and functioning of the nervous system and muscle tissue.

The pericardium is the double-walled sac that surrounds the heart. It has an outer fibrous layer and an inner serous layer, which further divides into two parts: the parietal layer lining the fibrous pericardium and the visceral layer (epicardium) closely adhering to the heart surface.

The space between these two layers is filled with a small amount of lubricating serous fluid, allowing for smooth movement of the heart within the pericardial cavity. The pericardium provides protection, support, and helps maintain the heart's normal position within the chest while reducing friction during heart contractions.

Cardiac electrophysiology is a branch of medicine that deals with the study and understanding of the electrical activities of the heart. It involves the diagnosis and treatment of various heart rhythm disorders (arrhythmias) such as bradycardia (slow heart rate), tachycardia (fast heart rate), atrial fibrillation, atrial flutter, ventricular fibrillation, and other rhythm abnormalities.

Cardiac electrophysiologists use various diagnostic tests, including electrocardiograms (ECGs), Holter monitors, event monitors, and invasive procedures such as electrophysiology studies (EPS) and catheter ablation to evaluate and treat heart rhythm disorders. The goal of treatment is to restore a normal heart rhythm and prevent complications associated with arrhythmias, such as stroke or heart failure.

Metabolic syndrome, also known as Syndrome X, is a cluster of conditions that increase the risk of heart disease, stroke, and diabetes. It is not a single disease but a group of risk factors that often co-occur. According to the American Heart Association and the National Heart, Lung, and Blood Institute, a person has metabolic syndrome if they have any three of the following five conditions:

1. Abdominal obesity (waist circumference of 40 inches or more in men, and 35 inches or more in women)
2. Triglyceride level of 150 milligrams per deciliter of blood (mg/dL) or greater
3. HDL cholesterol level of less than 40 mg/dL in men or less than 50 mg/dL in women
4. Systolic blood pressure of 130 millimeters of mercury (mmHg) or greater, or diastolic blood pressure of 85 mmHg or greater
5. Fasting glucose level of 100 mg/dL or greater

Metabolic syndrome is thought to be caused by a combination of genetic and lifestyle factors, such as physical inactivity and a diet high in refined carbohydrates and unhealthy fats. Treatment typically involves making lifestyle changes, such as eating a healthy diet, getting regular exercise, and losing weight if necessary. In some cases, medication may also be needed to manage individual components of the syndrome, such as high blood pressure or high cholesterol.

Pre-excitation syndromes are a group of cardiac conditions characterized by the presence of an accessory electrical pathway between the atria and ventricles of the heart. This pathway allows electrical impulses to bypass the normal conduction system, leading to early activation (pre-excitation) of a portion of the ventricular muscle. The most common pre-excitation syndrome is Wolff-Parkinson-White (WPW) syndrome, but other types include Lown-Ganong-Levine syndrome and Mahaim syndrome. These conditions can potentially lead to tachyarrhythmias or abnormally fast heart rhythms, which in some cases can be life-threatening if not properly managed.

Sudden death is a term used to describe a situation where a person dies abruptly and unexpectedly, often within minutes to hours of the onset of symptoms. It is typically caused by cardiac or respiratory arrest, which can be brought on by various medical conditions such as heart disease, stroke, severe infections, drug overdose, or trauma. In some cases, the exact cause of sudden death may remain unknown even after a thorough post-mortem examination.

It is important to note that sudden death should not be confused with "sudden cardiac death," which specifically refers to deaths caused by the abrupt loss of heart function (cardiac arrest). Sudden cardiac death is often related to underlying heart conditions such as coronary artery disease, cardiomyopathy, or electrical abnormalities in the heart.

Lidocaine is a type of local anesthetic that numbs painful areas and is used to prevent pain during certain medical procedures. It works by blocking the nerves that transmit pain signals to the brain. In addition to its use as an anesthetic, lidocaine can also be used to treat irregular heart rates and relieve itching caused by allergic reactions or skin conditions such as eczema.

Lidocaine is available in various forms, including creams, gels, ointments, sprays, solutions, and injectable preparations. It can be applied directly to the skin or mucous membranes, or it can be administered by injection into a muscle or vein. The specific dosage and method of administration will depend on the reason for its use and the individual patient's medical history and current health status.

Like all medications, lidocaine can have side effects, including allergic reactions, numbness that lasts too long, and in rare cases, heart problems or seizures. It is important to follow the instructions of a healthcare provider carefully when using lidocaine to minimize the risk of adverse effects.

A phenotype is the physical or biochemical expression of an organism's genes, or the observable traits and characteristics resulting from the interaction of its genetic constitution (genotype) with environmental factors. These characteristics can include appearance, development, behavior, and resistance to disease, among others. Phenotypes can vary widely, even among individuals with identical genotypes, due to differences in environmental influences, gene expression, and genetic interactions.

The Autonomic Nervous System (ANS) is a part of the nervous system that controls involuntary actions, such as heart rate, digestion, respiratory rate, pupillary response, urination, and sexual arousal. It consists of two subdivisions: the sympathetic and parasympathetic nervous systems, which generally have opposing effects and maintain homeostasis in the body.

Autonomic Nervous System Diseases (also known as Autonomic Disorders or Autonomic Neuropathies) refer to a group of conditions that affect the functioning of the autonomic nervous system. These diseases can cause damage to the nerves that control automatic functions, leading to various symptoms and complications.

Autonomic Nervous System Diseases can be classified into two main categories:

1. Primary Autonomic Nervous System Disorders: These are conditions that primarily affect the autonomic nervous system without any underlying cause. Examples include:
* Pure Autonomic Failure (PAF): A rare disorder characterized by progressive loss of autonomic nerve function, leading to symptoms such as orthostatic hypotension, urinary retention, and constipation.
* Multiple System Atrophy (MSA): A degenerative neurological disorder that affects both the autonomic nervous system and movement coordination. Symptoms may include orthostatic hypotension, urinary incontinence, sexual dysfunction, and Parkinsonian features like stiffness and slowness of movements.
* Autonomic Neuropathy associated with Parkinson's Disease: Some individuals with Parkinson's disease develop autonomic symptoms such as orthostatic hypotension, constipation, and urinary dysfunction due to the degeneration of autonomic nerves.
2. Secondary Autonomic Nervous System Disorders: These are conditions that affect the autonomic nervous system as a result of an underlying cause or disease. Examples include:
* Diabetic Autonomic Neuropathy: A complication of diabetes mellitus that affects the autonomic nerves, leading to symptoms such as orthostatic hypotension, gastroparesis (delayed gastric emptying), and sexual dysfunction.
* Autoimmune-mediated Autonomic Neuropathies: Conditions like Guillain-Barré syndrome or autoimmune autonomic ganglionopathy can cause autonomic symptoms due to the immune system attacking the autonomic nerves.
* Infectious Autonomic Neuropathies: Certain infections, such as HIV or Lyme disease, can lead to autonomic dysfunction as a result of nerve damage.
* Toxin-induced Autonomic Neuropathy: Exposure to certain toxins, like heavy metals or organophosphate pesticides, can cause autonomic neuropathy.

Autonomic nervous system disorders can significantly impact a person's quality of life and daily functioning. Proper diagnosis and management are crucial for improving symptoms and preventing complications. Treatment options may include lifestyle modifications, medications, and in some cases, devices or surgical interventions.

Body Surface Potential Mapping (BSPM) is a non-invasive medical technique used to record and analyze the electrical activity of the heart from the surface of the body. It involves placing multiple electrodes on the skin of the chest, back, and limbs to measure the potential differences between these points during each heartbeat. This information is then used to create a detailed, visual representation of the electrical activation pattern of the heart, which can help in the diagnosis and evaluation of various cardiac disorders such as arrhythmias, myocardial infarction, and ventricular hypertrophy.

The BSPM technique provides high-resolution spatial and temporal information about the cardiac electrical activity, making it a valuable tool for both clinical and research purposes. It can help identify the origin and spread of abnormal electrical signals in the heart, which is crucial for determining appropriate treatment strategies. Overall, Body Surface Potential Mapping is an important diagnostic modality that offers unique insights into the electrical functioning of the heart.

I'm sorry for any confusion, but "Web Browser" is not a medical term. A web browser is a software application used to access and display information on the World Wide Web. It retrieves, renders, and displays content located on web pages, which may include text, images, videos, and other multimedia elements. Examples of web browsers include Google Chrome, Mozilla Firefox, Microsoft Edge, and Apple Safari.

The heart ventricles are the two lower chambers of the heart that receive blood from the atria and pump it to the lungs or the rest of the body. The right ventricle pumps deoxygenated blood to the lungs, while the left ventricle pumps oxygenated blood to the rest of the body. Both ventricles have thick, muscular walls to generate the pressure necessary to pump blood through the circulatory system.

Cardiac arrest, also known as heart arrest, is a medical condition where the heart suddenly stops beating or functioning properly. This results in the cessation of blood flow to the rest of the body, including the brain, leading to loss of consciousness and pulse. Cardiac arrest is often caused by electrical disturbances in the heart that disrupt its normal rhythm, known as arrhythmias. If not treated immediately with cardiopulmonary resuscitation (CPR) and defibrillation, it can lead to death or permanent brain damage due to lack of oxygen supply. It's important to note that a heart attack is different from cardiac arrest; a heart attack occurs when blood flow to a part of the heart is blocked, often by a clot, causing damage to the heart muscle, but the heart continues to beat. However, a heart attack can sometimes trigger a cardiac arrest.

Channelopathies are genetic disorders that are caused by mutations in the genes that encode for ion channels. Ion channels are specialized proteins that regulate the flow of ions, such as sodium, potassium, and calcium, across cell membranes. These ion channels play a crucial role in various physiological processes, including the generation and transmission of electrical signals in the body.

Channelopathies can affect various organs and systems in the body, depending on the type of ion channel that is affected. For example, mutations in sodium channel genes can cause neuromuscular disorders such as epilepsy, migraine, and periodic paralysis. Mutations in potassium channel genes can cause cardiac arrhythmias, while mutations in calcium channel genes can cause neurological disorders such as episodic ataxia and hemiplegic migraine.

The symptoms of channelopathies can vary widely depending on the specific disorder and the severity of the mutation. Treatment typically involves managing the symptoms and may include medications, lifestyle modifications, or in some cases, surgery.

Electric countershock, also known as defibrillation, is a medical procedure that uses an electric current to restore normal heart rhythm in certain types of cardiac arrhythmias, such as ventricular fibrillation or pulseless ventricular tachycardia. The procedure involves delivering a therapeutic dose of electrical energy to the heart through electrodes placed on the chest wall or directly on the heart. This electric current helps to depolarize a large number of cardiac cells simultaneously, which can help to interrupt the abnormal electrical activity in the heart and allow the normal conduction system to regain control and restore a normal rhythm. Electric countershock is typically delivered using an automated external defibrillator (AED) or a manual defibrillator, and it is a critical component of advanced cardiac life support (ACLS).

Ambulatory electrocardiography, also known as ambulatory ECG or Holter monitoring, is a non-invasive method of recording the electrical activity of the heart over an extended period of time (typically 24 hours or more) while the patient goes about their daily activities. The device used to record the ECG is called a Holter monitor, which consists of a small, portable recorder that is attached to the patient's chest with electrodes.

The recorded data provides information on any abnormalities in the heart's rhythm or electrical activity during different stages of activity and rest, allowing healthcare providers to diagnose and evaluate various cardiac conditions such as arrhythmias, ischemia, and infarction. The ability to monitor the heart's activity over an extended period while the patient performs their normal activities provides valuable information that may not be captured during a standard ECG, which only records the heart's electrical activity for a few seconds.

In summary, ambulatory electrocardiography is a diagnostic tool used to evaluate the electrical activity of the heart over an extended period, allowing healthcare providers to diagnose and manage various cardiac conditions.

Genetic testing is a type of medical test that identifies changes in chromosomes, genes, or proteins. The results of a genetic test can confirm or rule out a suspected genetic condition or help determine a person's chance of developing or passing on a genetic disorder. Genetic tests are performed on a sample of blood, hair, skin, amniotic fluid (the fluid that surrounds a fetus during pregnancy), or other tissue. For example, a physician may recommend genetic testing to help diagnose a genetic condition, confirm the presence of a gene mutation known to increase the risk of developing certain cancers, or determine the chance for a couple to have a child with a genetic disorder.

There are several types of genetic tests, including:

* Diagnostic testing: This type of test is used to identify or confirm a suspected genetic condition in an individual. It may be performed before birth (prenatal testing) or at any time during a person's life.
* Predictive testing: This type of test is used to determine the likelihood that a person will develop a genetic disorder. It is typically offered to individuals who have a family history of a genetic condition but do not show any symptoms themselves.
* Carrier testing: This type of test is used to determine whether a person carries a gene mutation for a genetic disorder. It is often offered to couples who are planning to have children and have a family history of a genetic condition or belong to a population that has an increased risk of certain genetic disorders.
* Preimplantation genetic testing: This type of test is used in conjunction with in vitro fertilization (IVF) to identify genetic changes in embryos before they are implanted in the uterus. It can help couples who have a family history of a genetic disorder or who are at risk of having a child with a genetic condition to conceive a child who is free of the genetic change in question.
* Pharmacogenetic testing: This type of test is used to determine how an individual's genes may affect their response to certain medications. It can help healthcare providers choose the most effective medication and dosage for a patient, reducing the risk of adverse drug reactions.

It is important to note that genetic testing should be performed under the guidance of a qualified healthcare professional who can interpret the results and provide appropriate counseling and support.

Heterozygote detection is a method used in genetics to identify individuals who carry one normal and one mutated copy of a gene. These individuals are known as heterozygotes and they do not typically show symptoms of the genetic disorder associated with the mutation, but they can pass the mutated gene on to their offspring, who may then be affected.

Heterozygote detection is often used in genetic counseling and screening programs for recessive disorders such as cystic fibrosis or sickle cell anemia. By identifying heterozygotes, individuals can be informed of their carrier status and the potential risks to their offspring. This information can help them make informed decisions about family planning and reproductive options.

Various methods can be used for heterozygote detection, including polymerase chain reaction (PCR) based tests, DNA sequencing, and genetic linkage analysis. The choice of method depends on the specific gene or mutation being tested, as well as the availability and cost of the testing technology.

Patch-clamp techniques are a group of electrophysiological methods used to study ion channels and other electrical properties of cells. These techniques were developed by Erwin Neher and Bert Sakmann, who were awarded the Nobel Prize in Physiology or Medicine in 1991 for their work. The basic principle of patch-clamp techniques involves creating a high resistance seal between a glass micropipette and the cell membrane, allowing for the measurement of current flowing through individual ion channels or groups of channels.

There are several different configurations of patch-clamp techniques, including:

1. Cell-attached configuration: In this configuration, the micropipette is attached to the outer surface of the cell membrane, and the current flowing across a single ion channel can be measured. This configuration allows for the study of the properties of individual channels in their native environment.
2. Whole-cell configuration: Here, the micropipette breaks through the cell membrane, creating a low resistance electrical connection between the pipette and the inside of the cell. This configuration allows for the measurement of the total current flowing across all ion channels in the cell membrane.
3. Inside-out configuration: In this configuration, the micropipette is pulled away from the cell after establishing a seal, resulting in the exposure of the inner surface of the cell membrane to the solution in the pipette. This configuration allows for the study of the properties of ion channels in isolation from other cellular components.
4. Outside-out configuration: Here, the micropipette is pulled away from the cell after establishing a seal, resulting in the exposure of the outer surface of the cell membrane to the solution in the pipette. This configuration allows for the study of the properties of ion channels in their native environment, but with the ability to control the composition of the extracellular solution.

Patch-clamp techniques have been instrumental in advancing our understanding of ion channel function and have contributed to numerous breakthroughs in neuroscience, pharmacology, and physiology.

Disopyramide is an antiarrhythmic medication that is primarily used to treat certain types of irregular heart rhythms (arrhythmias), such as ventricular tachycardia and atrial fibrillation. It works by blocking the activity of sodium channels in the heart, which helps to slow down and regulate the heart rate.

Disopyramide is available in immediate-release and extended-release forms, and it may be taken orally as a tablet or capsule. Common side effects of this medication include dry mouth, blurred vision, constipation, and difficulty urinating. More serious side effects can include dizziness, fainting, irregular heartbeat, and allergic reactions.

It is important to take disopyramide exactly as directed by a healthcare provider, as improper use or dosing can lead to serious complications. Additionally, individuals with certain medical conditions, such as heart failure, kidney disease, or myasthenia gravis, may not be able to safely take this medication.

Pinacidil is not typically defined in a medical dictionary as it is a specific pharmaceutical compound, rather than a general medical term. However, I can provide you with information about what Pinacidil is.

Pinacidil is an oral antihypertensive medication that acts as a direct activator of ATP-sensitive potassium (KATP) channels. These channels are present in various tissues, including the pancreas, heart, and smooth muscle cells. By opening KATP channels, Pinacidil causes hyperpolarization of the cell membrane, which leads to relaxation of smooth muscles in blood vessels. This results in vasodilation and a decrease in blood pressure.

Pinacidil is used off-label for the treatment of pulmonary arterial hypertension (PAH) due to its ability to dilate pulmonary arteries. However, it is not commonly prescribed for this purpose due to the availability of other FDA-approved medications specifically designed for PAH treatment.

Please consult a healthcare professional or pharmacist for more detailed information about Pinacidil and its uses, side effects, and potential interactions with other medications.

Propafenone is an antiarrhythmic medication used to treat certain types of irregular heartbeats (such as atrial fibrillation, paroxysmal supraventricular tachycardia). It works by blocking certain electrical signals in the heart to help it beat regularly. Propafenone belongs to a class of drugs known as Class IC antiarrhythmics.

It is important to note that this definition provides an overview of what propafenone is and how it is used, but it does not cover all possible uses, precautions, side effects, and interactions related to the drug. For more detailed information about propafenone, including its specific indications, contraindications, and potential adverse effects, consult a reliable medical reference or speak with a healthcare professional.

Computer-assisted signal processing is a medical term that refers to the use of computer algorithms and software to analyze, interpret, and extract meaningful information from biological signals. These signals can include physiological data such as electrocardiogram (ECG) waves, electromyography (EMG) signals, electroencephalography (EEG) readings, or medical images.

The goal of computer-assisted signal processing is to automate the analysis of these complex signals and extract relevant features that can be used for diagnostic, monitoring, or therapeutic purposes. This process typically involves several steps, including:

1. Signal acquisition: Collecting raw data from sensors or medical devices.
2. Preprocessing: Cleaning and filtering the data to remove noise and artifacts.
3. Feature extraction: Identifying and quantifying relevant features in the signal, such as peaks, troughs, or patterns.
4. Analysis: Applying statistical or machine learning algorithms to interpret the extracted features and make predictions about the underlying physiological state.
5. Visualization: Presenting the results in a clear and intuitive way for clinicians to review and use.

Computer-assisted signal processing has numerous applications in healthcare, including:

* Diagnosing and monitoring cardiac arrhythmias or other heart conditions using ECG signals.
* Assessing muscle activity and function using EMG signals.
* Monitoring brain activity and diagnosing neurological disorders using EEG readings.
* Analyzing medical images to detect abnormalities, such as tumors or fractures.

Overall, computer-assisted signal processing is a powerful tool for improving the accuracy and efficiency of medical diagnosis and monitoring, enabling clinicians to make more informed decisions about patient care.

Nephrotic syndrome is a group of symptoms that indicate kidney damage, specifically damage to the glomeruli—the tiny blood vessel clusters in the kidneys that filter waste and excess fluids from the blood. The main features of nephrotic syndrome are:

1. Proteinuria (excess protein in urine): Large amounts of a protein called albumin leak into the urine due to damaged glomeruli, which can't properly filter proteins. This leads to low levels of albumin in the blood, causing fluid buildup and swelling.
2. Hypoalbuminemia (low blood albumin levels): As albumin leaks into the urine, the concentration of albumin in the blood decreases, leading to hypoalbuminemia. This can cause edema (swelling), particularly in the legs, ankles, and feet.
3. Edema (fluid retention and swelling): With low levels of albumin in the blood, fluids move into the surrounding tissues, causing swelling or puffiness. The swelling is most noticeable around the eyes, face, hands, feet, and abdomen.
4. Hyperlipidemia (high lipid/cholesterol levels): The kidneys play a role in regulating lipid metabolism. Damage to the glomeruli can lead to increased lipid production and high cholesterol levels in the blood.

Nephrotic syndrome can result from various underlying kidney diseases, such as minimal change disease, membranous nephropathy, or focal segmental glomerulosclerosis. Treatment depends on the underlying cause and may include medications to control inflammation, manage high blood pressure, and reduce proteinuria. In some cases, dietary modifications and lifestyle changes are also recommended.

Genetic predisposition to disease refers to an increased susceptibility or vulnerability to develop a particular illness or condition due to inheriting specific genetic variations or mutations from one's parents. These genetic factors can make it more likely for an individual to develop a certain disease, but it does not guarantee that the person will definitely get the disease. Environmental factors, lifestyle choices, and interactions between genes also play crucial roles in determining if a genetically predisposed person will actually develop the disease. It is essential to understand that having a genetic predisposition only implies a higher risk, not an inevitable outcome.

Sjögren's syndrome is a chronic autoimmune disorder in which the body's immune system mistakenly attacks its own moisture-producing glands, particularly the tear and salivary glands. This can lead to symptoms such as dry eyes, dry mouth, and dryness in other areas of the body. In some cases, it may also affect other organs, leading to a variety of complications.

There are two types of Sjögren's syndrome: primary and secondary. Primary Sjögren's syndrome occurs when the condition develops on its own, while secondary Sjögren's syndrome occurs when it develops in conjunction with another autoimmune disease, such as rheumatoid arthritis or lupus.

The exact cause of Sjögren's syndrome is not fully understood, but it is believed to involve a combination of genetic and environmental factors. Treatment typically focuses on relieving symptoms and may include artificial tears, saliva substitutes, medications to stimulate saliva production, and immunosuppressive drugs in more severe cases.

Follow-up studies are a type of longitudinal research that involve repeated observations or measurements of the same variables over a period of time, in order to understand their long-term effects or outcomes. In medical context, follow-up studies are often used to evaluate the safety and efficacy of medical treatments, interventions, or procedures.

In a typical follow-up study, a group of individuals (called a cohort) who have received a particular treatment or intervention are identified and then followed over time through periodic assessments or data collection. The data collected may include information on clinical outcomes, adverse events, changes in symptoms or functional status, and other relevant measures.

The results of follow-up studies can provide important insights into the long-term benefits and risks of medical interventions, as well as help to identify factors that may influence treatment effectiveness or patient outcomes. However, it is important to note that follow-up studies can be subject to various biases and limitations, such as loss to follow-up, recall bias, and changes in clinical practice over time, which must be carefully considered when interpreting the results.

Sarquella-Brugada G, Campuzano O, Arbelo E, Brugada J, Brugada R (January 2016). "Brugada syndrome: clinical and genetic ... Brugada J, Brugada P, Brugada R (July 1999). "The syndrome of right bundle branch block ST segment elevation in V1 to V3 and ... Mascia G, Arbelo E, Ojeda JH, Solimene F, Brugada R, Brugada J (July 2017). "Brugada Syndrome and Exercise Practice: Current ... BrugadaDrugs.org, contains a list of drugs to avoid in people with the Brugada syndrome GeneReviews: Brugada syndrome (CS1 ...
Antzelevitch C. Brugada Syndrome. In: Encyclopedia of Cardiovascular Research and Medicine. Cardiac Electrophysiology, ... Antzelevitch, Charles; Patocskai, Bence (2016-01-09). "Brugada Syndrome. Clinical, Genetic, Molecular, Cellular and Ionic ... J-Wave syndromes expert consensus conference report: Emerging concepts and gaps in knowledge: Endorsed by the Asia Pacific ... "J-Wave syndromes expert consensus conference report: Emerging concepts and gaps in knowledge". Journal of Arrhythmia. 32 (5): ...
2008 "Brugada Syndrome". NORD (National Organization for Rare Disorders). 2016. Retrieved 28 October 2017. "Brugada syndrome". ... One relatively common type is known as Brugada syndrome. The syndrome is rare in most areas around the world but occurs in ... Brugada syndrome Night hag Sleep paralysis Sudden infant death syndrome Sudden unexpected death in epilepsy Sudden unexplained ... Rare diseases called ion channelopathies may play a role such as long QT syndrome (LQTS), Brugada syndrome (BrS), CPVT ( ...
Brugada syndrome first recognised. Hungary becomes a member of CERN. November 23 - The IBM Simon, a touchscreen mobile phone ... ISBN 978-1-84724-008-8. Brugada, P.; Brugada, J. (November 1992). "Right bundle branch block, persistent ST segment elevation ... and sudden cardiac death: a distinct clinical and electrocardiographic syndrome. A multicenter report". Journal of the American ...
Brugada syndrome - a genetic disorder characterized by an abnormal EKG and is one of the most common causes of sudden cardiac ... "Brugada syndrome: MedlinePlus Genetics". medlineplus.gov. Retrieved 19 November 2022. Davidson's 2010, pp. 527-534. Davidson, ... Long QT syndrome is the most common form of cardiac channelopathy. Long QT Syndrome (LQTS) - Mostly hereditary. On EKG can be ... Cardiac ion channelopathies may explain some of the cases of sudden death syndrome and sudden arrhythmic death syndrome. ...
Brugada syndrome is a familial condition that is also very uncommon, and also a known source of sudden death in young people. ... Polovina MM, Vukicevic M, Banko B, Lip GY, Potpara TS (October 2017). "Brugada syndrome: A general cardiologist's perspective ... Wolff-Parkinson-White syndrome (WPW) syndrome is a known cause of arrhythmia in young people. It causes supraventricular ... Long QT syndrome is a familial condition that is uncommon but is a known source of sudden death in young people. It can cause ...
Mutations in SCN10A are associated with Brugada syndrome. Nerve growth factor levels in inflamed or injured tissues are ... "Brugada Syndrome: Oligogenic or Mendelian Disease?". Int J Mol Sci. 21 (5): 1687. doi:10.3390/ijms21051687. PMC 7084676. PMID ... "Mutations in SCN10A are responsible for a large fraction of cases of Brugada syndrome". Journal of the American College of ... "Comparable clinical characteristics in Brugada syndrome patients harboring SCN5A or novel SCN10A variants". Europace. 21 (10): ...
Antzelevitch C, Yan GX, editors (2016). J Wave Syndromes: Brugada and Early Repolarization Syndromes. Cham (Switzerland): ... In 2015, Yan served as co-chair of the J-Wave Syndromes Expert Consensus Conference in Shanghai, China, and edited a medical ... long QT syndrome, and other abnormalities that can lead to sudden cardiac death. Yan is a professor at Lankenau Institute for ... "J-Wave syndromes expert consensus conference report: Emerging concepts and gaps in knowledge". Journal of Arrhythmia. 32 (5): ...
GeneReviews/NIH/NCBI/UW entry on Brugada syndrome CACNA1C+protein,+human at the U.S. National Library of Medicine Medical ... and also with Brugada syndrome. Large-scale genetic analyses have shown the possibility that CACNA1C is associated with bipolar ... "The genetic basis of Brugada syndrome: a mutation update". Human Mutation. 30 (9): 1256-66. doi:10.1002/humu.21066. PMID ... are associated with a variant of Long QT syndrome called Timothy's syndrome and more broadly with other CACNA1C-related ...
Inactivation anomalies have also been linked to Brugada syndrome. Mutations in genes encoding the α subunit in cardiac sodium ... "Inherited Brugada and long QT-3 syndrome mutations of a single residue of the cardiac sodium channel confer distinct channel ...
For example, in Brugada Syndrome, sodium channels are affected. In certain forms of long QT syndrome, the potassium inward ... Recently described syndromes such as the Brugada Syndrome may give clues to the underlying mechanism of ventricular arrhythmias ... Brugada syndrome, long QT syndrome, electric shock, or intracranial hemorrhage. Diagnosis is by an electrocardiogram (ECG) ... In the Brugada syndrome, changes may be found in the resting ECG with evidence of right bundle branch block (RBBB) and ST ...
Antzelevitch C, Patocskai B (January 2016). "Brugada Syndrome: Clinical, Genetic, Molecular, Cellular, and Ionic Aspects". ... Recently, a mixed syndrome mutation that causes periodic paralysis and myotonia in the skeletal sodium channel has been shown ... in patients with irritable bowel syndrome". Gastroenterology. 146 (7): 1659-1668. doi:10.1053/j.gastro.2014.02.054. PMC 4096335 ...
... are associated with a variant of long QT syndrome called Timothy's syndrome and also with Brugada syndrome. Large-scale genetic ... "The genetic basis of Brugada syndrome: a mutation update". Human Mutation. 30 (9): 1256-66. doi:10.1002/humu.21066. PMID ... Pagon RA, Bird TC, Dolan CR, Stephens K, Splawski I, Timothy KW, Priori SG, Napolitano C, Bloise R (1993). "Timothy Syndrome". ... Voltage-gated calcium channels antibodies are associated with Lambert-Eaton myasthenic syndrome and have also been implicated ...
... including sudden cardiac death syndromes such as the Long QT syndrome, Short QT syndrome, Brugada syndrome and Early ... The MMRI named this the Brugada syndrome in 1996, after Josep and Pedro Brugada, who first described this as a new clinical ... "Brugada syndrome delved into in the New York Times". Medscape, Michael O'Riordan February 10, 2004 Inborn Genetic Diseases: ... In 2012 they also identified Wenxin Keli and Milrinone as potential pharmacological therapies for the Brugada syndrome. The ...
Brugada syndrome is a genetic disease that can result in mutations in the sodium ion channel (gene SCN5A) of the myocytes in ... Individuals suffering from Brugada syndrome will be more susceptible to the arrhythmogenic effects of the drug, and this can be ... Brugada syndrome can result in ventricular fibrillation and potentially death. It is a major cause of sudden unexpected cardiac ... Ajmaline is used intravenously to test for Brugada syndrome since they both affect the sodium ion channel. In an afflicted ...
... en.ecgpedia.org/wiki/Brugada_Syndrome v t e (Articles needing cleanup from August 2022, Articles with bare URLs for citations ... The RVOT is pathophysiologically affected in Brugada syndrome. Velocity time integral Gray's anatomy for students, 2nd edition ...
... such as long QT syndrome and Brugada syndrome. Heart related causes also often have little history of a prodrome. Low blood ... such as long QT syndrome and Brugada syndrome. Heart related causes also often have little history of a prodrome. Low blood ... Brugada syndrome also commonly presents with syncope secondary to arrhythmia. Typically, tachycardic-generated syncope is ... Adams-Stokes syndrome is a cardiac syncope that occurs with seizures caused by complete or incomplete heart block. Symptoms ...
In individuals suspected of having the Brugada syndrome, the administration of flecainide may help reveal the ECG findings that ... "Flecainide test in Brugada syndrome: a reproducible but risky tool". Pacing and Clinical Electrophysiology. 26 (1P2): 338-341. ... and Wolff-Parkinson-White syndrome (WPW). It also has limited use in the treatment of certain forms of ventricular tachycardia ... "Flecainide-associated pneumonitis with acute respiratory failure in a patient with the LEOPARD syndrome". Acta Cardiologica. 55 ...
"Long QT and Brugada syndrome gene mutations in New Zealand". Heart Rhythm. 4 (10): 1306-14. doi:10.1016/j.hrthm.2007.06.022. ... "Contribution of long-QT syndrome genetic variants in sudden infant death syndrome". Pediatric Cardiology. 30 (4): 502-9. doi: ... "Prevalence of long-QT syndrome gene variants in sudden infant death syndrome". Circulation. 115 (3): 361-7. doi:10.1161/ ... Long QT syndrome predisposes to potentially lethal ventricular cardiac arrhythmias including torsades de pointe, which can ...
An underlying factor of sudden cardiac death may be Brugada syndrome (BrS) - BrS mutations that overlap with those linked with ... "Pathogenesis and management of Brugada syndrome in schizophrenia: A scoping review". General Hospital Psychiatry. 67: 83-91. ... DiGeorge syndrome) and 17q12 (17q12 microdeletion syndrome), duplications at 16p11.2 (most frequently found) and deletions at ... integration-dysregulation syndrome') to reduce stigma. The new name, also interpreted as "integration disorder", was inspired ...
GPDH has also been found to play a role in Brugada syndrome. Mutations in the gene encoding GPD1 have been proven to cause ... mutations in sudden infant death syndrome". Circulation. 116 (20): 2253-9. doi:10.1161/CIRCULATIONAHA.107.704627. PMC 3332545. ...
Wilde AA, Amin AS (May 2018). "Clinical Spectrum of SCN5A Mutations: Long QT Syndrome, Brugada Syndrome, and Cardiomyopathy". ... In cardiology, genetic conditions such as Brugada syndrome can share features with related disorders caused by mutations in the ... Sometimes polyangiitis overlap syndrome is used as a synonym for MPA. In gastroenterology, the term overlap syndrome may be ... Brugada syndrome can also overlap with arrhythmogenic cardiomyopathy due to certain mutations in the plakophilin gene. In ...
Brugada syndrome Incubus Sleep apnea Sleep paralysis Pesanta Lietuvēns Ramos, Maximo D. (1971). Creatures of Philippine Lower ...
Brugada syndrome is a relatively rare but lethal ventricular arrhythmia most commonly linked to voltage-gated sodium channel ... Inherited sequence variants in human KCNE5 are associated with atrial fibrillation and Brugada syndrome. Atrial fibrillation is ... giving a possible mechanism for Brugada syndrome, i.e., increased ventricular Ito density. A KCNE5 non-coding region gene ... variants are novel modulators of Brugada syndrome and idiopathic ventricular fibrillation". Circulation: Arrhythmia and ...
PKP2 mutations were also found to coexist with sodium channelopathies in patients with Brugada syndrome. Additionally, ... "Missense mutations in plakophilin-2 cause sodium current deficit and associate with a Brugada syndrome phenotype". Circulation ... implications for arrhythmogenic cardiomyopathy and Brugada syndrome". Trends in Cardiovascular Medicine. 24 (5): 184-90. doi: ... Skin fragility syndrome GRCh38: Ensembl release 89: ENSG00000057294 - Ensembl, May 2017 GRCm38: Ensembl release 89: ...
April 2007). "Electrical storms in Brugada syndrome successfully treated with isoproterenol infusion and quinidine orally". ... It is used to treat heart block and episodes of Adams-Stokes syndrome that are not caused by ventricular tachycardia or ...
Furthermore, mutations in SCN5A can cause Brugada syndrome, cardiac conduction disease, and dilated cardiomyopathy. In rare ... Long QT syndrome Jervell and Lange-Nielsen syndrome Andersen-Tawil syndrome Timothy syndrome Tester DJ, Schwartz PJ, Ackerman ... Romano-Ward syndrome is a descriptive term for a group of subtypes of long QT syndrome, specifically subtypes LQT1-6 and LQT9- ... Romano-Ward syndrome is the most common form of congenital Long QT syndrome (LQTS), a genetic heart condition that affects the ...
Brugada syndrome is another ventricular arrhythmia caused by voltage-gated sodium channel gene mutations. Polymicrogyria is a ... Familial hemiplegic migraine (FHM) Spinocerebellar ataxia type 13 Long QT syndrome is a ventricular arrhythmia syndrome caused ...
Common variants of SCN5A, SCN10A, and HEY2 (this gene) are associated with Brugada syndrome. HEY2 has been shown to interact ... September 2013). "Common variants at SCN5A-SCN10A and HEY2 are associated with Brugada syndrome, a rare disease with high risk ... mice and absence of HEY2 mutations in patients with congenital heart defects or Alagille syndrome". Mammalian Genome. 15 (9): ...
When Kush is diagnosed with the hereditary Brugada Syndrome, Stacey becomes worried for Arthur; they learn he is at high risk ...
Sarquella-Brugada G, Campuzano O, Arbelo E, Brugada J, Brugada R (January 2016). "Brugada syndrome: clinical and genetic ... Brugada J, Brugada P, Brugada R (July 1999). "The syndrome of right bundle branch block ST segment elevation in V1 to V3 and ... Mascia G, Arbelo E, Ojeda JH, Solimene F, Brugada R, Brugada J (July 2017). "Brugada Syndrome and Exercise Practice: Current ... BrugadaDrugs.org, contains a list of drugs to avoid in people with the Brugada syndrome GeneReviews: Brugada syndrome (CS1 ...
Brugada syndrome is a condition that causes a disruption of the hearts normal rhythm . Explore symptoms, inheritance, genetics ... Brugada R, Campuzano O, Sarquella-Brugada G, Brugada P, Brugada J, Hong K. Brugada Syndrome. 2005 Mar 31 [updated 2022 Aug 25 ... Brugada R, Campuzano O, Sarquella-Brugada G, Brugada J, Brugada P. Brugada syndrome. Methodist Debakey Cardiovasc J. 2014 Jan- ... medlineplus.gov/genetics/condition/brugada-syndrome/ Brugada syndrome. ...
Brugada syndrome is a disorder characterized by sudden death associated with one of several ECG patterns characterized by ... Brugada J, Campuzano O, Arbelo E, Sarquella-Brugada G, Brugada R. Present status of Brugada syndrome: JACC state-of-the-art ... Antzelevitch C, Brugada P, Brugada J, Brugada R. Brugada syndrome: from cell to bedside. Curr Probl Cardiol. 2005 Jan. 30(1):9- ... Brugada P, Geelen P, Brugada R, Mont L, Brugada J. Prognostic value of electrophysiologic investigations in Brugada syndrome. J ...
Brugada syndrome (BS) is a genetic pathological condition associated with a high risk for sudden cardiac death (SCD). ...
Diagnosis of Brugada Syndrome. (Gregory Dendramis and Pedro Brugada). Chapter 5. Modulating-Precipitating Factors and Brugada ... Gregory Dendramis, Pedro Brugada, and Claudia Paleologo). Chapter 8. Treatment of Brugada Syndrome. (Gregory Dendramis, Maria ... Gregory Dendramis, Charles Antzelevitch, and Pedro Brugada). Chapter 2. Genetic Basis of Brugada Syndrome. (Gregory Dendramis, ... Brugada Syndrome: Diagnosis, Clinical Manifestations, Risk Stratification and Treatment. $95.00. Gregory Dendramis, MD (Editor) ...
Timothy syndrome is also called Long QT syndrome with syndactyly or long QT syndrome (LQT8) (Krause et al. 2011). Two forms of ... Brugada syndrome (BrS) is a potentially life-threating rhythm disorder characterized by ST segment elevation on ECG. Other ... Brugada syndrome is treatable with preventive measures such as reducing fever, avoiding certain medications and using ... Type 2, or the atypical type, causes a more severe form of long QT syndrome and a greater risk of arrhythmia and sudden death. ...
Brugada syndrome is a disorder characterized by sudden death associated with one of several ECG patterns characterized by ... Antzelevitch C, Brugada P, Brugada J, Brugada R. Brugada syndrome: from cell to bedside. Curr Probl Cardiol. 2005 Jan. 30(1):9- ... Guideline] Antzelevitch C, Brugada P, Borggrefe M, Brugada J, Brugada R, Corrado D, et al. Brugada syndrome: report of the ... Brugada P, Geelen P, Brugada R, Mont L, Brugada J. Prognostic value of electrophysiologic investigations in Brugada syndrome. J ...
ERN GUARD-Heart. European Reference Network for Rare and Low Prevalence Complex Diseases of the Heart. ...
This review offers important information and updates on Brugada syndrome. ... Brugada syndrome was first identified as a common cause of sudden death in young males of Southeast Asian descent. However, the ... In short, the Brugada syndrome is an abnormality in the electrical system of the heart that predisposes patients to develop ... However, for those who are familiar with the Brugada syndrome, a review of the most recent literature on this topic is in order ...
113.Campuzano O, Sarquella-Brugada G, Cesar S, Arbelo E, Brugada J, Brugada R. Update on genetic basis of brugada syndrome: ... 74.Campuzano O, Berne P, Selga E, Allegue C, Iglesias A, Brugada J, Brugada R. Brugada syndrome and p.E61X_RANGRF. Cardiol J. ... These mutations are associated with long QT syndromes, Timothy syndrome (TS, OMIM 601005)114, Brugada syndromes 3 BRGDA3, OMIM ... Gain-of-function kcnh2 mutations in patients with brugada syndrome: novel kcnh2 mutations in brugada syndrome. J Cardiovasc ...
Learn Brugada Syndrome - Electrocardiography & Arrhythmias - Physiology - Picmonic for Medicine faster and easier with ... Patients with Brugada syndrome are at risk for experiencing long runs of ventricular tachycardia, in which the ventricles beat ... Patients with Brugada syndrome who have experienced syncope or episodes of Vtach should have an implantable cardioverter- ... Patients with Brugada syndrome may experience syncopal episodes due to sustained runs of ventricular tachycardia, causing ...
Brugada Syndrome - Etiology, pathophysiology, symptoms, signs, diagnosis & prognosis from the MSD Manuals - Medical ... Symptoms and Signs of Brugada Syndrome In some patients, Brugada syndrome has no clinical expression. However, in many patients ... the type 1 Brugada ECG pattern (see figure Type 1 Brugada ECG pattern Type 1 Brugada ECG pattern ). The type 1 Brugada ECG ... as are overlap syndromes with long QT syndrome type 3 Long QT Interval Syndromes The long QT interval syndromes (LQTS) result ...
This project is supported by the Canadian Institutes of Health Research, Canada Foundation for Innovation, and by The Metabolomics Innovation Centre (TMIC), a nationally-funded research and core facility that supports a wide range of cutting-edge metabolomic studies. TMIC is funded by Genome Canada, Genome Alberta, and Genome British Columbia, a not-for-profit organization that is leading Canadas national genomics strategy with $900 million in funding from the federal government ...
Brugada syndrome: Lithium shouldnt be used in people who have Brugada syndrome or those who have a history of abnormal ECG ... Landa E, Wagner S, Makkar A, Liu A, Jung D. An atypical presentation of serotonin syndrome. Cureus. 2021;13(2):e13377.View ... Lithium carbonate-induced Stevens-Johnson syndrome: the first case report. Int J Dermatol 2023;62(3):e165-e167. View abstract. ...
Keywords: Brugada syndrome; NaV1.5 voltage-gated sodium channel; SCN5A protein, human; atrial tachyarrhythmia with short PR; ...
Parasympathetic system Arrhythmogenesis Autonomic function Brugada syndrome Cardioprotection Exercise Time-frequency analysis ... Sex differences in autonomic response to exercise testing in patients with brugada syndrome. ... Sex differences in autonomic response to exercise testing in patients with brugada syndrome. Sex-Specific Analysis of ...
In the copious list of rhythm disturbances, diseases of the conduction system, as sick sinus syndrome, Brugada syndrome, and ... In the copious list of rhythm disturbances, diseases of the conduction system, as sick sinus syndrome, Brugada syndrome, and ... Iop et al Cells 2021_Inherited and Acquired Rhythm Disturbances in Sick Sinus Syndrome, Brugada Syndrome, and Atrial ... Inherited and acquired rhythm disturbances in sick sinus syndrome, brugada syndrome, and atrial fibrillation: Lessons from ...
Brugada syndrome is characterized by a coved ST segment in the right precordial leads. The syndrome may cause sudden death due ... Antzelevitch C. Brugada syndrome. Pacing Clin Electrophysiol. 2006 Oct. 29(10):1130-59. [QxMD MEDLINE Link]. [Full Text]. ... Congenital long QT syndromes (adrenergic-dependent). The following congenital syndromes are associated with torsade:. * Jervell ... Another form of familial or congenital long QT syndrome is Romano-Ward syndrome, in which hearing is normal and an autosomal ...
Lithium should generally be avoided in patients with Brugada Syndrome or those suspected of having Brugada Syndrome. ... A condition known as Brugada Syndrome may pre-exist and be unmasked by lithium therapy. Brugada Syndrome is a heart disorder ... This encephalopathic syndrome may be similar to or the same as Neuroleptic Malignant Syndrome (NMS). Serotonin Syndrome Lithium ... is under consideration for patients suspected of having Brugada Syndrome or patients who have risk factors for Brugada Syndrome ...
This is possible if you have auto-brewery syndrome. Find out all about this rare condition... ... However, read on to find out all about the syndrome.. Also read: Brugada Syndrome: Small signs of sudden cardiac arrest ... One such condition is auto brewery syndrome, which is also known as gut fermentation syndrome. The word fermentation should ... Auto brewery syndrome is a rare condition, in which the yeast in the gut produces a large amount of ethanol. Those with the ...
Brugada syndrome (a genetic heart rhythm disorder) or. *Cardiogenic shock (shock caused by heart attack) or ... Sick sinus node syndrome (type of abnormal heart rhythm), with no pacemaker-Should not be used in patients with these ...
ASSOCIATED WITH Brugada syndrome (ortholog); genetic disease (ortholog); Immunodeficiency 68 (ortholog); FOUND IN mitochondrial ... Brugada syndrome ISO. SLC22A14 (Homo sapiens). 8554872. ClinVar Annotator: match by term: Brugada syndrome. ClinVar. PMID: ... Metabolic Syndrome Renal Disease Respiratory Disease Sensory Organ Disease ...
Inherited Disorder: Brugada syndrome, ERS and Idiopathic VF. 40. Inherited Disorder: Long QT syndrome, ARVC, and Others. ... Risk Stratification of Early Repolarization Syndrome. English. Symposium. Patient Management of Pain and Anxiety during ... Sleep Apnea Syndrome and Arrhythmias -Relations with the Autonomic Nervous System-. English. ...
In SADS cases, death is most likely caused by primary arrhythmia syndromes, such as long QT syndrome, Brugada syndrome or ... The Diagnostic Yield of Brugada Syndrome After Sudden Death With Normal Autopsy. J. Am. Coll. Cardiol. 2018, 71, 1204-1214. [ ... myocardial infarctions and acute coronary syndromes). 2015-2019. (5). Physically active population (competitive and non- ... Utility of Post-Mortem Genetic Testing in Cases of Sudden Arrhythmic Death Syndrome. J. Am. Coll. Cardiol. 2017, 69, 2134-2145 ...
Antzelevitch C, Brugada P, Borggrefe M, et al. Brugada syndrome: report of the second consensus conference: endorsed by the ... Campuzano O, Brugada R, Iglesias A. Genetics of Brugada syndrome. Curr Opin Cardiol 2010;25:210-5. ... The ECG shows evidence of Brugada Syndrome (congenital Na channelopathy) with the classical findings of Type 1 Brugada pattern ... Brugada syndrome is an inherited Sodium channel defect. Three ECG repolarization patterns in the right precordial leads are ...
2] long QT syndrome, [3] and J wave syndromes [4] such as Brugada syndrome [5] (see Table 1 below). ... 6] References are available that list medications to avoid with long QT syndrome and Brugada syndrome. [7] ... Safe drug use in long QT syndrome and Brugada syndrome: comparison of website statistics. Europace. 2013 Jul. 15 (7):1042-9. [ ... Anesthetic management of patients with Brugada syndrome: a case series and literature review. Can J Anaesth. 2011 Sep. 58 (9): ...
Long QT syndrome (LQTS) and other heart signaling problems. Conditions such as long QT syndrome and Brugada syndrome cause the ... Genetic tests can be done to see if you have long QT syndrome, a common cause of sudden cardiac death. Check with your insurer ... Pre-test probability and genes and variants of uncertain significance in familial long QT syndrome. Heart, Lung and Circulation ...
Numerous Brugada syndrome-associated genetic variants have no effect on J-point elevation, syncope susceptibility, malignant ... Rare genetic variants previously associated with congenital forms of long QT syndrome have little or no effect on the QT ... We initially examined 31 additional genes associated with hereditary cancer syndromes. These genes are also associated with ...
These include hypertrophic cardiomyopathy, long QT syndrome, Marfan syndrome, Brugada syndrome, and others. Another example of ...
  • Syncope and cardiac arrest are the most common clinical manifestations leading to the diagnosis of Brugada syndrome. (medscape.com)
  • However, some patients remain asymptomatic, and the diagnosis of Brugada syndrome is suggested by a routine ECG showing ST-segment elevation in leads V 1 through V 3 . (medscape.com)
  • The average age at diagnosis of Brugada syndrome is about 40 years. (medscape.com)
  • Chen first described the genetic abnormality of SCN5A channels [49] While many of those with Brugada syndrome do not have any symptoms, Brugada syndrome may cause fainting or sudden cardiac death due to serious abnormal heart rhythms such as ventricular fibrillation or polymorphic ventricular tachycardia. (wikipedia.org)
  • A family history of sudden cardiac death is common, though not universal, as the syndrome can occur sporadically. (medscape.com)
  • Brugada J, Brugada R, Brugada P. Determinants of sudden cardiac death in individuals with the electrocardiographic pattern of Brugada syndrome and no previous cardiac arrest. (medscape.com)
  • Brugada P, Brugada J. Right bundle branch block, persistent ST segment elevation and sudden cardiac death: a distinct clinical and electrocardiographic syndrome. (medscape.com)
  • There is general consensus that ICD implantation is recommended in patients with type 1 Brugada ECG (either spontaneously or after Na+ channel blockade) and a history of aborted sudden cardiac death (SCD) or related symptoms such as syncope, seizure, or nocturnal agonal respiration, given that non-cardiac causes of these symptoms have been carefully excluded. (acc.org)
  • However, only 20% of cases of Brugada syndrome are associated with mutations in SCN5A, as in the majority of patients with Brugada syndrome genetic testing is unable to identify the genetic mutation responsible. (wikipedia.org)
  • The third is the indication of ICDs for infant cases of Brugada syndrome, in which the size of the ICD is too large for implantation 11 , 12 , 13 . (southampton.ac.uk)
  • Timothy syndrome is characterized by physical malformations, neurological and developmental defects, including syndactyly, heart QT-prolongation and arrhythmias, developmental delay and autism spectrum disorders. (preventiongenetics.com)
  • Incidence, clinical implications and prognosis of atrial arrhythmias in Brugada syndrome. (medscape.com)
  • However, blackouts can occur in those with Brugada syndrome despite a normal heart rhythm due to a sudden drop in blood pressure, known as vasovagal syncope. (wikipedia.org)
  • The lack of a prodrome has been reported to be more common in patients with ventricular fibrillation documented as the cause of syncope in patients with Brugada syndrome. (medscape.com)
  • A 2012 study suggests that the quality of symptoms prior to syncope can predict a benign or malignant cause in patients with Brugada syndrome. (medscape.com)
  • Identification of high-risk syncope related to ventricular fibrillation in patients with Brugada syndrome. (medscape.com)
  • Patients with Brugada syndrome who have experienced syncope or episodes of Vtach should have an implantable cardioverter-defibrillator or ICD implanted. (picmonic.com)
  • Brugada syndrome is an inherited channelopathy causing an increased risk of ventricular tachycardia (VT) and ventricular fibrillation (VF) leading to syncope and sudden death. (msdmanuals.com)
  • It is an autosomal dominant syndrome with non-exertional syncope as hallmarks as well as far east Asian descent. (acc.org)
  • Brugada syndrome is inherited in an autosomal dominant manner, meaning that only one copy of the defective gene is needed to produce the syndrome. (wikipedia.org)
  • CACNA1C -related Timothy and Brugada syndrome are inherited in an autosomal dominant manner. (preventiongenetics.com)
  • Brugada syndrome has an autosomal dominant inheritance pattern, though it exhibits variable expression. (picmonic.com)
  • Brugada syndrome is suggested to be a primary electrical disease, and two dozen mutations of the cardiac sodium channel gene "SCN5A", which lead to a loss of the channel function, have been found in about 15-20 % of patients with Brugada syndrome, and an autosomal mode of transmission has been demonstrated 4 , 5 , 6 , 7 , 8 . (southampton.ac.uk)
  • Cardiac histological substrate in patients with clinical phenotype of Brugada syndrome. (medscape.com)
  • The prevailing theory regarding the pathophysiology of Brugada syndrome is that it is a sodium channelopathy caused by a genetic mutation. (medscape.com)
  • This review aims to offer a critical overview on the effective ability of in silico bioinformatic tools, in vivo animal studies, in vitro models to provide insights on human heart rhythm pathophysiology in case of sick sinus syndrome, Brugada syndrome, and atrial fibrillation and advance their safe and successful translation into the cardiology arena. (unipd.it)
  • Sodium channel blocking medications, commonly used to treat cardiac arrhythmia, may also worsen the tendency to abnormal heart rhythms in patients with Brugada syndrome and should be avoided. (wikipedia.org)
  • Type 2, or the atypical type, causes a more severe form of long QT syndrome and a greater risk of arrhythmia and sudden death. (preventiongenetics.com)
  • Mutations in the genes encoding β subunits are linked to a number of diseases, including epilepsy, sudden death syndromes like SUDEP and SIDS, and cardiac arrhythmia. (annualreviews.org)
  • Pregnancy in women with Brugada syndrome: Is there an increased arrhythmia risk? (bvsalud.org)
  • Campuzano O, Brugada R, Iglesias A. Genetics of Brugada syndrome. (acc.org)
  • As a genetic condition, the syndrome is ultimately caused by changes to a person's DNA, known as genetic mutations. (wikipedia.org)
  • The first mutations described in association with Brugada syndrome were in a gene responsible for a protein or ion channel that controls the flow of sodium ions through the cell membrane of heart muscle cells - the cardiac sodium channel. (wikipedia.org)
  • Many of the genetic mutations that have subsequently been described in association with Brugada syndrome influence the sodium current in some way, or affect other ionic currents. (wikipedia.org)
  • The gene in which mutations are most commonly found in Brugada syndrome, known as SCN5A, is responsible for the cardiac sodium channel. (wikipedia.org)
  • Mutations in SCN5A associated with Brugada syndrome generally cause the flow of sodium ions to decrease. (wikipedia.org)
  • Brugada syndrome can be caused by mutations in one of several genes. (medlineplus.gov)
  • Mutations in other genes can also cause Brugada syndrome. (medlineplus.gov)
  • 2011). Two forms of Timothy syndrome have been described: the classic type (type 1) and a second form caused by mutations in an alternatively spliced form (type 2). (preventiongenetics.com)
  • Thus, we believe that this in-depth analytical study of the countless mutations attributed to BrS may constitute a real cornerstone that will help to better understand this intriguing syndrome. (bvsalud.org)
  • All patients with symptoms suggestive of Brugada syndrome and Timothy syndrome are candidates for this test. (preventiongenetics.com)
  • Choice C is incorrect as the ECG changes of ST elevation are restricted to septal leads but given no reciprocal ECG changes and lack of acute coronary syndrome (ACS) symptoms, the possibility of ACS is low. (acc.org)
  • Brugada syndrome (BrS) is a genetic disorder in which the electrical activity of the heart is abnormal due to channelopathy. (wikipedia.org)
  • Long QT Interval Syndromes The long QT interval syndromes (LQTS) result from any congenital or acquired disorder of cardiac ion channel function or regulation (channelopathy) that prolongs ventricular myocyte action potential. (msdmanuals.com)
  • The ECG shows evidence of Brugada Syndrome (congenital Na channelopathy) with the classical findings of Type 1 Brugada pattern. (acc.org)
  • Sudden unexplained nocturnal death syndrome (SUNDS) is a condition characterized by unexpected cardiac arrest in young adults, usually at night during sleep. (medlineplus.gov)
  • Pathophysiological mechanisms of Brugada syndrome: depolarization disorder, repolarization disorder, or more? (medscape.com)
  • The abnormality underlying both acquired and congenital long QT syndromes is in the ionic current flow during repolarization, which affects the QT interval. (medscape.com)
  • Atrial fibrillation in patients with Brugada syndrome relationships of gene mutation, electrophysiology, and clinical backgrounds. (medscape.com)
  • In the copious list of rhythm disturbances, diseases of the conduction system, as sick sinus syndrome, Brugada syndrome, and atrial fibrillation, have found extensive preclinical modeling. (unipd.it)
  • however, theoretically, drugs that counteract the ionic current imbalance in Brugada syndrome could be used to treat it. (medscape.com)
  • Vorobiof G, Kroening D, Hall B, Brugada R, Huang D. Brugada syndrome with marked conduction disease: dual implications of a SCN5A mutation. (medscape.com)
  • 312 amino acid substitution-causing variant in 3 long QT syndrome gene SCN5A in F10, LQT in transmembrane domain (N/TM/C) in F11, LQT in loop regions in F12. (lu.se)
  • However, arrhythmic events related to Brugada syndrome are reported in patients ranging from 2 days to 84 years of age. (medscape.com)
  • Brugada syndrome (BrS) is a hereditary clinical-electrocardiographic arrhythmic entity with low worldwide prevalence. (bvsalud.org)
  • Three types of ST-segment elevation in Brugada syndrome, as shown in the precordial leads on ECG in the same patient at different times. (medscape.com)
  • Electrocardiographically characterized by a distinct ST-segment elevation in the right precordial leads, Brugada syndrome (BrS) is an arrhythmogenic disease reported to be responsible for at least 4% of all sudden deaths (at least 20% of sudden deaths in those without structural heart disease), and is a leading cause of death in subjects under the age of forty years. (novapublishers.com)
  • Brugada syndrome (BrS) is a potentially life-threating rhythm disorder characterized by ST segment elevation on ECG. (preventiongenetics.com)
  • Typically, the ECG findings of Brugada syndrome consist of a pseudo-right bundle branch block and persistent ST segment elevation in leads V1 to V2. (picmonic.com)
  • Such changes may affect the right ventricular epicardium more markedly than the endocardium and produce a marked voltage gradient in the membrane potential between the end- and epi-cardial sides of the right ventricular muscle fibers during the phase 2 (a change corresponding to the characteristic ST-segment elevation in V1 through V3 in the ECGs of Brugada Syndrome 4 , 6 , 7 , 8 . (southampton.ac.uk)
  • In patients with Brugada syndrome, an abnormal spike-and-dome configuration of the epicardial monophasic action potentials (MAPs) obtained from the right ventricular outflow tract, may create a prominent J point elevation 14 . (southampton.ac.uk)
  • Electrophysiologists typically will use potent sodium-channel blockers in the electrophysiology laboratory as part of the diagnostic testing for the Brugada syndrome. (medscape.com)
  • Brugada syndrome is an inherited Sodium channel defect. (acc.org)
  • Longer repolarization in the epicardium at the right ventricular outflow tract causes type 1 electrocardiogram in patients with Brugada syndrome. (medscape.com)
  • In affected people without an identified gene mutation, the cause of Brugada syndrome is often unknown. (medlineplus.gov)
  • The abnormal heart rhythms seen in those with Brugada syndrome often occur at rest. (wikipedia.org)
  • The abnormal heart rhythms seen in Brugada syndrome often occur at rest, following a heavy meal, or even during sleep. (wikipedia.org)
  • A disruption in ion transport alters the way the heart beats, leading to the abnormal heart rhythm characteristic of Brugada syndrome. (medlineplus.gov)
  • To date, the only treatment that has proven effective in treating ventricular tachycardia and fibrillation and preventing sudden death in patients with Brugada syndrome is implantation of an automatic implantable cardiac defibrillator (ICD). (medscape.com)
  • Researchers have determined that SUNDS and Brugada syndrome are the same disorder. (medlineplus.gov)
  • Brugada syndrome is a disorder characterized by sudden death associated with one of several ECG patterns characterized by incomplete right bundle-branch block and ST-segment elevations in the anterior precordial leads. (medscape.com)
  • According to a consensus report (Antzelevitch, 2005), the type 1 ECG pattern is diagnostic of Brugada syndrome. (medscape.com)
  • Brugada syndrome is treatable with preventive measures such as reducing fever, avoiding certain medications and using implantable cardiac defibrillator (Francis and Antzelevitch 2005). (preventiongenetics.com)
  • Antzelevitch C, Brugada P, Brugada J, Brugada R. Brugada syndrome: from cell to bedside. (medscape.com)
  • A pseudo-right bundle branch block pattern and persistent ST elevations in leads V1-V2 is the characteristic finding on EKG associated with Brugada syndrome. (picmonic.com)
  • The pathology seen in Brugada syndrome is thought to be due to defective myocardial sodium channels that reduce the sodium inflow current, thereby reducing the duration of action potentials. (picmonic.com)
  • Only the type 1 ECG pattern is diagnostic of the Brugada syndrome, with type 2 and type 3 ECG patterns being suggestive but not specific. (acc.org)
  • Fever is often reported to trigger or exacerbate the clinical manifestations of Brugada syndrome. (medscape.com)
  • Alings M, Wilde A. "Brugada" syndrome: clinical data and suggested pathophysiological mechanism. (medscape.com)
  • In some patients, Brugada syndrome has no clinical expression. (msdmanuals.com)
  • This contrasts with other heart diseases associated with sudden death, such as hypertrophic cardiomyopathy and long QT syndrome, which typically occur at younger ages. (medscape.com)
  • The exact prevalence of Brugada syndrome is unknown, although it is estimated to affect 5 in 10,000 people worldwide. (medlineplus.gov)
  • In short, the Brugada syndrome is an abnormality in the electrical system of the heart that predisposes patients to develop episodes of ventricular tachycardia and loss of consciousness. (medscape.com)
  • Most patients with Brugada syndrome have a normal physical examination. (medscape.com)
  • The physical examination is usually normal in patients with Brugada syndrome. (medscape.com)
  • Patients with severe malaria are at risk for life-threatening complications including: renal failure, acute respiratory distress syndrome (ARDS), severe hemolytic anemia, and cerebral malaria. (cdc.gov)
  • The incidence of Brugada syndrome is approximately 1 in 1000 and is higher in people with Asian ancestry. (msdmanuals.com)
  • Lithium shouldn't be used in people who have Brugada syndrome or those who have a history of abnormal ECG readings. (webmd.com)
  • This condition may explain some cases of sudden infant death syndrome (SIDS), which is a major cause of death in babies younger than 1 year. (medlineplus.gov)
  • Definitive testing for Brugada syndrome is done in the electrophysiology laboratory, where, if the diagnosis is confirmed, an implantable cardioverter-defibrillator ( ICD ) is placed. (medscape.com)
  • Those with the auto-brewery syndrome report abnormally high blood alcohol levels, even if they consume no alcohol, according to Medical News Today. (indiatimes.com)
  • One of the key signs of auto-brewery syndrome is being drunk without drinking any alcohol. (indiatimes.com)
  • Patients with Brugada syndrome are at risk for experiencing long runs of ventricular tachycardia, in which the ventricles beat at an excessively fast rate that does not allow for adequate ventricular filling during diastole, resulting in significantly compromised cardiac output. (picmonic.com)
  • Patients with Brugada syndrome may experience syncopal episodes due to sustained runs of ventricular tachycardia, causing significantly reduced cardiac output to the brain. (picmonic.com)
  • Brugada syndrome usually becomes apparent in adulthood, although it can develop any time throughout life. (medlineplus.gov)
  • The majority of patients with clinically apparent Brugada syndrome are male. (msdmanuals.com)
  • A long list of factors that can generate a Brugada ECG pattern have been described, including certain medications, electrolyte disturbances such as a decrease in the levels of potassium in the blood, and a reduction in blood supply to key areas of the heart, specifically the right ventricular outflow tract. (wikipedia.org)
  • For example, quinidine, which blocks the calcium-independent transient outward potassium current (Ito), has been shown to normalize the ECG pattern in patients with Brugada syndrome. (medscape.com)
  • Choice A is incorrect as Brugada pattern is clearly seen. (acc.org)
  • Brugada syndrome: report of the second consensus conference: endorsed by the Heart Rhythm Society and the European Heart Rhythm Association. (acc.org)
  • There are 3 patterns of Brugada syndrome, classified based on ECG parameters. (msdmanuals.com)
  • First identified and described in the early 1990s, the Brugada syndrome has become one of the most intriguing topics that emergency physicians and cardiologists have been learning about in ECG over the past 2 decades. (medscape.com)
  • In less than three decades since the discovery of Brugada syndrome, the concept of Mendelian heredity has come undone. (bvsalud.org)
  • Timothy syndrome is also called Long QT syndrome with syndactyly or long QT syndrome (LQT8) (Krause et al. (preventiongenetics.com)
  • Abnormally high blood levels of calcium (hypercalcemia) or potassium (hyperkalemia), as well as unusually low potassium levels (hypokalemia), also have been associated with acquired Brugada syndrome. (medlineplus.gov)
  • It was firstly described by Andrea Nava and Bortolo Martini in Padova in 1989 [48] but it is named after the Catalan cardiologists Pedro and Josep Brugada who described the condition in 1992. (wikipedia.org)
  • The individual heart muscle cells communicate with each other with electrical signals that are disrupted in those with Brugada syndrome. (wikipedia.org)
  • Some of the additional genes involved in Brugada syndrome provide instructions for making proteins that ensure the correct location or function of sodium channels in heart muscle cells. (medlineplus.gov)
  • Elsa suffers from Brugada syndrome, a rare disease that leaves her constantly at risk of fatal heart attack, yet she is strangely buoyant. (independent.com)

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