Abnormally rapid heartbeats caused by reentry of atrial impulse into the dual (fast and slow) pathways of ATRIOVENTRICULAR NODE. The common type involves a blocked atrial impulse in the slow pathway which reenters the fast pathway in a retrograde direction and simultaneously conducts to the atria and the ventricles leading to rapid HEART RATE of 150-250 beats per minute.
A generic expression for any tachycardia that originates above the BUNDLE OF HIS.
Abnormally rapid heartbeats caused by reentry circuit in or around the SINOATRIAL NODE. It is characterized by sudden onset and offset episodes of tachycardia with a HEART RATE of 100-150 beats per minute. The P wave is identical to the sinus P wave but with a longer PR interval.
The use of freezing as a special surgical technique to destroy or excise tissue.
Removal of tissue with electrical current delivered via electrodes positioned at the distal end of a catheter. Energy sources are commonly direct current (DC-shock) or alternating current at radiofrequencies (usually 750 kHz). The technique is used most often to ablate the AV junction and/or accessory pathways in order to interrupt AV conduction and produce AV block in the treatment of various tachyarrhythmias.
A small nodular mass of specialized muscle fibers located in the interatrial septum near the opening of the coronary sinus. It gives rise to the atrioventricular bundle of the conduction system of the heart.
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.
Abnormally rapid heartbeat, usually with a HEART RATE above 100 beats per minute for adults. Tachycardia accompanied by disturbance in the cardiac depolarization (cardiac arrhythmia) is called tachyarrhythmia.
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.
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).
Abnormally rapid heartbeats with sudden onset and cessation.
Abnormally rapid heartbeats originating from one or more automatic foci (nonsinus pacemakers) in the HEART ATRIUM but away from the SINOATRIAL NODE. Unlike the reentry mechanism, automatic tachycardia speeds up and slows down gradually. The episode is characterized by a HEART RATE between 135 to less than 200 beats per minute and lasting 30 seconds or longer.
Simple rapid heartbeats caused by rapid discharge of impulses from the SINOATRIAL NODE, usually between 100 and 180 beats/min in adults. It is characterized by a gradual onset and termination. Sinus tachycardia is common in infants, young children, and adults during strenuous physical activities.
Abnormally rapid heartbeats caused by reentrant conduction over the accessory pathways between the HEART ATRIA and the HEART VENTRICLES. The impulse can also travel in the reverse direction, as in some cases, atrial impulses travel to the ventricles over the accessory pathways and back to the atria over the BUNDLE OF HIS and the ATRIOVENTRICULAR NODE.
A rare form of supraventricular tachycardia caused by automatic, not reentrant, conduction initiated from sites at the atrioventricular junction, but not the ATRIOVENTRICULAR NODE. It usually occurs during myocardial infarction, after heart surgery, or in digitalis intoxication with a HEART RATE ranging from 140 to 250 beats per minute.
Methods to induce and measure electrical activities at specific sites in the heart to diagnose and treat problems with the heart's electrical system.
Regulation of the rate of contraction of the heart muscles by an artificial pacemaker.
A syndrome of ORTHOSTATIC INTOLERANCE combined with excessive upright TACHYCARDIA, and usually without associated ORTHOSTATIC HYPOTENSION. All variants have in common an excessively reduced venous return to the heart (central HYPOVOLEMIA) while upright.
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)
Small band of specialized CARDIAC MUSCLE fibers that originates in the ATRIOVENTRICULAR NODE and extends into the membranous part of the interventricular septum. The bundle of His, consisting of the left and the right bundle branches, conducts the electrical impulses to the HEART VENTRICLES in generation of MYOCARDIAL CONTRACTION.
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.
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.
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.
A form of ventricular pre-excitation characterized by a short PR interval and a long QRS interval with a delta wave. In this syndrome, atrial impulses are abnormally conducted to the HEART VENTRICLES via an ACCESSORY CONDUCTING PATHWAY that is located between the wall of the right or left atria and the ventricles, also known as a BUNDLE OF KENT. The inherited form can be caused by mutation of PRKAG2 gene encoding a gamma-2 regulatory subunit of AMP-activated protein kinase.

AV reentrant and idiopathic ventricular double tachycardias: complicated interactions between two tachycardias. (1/332)

An electrophysiological study was performed in a 61 year old man with Wolff- Parkinson-White (WPW) syndrome. At baseline, neither ventricular nor supraventricular tachycardias could be induced. During isoprenaline infusion, ventricular tachycardia originating from the right ventricular outflow tract (RVOT) with a cycle length of 280 ms was induced and subsequently atrioventricular reentrant tachycardia (AVRT) with a cycle length of 300 ms using an accessory pathway in the left free wall appeared. During these tachycardias, AVRT was entrained by ventricular tachycardia. The earliest ventricular activation site during the ventricular tachycardia was determined to be the RVOT site and a radiofrequency current at 30 W successfully ablated the ventricular tachycardia at this site. The left free wall accessory pathway was also successfully ablated during right ventricular pacing. The coexistence of WPW syndrome and cathecolamine sensitive ventricular tachycardia originating from the RVOT has rarely been reported. Furthermore, the tachycardias were triggered by previous tachycardias.  (+info)

Electrophysiologic effects of adenosine in patients with supraventricular tachycardia. (2/332)

BACKGROUND: We correlated the electrophysiologic (EP) effects of adenosine with tachycardia mechanisms in patients with supraventricular tachycardias (SVT). METHODS AND RESULTS: Adenosine was administered to 229 patients with SVTs during EP study: atrioventricular (AV) reentry (AVRT; n=59), typical atrioventricular node reentry (AVNRT; n=82), atypical AVNRT (n=13), permanent junctional reciprocating tachycardia (PJRT; n=12), atrial tachycardia (AT; n=53), and inappropriate sinus tachycardia (IST; n=10). There was no difference in incidence of tachycardia termination at the AV node in AVRT (85%) versus AVNRT (86%) after adenosine, but patients with AVRT showed increases in the ventriculoatrial (VA) intervals (13%) compared with typical AVNRT (0%), P<0.005. Changes in atrial, AV, or VA intervals after adenosine did not predict the mode of termination of long R-P tachycardias. For patients with AT, there was no correlation with location of the atrial focus and adenosine response. AV block after adenosine was only observed in AT patients (27%) or IST (30%). Patients with IST showed atrial cycle length increases after adenosine (P<0.05) with little change in activation sequence. The incidence of atrial fibrillation after adenosine was higher for those with AVRT (15%) compared with typical AVNRT (0%) P<0.001, or atypical AVNRT (0%) but similar to those with AT (11%) and PJRT (17%). CONCLUSIONS: The EP response to adenosine proved of limited value to identify the location of AT or SVT mechanisms. Features favoring AT were the presence of AV block or marked shortening of atrial cycle length before tachycardia suppression. Atrial fibrillation was more common after adenosine in patients with AVRT, PJRT, or AT. Patients with IST showed increases in cycle length with little change in atrial activation sequence after adenosine.  (+info)

Atrioventricular block occurring several months after radiofrequency ablation for the treatment of atrioventricular nodal re-entrant tachycardia. (3/332)

Atrioventricular (AV) block following radiofrequency (RF) ablation for the treatment of AV nodal re-entrant tachycardia (AVNRT) is a rare but well recognised complication of the procedure--the reported incidence ranges from 1% to 21%. Almost all cases of AV block occur during or shortly after the procedure, are transient, and recover quickly. Two patients (a 22 year man and a 72 year old woman) with symptomatic AV block occurring several months after slow pathway RF ablation, requiring permanent pacemaker implantation, are described. Both patients had had several 24 hour Holter recordings before the procedure, and in neither case was there any evidence of intermittent or persistent AV block. This is a rare complication with no definitive predictors; however, all efforts should be made to exclude AV block in patients presenting with suggestive symptoms following RF ablation. With the wide use of RF ablation for the treatment of AVNRT, more cases are likely to occur. A registry should allow documentation of the incidence of this complication.  (+info)

A technique for the rapid diagnosis of atrial tachycardia in the electrophysiology laboratory. (4/332)

OBJECTIVE: The purpose of this study was to determine if the atrial response upon cessation of ventricular pacing associated with 1:1 ventriculoatrial conduction during paroxysmal supraventricular tachycardia is a useful diagnostic maneuver in the electrophysiology laboratory. BACKGROUND: Despite various maneuvers, it can be difficult to differentiate atrial tachycardia from other forms of paroxysmal supraventricular tachycardia. METHODS: The response upon cessation of ventricular pacing associated with 1:1 ventriculoatrial conduction was studied during four types of tachycardia: 1) atrioventricular nodal reentry (n = 102), 2) orthodromic reciprocating tachycardia (n = 43), 3) atrial tachycardia (n = 19) and 4) atrial tachycardia simulated by demand atrial pacing in patients with inducible atrioventricular nodal reentry or orthodromic reciprocating tachycardia (n = 32). The electrogram sequence upon cessation of ventricular pacing was, categorized as "atrial-ventricular" (A-V) or "atrial-atrial-ventricular" (A-A-V). RESULTS: The A-V response was observed in all cases of atrioventricular nodal reentrant and orthodromic reciprocating tachycardia. In contrast, the A-A-V response was observed in all cases of atrial tachycardia and simulated atrial tachycardia, even in the presence of dual atrioventricular nodal pathways or a concealed accessory atrioventricular pathway. CONCLUSIONS: In conclusion, an A-A-V response upon cessation of ventricular pacing associated with 1:1 ventriculoatrial conduction is highly sensitive and specific for the identification of atrial tachycardia in the electrophysiology laboratory.  (+info)

Radiofrequency catheter ablation of coexistent atrioventricular reciprocating tachycardia and left ventricular tachycardia originating in the left anterior fascicle. (5/332)

Coexistence of supraventricular tachycardia and ventricular tachycardia is rare. A patient with no structural heart disease and wide QRS complex tachycardia with a right bundle block configuration and right-axis deviation underwent electrophysiological examination. A concealed left atrioventricular pathway (AP) was found, and atrioventricular reciprocating tachycardia (AVRT) and left ventricular tachycardia (VT) originating in or close to the anterior fascicle of the left ventricle were both induced. Radiofrequency (RF) catheter ablation of the concealed left AP was successfully performed. Ten months later, VT recurred and was successfully ablated using a local Purkinje potential as a guide. Coexistent AVRT and idiopathic VT originating from within or near the left anterior fascicle were successfully ablated.  (+info)

Comparison of late results of surgical or radiofrequency catheter modification of the atrioventricular node for atrioventricular nodal reentrant tachycardia. (6/332)

AIMS: Although arrhythmia surgery and radiofrequency catheter ablation to cure atrioventricular nodal reentrant tachycardia differ in technical concept, the late results of both methods, in terms of elimination of the arrhythmogenic substrate and procedure-related new and different arrhythmias, have never been compared. This constituted the purpose of this prospective follow-up study. METHODS AND RESULTS: Between 1988 and 1992, 26 patients were surgically treated using perinodal dissection or 'skeletonization', and from 1991 up to 1995, 120 patients underwent radiofrequency modification of the atrioventricular node for atrioventricular nodal reentrant tachycardia. The acute success rates of surgery and radiofrequency catheter ablation were 96% and 92%, respectively. Late recurrence, rate in the surgical and radiofrequency catheter ablation groups was 12% and 17%, respectively. Mean follow-up was 53 months in the surgical group and 28 months in the radiofrequency catheter ablation group. The final success rate after repeat intervention was 100% in the surgical group and 98% in the radiofrequency catheter ablation group. Comparison of the initial and recent series of radiofrequency catheter ablated patients showed an increased initial success rate with fewer applications. In the radiofrequency catheter ablation group, a second- or third-degree block developed in three patients (2%), requiring permanent pacing, whereas in the surgical group no complete atrioventricular block was observed. Inappropriate sinus tachycardia needing drug treatment was observed in 13 patients (11%), mostly after fast pathway ablation, but was never observed after surgery. New and different supraventricular tachyarrhythmias arose in 27% of the patients in the surgical group and in 11% of the radiofrequency catheter ablation group, but did not clearly differ. CONCLUSION: This one-institutional follow-up study demonstrated comparable initial and late success rates as well as incidence of new and different supraventricular arrhythmias following arrhythmia surgery and radiofrequency catheter ablation for atrioventricular nodal reentrant tachycardia. Today radiofrequency catheter ablation has replaced arrhythmia surgery for various reasons, but the late arrhythmic side-effects warrant refinement of technique.  (+info)

The response of the slow atrioventricular nodal pathway to temperature. (7/332)

The present study attempted to determine the lowest temperature at which the slow atrioventricular nodal pathway responds to heating and the temperature necessary for successful ablation of the slow pathway in patients with atrioventricular nodal reentrant tachycardia (AVNRT). The study group comprised 23 consecutive patients (14 women, 9 men) with symptomatic AVNRT. Radiofrequency current was delivered at the slow pathway potential recording site using a HAT 200S catheter ablation system. Successful radiofrequency ablation of the slow pathway was achieved in all 23 patients. Junctional beats, suggesting the response of the slow pathway to temperature, were detected in 62 of the total 136 applications. The temperature measured at the first junctional beat was 45.4+/-4.2 degrees C. The maximum temperature required for the successful ablation of AVNRT ranged from 45 to 88 degrees C. There were no complications except for 1 patient with transient atrioventricular (AV) block. There were no recurrences of AVNRT during follow-up. The lowest temperature at which the slow pathway was responsive to heat was quite similar to that for accessory pathways or the AV junction. However, the temperature required for the successful ablation of AVNRT differed markedly among the patients.  (+info)

Exercise-induced uncommon atrioventricular nodal reentrant tachycardia with sick sinus syndrome: a case report. (8/332)

Exercise seldom provokes tachycardia in patients with paroxysmal supraventricular tachycardia (PSVT). This report presents a case of exercise-induced uncommon atrioventricular nodal reentrant tachycardia (AVNRT) with sick sinus syndrome. Treadmill exercise testing provoked AVNRT of long RP' with good reproducibility. Uncommon AVNRT was confirmed by the lack of atrial pre-excitation during PSVT and para-Hisian pacing. The patient has been successfully treated with verapamil and DDD pacing for 5 years.  (+info)

Atrioventricular (AV) nodal reentrant tachycardia (AVNRT) is a type of supraventricular tachycardia (SVT), which is a rapid heart rhythm originating at or above the atrioventricular node. In AVNRT, an abnormal electrical circuit in or near the AV node creates a reentry pathway that allows for rapid heart rates, typically greater than 150-250 beats per minute.

In normal conduction, the electrical impulse travels from the atria to the ventricles through the AV node and then continues down the bundle branches to the Purkinje fibers, resulting in a coordinated contraction of the heart. In AVNRT, an extra electrical pathway exists that allows for the reentry of the electrical impulse back into the atria, creating a rapid and abnormal circuit.

AVNRT is classified based on the direction of the reentry circuit:

1. Typical or common AVNRT: The most common form, accounting for 90% of cases. In this type, the reentry circuit involves an "anterior" and a "posterior" loop in or near the AV node. The anterior loop has slower conduction velocity than the posterior loop, creating a "short" reentry circuit that is responsible for the rapid heart rate.
2. Atypical AVNRT: Less common, accounting for 10% of cases. In this type, the reentry circuit involves an "outer" and an "inner" loop around the AV node. The outer loop has slower conduction velocity than the inner loop, creating a "long" reentry circuit that is responsible for the rapid heart rate.

AVNRT can present with symptoms such as palpitations, dizziness, lightheadedness, shortness of breath, chest discomfort, or syncope (fainting). Treatment options include observation, vagal maneuvers, medications, and catheter ablation. Catheter ablation is a curative treatment that involves the destruction of the abnormal electrical pathway using radiofrequency energy or cryotherapy.

Supraventricular tachycardia (SVT) is a rapid heart rhythm that originates above the ventricles (the lower chambers of the heart). This type of tachycardia includes atrial tachycardia, atrioventricular nodal reentrant tachycardia (AVNRT), and atrioventricular reentrant tachycardia (AVRT). SVT usually causes a rapid heartbeat that starts and stops suddenly, and may not cause any other symptoms. However, some people may experience palpitations, shortness of breath, chest discomfort, dizziness, or fainting. SVT is typically diagnosed through an electrocardiogram (ECG) or Holter monitor, and can be treated with medications, cardioversion, or catheter ablation.

Tachycardia is a heart rate that is faster than normal. In sinoatrial nodal reentry tachycardia (SANRT), the abnormally fast heart rhythm originates in the sinoatrial node, which is the natural pacemaker of the heart. This type of tachycardia occurs due to a reentry circuit within the sinoatrial node, where an electrical impulse travels in a circular pattern and repeatedly stimulates the node to fire off abnormal rapid heartbeats. SANRT is typically characterized by a heart rate of over 100 beats per minute, palpitations, lightheadedness, or occasionally chest discomfort. It is usually a benign condition but can cause symptoms that affect quality of life. In some cases, treatment may be required to prevent recurrences and manage symptoms.

Cryosurgery is a medical procedure that uses extreme cold, such as liquid nitrogen or argon gas, to destroy abnormal or unwanted tissue. The intense cold causes the water inside the cells to freeze and form ice crystals, which can rupture the cell membrane and cause the cells to die. Cryosurgery is often used to treat a variety of conditions including skin growths such as warts and tumors, precancerous lesions, and some types of cancer. The procedure is typically performed in a doctor's office or outpatient setting and may require local anesthesia.

Catheter ablation is a medical procedure in which specific areas of heart tissue that are causing arrhythmias (irregular heartbeats) are destroyed or ablated using heat energy (radiofrequency ablation), cold energy (cryoablation), or other methods. The procedure involves threading one or more catheters through the blood vessels to the heart, where the tip of the catheter can be used to selectively destroy the problematic tissue. Catheter ablation is often used to treat atrial fibrillation, atrial flutter, and other types of arrhythmias that originate in the heart's upper chambers (atria). It may also be used to treat certain types of arrhythmias that originate in the heart's lower chambers (ventricles), such as ventricular tachycardia.

The goal of catheter ablation is to eliminate or reduce the frequency and severity of arrhythmias, thereby improving symptoms and quality of life. In some cases, it may also help to reduce the risk of stroke and other complications associated with arrhythmias. Catheter ablation is typically performed by a specialist in heart rhythm disorders (electrophysiologist) in a hospital or outpatient setting under local anesthesia and sedation. The procedure can take several hours to complete, depending on the complexity of the arrhythmia being treated.

It's important to note that while catheter ablation is generally safe and effective, it does carry some risks, such as bleeding, infection, damage to nearby structures, and the possibility of recurrent arrhythmias. Patients should discuss the potential benefits and risks of the procedure with their healthcare provider before making a decision about treatment.

The atrioventricular (AV) node is a critical part of the electrical conduction system of the heart. It is a small cluster of specialized cardiac muscle cells located in the lower interatrial septum, near the opening of the coronary sinus. The AV node receives electrical impulses from the sinoatrial node (the heart's natural pacemaker) via the internodal pathways and delays their transmission for a brief period before transmitting them to the bundle of His and then to the ventricles. This delay allows the atria to contract and empty their contents into the ventricles before the ventricles themselves contract, ensuring efficient pumping of blood throughout the body.

The AV node plays an essential role in maintaining a normal heart rhythm, as it can also function as a backup pacemaker if the sinoatrial node fails to generate impulses. However, certain heart conditions or medications can affect the AV node's function and lead to abnormal heart rhythms, such as atrioventricular block or atrial tachycardia.

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.

Tachycardia is a medical term that refers to an abnormally rapid heart rate, often defined as a heart rate greater than 100 beats per minute in adults. It can occur in either the atria (upper chambers) or ventricles (lower chambers) of the heart. Different types of tachycardia include supraventricular tachycardia (SVT), atrial fibrillation, atrial flutter, and ventricular tachycardia.

Tachycardia can cause various symptoms such as palpitations, shortness of breath, dizziness, lightheadedness, chest discomfort, or syncope (fainting). In some cases, tachycardia may not cause any symptoms and may only be detected during a routine physical examination or medical test.

The underlying causes of tachycardia can vary widely, including heart disease, electrolyte imbalances, medications, illicit drug use, alcohol abuse, smoking, stress, anxiety, and other medical conditions. In some cases, the cause may be unknown. Treatment for tachycardia depends on the underlying cause, type, severity, and duration of the arrhythmia.

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.

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.

Paroxysmal Tachycardia is a type of arrhythmia (abnormal heart rhythm) characterized by rapid and abrupt onset and offset of episodes of tachycardia, which are faster than normal heart rates. The term "paroxysmal" refers to the sudden and recurring nature of these episodes.

Paroxysmal Tachycardia can occur in various parts of the heart, including the atria (small upper chambers) or ventricles (larger lower chambers). The two most common types are Atrial Paroxysmal Tachycardia (APT) and Ventricular Paroxysmal Tachycardia (VPT).

APT is more common and typically results in a rapid heart rate of 100-250 beats per minute. It usually begins and ends suddenly, lasting for seconds to hours. APT can cause symptoms such as palpitations, lightheadedness, shortness of breath, chest discomfort, or anxiety.

VPT is less common but more serious because it involves the ventricles, which are responsible for pumping blood to the rest of the body. VPT can lead to decreased cardiac output and potentially life-threatening conditions such as syncope (fainting) or even cardiac arrest.

Treatment options for Paroxysmal Tachycardia depend on the underlying cause, severity, and frequency of symptoms. These may include lifestyle modifications, medications, cardioversion (electrical shock to restore normal rhythm), catheter ablation (destroying problematic heart tissue), or implantable devices such as pacemakers or defibrillators.

Tachycardia is a heart rate that is faster than normal when resting. In adults, a normal resting heart rate is typically between 60 and 100 beats per minute (bpm). Tachycardia is generally considered to be a heart rate of more than 100 bpm.

Ectopic atrial tachycardia (EAT) is a type of supraventricular tachycardia (SVT), which means that the abnormal rapid heartbeats originate in the atria, the upper chambers of the heart. EAT is caused by an ectopic focus, or an abnormal electrical focus outside of the sinoatrial node (the heart's natural pacemaker). This ectopic focus can be located in one of the pulmonary veins or in other atrial tissue.

EAT may present with symptoms such as palpitations, lightheadedness, shortness of breath, chest discomfort, or syncope (fainting). In some cases, EAT may not cause any symptoms and can be an incidental finding on an electrocardiogram (ECG) or Holter monitor.

The diagnosis of EAT is typically made based on the ECG findings, which show a regular narrow QRS complex tachycardia with P waves that are inverted in the inferior leads and often dissociated from the QRS complexes. Treatment options for EAT include observation, pharmacologic therapy, cardioversion, or catheter ablation.

Sinus tachycardia is a type of rapid heart rate, characterized by an abnormally fast sinus rhythm, with a rate greater than 100 beats per minute in adults. The sinoatrial node (SA node), which is the natural pacemaker of the heart, generates these impulses regularly and at an increased rate.

Sinus tachycardia is usually a physiological response to various stimuli or conditions, such as physical exertion, strong emotions, fever, anxiety, pain, or certain medications. It can also be caused by hormonal imbalances, anemia, hyperthyroidism, or other medical disorders.

In most cases, sinus tachycardia is not harmful and resolves once the underlying cause is addressed. However, if it occurs persistently or is associated with symptoms like palpitations, shortness of breath, dizziness, or chest discomfort, further evaluation by a healthcare professional is recommended to rule out any underlying heart conditions or other medical issues.

Reciprocating tachycardia is a type of supraventricular tachycardia (SVT), which is a rapid heart rhythm originating in the atria or atrioventricular node. In reciprocating tachycardia, there are abnormal electrical connections between the atria and ventricles called "accessory pathways" that allow electrical impulses to bypass the normal conduction system.

In this type of tachycardia, an electrical impulse originates in one of the atria and travels down the normal conduction system to the ventricles, but then instead of following the normal route back up to the atria, it takes a shortcut through an accessory pathway. This creates a reentry circuit, where the electrical impulse continuously circulates between the atria and ventricles, causing a rapid heart rate.

Reciprocating tachycardia can be classified as either orthodromic or antidromic, depending on the direction of the electrical impulse through the accessory pathway. In orthodromic reciprocating tachycardia, the electrical impulse travels down the normal conduction system to the ventricles and then returns up the accessory pathway to the atria. This type of reciprocating tachycardia is more common than antidromic reciprocating tachycardia, which occurs when the electrical impulse travels down the accessory pathway to the ventricles and then returns up the normal conduction system to the atria.

Symptoms of reciprocating tachycardia may include palpitations, lightheadedness, shortness of breath, chest discomfort, or syncope (fainting). Treatment options for reciprocating tachycardia include medications, cardioversion, catheter ablation, and surgery.

Tachycardia refers to a rapid heart rate, typically defined as over 100 beats per minute in adults. Ectopic junctional tachycardia (EJT) is a specific type of abnormal heart rhythm that originates from the junction between the atria (the upper chambers of the heart) and ventricles (the lower chambers).

In EJT, the electrical impulse arises from an ectopic focus (an area outside of the normal conduction system) located in or near the atrioventricular (AV) node. This results in a rapid heart rate that can range from 100 to 250 beats per minute.

EJT is often seen in patients after cardiac surgery, and it can also occur in other conditions such as myocarditis, digoxin toxicity, or following congenital heart disease repair. It may cause symptoms such as palpitations, shortness of breath, chest discomfort, or dizziness. Treatment options for EJT include medications, cardioversion, or ablation therapy, depending on the underlying cause and severity of symptoms.

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.

Artificial cardiac pacing is a medical procedure that involves the use of an artificial device to regulate and stimulate the contraction of the heart muscle. This is often necessary when the heart's natural pacemaker, the sinoatrial node, is not functioning properly and the heart is beating too slowly or irregularly.

The artificial pacemaker consists of a small generator that produces electrical impulses and leads that are positioned in the heart to transmit the impulses. The generator is typically implanted just under the skin in the chest, while the leads are inserted into the heart through a vein.

There are different types of artificial cardiac pacing systems, including single-chamber pacemakers, which stimulate either the right atrium or right ventricle, and dual-chamber pacemakers, which stimulate both chambers of the heart. Some pacemakers also have additional features that allow them to respond to changes in the body's needs, such as during exercise or sleep.

Artificial cardiac pacing is a safe and effective treatment for many people with abnormal heart rhythms, and it can significantly improve their quality of life and longevity.

Postural Orthostatic Tachycardia Syndrome (POTS) is a condition characterized by an abnormally rapid heart rate (tachycardia) that occurs upon standing, leading to symptoms such as dizziness, lightheadedness, and fainting. The diagnostic criteria for POTS include:

1. A heart rate increase of 30 beats per minute or more within the first 10 minutes of standing or a heart rate of 120 beats per minute or more within the first 10 minutes of standing, measured by a heart rate monitor.
2. The presence of symptoms such as lightheadedness, dizziness, blurred vision, weakness, fatigue, headache, shortness of breath, or chest pain upon standing that are relieved by lying down.
3. Symptoms must be present for at least three months and occur in the absence of other medical conditions that could explain them.

POTS is thought to be caused by a dysfunction of the autonomic nervous system, which controls involuntary functions such as heart rate and blood pressure. Treatment may include lifestyle modifications, such as increasing fluid and salt intake, wearing compression stockings, and avoiding prolonged standing or sitting. Medications that help regulate blood pressure and heart rate may also be prescribed.

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.

The Bundle of His is a bundle of specialized cardiac muscle fibers that conduct electrical impulses to the Purkinje fibers, which then stimulate contraction of the ventricles in the heart. It is named after Wilhelm His, Jr., who first described it in 1893.

The Bundle of His is a part of the electrical conduction system of the heart that helps coordinate the contraction of the atria and ventricles to ensure efficient pumping of blood. The bundle originates from the atrioventricular node, which receives electrical impulses from the sinoatrial node (the heart's natural pacemaker) and transmits them through the Bundle of His to the Purkinje fibers.

The Bundle of His is divided into two main branches, known as the right and left bundle branches, which further divide into smaller fascicles that spread throughout the ventricular myocardium. This ensures a coordinated contraction of the ventricles, allowing for efficient pumping of blood to the rest of the body.

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.

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.

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.

Wolff-Parkinson-White (WPW) Syndrome is a heart condition characterized by the presence of an accessory pathway or abnormal electrical connection between the atria (the upper chambers of the heart) and ventricles (the lower chambers of the heart). This accessory pathway allows electrical impulses to bypass the normal conduction system, leading to a shorter PR interval and a "delta wave" on the electrocardiogram (ECG), which is the hallmark of WPW Syndrome.

Individuals with WPW Syndrome may experience no symptoms or may have palpitations, rapid heartbeat (tachycardia), or episodes of atrial fibrillation. In some cases, WPW Syndrome can lead to more serious heart rhythm disturbances and may require treatment, such as medication, catheter ablation, or in rare cases, surgery.

It is important to note that not all individuals with WPW Syndrome will experience symptoms or complications, and many people with this condition can lead normal, active lives with appropriate monitoring and management.

"Atrioventricular Nodal Reentry Tachycardia (AVNRT)". eMedicine. WebMD. Retrieved 24 December 2009. "Andersen-Tawil syndrome". ... Cardiac electrophysiology AV nodal reentrant tachycardia (Atrioventricular nodal reentrant tachycardia) Accelerated ... First-degree atrioventricular block (First-degree AV block, PR prolongation) Heart block Inappropriate sinus tachycardia ... Atherosclerosis Atrial flutter Atrial septal defect Atrioventricular canal defect Atrioventricular septal defect Avascular ...
Supraventricular Tachycardia: Atrioventricular Nodal Reentry and Wolff-Parkinson-White Syndrome. Goodman & Gilman's The ... Re-entry is divided into two major types: [Anatomically Defined] re-entry and [Functionally Defined] re-entry. The circus ... AV reentrant tachycardia AV nodal reentrant tachycardia "Cardiac Arrhythmias". Retrieved 2007-07-21. Am J Cardiol. 1984 Jul 30; ... Re-entry ventricular arrhythmia is a type of paroxysmal tachycardia occurring in the ventricle where the cause of the ...
"Atrioventricular Nodal Reentry Tachycardia (AVNRT)", StatPearls, StatPearls Publishing, PMID 29763111, retrieved 2019-08-15 " ... "Alternative Treatment Options for Atrioventricular-Nodal-Reentry Tachycardia: An Emergency Medicine Review". The Journal of ... "Atrioventricular Nodal Reentrant Tachycardia (AVNRT)". 2009-09-30. Shen, Sharon; Knight, Bradley P. (2014), Kibos, Ambrose S.; ... AV-nodal reentrant tachycardia (AVNRT) is a type of abnormal fast heart rhythm. It is a type of supraventricular tachycardia ( ...
AV nodal reentrant tachycardia Atrioventricular reentrant tachycardia Junctional ectopic tachycardia Atrial tachycardia Ectopic ... as well as terminate supraventricular tachycardia caused by re-entry. An intracardiac electrogram (ICEG) is essentially an ECG ... AV nodal reentrant tachycardia and orthodromic atrioventricular reentrant tachycardia. It can also evaluate the risk in people ... Multifocal atrial tachycardia Paroxysmal atrial tachycardia Sinoatrial nodal reentrant tachycardia Torsades de pointes ( ...
... atrioventricular reciprocating tachycardia, and atrioventricular nodal reentry tachycardia. Atrial fibrillation is the most ... Tachycardia-induced cardiomyopathy (TIC) is a disease where prolonged tachycardia (a fast heart rate) or arrhythmia (an ... TIC has been associated with supraventricular tachycardia (SVT), ventricular tachycardia (VT), frequent premature ventricular ... Treatment of TIC can involve treating the heart failure as well as the tachycardia or arrhythmia. TIC has a good prognosis with ...
Atrioventricular nodal re-entry tachycardia, which is caused by a dual AV node physiology and AVNRT can only occur in people ... Cystic tumour of atrioventricular nodal region (CTAVN) CTAVN is of endodermal origin and occurs exclusively in the area of the ... The blood supply of the AV node is from the atrioventricular nodal branch. The origin of this artery is most commonly (80-90% ... "Dual Atrioventricular Nodal Physiology - an overview , ScienceDirect Topics". www.sciencedirect.com. Retrieved 2022-11-14. ...
... tachycardia, atrioventricular nodal reentry MeSH C23.550.073.845.880.315 - tachycardia, ectopic atrial MeSH C23.550.073.845. ... tachycardia, sinoatrial nodal reentry MeSH C23.550.073.845.880.845 - tachycardia, sinus MeSH C23.550.073.845.940 - tachycardia ... tachycardia MeSH C23.550.073.845.695 - tachycardia, paroxysmal MeSH C23.550.073.845.880 - tachycardia, supraventricular MeSH ... 880.320 - tachycardia, ectopic junctional MeSH C23.550.073.845.880.840 - ...
In some conditions, especially forms of intra-nodal re-entry (the most common type of SVT), also called atrioventricular nodal ... 2010). "Cryoablation Versus Radiofrequency Energy for the Ablation of Atrioventricular Nodal Reentrant Tachycardia (the CYRANO ... It is used in recurrent atrial flutter (Afl), atrial fibrillation (AF), supraventricular tachycardia (SVT), atrial tachycardia ... Multifocal Atrial Tachycardia (MAT) and some types of ventricular arrhythmia. The energy-emitting probe (electrode) is at the ...
... tachycardia, atrioventricular nodal reentry MeSH C14.280.067.845.880.315 - tachycardia, ectopic atrial MeSH C14.280.067.845. ... tachycardia, sinoatrial nodal reentry MeSH C14.280.067.845.880.845 - tachycardia, sinus MeSH C14.280.067.845.940 - tachycardia ... tachycardia MeSH C14.280.067.845.695 - tachycardia, paroxysmal MeSH C14.280.067.845.880 - tachycardia, supraventricular MeSH ... 880.320 - tachycardia, ectopic junctional MeSH C14.280.067.845.880.840 - ...
Atrioventricular origin: AV nodal reentrant tachycardia (AVNRT) or junctional reciprocating tachycardia (JRT) AV reciprocating ... AV nodal reentrant tachycardia (AVNRT) involves a reentry circuit forming next to, or within, the AV node. The circuit most ... Atrioventricular reciprocating tachycardia (AVRT), also results from a reentry circuit, although one physically much larger ... "Long-term follow-up after catheter ablation for atrioventricular nodal reentrant tachycardia: a comparison of cryothermal and ...
AV nodal re-entrant tachycardia (AVNRT) makes up 56% of cases Atrioventricular reentrant tachycardia (AVRT) makes up 27% of ... The underlying mechanism typically involves an accessory pathway that results in re-entry. Diagnosis is typically by an ... Paroxysmal supraventricular tachycardia (PSVT) is a type of supraventricular tachycardia, named for its intermittent episodes ... "Tachycardia , Fast Heart Rate". American Heart Association. Archived from the original on 12 April 2013. Retrieved 19 April ...
AV nodal reentrant tachycardia and orthodromic atrioventricular reentrant tachycardia. It can also evaluate the risk in people ... Re-entry is also responsible for most paroxysmal supraventricular tachycardia, and dangerous ventricular tachycardia. These ... AV nodal reentrant tachycardia AV nodal reentrant tachycardia Junctional rhythm Junctional tachycardia Premature junctional ... AV nodal reentrant tachycardia is often curable by ablating one of the pathways in the AV node (usually the slow pathway). ...
AV reentrant tachycardia (AVRT) and AV nodal reentrant tachycardia (AVNRT). In addition, atrial tachycardia can sometimes be ... This includes any re-entrant arrhythmias that require the AV node for the re-entry, e.g., ... When it is administered intravenously, adenosine causes transient heart block in the atrioventricular (AV) node. This is ... Mitchell J, Lazarenko G (November 2008). "Wide QRS complex tachycardia. Diagnosis: Supraventricular tachycardia with aberrant ...
"Closed-Chest Ablation of Retrograde Conduction in Patients with Atrioventricular Nodal Reentrant Tachycardia". New England ... or reentry (Georges Ralph Mines, 1913). A combination of spatiotemporal factors is required to establish reentry, a process ... "Catheter ablation of Mahaim fibers with preservation of atrioventricular nodal conduction". Circulation. 82 (2): 418-427. doi: ... such as accessory pathway-related tachycardia (Wolff-Parkinson-White syndrome or Mahaim fibers), and junctional tachycardia. He ...
In fact, reentry often is not the mechanism of arrhythmia development in these clinical cases: the arrhythmias may be caused by ... Tachycardia has been observed in standing rats, after hindlimb-unloading for 28 days. A trend in decreased cardiac mass has ... One crewmember during Apollo 15 experienced a 22-beat nodal bigeminal rhythm, which was followed by premature atrial beats. ... These included two consecutive PVCs in one astronaut during exercise and an episode of atrioventricular dissociation preceded ...
... and other forms of supraventricular tachycardia (e.g., AV nodal reentrant tachycardia). Adults who survived congenital heart ... Other mutations in genes, such as GJA5, affect gap junctions, generating a cellular uncoupling that promotes re-entries and a ... A heartbeat results when an electrical impulse from the atria passes through the atrioventricular (AV) node to the ventricles ... which may make it more difficult to separate from other supraventricular tachycardias or ventricular tachycardia. QRS complexes ...
"High prevalence of concealed Brugada syndrome in patients with atrioventricular nodal reentrant tachycardia". Heart Rhythm. 12 ... referred to as re-entry, and causing an abnormal heart rhythm. Those who support this view (known as the depolarisation ... are also more likely to experience rapid heart rates due to less dangerous arrhythmias such as AV nodal re-entrant tachycardia ... Catecholaminergic polymorphic ventricular tachycardia Sudden arrhythmic death syndrome "Brugada syndrome". Genetics Home ...
... is the most common type of reentrant supraventricular tachycardia (SVT). The substrate for AVNRT is the presence of dual AV ... encoded search term (Atrioventricular Nodal Reentry Tachycardia) and Atrioventricular Nodal Reentry Tachycardia What to Read ... Atrioventricular Nodal Reentry Tachycardia. Atypical atrioventricular nodal (AV) reentry tachycardia. Often, an inverted P wave ... Atrioventricular Nodal Reentry Tachycardia. Atypical atrioventricular nodal (AV) reentry tachycardia. Often, an inverted P wave ...
... is the most common type of reentrant supraventricular tachycardia (SVT). The substrate for AVNRT is the presence of dual AV ... encoded search term (Atrioventricular Nodal Reentry Tachycardia) and Atrioventricular Nodal Reentry Tachycardia What to Read ... Atrioventricular nodal reentry tachycardia (AVNRT) is the most common type of reentrant supraventricular tachycardia (SVT). The ... Atrioventricular Nodal Reentry Tachycardia. Updated: Dec 27, 2017 * Author: Brian Olshansky, MD; Chief Editor: Jose M Dizon, MD ...
"Atrioventricular Nodal Reentry Tachycardia (AVNRT)". eMedicine. WebMD. Retrieved 24 December 2009. "Andersen-Tawil syndrome". ... Cardiac electrophysiology AV nodal reentrant tachycardia (Atrioventricular nodal reentrant tachycardia) Accelerated ... First-degree atrioventricular block (First-degree AV block, PR prolongation) Heart block Inappropriate sinus tachycardia ... Atherosclerosis Atrial flutter Atrial septal defect Atrioventricular canal defect Atrioventricular septal defect Avascular ...
The heart can beat too fast (tachycardia), too slow (bradycardia), or irregularly. ... The heart can beat too fast (tachycardia), too slow (bradycardia), or irregularly. ... Atrioventricular nodal reentry tachycardia (AVNRT). *Heart block or atrioventricular block. *Multifocal atrial tachycardia ... The heart can beat too fast (tachycardia), too slow (bradycardia), or irregularly. ...
In atrioventricular nodal reentry tachycardia (AVNRT), we target the slow pathway; in Wolff-Parkinson-White (WPW) syndrome, the ... This second theory of AF depends on the importance of areas of the atria that harbor focal impulses or localized reentry. On ... accessory pathway; and in ventricular tachycardia (VT), important areas in and around the scar. Thats because, unlike in AF, ...
Tachycardia, Atrioventricular Nodal Reentry. *Tachycardia, Paroxysmal. *Wolff-parkinson-white Syndrome. How long have you been ...
Two athletes had diagnoses of atrioventricular nodal re-entry tachycardia (circus movement tachycardia). Even though the ... Because of the benign nature of the tachycardia and the minor disability the athletes perceived no treatment was indicated. The ... their history was so specific that there was still a high suspicion of a benign supraventricular tachycardia. ...
Atrioventricular nodal re-entry tachycardia, which is caused by a dual AV node physiology and AVNRT can only occur in people ... Cystic tumour of atrioventricular nodal region (CTAVN) CTAVN is of endodermal origin and occurs exclusively in the area of the ... The blood supply of the AV node is from the atrioventricular nodal branch. The origin of this artery is most commonly (80-90% ... "Dual Atrioventricular Nodal Physiology - an overview , ScienceDirect Topics". www.sciencedirect.com. Retrieved 2022-11-14. ...
... that does not require the atrioventricular (AV) junction, accessory pathways, or ventricular tissue for its initiation and ... Atrial tachycardia can be observed in persons with normal hearts and in those with structurally abnormal hearts, including ... Atrial tachycardia is defined as a supraventricular tachycardia (SVT) ... These features essentially exclude atrioventricular nodal reentry tachycardia and atrioventricular tachycardia via an accessory ...
Atrioventricular Nodal Reentry Tachycardia (AVNRT). *Wolff-Parkinson-White Syndrome (WPW). *Others. In terms of indications, ...
... and possible diagnoses include atrioventricular nodal reentry tachycardia (AVNRT) and the existence of an accessory pathway. ... Persistent supraventricular tachycardia after volatile inhalational anaesthetic induction with sevoflurane in a pediatric ... Persistent supraventricular tachycardia after volatile inhalational anaesthetic induction with sevoflurane in a pediatric ... We present a four year-old child who developed a persistent supraventricular tachycardia after inhaled anaesthetic induction ...
... narrow complex tachycardia.mp) OR (exp Tachycardia, Atrioventricular Nodal Reentry/)] OR[(Tachycardia, Supraventricular/dt, th ... narrow complex tachycardia.mp) OR (exp Tachycardia, Atrioventricular Nodal Reentry/)] OR [(Tachycardia, Supraventricular/dt, th ... She is diagnosed with atriventricular nodal reentrant tachycardia and the valsava manoeuvre is attempted unsuccessfully. IV ... Comparison of Esmolol vs Propanolol in achieving and maintaining sinus rhythm in narrow complex tachycardia in an acute setting ...
AF, atrial fibrillation; AVNRT, atrioventricular nodal re-entry tachycardia; AVRT, atrioventricular re-entry tachycardia; EAT, ... F. The most common form of paroxysmal supraventricular tachycardia (PSVT) is AV nodal reentry due to dual pathways of ... Re-entry in the sinoatrial node (SANRT), atrioventricular node (AVNRT), and atrial myocardium (atrial tachycardia): right ... B. The persistent ones (sinus tachycardia, nonparoxysmal ectopic atrial tachycardia, multifocal atrial tachycardia, longer ...
Atrioventricular nodal re-entry tachycardia (AVNRT) December 20, 2021. ECG Case 102: Ventricular Tachycardia, probably Right ...
Atrioventricular Nodal Reentry Tachycardia 19% * Incidence 19% 98 Scopus citations * Gender differences in the proarrhythmic ... Light on wide-QRS tachycardia, part 2: ECG diagnosis, treatment. Patel, H. M., Luck, J. C., DellOrfano, J. T., Wolbrette, D. L ... Light on wide-QRS tachycardia, part 1: Distinguishing the mechanisms - Physiologic and clinical correlations that clarify a ...
Voltage bridge mapping in atrioventricular nodal reentry tachycardia ablation in adult population: results from a multicenter ...
Atrial tachycardia (AT). *Paroxysmal supraventricular tachycardia (PSVT). *Atrioventricular nodal re-entry tachycardia (AVNRT) ...
keywords = "AVNRT, Recurrence, Reentry, Slow pathway modification, Supraventricular tachycardia",. author = "Daniel Marks and ... atrioventricular nodal reentry years after successful slow pathway ablation for typical atrioventricular nodal reentry. In: ... atrioventricular nodal reentry years after successful slow pathway ablation for typical atrioventricular nodal reentry. ... atrioventricular nodal reentry years after successful slow pathway ablation for typical atrioventricular nodal reentry, ...
BACKGROUND: Cryoablation is increasingly used to treat atrioventricular nodal reentry tachycardia (AVNRT) due to its safety ... Identifying an Appropriate Endpoint for Cryoablation in Children with Atrioventricular Nodal Reentry Tachycardia: Is Residual ... Optimal sampling densities for LA tachycardias were 0.670.17points/cm2 (focal activation), 1.050.32points/cm2 (macro-re-entry) ... macro-re-entry, and (3) localized re-entry. In silico activation was simulated on a 44cm atrial monolayer, sampled randomly at ...
Given orally Verapamil is useful for the prophylaxis of atrioventricular reentry tachycardia, and also in modulating the ... atrioventricular nodal response in atrial fibrillation[2].. Verapamil is injected i.v. into a femoral vein prior to ischemia. ... ventricular tachycardia (VT) and ventricular fibrillation (VF) for 45-min coronary artery occlusion. Total arrhythmia scores ...
... figure Initiation of an atrioventricular nodal reentry tachycardia Initiation of an atrioventricular nodal reentry tachycardia ... Initiation of an atrioventricular nodal reentry tachycardia There is an abnormal P wave (P′) and atrioventricular nodal delay ( ... Mechanism of typical reentry. Atrioventricular nodal reentry is used here as an example. Two pathways connect the same points. ... The most common forms of paroxysmal SVT (AV nodal reentry and orthodromic reciprocating tachycardia) must terminate if AV block ...
Plasma natriuretic peptides during supraventricular tachycardia: A study in patients with atrioventricular nodal reentry ... tachycardia. Pecini, R., Pehrson, S., Chen, X., Thøgersen, A. M., Kjær, A. & Svendsen, J. H., 2013, In: World Journal of ...
Delayed ablation of atrioventricular nodal reentry tachycardia as a risk factor for future atrial fibrillation ...
Atrioventricular Nodal Reentry Tachycardia Medscape Consult. Latest News & Perspective. * Inappropriate Cardiac Imaging ...
Tachycardia, Atrioventricular Nodal Reentry. C14.280.67.845.880.95 C14.280.67.845.787.249. C23.550.73.845.880.95 C23.550.73.845 ... Tachycardia, Sinoatrial Nodal Reentry C14.280.67.845.880.840 C14.280.67.845.787.500. C23.550.73.845.880.840 C23.550.73.845. ...
Tachycardia, Atrioventricular Nodal Reentry. C14.280.67.845.880.95 C14.280.67.845.787.249. C23.550.73.845.880.95 C23.550.73.845 ... Tachycardia, Sinoatrial Nodal Reentry C14.280.67.845.880.840 C14.280.67.845.787.500. C23.550.73.845.880.840 C23.550.73.845. ...
Tachycardia, Atrioventricular Nodal Reentry. C14.280.67.845.880.95 C14.280.67.845.787.249. C23.550.73.845.880.95 C23.550.73.845 ... Tachycardia, Sinoatrial Nodal Reentry C14.280.67.845.880.840 C14.280.67.845.787.500. C23.550.73.845.880.840 C23.550.73.845. ...
Tachycardia, Atrioventricular Nodal Reentry. C14.280.67.845.880.95 C14.280.67.845.787.249. C23.550.73.845.880.95 C23.550.73.845 ... Tachycardia, Sinoatrial Nodal Reentry C14.280.67.845.880.840 C14.280.67.845.787.500. C23.550.73.845.880.840 C23.550.73.845. ...
Tachycardia, Atrioventricular Nodal Reentry. C14.280.67.845.880.95 C14.280.67.845.787.249. C23.550.73.845.880.95 C23.550.73.845 ... Tachycardia, Sinoatrial Nodal Reentry C14.280.67.845.880.840 C14.280.67.845.787.500. C23.550.73.845.880.840 C23.550.73.845. ...
Tachycardia, Atrioventricular Nodal Reentry. C14.280.67.845.880.95 C14.280.67.845.787.249. C23.550.73.845.880.95 C23.550.73.845 ... Tachycardia, Sinoatrial Nodal Reentry C14.280.67.845.880.840 C14.280.67.845.787.500. C23.550.73.845.880.840 C23.550.73.845. ...
  • Atrioventricular nodal reentry tachycardia (AVNRT) is the most common type of reentrant supraventricular tachycardia (SVT). (medscape.com)
  • The substrate for AVNRT is the presence of dual AV nodal pathways that are bounded by Koch's triangle - generally a slow and a fast pathway but sometimes two slow pathways. (medscape.com)
  • The substrate for atrioventricular (AV) nodal reentry tachycardia (AVNRT) is anatomic. (medscape.com)
  • Electrophysiologic mechanism of atrioventricular nodal reentry tachycardia (AVNRT). (medscape.com)
  • In most patients with AVNRT, the tachycardia is initiated when an atrial premature complex is blocked in the fast pathway but can conduct via the slow pathway. (medscape.com)
  • In the United States, atrioventricular nodal reentry tachycardia (AVNRT) occurs in 60% of patients (with a female predominance) presenting with paroxysmal supraventricular tachycardia (SVT), the other major types being bypass-mediated tachycardias and atrial tachycardias. (medscape.com)
  • The substrate for AVNRT is the presence of dual AV nodal pathways. (medscape.com)
  • The prognosis for patients with atrioventricular nodal reentry tachycardia (AVNRT) is usually good in the absence of structural heart disease. (medscape.com)
  • Atrioventricular nodal re-entry tachycardia, which is caused by a dual AV node physiology and AVNRT can only occur in people with it, however almost half of the population have it, though only a few of them will develop AVNRT at some point in life. (wikipedia.org)
  • The exact mechanism for such a causal relationship with sevoflurane administration is unknown, and possible diagnoses include atrioventricular nodal reentry tachycardia (AVNRT) and the existence of an accessory pathway. (cun.es)
  • BACKGROUND: To investigate the predictors of long-term success after catheter ablation of atrioventricular nodal reentrant tachycardia (AVNRT). (edu.au)
  • Atrioventricular Nodal Reentrant Tachycardia (AVNRT) causes fast beating of the heart, or arrhythmia. (shakerdesignproject.com)
  • AVNRT is caused by a reentry circuit in or around the AV node. (shakerdesignproject.com)
  • AVNRT is a tachycardia that is caused by an abnormal fast pathway in your AV node that allows for abnormally fast heart rates to develope. (shakerdesignproject.com)
  • Atrioventricular nodal reentrant tachycardia (AVNRT) is a rapid, regular cardiac arrhythmia that starts suddenly and without warning, and stops just as suddenly. (shakerdesignproject.com)
  • DUBLIN , Feb. 18, 2022 / PRNewswire / -- Medtronic plc (NYSE:MDT), a global leader in healthcare technology, today announced that the Freezorâ„¢ and Freezorâ„¢ Xtra Cardiac Cryoablation Focal Catheters are the first and only ablation catheters approved by the U.S. Food and Drug Administration (FDA) to treat the growing prevalence of pediatric Atrioventricular Nodal Reentrant Tachycardia (AVNRT). (medtronic.com)
  • AVNRT is the most common form of supraventricular tachycardia (SVT), and is a life-threatening abnormal heart rhythm, with 89,000 cases each year and growing. (medtronic.com)
  • It is often used synonymously with AV nodal re-entry tachycardia (AVNRT), a form of SVT. (edu.pl)
  • Ear drops?AutoPap: Computer-assisted cytology interpretation system?AV: Aortic valve?AV: Atrioventricular?A-V: Arteriovenous?AVERT: Atorvastatin Versus Revascularization treatment?AVID: ?AVM: Arteriovenous Malformation?AVNRT: AV nodal reentry tachycardia?AVP: Arginine vasopressin?AVR: Aortic valve replacement?AVR: Augmented V lead, right arm (ECG)?AVRT: ?AVS: Arteriovenous shunt?AWS: Alcohol withdrawal syndrome?AXR: Abdominal X ray?AZF: Azoospermia factor genes?AZT: Azidothymidine (zidovudine)?B & O: Belladonna and opium?B Bx. (kuwaitpharmacy.com)
  • Among 34 patients consecutively enrolled in this study, 28 (82.4%) patients were referred for radiofrequency ablation (RFA) of AF, 3 (8.8%) patients for ablation of right ventricular outflow tract (RVOT) ventricular extrasystole (VES), 1 (2.9%) patient for ablation of atrioventricular nodal reentry tachycardia (AVNRT), 2 (5.9%) patients for typical atrial flutter ablation. (viamedica.pl)
  • Because of the abrupt onset and termination of the reentrant SVT, the nonspecific term paroxysmal supraventricular tachycardia (or even the misleading term paroxysmal atrial tachycardia [PAT]) has been used to refer to these tachyarrhythmias. (medscape.com)
  • With improved knowledge of the electrophysiology of reentrant SVT, greater specificity in nomenclature, based on the mechanism of reentry, has been possible. (medscape.com)
  • Less commonly, the reentrant circuit can be over two slow pathways, the so-called slow-slow AV nodal reentry. (medscape.com)
  • Atrial tachycardia due to enhanced automaticity may be nonsustained but repetitive or it may be continuous or sustained, as in reentrant forms of atrial tachycardia. (medscape.com)
  • Reentrant atrial tachycardia is not uncommon in patients with a history of a surgically repaired atrial septal defect. (medscape.com)
  • She is diagnosed with atriventricular nodal reentrant tachycardia and the valsava manoeuvre is attempted unsuccessfully. (bestbets.org)
  • What may cause atrioventricular nodal reentrant tachycardia? (shakerdesignproject.com)
  • What is atrioventricular reentrant tachycardia? (shakerdesignproject.com)
  • Michiel J. Janse, MD, PhD Background Atrioventricular junctional (AV nodal) reentrant tachycardia can be cured by catheter ablation of the slow pathway, which is part of the reentrant circuit. (pdfkul.com)
  • HL double potentials were found along the Atrioventricular junctional reentrant tachycardia ~4 (AVJRT) can be cured by catheter ablation of 1k sites near the coronary sinus orifice.1-3 This technique damages the slow pathway, part of the reentrant circuit used by this tachycardia. (pdfkul.com)
  • For patient education information, see the Heart Health Center , as well as Supraventricular Tachycardia (SVT, PSVT) . (medscape.com)
  • In a patient with supraventricular tachycardia (SVT), the presence of warm-up phenomenon on an electrocardiogram (eg, on Holter monitoring) suggests that the SVT is atrial tachycardia. (medscape.com)
  • We present a four year-old child who developed a persistent supraventricular tachycardia after inhaled anaesthetic induction with sevoflurane. (cun.es)
  • An episode of persistent supraventricular tachycardia with a clear causal relationship with sevoflurane administration is not found in the literature. (cun.es)
  • The use of ultra-short acting beta-blocking agents in the acute management of supraventricular tachycardias in the haemodinamically stable patient allows rapid titration of the drug effect and rapid dissipation of adverse effects when treatment terminates. (bestbets.org)
  • Esmolol is an agent to consider when treating haemodinamically stable supraventricular tachycardias amenable to beta-blockade and without limiting hypotension. (bestbets.org)
  • Supraventricular tachycardias (SPVT) usually have narrow QRS complexes, but they may be wide because of aberrant counduction through the intraventricular conducting tissue, participation of a bypass tract in the intraventricular depolarization pattern,or in the presence of a coexiting bundle branch block. (rjmatthewsmd.com)
  • F. The most common form of paroxysmal supraventricular tachycardia (PSVT) is AV nodal reentry due to dual pathways of excitation in the region of the AV node (see Figure 1). (rjmatthewsmd.com)
  • Atrioventricular nodal reentry tachycardia, a form of supraventricular tachycardia, is the most common narrow-complex tachycardic arrhythmia in healthy individuals and only second to atrial fibrillation and atrial flutter in the general population. (shakerdesignproject.com)
  • Supraventricular tachycardia (SVT) is as an irregularly fast or erratic heartbeat (arrhythmia) that affects the heart's upper chambers. (edu.pl)
  • SVT is also called paroxysmal supraventricular tachycardia. (edu.pl)
  • With SVT (supraventricular tachycardia), your fast heart rate begins in your upper heart chambers. (edu.pl)
  • The term supraventricular tachycardia (SVT) refers to any tachydysrhythmia arising from above the level of the Bundle of His, and encompasses regular atrial, irregular atrial, and regular atrioventricular tachycardias. (edu.pl)
  • Supraventricular tachycardia (SVT) refers to rapid rhythms that originate and are sustained in atrial or atrioventricular nodal tissue, and then transmit through the bundle of His and cause rapid. (edu.pl)
  • Supraventricular tachycardia (SVT) is a common cause of hospital admissions and can cause significant patient discomfort and distress. (edu.pl)
  • and in ventricular tachycardia (VT), important areas in and around the scar. (medscape.com)
  • Electrical storm due to recurrent ventricular tachycardias (VTs) is a life-threatening arrhythmic emergency. (bvsalud.org)
  • Flecainide is an IC antiarrhythmic drug approved in 1984 from Food and Drug Administration for the suppression of sustained ventricular tachycardia and later for acute cardioversion of atrial fibrillation (AF) and for sinus rhythm maintenance. (encyclopedia.pub)
  • Flecainide was first synthesized in 1972 and approved in 1984 from the Food and Drug Administration (FDA) for the suppression of sustained ventricular tachycardia [ 1 ] and later for acute cardioversion of AF and for sinus rhythm maintenance. (encyclopedia.pub)
  • We reported four cases receiving catheter ablation due to atrioventricular nodal reentry tachycardia, atrial fibrillation and right ventricular arrhythmia via superior approach facilitated by 3-D mapping system with fewer vascular access and catheters. (authorea.com)
  • The blood supply of the AV node is from the atrioventricular nodal branch. (wikipedia.org)
  • The atrioventricular node delays impulses by approximately 0.09s. (wikipedia.org)
  • Cystic tumour of atrioventricular nodal region (CTAVN) CTAVN is of endodermal origin and occurs exclusively in the area of the AV node, tricuspid valve, and interatrial septum. (wikipedia.org)
  • Impulses are transmitted through the atria to the atrioventricular (AV) node via preferentially conducting internodal tracts and unspecialized atrial myocytes. (msdmanuals.com)
  • When the electrical impulse reaches the atrioventricular node (3), it is delayed slightly. (msdmanuals.com)
  • Second-degree block at the level of the atrioventricular node (AVN) may be due to digoxin, beta-blockers, or calcium channel blockers. (medscape.com)
  • It occurs because of one or more extra electrical pathways near the Atrioventricular or AV node allows an electrical impulse to loop back on itself or short circuit. (shakerdesignproject.com)
  • The band of nodaltype cells is not part of the compact AV node and may represent the substrate of the slow AV nodal pathway. (pdfkul.com)
  • Key Words * atrioventricular node * tachycardia reentry * action potentials * radiofrequency ablation tissues of origin of these potentials. (pdfkul.com)
  • The compact portion of the atrioventricular (AV) node is a superficial structure located just beneath the RA endocardium, anterior to the ostium of the coronary sinus, and directly above the insertion of the septal leaflet of the tricuspid valve. (medscape.com)
  • The stippled area adjacent to the central fibrous body is the approximate site of the compact atrioventricular node. (medscape.com)
  • In addition to the typical mechanism of AV nodal reentry described above, atypical AV nodal reentry can occur in the opposite direction, with antegrade conduction in the fast pathway and retrograde conduction in the slow pathway. (medscape.com)
  • Marks, D & Knight, BP 2020, ' Delayed occurrence of atypical fast-slow atrioventricular nodal reentry years after successful slow pathway ablation for typical atrioventricular nodal reentry ', HeartRhythm Case Reports , vol. 6, no. 12, pp. 960-962. (northwestern.edu)
  • Residual dual atrioventricular nodal pathway after apparently successful ablation also carries a high risk of recurrence. (edu.au)
  • Atrioventricular conduction disease (AV block) describes impairment of the electrical continuity between the atria and ventricles. (wikipedia.org)
  • However, in rapid atrial tachycardias with variable atrioventricular (AV) conduction and in MAT, the pulse may be irregular. (medscape.com)
  • Predictors of long-term success in catheter ablation of atrioventricular nodal re-entrant tachycardia: a multivariate regression analysis. (edu.au)
  • Atypical atrioventricular nodal (AV) reentry tachycardia. (medscape.com)
  • In most atrial tachycardias, the rate is regular. (medscape.com)
  • BestBets: Comparison of Esmolol vs Propanolol in achieving and maintaining sinus rhythm in narrow complex tachycardia in an acute setting. (bestbets.org)
  • Findings on ECG include the following: Narrow complex tachycardia. (shakerdesignproject.com)
  • In patients with multifocal atrial tachycardia (MAT), the history may disclose an underlying illness that is causing the tachycardia. (medscape.com)
  • We analyzed the clinical and electrophysiological features, and the final outcome, in 19 children affected by typical atrioventricular nodal re-entrant tachycardia diagnosed by a transoesophageal electrophysiological study. (cambridge.org)
  • This second theory of AF depends on the importance of areas of the atria that harbor focal impulses or localized reentry. (medscape.com)
  • Any heart disorder, including congenital abnormalities of structure (eg, accessory atrioventricular connection) or function (eg, hereditary ion channelopathies), can disturb rhythm. (msdmanuals.com)
  • The mean cycle length was significantly shorter in the children who presented episodes of 2 to 1 atrioventricular block than in those who did not. (cambridge.org)
  • During a mean follow-up period of 41 months, 2 children with rare, but sustained, episodes of tachycardia that initially had not been treated were submitted to radiofrequency transcatheter ablation. (cambridge.org)
  • Among children treated pharmacologically, 1 teenager was submitted to radiofrequency transcatheter ablation on the basis of parental choice, 3 children have discontinued medical therapy recording only sporadic episodes of tachycardia, and 2 children are still treated with antiarrhythmic drugs. (cambridge.org)
  • Weber R, Letsas KP, Arentz T, Kalusche D. Adenosine sensitive focal atrial tachycardia originating from the non-coronary aortic cusp. (medscape.com)
  • Second-degree atrioventricular (AV) block in the asymptomatic patient does not require any specific therapy in the prehospital setting. (medscape.com)
  • In 1930, Wolff, Parkinson, and White described a series of young patients who had a bundle branch block pattern on electrocardiography (ECG), a short PR interval, and paroxysms of tachycardia. (rjmatthewsmd.com)
  • AV nodal transmission time is heart-rate-dependent and is modulated by autonomic tone and circulating catecholamines to maximize cardiac output at any given atrial rate. (msdmanuals.com)
  • The heart can beat too fast (tachycardia), too slow (bradycardia), or irregularly. (medlineplus.gov)
  • In patients with frequent or incessant tachycardias, a decline in effort tolerance and symptoms of heart failure may represent early manifestations of tachycardia-induced cardiomyopathy. (medscape.com)
  • Paradoks embolisering hos en patient med lungeemboli og uerkendt persisterende foramen ovale. (regionh.dk)
  • As with Mobitz I block, AV nodal agents should be avoided, and an anti-ischemic regimen should be instituted if ischemia is suspected. (medscape.com)
  • The low-frequency component was caused by depolarization of cells with nodal characteristics close to the endocardium. (pdfkul.com)
  • The most common SVTs include atrioventricular nodal re-entrant tachycardia, atrioventricular re-entrant tachycardia and atrial tachycardia. (edu.pl)