• Reentry mechanisms are important components of ventricular arrhythmias and may be as simple as a premature ventricular beat coupled to a normal beat or as serious as a dangerous ventricular tachycardia. (britannica.com)
  • Even ventricular tachycardia can potentially cause shock and be lethal in its own right. (britannica.com)
  • However, the primary danger of ventricular tachycardia is that it will decay into ventricular fibrillation, which is incapable of sustaining life and represents the majority of sudden cardiac death cases. (britannica.com)
  • Thus, the indication that ventricular tachycardia or ventricular fibrillation might occur demands prompt therapeutic intervention. (britannica.com)
  • Following myocardial infarction (MI), the myocardium is prone to calcium-driven alternans, which typically precedes ventricular tachycardia and fibrillation. (frontiersin.org)
  • Ventricular tachycardia (427.1) is abnormal electrical impulses that originate in the ventricles. (fortherecordmag.com)
  • If not treated promptly, sustained ventricular tachycardia may progress into ventricular fibrillation. (fortherecordmag.com)
  • Mexiletine hydrochloride, at doses of 200-400 mg q8h, produced a significant reduction of ventricular premature beats, paired beats, and episodes of non- sustained ventricular tachycardia compared to placebo and was similar in effectiveness to the active agents. (nih.gov)
  • Tachyarrhythmias secondary to triggered activity may not have specific morphologic ECG characteristics, however, Torsade de Pointes (polymorphic ventricular tachyarrhythmia with "twisting of the points") and inherited superfast ventricular tachycardia in German shepherds are examples of triggered activity caused by early or delayed after depolarizations. (vin.com)
  • Strobel, G, Shiva P Ponamgi, Attila Roka, Ahmed Aboeata "Exercise-induced Brugada pattern and ventricular tachycardia during capecitabine treatment. (creighton.edu)
  • The lower chambers of the heart (ventricles) can flutter or quiver (ventricular fibrillation) or the heart can beat very quickly (ventricular tachycardia). (clevelandclinic.org)
  • If they get out of synch because of ventricular tachycardia or fibrillation, the CRT-D sends a shock to restore a normal rhythm. (clevelandclinic.org)
  • Other heart problems that occur in ankyrin-B syndrome include irregular and uncoordinated electrical activity in the heart's upper chambers (atrial fibrillation) or lower chambers (ventricular fibrillation) and an abnormality called catecholaminergic polymorphic ventricular tachycardia (CPVT), in which an increase in the heart rate can trigger an abnormally fast and irregular heartbeat called ventricular tachycardia . (medlineplus.gov)
  • This atlas may be useful in comparing the localisation of ventricular tachycardia with the site of underlying cardiac disease and may facilitate mapping in patients with refractory ventricular tachycardia requiring ablation (either surgical or by high energy impulses). (bmj.com)
  • 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). (embl.de)
  • Ventricular tachycardia (VT) refers to a potentially life-threatning condition of abnormally fast heart beat (arrhythmia). (petyourdog.com)
  • Hence, ventricular tachycardia is a rapid heart beat that originates in one of the lower chambers (the ventricles) of the heart. (petyourdog.com)
  • Ventricular tachycardia is a fast but regular rhythm. (petyourdog.com)
  • nbsp;Ventricular tachycardia is related to abnormal behavior in the ventricles. (petyourdog.com)
  • Ventricular tachycardia  may occur in structurally normal hearts, as hereditary arrhythmias, or may be a consequence of myocardial abnormalities associated with cardiomyopathy (heart muscle disease), significant valvular disease, or myocarditis (heart muscle inflammation). (petyourdog.com)
  • The literature reports the detection and identification of life-threatening arrhythmias and, particularly, congestive heart failure, ventricular and atrial fibrillation, and ventricular tachycardia. (hindawi.com)
  • Atrio-ventricular re-entrant tachycardia (AVRT). (cincinnatichildrens.org)
  • Many infants with atrio-ventricular re-entrant tachycardia "outgrow" the tachycardia during the first year of life as the accessory pathway becomes unable to function. (cincinnatichildrens.org)
  • This tachycardia may be seen in patients who have had recent surgery involving this area, for example repair of a ventricular septal defect (VSD) , atrioventricular septal defect or tetralogy of Fallot . (cincinnatichildrens.org)
  • When the source of the fast heart rhythm is the lower chambers (ventricles), ventricular tachycardia (VT) is present. (cincinnatichildrens.org)
  • relevance to drug-induced multiform ventricular tachycardia. (cdc.gov)
  • Almost all of these deaths are related to ventricular fibrillation . (britannica.com)
  • Some of the more commonly seen arrhythmias are ventricular fibrillation with a pulse, rapid atrial fibrillation/flutter, and supraventricular tachycardias. (bellaonline.com)
  • Rarely, a patient will present with ventricular fibrillation and appear fine. (bellaonline.com)
  • The cardiac monitor senses the ventricular contraction and times the electrical impulse to prevent triggering ventricular fibrillation. (bellaonline.com)
  • Ventricular fibrillation (427.41) is rapid, chaotic electrical impulses causing the ventricles to fibrillate ineffectively so they fail to pump blood. (fortherecordmag.com)
  • Without treatment, ventricular flutter may progress to ventricular fibrillation. (fortherecordmag.com)
  • In acute mitral regurgitation, patients are in sinus rhythm rather than atrial fibrillation and have little or no enlargement of the left atrium, no calcification of the mitral valve, no associated mitral stenosis , and in many cases little left ventricular dilation. (health.am)
  • The majority of arrhythmias are associated with ventricular fibrillation. (sru.edu)
  • Ventricular fibrillation is a condition where the heart's electrical impulses become irregular, resulting in blood no longer being pumped efficiently throughout the body. (sru.edu)
  • Ventricular Fibrillation" is a descriptor in the National Library of Medicine's controlled vocabulary thesaurus, MeSH (Medical Subject Headings) . (harvard.edu)
  • Such asynchronous ventricular quivering or fibrillation prevents any effective cardiac output and results in unconsciousness (SYNCOPE). (harvard.edu)
  • This graph shows the total number of publications written about "Ventricular Fibrillation" by people in Harvard Catalyst Profiles by year, and whether "Ventricular Fibrillation" was a major or minor topic of these publication. (harvard.edu)
  • Below are the most recent publications written about "Ventricular Fibrillation" by people in Profiles. (harvard.edu)
  • Circulating linoleic acid at the time of myocardial infarction and risk of primary ventricular fibrillation. (harvard.edu)
  • ATP1A3-Encoded Sodium-Potassium ATPase Subunit Alpha 3 D801N Variant Is Associated With Shortened QT Interval and Predisposition to Ventricular Fibrillation Preceded by Bradycardia. (harvard.edu)
  • The most common life-threatening arrhythmia is ventricular fibrillation, which is an erratic, disorganized firing of impulses from the ventricles (the heart's lower chambers). (onteenstoday.com)
  • Furthermore, it presents here to forth unknown mechanism that can lead to ventricular fibrillation and sudden cardiac death. (mpg.de)
  • The condition can deteriorate into fast and irregular rhythm known as ventricular fibrillation (muscular twitching involving individual muscle fibers acting without coordination). (petyourdog.com)
  • Ventricular arrhythmias represent the major mechanism of cardiac sudden death , which is the leading cause of death in the United States , where each year more than 325,000 people die suddenly. (britannica.com)
  • The mechanism by which ventricular arrhythmias occur is not completely understood. (britannica.com)
  • The chaotic nature of excitation and inefficient ventricular contraction in pathological ventricular arrhythmias frequently compromises circulation . (britannica.com)
  • There has been considerable investigation into methods of evaluating premonitory signs that might predict susceptibility to serious ventricular arrhythmias. (britannica.com)
  • In addition to evaluating ventricular rhythm disturbances associated with serious cardiac arrhythmias, this method also allows for the identification of potential causative conditions. (britannica.com)
  • This is a useful way of predicting potential problems associated with ventricular arrhythmias in these patients. (britannica.com)
  • Since coronary artery disease is the most common cause of ventricular arrhythmias, correction of coronary occlusion either by angioplasty or coronary artery bypass is quite common and successful. (britannica.com)
  • However, if the ventricle has already been significantly damaged, ventricular arrhythmias may persist. (britannica.com)
  • In addition, a significant group of people who have no evidence of coronary artery disease develop a propensity for ventricular arrhythmias. (britannica.com)
  • Treatment of ventricular arrhythmias in patients without coexisting cardiac disease is variable and, in some cases, is not required. (britannica.com)
  • The efficacy of these drugs was assessed based on their ability to control the frequency of premature ventricular contractions and other transient ventricular arrhythmias. (britannica.com)
  • In animal studies, mexiletine has been shown to be effective in the suppression of induced ventricular arrhythmias, including those induced by glycoside toxicity and coronary artery ligation. (nih.gov)
  • Theoretically, therefore, mexiletine may be useful in the treatment of ventricular arrhythmias associated with a prolonged QT interval. (nih.gov)
  • Predicting Malignant Ventricular Arrhythmias Using Real-Time Remote Monitoring. (harvard.edu)
  • Investigator-reported ventricular arrhythmias and mortality in heart failure with mildly reduced or preserved ejection fraction. (harvard.edu)
  • Ventricular arrhythmias after fibroma resection: Are patients still at risk? (harvard.edu)
  • Patients with heart failure are about 6 to 9 times more likely than the general population to have ventricular arrhythmias that can lead to SCA. (clevelandclinic.org)
  • An electrocardiographic atlas of ventricular tachycardias was produced by pacing 27 epicardial sections of the heart and the mitral papillary muscles to simulate focal ventricular arrhythmias and simultaneously recording their 12 lead electrocardiographic appearances. (bmj.com)
  • Simulated right ventricular arrhythmias had either inferior frontal plane QRS axes (from the anterobasal region) or superior frontal plane QRS axes (from the apical and posterior right ventricular sections). (bmj.com)
  • Left ventricular arrhythmias with a superior frontal plane QRS axis were readily distinguished by their horizontal plane QRS axes: posterorightwards from the anterior and anterorightwards from the posterior left ventricular sections. (bmj.com)
  • The electrocardiogram was most accurate in localising ventricular arrhythmias from the anterior left ventricle and least accurate for those arising from the inferior right ventricle. (bmj.com)
  • It is used in management of ventricular tachyarrhythmias and is also used in treatment of atrial arrhythmias. (pharmacology2000.com)
  • Fast arrhythmias that originate from the lower chambers (i.e., the ventricles) are called ventricular tachycardias. (cincinnatichildrens.org)
  • Furthermore, sudden deaths can also result from bradyarrhythmias, electromechanical dissociation and ventricular arrhythmias that are refractory to ICD-delivered therapy [2]. (escardio.org)
  • The clinical cardiologist should therefore identify potentially reversible causes of ventricular arrhythmias (e.g., myocardial ischaemia, electrolyte imbalances, etc.) and treat them, whenever possible. (escardio.org)
  • A second mechanism of ventricular arrhythmia is associated with reentry of an impulse. (britannica.com)
  • This sets up an electrical impulse circuit within the ventricle that may progress into an arrhythmia. (britannica.com)
  • Under any circumstance where cardiac injury has occurred, a ventricular arrhythmia may potentially become a lethal ventricular event. (britannica.com)
  • An arrhythmia (also called dysrhythmia) is a deviation from the normal cardiac rate and rhythm, site of origin of the cardiac impulse, or sequence of activation of the atria or the ventricles. (vin.com)
  • Premature ventricular contractions are a common type of irregular heartbeat (arrhythmia). (nchmd.org)
  • A potentially lethal cardiac arrhythmia that is characterized by uncoordinated extremely rapid firing of electrical impulses (400-600/min) in HEART VENTRICLES. (harvard.edu)
  • These bundles branch into smaller elements and eventually form terminal ends that burrow into left and right ventricular chamber muscles. (microscopyu.com)
  • Tetralogy of Fallot consists of 4 features: a large ventricular septal defect, right ventricular outflow tract obstruction and pulmonic valve stenosis, right ventricular hypertrophy, and over-riding of the aorta. (msdmanuals.com)
  • Pathophysiology depends on the degree of right ventricular outflow obstruction. (msdmanuals.com)
  • As part of the electrical conduction system of the heart, it transmits the electrical impulses from the atrioventricular node (located between the atria and the ventricles) to the point of the apex of the fascicular branches via the bundle branches. (wikipedia.org)
  • The bundle of His is an important part of the electrical conduction system of the heart, as it transmits impulses from the atrioventricular node, located at the anterior-inferior end of the interatrial septum, to the ventricles of the heart. (wikipedia.org)
  • The ventricular conduction system comprises the bundle branches and the Purkinje networks. (wikipedia.org)
  • It is not clear whether this condition results from pathologically altered ventricular cells or from cells in the specialized conduction system. (britannica.com)
  • The atrioventricular node delays impulses for ~0.1 second before allowing impulses through to the His-Purkinje conduction system, which spreads impulses to the ventricular walls. (wikidoc.org)
  • Last, a new glycogen storage cardiomyopathy associated with ventricular preexcitation and progressive conduction system degeneration will be reviewed. (medscape.com)
  • The heart achieves the coordinated contraction of the atrial and ventricular chambers due to the precise timing of the cardiac conduction system (CCS), a specialized complex and heterogeneous network of cells that initiate and allow propagation of action potentials through the heart. (medscape.com)
  • The shapes of the waves show how well the heart's electrical impulses are working, the size of the heart , and how well the individual parts of the heart are working together. (akronchildrens.org)
  • In this situation, slowed impulse conduction in the ventricle leads to the generation of ectopic impulses (electrical impulses derived from an area of the heart other than the sinus node) that are primarily the result of temporal dispersion of the impulse between adjacent areas of the ventricle. (britannica.com)
  • An AV-junctional rhythm , or atrioventricular nodal bradycardia, is usually caused by the absence of the electrical impulse from the sinus node . (wikipedia.org)
  • [4] This dysrhythmia also may occur when the electrical impulses from the SA node fail to reach the AV node because of SA or AV block . (wikipedia.org)
  • This is a safety mechanism when a lack of electrical impulse or stimuli from the atrium occurs. (wikipedia.org)
  • Heart rhythm problems occur when the electrical impulses in the heart don't function properly, causing the heart to beat too fast, too slow, or irregularly. (fortherecordmag.com)
  • The electrical impulses generate from the pacemaker through this electrode tip and will cause rhythmic contraction of the heart. (innerbody.com)
  • Mechanisms of arrhythmogenesis primarily include disorders of cardiac electrical impulse formation and electrical impulse conduction. (vin.com)
  • In a typical heart rhythm, a tiny cluster of cells at the sinus node sends out an electrical signal (impulse). (nchmd.org)
  • Three wires (leads) are attached to the pacemaker and keep the ventricles pumping together by sending small electrical impulses to the heart muscle. (clevelandclinic.org)
  • Electrophysiologists, as the name suggests, deal with electricity-specifically, with the electrical impulses in the heart that control its rhythm and trigger heartbeats. (rapidesregional.com)
  • Heart block, in which electrical impulses originating from the upper chambers of the heart don't reach the lower chambers as they should. (rapidesregional.com)
  • The atrioventricular node is an area of specialized tissue between the atria and the ventricles of the heart , which conducts the normal electrical impulse from the atria to the ventricles. (wikidoc.org)
  • Individuals with ankyrin-B syndrome may have problems with the sinoatrial (SA) node, which generates the electrical impulses that start each heartbeat. (medlineplus.gov)
  • Due to self-organized electrical impulses, the atria of the heart get out of sync. (mpg.de)
  • The discovery of this generic mechanism of rotor generation opens up important new insights for the prevention of malignant electrical impulses of the heart muscle. (mpg.de)
  • Cardiac Resynchronization Therapy or CRT uses the pacemaker called the biventricular pacemaker which stimulates the muscles of the heart using electrical impulses. (phdsc.org)
  • These electrical impulses are triggered by the pacemaker which contracts the muscles of the heart and does the sufficient pumping of blood to the body. (phdsc.org)
  • and (iv) automatically charges and requests delivery of an electrical impulse to an individual's heart upon determining that defibrillation should be performed. (virginia.gov)
  • VT is rapid, erratic heart beats, caused by abnormal electrical impulses that are generated somewhere within the ventricles of the heart. (petyourdog.com)
  • nbsp;Sinus or sinoatrial (SA) node starts electrical impulse which causes atria to contract, pumping blood into ventricles. (petyourdog.com)
  • Electrical impulse moves through the atrioventricular (AV) node and into the ventricles, causing the ventricles to contract and to pump blood to the lungs (right ventricle) and the body (left ventricle). (petyourdog.com)
  • The goal is to produce a device that can defibrillate the atria with a painless series of electrical impulses. (duke.edu)
  • Complete heart block, also known as complete atrioventricular (AV) block, is a condition in which the electrical impulses generated by the sino-atrial node in the atria of the heart are not conducted to the ventricles. (pediatriconcall.com)
  • Re-entry occurs from a "circuit" where electrical impulses travel in a circular way, faster than the normal pacemaker. (cincinnatichildrens.org)
  • In a functional syncytium, electrical impulses propagate freely between cells in every direction, so that the myocardium functions as a single contractile unit. (wikipedia.org)
  • [ 1 ] The impulse is then conducted through the atrium to the atrioventricular junction from where, after a delay, the electrical signal is propagated to the ventricles along bundles of specialized conduction tissue to the distal Purkinje fibers, which ramify among the contractile myocardium. (medscape.com)
  • Abnormalities of impulse formation can produce both tachyarrhythmias and bradyarrhythmias. (vin.com)
  • x-ray shows left atrial and ventricular enlargement. (health.am)
  • Ventricular Septal Defect (VSD) A ventricular septal defect (VSD) is an opening in the interventricular septum, causing a shunt between ventricles. (msdmanuals.com)
  • The ventricular septal defect in tetralogy of Fallot is often described as a malalignment type, since the conal septum is displaced anteriorly. (msdmanuals.com)
  • An abnormally rapid ventricular rhythm usually in excess of 150 beats per minute. (embl.de)
  • The appearance of the paced electrocardiograms was slightly modified by underlying disease such as myocardial infarction and left ventricular hypertrophy. (bmj.com)
  • In contrast, premature ventricular contractions can occur spontaneously in healthy people without any consequence. (britannica.com)
  • Ventricular flutter (427.42) is rapid contractions of the ventricles of the heart. (fortherecordmag.com)
  • The electrode tip of a pacemaker is passed into the right ventricle down to the inferior aspect of the heart where ventricular contractions originate. (innerbody.com)
  • Premature ventricular contractions (PVCs) are extra heartbeats that begin in one of the heart's two lower pumping chambers (ventricles). (nchmd.org)
  • Occasional premature ventricular contractions in people without heart disease usually aren't a concern and likely don't need treatment. (nchmd.org)
  • You might need treatment if the premature ventricular contractions are very frequent or bothersome, or if you have an underlying heart condition. (nchmd.org)
  • Premature ventricular contractions often cause few or no symptoms. (nchmd.org)
  • To understand the cause of premature ventricular contractions (PVCs), it might help to learn more about how the heart typically beats. (nchmd.org)
  • The cause of premature ventricular contractions isn't always clear. (nchmd.org)
  • Certain lifestyle choices and health conditions may make a person more likely to develop premature ventricular contractions (PVCs). (nchmd.org)
  • Sotalol prolongs action potential duration, decreases automaticity, slows impulse transmission through the AV node and prolongs AV nodal refractoriness. (pharmacology2000.com)
  • The heart rate, normal, slow, or fast, impulse formation may originate in pace-making cells in the sinoatrial (SA) node or ectopically [ 7 , 8 ]. (hindawi.com)
  • The ECG shows a complete dissociation between the P-waves (representing the atrial rhythm) and the QRS complexes (representing the ventricular activity). (pediatriconcall.com)
  • A 2000 study found that direct His bundle pacing is more effective in producing synchronized ventricular contraction-and therefore in improving cardiac function-than apical pacing. (wikipedia.org)
  • Cardiac palpation reveals a diffuse apical impulse. (acponline.org)
  • Four pigs, three with focal infarctions in the apical intraventricular septum (IVS) and/or left ventricular free wall (LVFW), were imaged with an intracardiac echocardiography (ICE) transducer. (duke.edu)
  • 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. (bvsalud.org)
  • Due to this, the intrinsic electric rhythm of the ventricular muscle takes over the pacemaker role for the ventricles. (pediatriconcall.com)
  • The normal cardiac impulse of the vertebrate heart originates in the pacemaker cells of the sinoatrial node, located in the right atrium. (medscape.com)
  • Mexiletine did not prolong ventricular depolarization (QRS duration) or repolarization (QT intervals) as measured by electrocardiography. (nih.gov)
  • Based upon site of origin, tachyarrhythmias may be divided into supraventricular and ventricular . (vin.com)
  • Causes of SVT (and ventricular tachyarrhythmias) may for ease of remembrance be divided into 5 categories: 1) cardiac, 2) drugs and toxins, 3) autonomic imbalance, 4) metabolic / endocrine, and 5) usual suspects (e.g. (vin.com)
  • During left ventricular systole, the mitral leaflets do not close normally, and blood is ejected into the left atrium as well as through the aortic valve. (health.am)
  • the degree of left ventricular enlargement usually reflects the severity of regurgitation. (health.am)
  • Hemodynamically, left ventricular volume overload may ultimately lead to left ventricular failure and reduced cardiac output, but for many years the left ventricular end- diastolic pressure and the cardiac output may be normal at rest, even with considerable increase in left ventricular volume. (health.am)
  • Holmberg, J "Acute limb ischemia from embolization of left ventricular pseudoaneurysm thrombus: a rare case report. (creighton.edu)
  • Predictive value of global longitudinal strain by left ventricular ejection fraction. (harvard.edu)
  • Current guidelines give a class I recommendation for ICD implantation in patients with either ischaemic or non-ischaemic cardiomyopathy with severely depressed systolic function (left ventricular ejection fraction [LVEF] ≤35% for New York Heart Association [NYHA] Class II or III, ≤30% for NYHA Class I symptoms). (escardio.org)
  • These fibers distribute the impulse to the ventricular muscle. (wikipedia.org)
  • The conducting system of the heart consists of cardiac muscle cells and conducting fibers (not nervous tissue) that are specialized for initiating impulses and conducting them rapidly through the heart (see the image below). (medscape.com)
  • The heart is constituted by three types of muscle: atrial, ventricular, and specialized excitatory and conducting fibers. (bvsalud.org)
  • In all animals, acoustic radiation force impulse (ARFI) and shear wave elasticity imaging (SWEI) estimates indicated diastolic relaxation and systolic contraction in noninfarcted tissues. (duke.edu)
  • The clinical manifestations of WPW syndrome reflect the associated tachyarrhythmia episodes-rather than the anomalous ventricular excitation per se. (medscape.com)
  • A form of ventricular pre-excitation characterized by a short PR interval and a long QRS interval with a delta wave. (bvsalud.org)
  • Idioventricular rhythm , also known as atrioventricular bradycardia or ventricular escape rhythm, is a heart rate of less than 50 BPM. (wikipedia.org)
  • [7] Ventricular bradycardias occurs with sinus bradycardia, sinus arrest, and AV block. (wikipedia.org)
  • Sick sinus syndrome (427.81) occurs when the sinus node doesn't send proper impulses, causing the heart rate to be too slow or too fast. (fortherecordmag.com)
  • Intracardiac acoustic radiation force impulse (ARFI) and shear wave imaging in pigs with focal infarctions. (duke.edu)