An illustration of ectopic foci near papillary muscles in the left ventricle
Specialty
Electrophysiology, Cardiology
Symptoms
Isolated ectopic beats
Feeling faint
Palpitations
An ectopic pacemaker, also known as ectopic focus or ectopic foci, is an excitable group of cells that causes a premature heart beat outside the normally functioning SA node of the heart. It is thus a cardiac pacemaker that is ectopic, producing an ectopic beat. Acute occurrence is usually non-life-threatening, but chronic occurrence can progress into tachycardia,[1] bradycardia or ventricular fibrillation.[2] In a normal heart beat rhythm, the SA node usually suppresses the ectopic pacemaker activity due to the higher impulse rate of the SA node. However, in the instance of either a malfunctioning SA node or an ectopic focus bearing an intrinsic rate superior to SA node rate, ectopic pacemaker activity may take over the natural heart rhythm.[3] This phenomenon (an intrinsically slower pacemaker activity being unmasked by failure of faster pacemaker tissue 'upstream') is called an escape rhythm, the lower rhythm having escaped from the dominance of the upper rhythm. As a rule, premature ectopic beats (i.e. with a shorter than the prevailing preceding R-R' interval) indicate increased myocyte or conducting tissue excitability, whereas late ectopic beats (i.e. with a prolonged preceding R-R' interval) indicate proximal pacemaker or conduction failure with an escape 'ectopic' beat.
^Phibbs, B. (1963). "Paroxysmal Atrial Tachycardia with Block Around the Ectopic Pacemaker: Report of a Case". Circulation. 28 (5): 949–50. doi:10.1161/01.CIR.28.5.949. PMID 14079200.
^Tveito, Aslak; Lines, Glenn T. (2008). "A condition for setting off ectopic waves in computational models of excitable cells". Mathematical Biosciences. 213 (2): 141–50. doi:10.1016/j.mbs.2008.04.001. PMID 18539188.
^Rozanski, GJ (1991). "Atrial ectopic pacemaker escape mediated by phasic vagal nerve activity". The American Journal of Physiology. 260 (5 Pt 2): H1507–14. doi:10.1152/ajpheart.1991.260.5.H1507. PMID 2035673.
An ectopicpacemaker, also known as ectopic focus or ectopic foci, is an excitable group of cells that causes a premature heart beat outside the normally...
of acting as the default or "escape" pacemaker. An ectopicpacemaker also known as an ectopic focus or ectopic foci, is an excitable group of cells that...
believed that the atria had different ectopic foci that were spontaneously depolarizing, each foci acting as a pacemaker for the heart. However, the atrial...
heart's electrical impulse comes from an ectopicpacemaker (that is, an abnormally located cardiac pacemaker) in the upper chambers (atria) of the heart...
activity. Hence, the ectopicpacemaker is expected to fire at a fixed rate. Therefore, on ECG, the coupling intervals of the manifest ectopic beats will wander...
Ectopic beat is a disturbance of the cardiac rhythm frequently related to the electrical conduction system of the heart, in which beats arise from fibers...
of a pacemaker has been advocated in a subset of individuals, in order to cause asynchronous contraction of the left ventricle. Since the pacemaker activates...
Junctional ectopic tachycardia (JET) is a rare syndrome of the heart that manifests in patients recovering from heart surgery. It is characterized by...
usually caused by a malfunction of the sinus node, the heart's primary pacemaker. Tachycardia-bradycardia syndrome is a variant of sick sinus syndrome...
beats, in which the normal sinoatrial node fails, leaving a non-nodal pacemaker to initiate a late beat. The exact cause of PACs is unclear; while several...
considered a form of ectopicpacemaker activity that is unveiled by lack of other pacemakers to stimulate the ventricles. Ventricular pacemaker cells discharge...
which there is a single ectopic beat, or irregular heartbeat, following each regular heartbeat. Most often this is due to ectopic beats occurring so frequently...
definitive treatment with an implanted pacemaker. In atrioventricular causes of bradycardia, permanent pacemaker implantation is often required when no...
electrical activity begins in the sinoatrial node (the heart's natural pacemaker), which is situated on the upper right atrium. The impulse travels next...
evaluation, and those with LBBB and syncope or near-syncope may require a pacemaker. Some patients with LBBB, a markedly prolonged QRS (usually > 150 ms)...
called an ectopic focus and is, by definition, a pathological phenomenon. This may cause a single premature beat now and then, or, if the ectopic focus fires...
The slow heart rate may also lead to atrial, junctional, or ventricular ectopic rhythms. Bradycardia is not necessarily problematic. People who practice...
sometimes be distinguished by its prompt response to vagal maneuvers. Ectopic (unifocal) atrial tachycardia arises from an independent focus within the...
Pacemaker syndrome is a condition that represents the clinical consequences of suboptimal atrioventricular (AV) synchrony or AV dyssynchrony, regardless...
reduce blood clot risk. Anti-arrhythmics: to maintain normal heart rhythm. Pacemaker: Coordinates contractions between ventricles. In people at risk of arrhythmias...
artificial valves, hemodialysis, intravenous drug use, and electronic pacemakers. The bacterial most commonly involved are streptococci or staphylococci...
It is important to diagnose AV-blocks precisely because unnecessary pacemaker placement in patients with pseudo-AV blocks can worsen symptoms and create...
beat is a delayed heartbeat originating not from the atrium but from an ectopic focus somewhere in the atrioventricular junction. It occurs when the rate...
Global Information