Search results
Results From The WOW.Com Content Network
Emerging data also suggest that very frequent ventricular ectopy may be associated with cardiomyopathy through a mechanism thought to be similar to that of chronic right ventricular pacing associated cardiomyopathy. For patients with underlying chronic structural heart disease and complex ectopy, mortality is significantly increased. [3]
AIVR appears similar to ventricular tachycardia with wide QRS complexes (QRS >0.12s) and a regular rhythm. It can most easily be distinguished from VT in that the rate is less than 120 and usually less than 100 bpm. There may or may not be AV dissociation depending on whether it is due to ventricular escape or AV block. [8]
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 or group of fibers outside the region in the heart muscle ordinarily responsible for impulse formation (i.e., the sinoatrial node).
An ectopic pacemaker located in the atria is known as an atrial pacemaker and can cause the atrial contraction to be faster. [10] An ectopic pacemaker situated near the AV node and the septum is known as a junctional pacemaker. [11] The pacemaker that is operating in the ventricles is known as the ventricular. [12]
Ventricular fusion beats can occur when the heart's natural rhythm and the impulse from a pacemaker coincide to activate the same part of a ventricle at the same time, causing visible variation in configuration and height of the QRS complex of an electrocardiogram reading of the heart's activity. [2]
SVES should be viewed in contrast to a premature ventricular contraction that has a ventricular origin and the associated QRS change. Instead of the electrical impulse beginning in the sinoatrial (SA) node and propagating to the atrioventricular (AV) node, the signal is conducted both to the ventricle and back to the SA node where the signal began.
The QRS complex is often normal but can also be narrow in LGL syndrome, as opposed to WPW, because ventricular conduction is via the His-Purkinje system. Lown–Ganong–Levine syndrome is a clinical diagnosis that came about before the advent of electrophysiology studies.
Ashman beats are described as wide complex QRS complexes that follow a short R-R interval preceded by a long R-R interval. [3] This short QRS complex typically has a right bundle branch block morphology and represents an aberrantly conducted complex that originates above the AV node, rather than a complex that originates in either the right or left ventricle.