Atrioventricular Synchronization and Accrochage

Abstract

Complete heart block implies an absolute independence between atria and ventricles that does not in fact always exist. Segers showed that, after complete block was artificially produced in the frog's heart, atria and ventricles would sometimes begin to beat exactly in phase, most commonly in a 2 to 1 ratio. He subsequently reported one clinical example of 2 to 1 A-V synchronization in a patient with complete heart block. Two further cases that may illustrate different varieties of synchronization are here presented.

Electrophysiological Characteristics of Fetal Atrioventricular Block

“…At 37 weeks' gestation, pre-excitation was no longer present, but transient 3°AVB ( Fig. 1B) with accrochage (8), which refers to the tendency of dissociated atrial and ventricular rhythms to synchronize, was noted. Another fetus showed alternating low atrial (Fig.…”

Why Cardiac Resynchronization Therapy (CRT) is Usually Prescribed along with Automatic Implantable Defibrillation (AID)? Is it a Sensible Decision? Historical Perspective

“…In 2004, Bristow, Saxon, et al [27] in a group of selected patients, studied cardiac-resynchronization therapy alone and in conjunction with an automatic implant-A similar observation was described years later by Marriott [7]: Complete heart block implies an independence between atria and ventricles that does not always exist. Segers, as referred to above, showed that, after complete block was artificially produced in the frog's heart, atria and ventricles would sometimes begin to beat exactly in phase, most commonly in a 2 to 1 ratio.…”

ECG of the Month

“…Explanations for these findings include AIVR with LBBB morphology coupled to IAVD with synchronization type 2 5 and sinus rhythm associated with VP. 14 The term synchronization is used when the hook-up between cardiac elements is relatively long; when the phenomenon lasts for only a few beats, the term accrochage has been proposed. [11][12][13] The term isorhythmic is additionally used when rates of the independent pacemakers approximate each other over relatively long periods, despite different influences acting on each.…”