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.