An atypical case of atrioventricular block in an elderly man: A fortuitous escape.

Paroxysmal atrioventricular block (PAVB) is an important but under-recognized etiology of syncope. It is characterised by sudden and unexpected change from 1:1 atrioventricular conduction to complete atrioventricular block. This poorly defined entity is usually associated with absence or delayed emergence of an adequate escape rhythm.