Feldman R, Horowitz L N, Josephson M E
J Electrocardiol. 1978 Apr;11(2):181-4. doi: 10.1016/s0022-0736(78)80111-3.
Electrophysiologic studies in one patient with spontaneous 2:1 atrioventricular block and variable PR intervals revealed two sites of conduction block. Typical 4:3 A-V nodal Wenckebach was present in addition to Mobitz type II infra-His block. The HV of conducted complexes was 120 msec and the shortest recorded AH interval was 250 msec. When 2:1 A-V block with fixed PR interval was present, only 2:1 Mobitz type II infra His-block was present. The mechanism of this example of spontaneous multilevel A-V block is discussed and compared to other previously reported cases.
