In the majority of the reported cases where concealed extrasystoles caused pseudo AV block, impulse formation occurred above the so called bifurcation of the His bundle. The two patients reported in this communication, however, showed manifest and concealed ectopic impulses originating in the left bundle branch or its posteroinferior division. Both had prolonged HV intervals which were attributed to organic disease of the distal ventricular specialized conducting system. The ectopic beats remained confined to the two major compartments of the AV conducting system, namely AV nodal and ventricular specialized. Thus, for the purposes of concealment the AV junction extended from the atrial pre AV nodal regions to the peripheral (physiological) ventricular 'gates'.
ASJC Scopus subject areas
- Cardiology and Cardiovascular Medicine