Clinical Electrophysiological Study on Chronics Bifascicular Block

Clinical electrophysilogical study(EPS) was done in 5 patients with chronic bifascicular block of completa RBBB and left anterior fascicular block. The results were as follows. 1) In 2 patients who needed permenent pacemaker therapy, EPS disclosed prolonged HV interval(>70msec) and block distal to his bundle by atrial with cycle length of longer than 545msec. 2) In 3 patients who didn't need permenent pacemaker therapy, AV conduction and to choose the therapeutic measures in the patients with chronic bifascicular block and unexplained dizziness and/or syncope.