A-V block.

Abstract

In this report, 61 A-V block patients were analysed using HBE. According to the site of the block, these cases were classified into P(A)-H block, BH block H V block and mixed block. In P(A) H block group (23 cases), the permanent pacemaker implantation was not needed except for one patient with persistent heart failure due to marked bradycardia. Postmortem histology of this patient was well coincident to the results of HBE. In BH block group (18 cases), moderate number of patients were needed to have permanent pacemakers implanted (33%). RA pacing induced split H block with H-V prolongation and varied H and QRS configuration in two cases of this group. These phenomena may be well explained by the longitudinal dissociation theory. In H-V block patients, permanent pacemakers were implanted in all patients (12 cases). In this group, it is difficult to decide the exact location of block, either distal His, bifurcation or bundles, because of the difficulty to record the left or right bundle potentials in clinical practise. Finally, it is important to record the HBE in order to decide the exact site of block, and to choose the suitable therapy for A-V block patients.