Atrioventricular block (first of two parts).

The development of His-bundle (H) electrocardiography and the concept of hemiblocks have prompted a re-examination of conventional thinking about the indications for treatment of atrioventricular (AV) block. The technic of treatment is not the issue; ventricular pacemaking is the only really effective and reliable method. The problem for this review is what these recent developments have contributed to deciding when and if a pacemaker should be installed.