Abstract
Sixteen cases (10 men and 6 women of 71 to 88 years of age) of complete right bundle branch block (RBBB) with right axis deviation (RAD) were examined for the conduction system. There were 7 cases of hypertension, 2 myocardial infarction and 6 pulmonary disease. The electrical axis was from +90°to +150°with an average of +113°, and small q waves in leads II, III, and aVF were present in 11 cases. Duration of RBBB with RAD was within 2 months in 4 cases and over 1 year in 12. There was only 1 case who developed complete atrioventricular (AV) block.
Heart weight was from 220 to 445Gm with an average of 306Gm. Severe coronary sclerosis was found in 6 cases and myocardial infarction in 2. The AV node and the penetrating portion of the AV bundle showed only slight fibrosis, but the branching portion of the AV bundle showed moderate degeneration and fibrosis. Right bundle branch (RBB) was interrupted with fibrosis at the 1st portion in 7, 2nd portion in 8 and 3rd portion in 1. Complete interruption was found in 57 to 100% (average 87%) of the left posterior fascicles (LPF) and in 0 to 100% (average 28%) of the left anterior fascicles (LAF). It was concluded that the RBBB with RAD was produced by interruption of RBB and LPF.
