Spontaneous Bundle Branch Block in Rhesus Monkeys

Abstract
Naturally occurring ventricular conduction abnormalities are described in 23 rhesus monkeys and compared with findings in 15 control animals. Electrocardiograms and Frank vectorcardiograms were recorded and ventricular endocardial leads were obtained in four of the animals. Three examples of left bundle branch block and five of right bundle branch block were found. Less marked degrees of abnormal intraventricular conduction are described in 15 others.