The spatial vectorcardiograms of 24 subjects with electrocardiographic evidence of right bundle branch block are described. Correlation of the vectorcardiographic patterns observed, with clinical and roentgenologic data, suggests that the recognition of ventricular hypertrophy in the presence of such a conduction defect may be improved by this method of study.

A simple electrode arrangement, which permits the derivation of stereoscopic projections of the spatial vectorcardiogram, eliminates the need for constructing models. The visual impression obtained from this method agrees satisfactorily with that from carefully constructed models.