Vectorcardiogram of complete right bundle branch block with left axis deviation by the Frank and Kimura systems.

Vectorcardiogram (VCG) recorded by both the Frank and Kimura systems were examined in 45 patients with complete right bundle branch block (RBBB) and left axis deviation (LAD) to investigate the relationship seen on electrocardiogram (ECG) between RBBB with LAD and bilateral bundle. The sample included: 13 cases of type SI, SII, SIII, SaVF; 21 cases of type SI, SII, SIII, aVF; and 11 cases of types SI, SII, SIII. VCG recorded by the Frank system were classified into seven types according to the QRS loop pattern on the frontal plane and into three types according to the horizontal plane. The main findings were: (a) In the Frank system the QRS loop in the frontal plane showed a variety of patterns in RBBB with LAD. (b) On VCG of complete RBBB judged complicated by a left anterior hemiblock by the Frank system, the main portion of the QRS loop extended to the left superior or merely to the left in the frontal plane. The direction of rotation and position on the horizontal plane were not consistent. (c) The results of this study suggest the usefulness of the Kimura system as an auxiliary diagnostic technique.