The vectorcardiogram in right bundle branch block: correlation with cardiac failure and pulmonary disease.

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Abstract
Frank vectorcardiograms (VCG) and clinical records of 243 patients with right bundle branch block (RBBB) were compared. The patients were classified into three categories on the basis of VCG criteria. The first category included 100 patients with a normal frontal axis, and the second category included 44 patients with concomitant left anterior hemiblock. The third category consisted of 99 patients with RBBB and myocardial infarction. The VCGs were classified into three types accoriding to the QRS configuration in the transverse plane. In type I the initial forces were anterior and counterclockwise and the afferent limb crossed the midline posterior to E point; in type II the initial forces were anterior and counterclockwise and the afferent limb crossed the midline posterior to E point; in type II the initial forces were anterior and counterclockwise and the afferent limb crossed the midline anterior to or through E point; and in type III the entire transverse loop was clockwise and anterior to E point. The patients were further classified according to the presence or absence of cardic failure or severe pulmonary disease. In patients with RBBB and a normal axis, cardiac failure or severe pulmonary disease was found in five of 49 patients wtih type I, 17 of 31 with type II, and 18 of 20 with type III pattern. In patients with RBBB and left anterior hemiblock, significant disease was found in one of 17 with type I, five of 16 with type II, and eight of 11 with type III pattern. These data show that, in patients with RBBB, the position of the afferent limb in the transverse plane can be used to predict cardiac failure or severe pulmonary disease.