Right bundle-branch block with left axis deviation.

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Abstract
Twenty-three patients with right bundle-branch block and left axis deviation were analyzed vectorcardiographically utilizing the Frank lead system. Two basic vectorcardiographic patterns, types A and B, were identified, as well as an intermediate group. In type A, present in 10 patients, the characteristic findings were a rounded or flattened frontal loop and a horizontal loop showing the classical features of right bundle-branch block, ie terminal anterior and rightward delay with counterclockwise rotation. Type B, present in 7 cases, showed an elongated, narrow frontal loop. The horizontal loop was oriented predominantly anteriorly and showed clockwise rotation. The delay associated with bundle-branck block was usually more diffuse and pronounced in this type. These vectorcardiographic findings were correlated with the electrocardiographic alterations as well as the clinical data. The latter suggested more extensive myocardial disease and a poorer prognosis in type B as compared with type A.