Association of right bundle-branch block with left superior or inferior intraventricular block. Its relation to complete heart block and Adams-Stokes syndrome.

have considered that the fibres of the left bundle-branch may be thought of as being arranged into superior and inferior divisions. If a lesion involves a sufficiently large number of fibres of one radiation, the sequence of excitation of the left ventricle is altered. The electrocardiographic patterns of the left superior intraventricular block (Grant, 1956; Pryor and Blount, 1966) and of the left inferior intraventricular block (Pryor and Blount, 1966) have been described.