right bundle branch block (RBBB), impaired transmission or absence of transmission of electric impulses from the atrioventricular (AV) bundle of His to the right ventricle. The block may be complete or incomplete and may be caused by a lesion in the right bundle branch or a small, focal lesion in the AV bundle. RBBB is often associated with right ventricular hypertrophy, especially in athletes and individuals under 40 years of age. In older individuals RBBB is commonly caused by coronary artery disease. A complete RBBB commonly occurs after surgical closure of a ventricular septal defect.
