Absence of the right superior caval vein associated with disease of the sinus node.

Absence of the right superior caval vein has been shown by postmortem studies of infants and children to be associated with histological abnormalities of the sinus node. We report the case of a 32-yr-old man who presented with syncope due to disease of the sinus node and was found to have absence of the right superior caval vein. He was successfully managed with implantation of an epicardial atrioventricular sequential pacemaker.