Arterio-Atrial Shunting in Coronary Atherosclerosis

¹ Department of Medicine, University of Oklahoma Medical Center and Veterans Administration Hospital, Oklahoma City, Oklahoma

Two patients with abnormal communications between the right coronary artery and right atrium were observed during selective coronary arteriography. The arterio-atrial communication in these two patients appeared to differ from previously described fistulous communications in this location, most of which had been thought to be congenital. The patients in this study were older, the fistulous communication was smaller, and there was severe atherosclerosis of the right coronary artery. Because of these differences, it is postulated that these abnormal communications may, in fact, be a consequence of coronary atherosclerosis. Presumably, normal arteriole to atrial channels become dilated in branches of the coronary artery proximal to the site of occlusion. Whereas collateral vessels that develop at other sites in patients with coronary atherosclerosis are thought to be of functional benefit, the arterio-atrial shunts described in this report may have a detrimental effect on the patients involved.