Coronary Arterial-Right Heart Fistulae

Abstract

Long-term follow-up is described of seven patients with fistulae between a coronary artery and the right atrium or right ventricle. Left-to-right shunt flow ranged from minimal to 2.2:1. Of six patients followed 3½ to 17 years (average 10) without operation, five demonstrated symptomatic, electrocardiographic, hemodynamic, and angiographic stability. In the sixth patient, a second angiographic study, performed 15 years after the first one, showed the right coronary artery to be occluded proximal to its fistulous communication with the right ventricle, and a left-to-right shunt could no longer be detected. Four of the seven patients underwent operative closure of a fistulous opening into the right atrium, and all four have been restudied postoperatively. Right heart pressures and the degree of dilatation of the involved coronary artery were essentially unchanged following operation. One patient, who had a moderate-sized shunt preoperatively, noted alleviation of her fatigue and demonstrated electrocardiographic improvement. Analysis of flow dynamics did not suggest that the shunt predisposed to shear-induced intimal damage of the dilated feeding coronary artery, but did suggest such changes might occur in the narrow fistulous communication. We conclude that little anatomic and functional change occurs in patients with coronary artery fistulae and small-to-moderate shunts over rather prolonged medical follow-up periods, and that operative closure does not reduce the size of the dilated proximal coronary artery. Since it is unclear whether the abnormality predisposes to premature coronary atherosclerosis, a better understanding of the natural history of the disease is necessary before the precise role of operation in patients with small-to-moderate shunts can be defined.