Competition of coronary arteries and ventriculo-coronary arterial communications in pulmonary atresia with intact ventricular septum.

Pulmonary atresia with intact ventricular septum can be complicated by the presence of large ventriculo-coronary arterial communications which disturb normal myocardial perfusion. In the selection of patients for surgery the presence of these communications provides an additional problem. On the basis of previous cineangiocardiographic study, we performed a histopathological study of 16 cases. Twelve presented with ventriculo-coronary arterial communications and four only showed myocardial sinusoids. A tripartite right ventricle was seen in the latter group but not exclusively. It is shown that subepicardial coronary arterial pathology is exclusively present in cases with ventriculo-coronary arterial communications although not solely at a connection site between a communication and an artery. The affected coronary artery is itself focally abnormal and hypoplastic and can be blocked or even absent. The interruption of such an artery can also occur after birth and not necessarily at a site of connection with a communication. This implies that infants with communications either already have a coronary circulation partly or completely dependent on ventriculo-coronary arterial communications at birth or can develop such a condition in time. This hazard to myocardial perfusion, often compromised by a large "steal" from the aorta to the right ventricle, limits the choice of surgical procedures.