['To determine whether infundibular morphology is associated with coronary ostial atresia and/or right ventricle dependent coronary circulation in patients with pulmonary atresia with intact ventricular septum.', 'Neonatal echocardiograms of patients with pulmonary atresia with intact ventricular septum were evaluated for tricuspid valve size and infundibular anatomy (muscular pulmonary atresia vs. membranous pulmonary atresia). Right ventricle dependent coronary circulation and coronary ostial atresia were diagnosed angiographically. Medical record review determined patient outcome.', 'Tertiary-care pediatric hospital.', 'Of 72 patients, 24 had muscular pulmonary atresia including 23 with right ventricle dependent coronary circulation. Fourteen of these had unilateral or bilateral coronary ostial atresia. Of 46 patients with membranous pulmonary atresia, 5 five had right ventricle dependent coronary circulation and none had coronary ostial atresia. Muscular pulmonary atresia patients had smaller tricuspid valve z-scores and were less likely to achieve a biventricular repair than those with membranous pulmonary atresia (P < .01). Muscular pulmonary atresia had 82% sensitivity, 98% specificity, and 96% positive predictive value for presence of right ventricle dependent coronary circulation. In the group with membranous pulmonary atresia, there were two deaths, no transplants, and 23 (48%) achieved a biventricular repair. In contrast, of the 24 with muscular pulmonary atresia, there were seven deaths, two transplants, and no biventricular repairs.'] Is muscular infundibular atresia associated with coronary ostial atresia in pulmonary atresia with intact ventricular septum?