Aortic coarctation, multiple ventricular septal defects, and anomalous coronary artery arising from the right pulmonary artery

Abstract

The literature reveals no reports of a left coronary artery arising from the right pulmonary artery in association with aortic coarctation and multiple ventricular septal defects. The patient we describe here died of left myocardial infarction after palliative operation because this defect was unanticipated. Case report. The patient was admitted at the age of 12 days with a diagnosis of aortic coarctation and multiple ventricular septal defects. She had classic signs of aortic coarctation and predominantly left-sided heart failure, which responded partially to prostaglandin E1 and diuretics. Chest radiography revealed severe cardiomegaly and symmetrically plethoric lungs. The electrocardiogram showed sinus rhythm at 140 beats/min, right ventricular hypertrophy, and no signs of myocardial ischemia. Echocardiography demonstrated an aortic coarctation with long, severe hypoplasia of the arch, a large ductus arteriosus, and multiple ventricular septal defects. The left ventricle was neither hypokinetic nor hypoplastic. No coexisting mitral regurgitation was documented. There was also a left superior caval vein draining into the coronary sinus and a large ostium secundum–type atrial septal defect. The patient underwent pulmonary artery banding, division of the ductus arteriosus, and aortic coartectomy. Within 2 hours of the patient’s return to the intensive care unit, her condition deteriorated rapidly and dramatically, with a global but predominantly left-sided intractable heart failure, complete atrioventricular block, and cardiogenic shock. The postoperative electrocardiogram revealed signs of severe myocardial anterolateral ischemia and necrosis and a third-degree atrioventricular block (Fig. 1). Creatine kinase had increased to 530 U/L (normal range 15 to 100 U/L) with an MB fraction of 365 U/L (68%), representing a significant acute myocardial necrotic phenomenon. Postoperative cross-sectional echocardiography visualized a mildly dilated and severely hypokinetic left ventricle (less than 10% of shortening fraction) with severe impairment of diastolic function. The pulmonary artery banding was adequate, and there was no residual aortic coarctation. The right coronary artery was predominant, and the left coronary artery’s origin was not seen from the corresponding aortic Valsalva sinus. This raised suspicion of an anomalous left coronary artery arising from the pulmonary artery, which would provide an explanation for the myocardial infarction. Unfortunately, the child’s deteriorating condition did not allow performance of any further investigations. Despite maximum hemodynamic support and intravascular cardiac pacing with a 5F bipolar balloon pacing electrode (USCI International, BARD, C.R. Bard Ireland Ltd., Galway, Ireland), she died on the third postoperative day. Postmortem examination. The heart weighed 30 gm. There was, as expected, an abnormal left superior caval vein draining into the coronary sinus, a large ostium secundum–type atrial septal defect, and one large perimembranous and multiple muscular ventricular septal defects. The right ventricle was predominant, and the left one was small but not hypoplastic. Necrotic patches, confirmed by histologic analysis, were evident in the left anterolateral wall. The endocardium did not exhibit fibroelastosis. The aortic coarctation was well repaired, and the pulmonary banding was found to be in place. A tortuous, dilated right predominant coronary artery originated from the right aortic Valsalva sinus. The left coronary artery arose from the posterior right pulmonary artery wall immediately after the pulmonary bifurcation and followed a tortuous course over the anterior interventricular groove (Fig. 2). Discussion. Within the wide variety of left coronary anomalous origin, left coronary artery arising from the right pulmonary artery is extremely uncommon. The chief reason for this report, however, is the association of this origin with lesions producing high pulmonary flow, with consequent lack of clinical data suggesting such a diagnosis. Many factors led to misdiagnosis. First, this finding is not classically anticipated in cases of ventricular septal defects and aortic coarctation. Second, the left-to-right shunt provided normal perfusion to the aberrant coronary artery before the operation. Until palliation, this child’s left coronary blood flow was normal, and so were the left ventricular myocardial perfusion and oxygenation, because the pulmonary and aortic pressures and saturations were similar. The fall in pulmonary pressure to a low level after the pulmonary artery banding was therefore accompanied by a decline in the left coronary flow, with drops in coronary perfusion pressure and oxygen saturation leading to left ventricular ischemia and myocardial infarction. A similar physiopathologic condition related to closure of From the Department of Pediatric Cardiac Surgery, Centre Medico-Chirurgical de la Porte de Choisy, and the Department of Pediatric Cardiology, Institut de Puericulture de Paris, Paris, France.