tachycardia of 200/B/min, a ventricular gallop rhythm, and marked hepatomegaly, 6 cm below the right subcostal margin. Electrocardio- graphy revealed a large ...
Anomalous origin of the left coronary artery from the pulmonary artery: Scintigraphic diagnosis with Tc 99m lung scan Joong H. Choh, M.D., V. Srinivasan, M.D., Leon Levinsky, M.D., Daniel R. Pieroni, M.D., Robert L. Gingell, M.D., and S. Subramanian, M.D. A case of anomalous origin of the left coronary artery from the pulmonary artery is reported. The diagnosis was made on the basis of characteristic Tc 99m lung scan findings and was confirmed by subsequent angiocardiography and surgery.
Case Report A 9-week-old girl was referred to the Children's Hospital of Buff'alo because of a severe breathing problem. Her growth and development had been normal until the age of 6 weeks, wvhen her parents noted respiratory difficulty and occasional substernal retraction. She was treated for an upper respiratory infection for 3 weeks without improvement. At the age of 9 weeks, her clinical status deteriorated to include cyanosis, marked irritability, and respiratory distress. Upon arrival at the hospital, her respiratory rate was 80/min. Physical examination showed
From the Departments of Cardiology and Cardiovascular Surgery, Children's Hospital, Buffalo, New York.
Address for reprints: S. Subramanian, M.D., Chief, Division of Cardiovascular Surgery, and Professor of Surgery, State Uniiversity of New York at Buffalo, 219 Bryant Street, Buffalo, New York 14222. Cardiovascular Diseases, Bulletin of the Texas Heart Institute Volume 7 Number 4 344
December 1980
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tachycardia of 200/B/min, a ventricular gallop rhythm, and marked hepatomegaly, 6 cm below the right subcostal margin. Electrocardiography revealed a large Q wave in leads AVL, V5, and V6 (Fig. 1). The chest roentgenogram showed marked cardiomegalv with increased pulmonary vascularity (Fig. 2). The patient was digitalized and treated with intravenous furosemide. On the basis of' EKG f'indings, a diagnosis of' anomalous left coronary artery was considered, and a lung scan was performed with intravenous injection of Tc 99m macroaggregated serum albumin, which showed a heavy concentration of the isotope in the left myocardium (Fig. 3). Emergency cardiac catheterization and angiocardiographv demonstrated anomalous origin of the left coronary artery from the pulmonary artery, retrograde f'illing of the left coronary from the right coronary artery (Figs. 4 and 5), severe left ventricular dysfunction (LVEDP = 20 mm Hg) and slight nmitral regurgitation. The mean pulmonary artery pressure was 30 mm Hg, and the mean systemic arterial pressure was 50 mm Hg. Emergency surgery confirmed the diagnosis. The left coronary artery originated from the posterior aspect of' the main pulmonary artery. The left ventricle was markedly dilated and exhibited poor contractility. With the patient undergoing deep hypothermia and circulatory arrest, the left coronary artery was detached from the pulmonary artery, along with a cuff of the parent vessel. The left subclavian artery was dissected and divided at the apex of the left chest. The distal end of the left subclavian artery was
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anastomosed to the detached left coronary artery in end-to-end fashion. Unfortunately, the patient could not be weaned from cardiopulmonary bypass because of severe low cardiac output, and she expired on the operating table.
Discussion Anomalous origin of the left coronary artery from the pulmonary artery is an uncommon congenital cardiac anomaly with an incidence of 0.26% to 0.46% 1,2 among all congenital heart defects. Because of early myocardial infarction and severe heart failure, the prognosis is poor. A mortality of 80% to 85% during infancy has been reported. 1,2 Successful surgical management of this anomaly has been discussed in the current literature,3-6 but it is crucial to detect these infants before they develop irreversible myocardial damage. 347
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coronary system, which empties into the pulmonary artery.
Sfakianakis and colleagues7 have described the characteristic lung scan, which shows localized isotope uptake by the left ventricular myocardium in addition to visualization of both lungs. Our experience confirms these findings and suggests that the relatively noninvasive technique of Tc 99m lung scanning provides an important diagnostic tool even before cardiac catheterization. Note that in cases of atrial or ventricular right to left shunting, the myocardium is visualized, along with the kidneys, brain, and liver; in patients with this anomaly, however, the latter organs do not show any uptake. In our patient, cardiac catheterization showed retrograde filling of the left coronary artery from the right coronary artery despite the lung scan findings, which suggested blood flow from the pulmonary artery to the left coronary artery. This discrepancy is probably due to bidirectional flow in the coronary system or incomplete development of 348
collateral circulation.8 Nadas and co-workers9 describe three phases of coronary arterial blood flow in the anomalous coronary artery: (1) The first phase, which is seen in the newborn infant, is one of antegrade flow from a high-pressure pulmonary artery. (2) The second phase is transitional-it occurs before complete collateralization, when blood flow in the anomalous left coronary artery may be bidirectional. (3) The third phase occurs after collaterals have developed from branches of the right coronary artery; this phase exhibits retrograde flow that drains into a low-pressure pulmonary artery. In our patient, the blood flow was undergoing the transitional second phase, when the myocardium was especially at risk. On the basis of our experience, we suggest that lung scanning may be a useful initial noninvasive diagnostic procedure in infants with electrocardiographic findings of myocardial ischemia and other evidence of an anomalous left coronary artery.
References 1. Wesselhoeft H, Fawcett JS, Johnson AL: Anomalous origin of the left coronary artery from the pulmonary trunk: Its clinical spectrum, pathology, pathophysiology, based on a review of 140 cases with seven further cases. Circulation 38:403, 1968 2. Askenazi J, Nadas AS: Anomalous left coronary artery originating from the pulmonary artery: A report of 15 cases. Circulation 51:976, 1975 3. Grace RR, Angelini P, Coolev DA: Aortic implantation of anomalous left coronary artery arising from the pulmonary artery. Am J Cardiol 39:608,
1977 4. Suzuki Y, Horiuchi T, Ishizawa E Jr, Sato T, Fukuda M, Kakihata H: Subclavian-coronary arterv anastomosis in infants for the Bland-WhiteGarland syndrome: A two-year angiographic follow-up. Ann Thorac Surg
25:377, 1978 5. Neches WH, Mathews RA, Park S, Lexon CC, Zuberbuhler JR, Siewers R, Bahnson HT: Anomalous origin of the left coronary artery f'rom the pulmonary artery. Circulation 50:582, 1974 6. Venugopal P, Subramanian S: Anomalous origin of the left coronary artery from the pulmonary artery. Ann Thorac Surg 19:451, 1975 7. Sfakianakis GN, Damoulaki-Sfakianaki E, McClead RE, Craenen J: Anomalous origin of the left coronary arterv. Diagnosis by a lung scan. New Eng J Med 296:675, 1977 8. Edwards JE: Editorial: The direction of blood flow in coronary arteries arising from the pulmonary trunk. Circulation 29:163, 1964 9. Nadas AS, Gamboa R, Hugenholtz PG: Anomalous left coronary artery originating from the pulmonary artery. Report of two surgically treated cases with a proposal of hemodynamic and therapeutic classification. Circulation 29:167, 1964
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