Letter to the Editor A rare case of anomalous origin of the left anterior descending artery from the pulmonary artery Hironori Hara a , Hiroshi Yamashita a, ⁎, Atsuko Nakayama a , Yumiko Hosoya a , Jiro Ando a , Katsuya Iijima b,c , Yasunobu Hirata a , Issei Komuro a a Department of Cardiovascular Medicine, Graduate School of Medicine, The University of Tokyo b Department of Geriatric Medicine, Graduate School of Medicine, The University of Tokyo c Institute of Gerontology, The University of Tokyo article info Article history: Received 24 September 2013 Accepted 21 December 2013 Available online 27 December 2013 Keywords: Coronary anomaly ALCAPA Collateral circulation Multislice computed tomographic coronary angiography Scintigraphy A 71-year-old man with a history of hypertension, aortic regurgita- tion, atrial fibrillation and chronic heart failure presented to our emer- gency department with dyspnea and chest pain. Chest X-rays showed severe pulmonary edema. His electrocardiogram revealed atrial fibrilla- tion and ST-segment depression in leads I, aVL and V3–6. In transthorac- ic echocardiography, wall motion was decreased in the anteroseptal region. After urgent hospitalization, his acute pulmonary edema was improved by non-invasive positive pressure ventilation and intrave- nous administration of diuretics and nitrates. The ST-segment change was also relieved. His creatine phosphokinase (CK) and CK-MB levels increased marginally to a peak value of 279 units/L (reference range: 55–210 units/L) and 37 units/L, respectively, indicating non-ST seg- ment elevation myocardial infarction. Four months before the admission, he had undergone coronary computed-tomographic angiography due to diffusely decreased left ventricular systolic function detected by echocardiography. Multi- detector computed-tomography showed anomalous origin of the left anterior descending artery (LAD) from the pulmonary artery (PA). The ectatic left circumflex artery (LCx) arose from the left coronary cusp and supplied dilated and tortuous collaterals to the LAD. The hypoplastic right coronary artery (RCA) arose from the right coronary cusp (Fig. 1A). No stenotic lesions were observed in the coronary arter- ies. After improvement of the congestive heart failure, invasive coronary angiography was performed in order to delineate the anatomy and coronary circulation. Collaterals from the ectatic LCx and hypoplastic RCA flowed into the LAD and then retrogradely into the main PA (Fig. 1B). In the right heart catheterization, a step-up in oxygen satura- tion was noted, from 56.9% in the right ventricle to 62% in the PA. The calculated pulmonary to systemic blood flow ratio (Qp:Qs ratio) was 1.06 and insignificant. Exercise stress myocardial perfusion scintigraphy demonstrated reversible perfusion defect in the anteroseptal region corresponding to the distribution territory of the LAD (Fig. 2). Although surgical repair was recommended, he refused the operation and instead opted for medical treatment only. His symptoms were relieved with medical treatment that consisted of calcium channel blocker, angioten- sin II receptor blocker and diuretic administration. He was followed-up as an outpatient and was asymptomatic. Anomalous origin of the left coronary artery from the pulmonary ar- tery (ALCAPA) is a rare congenital anomaly [1]. Approximately 90% of patients with ALCAPA die in the first year of life (infant type) [2]. In pa- tients with ALCAPA, adequate collateral circulation from the RCA to the LCA is mandatory for survival beyond infancy (adult type). The present case is different from typical adult type ALCAPA in that only the LAD originated from the PA and that the LCx as well as the RCA arising from the aorta supplied fair collaterals to the LAD. Therefore, the extent of ischemia might have been less severe than that in patients with the typical type of adult ALCAPA, and thus, he was able to survive for as long as 71 years old. Due to the low pulmonary vascular resistance, col- lateral flow is preferentially directed into the pulmonary vascular bed away from the left ventricular myocardium. This left-to-right shunt is known as the coronary steal phenomenon and may cause myocardial is- chemia. In the present case, non-transmural myocardial ischemia was demonstrated in exercise stress scintigraphy and may have played a sig- nificant role in the development of congestive heart failure and non-ST segment elevation myocardial infarction. The optimal treatment of cases with only LAD originating from the PA is not established, but may be surgical intervention as in cases with typical ALCAPA; construction of a two-coronary system and ligation of the origin of the anomalous LAD to abolish the coronary steal under cer- tain stress conditions [3–5]. In our case, surgery may have been the best treatment, given the stress-induced myocardial ischemia in the broad International Journal of Cardiology 172 (2014) e66–e68 ⁎ Corresponding author at: Department of Cardiovascular Medicine, Graduate School of Medicine, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-8655, Japan. Tel.: +81 3 3815 5411x37153; fax: +81 3 3814 0021. E-mail address: heartmuscle-tky@umin.ac.jp (H. Yamashita). 0167-5273/$ – see front matter © 2013 Elsevier Ireland Ltd. All rights reserved. http://dx.doi.org/10.1016/j.ijcard.2013.12.050 Contents lists available at ScienceDirect International Journal of Cardiology journal homepage: www.elsevier.com/locate/ijcard