Diagnosis of Anomalous Origin of the Left Coronary Artery from the Pulmonary Artery with Echocardiography and Digital Subtraction Angiography

Anomalous origin of the left coronary artery from the pulmonary artery (ALCAPA) is a common coronary artery anomaly associated with high mortality and may lead to sudden death if left unrecognized and untreated. This report describes an 8-year-old female who had cardiac murmur but with no clinical symptoms. Electrocardiogram (ECG) was normal, but echocardiography made the diagnosis of ALCAPA. Digital subtraction angiography (DSA) with cardiac catheterization angiography (CAG) confirmed the diagnosis, and finally, the patient received surgery. This case demonstrates that echocardiography is a sensitive and convenient technique for establishing the initial diagnosis of ALCAPA in both symptomatic and asymptomatic patients.


Introduction
ALCAPA is a rare congenital cardiovascular malformation in which the left coronary artery originates from the pulmonary artery (PA) instead of the left coronary sinus [1]. e incidence is 1 in 300,000 live births and accounts for 0.25% to 0.5% of congenital heart disease cases. ALCAPA results in mortality as high as 90% in the rst year of life if the patient is not treated in a timely fashion [2]. Here, we present a case of a female patient diagnosed with ALCAPA. e patient's medical records, such as clinical symptoms, electrocardiogram (ECG), echocardiography, and cardiac catheterization angiography (CAG) images, were analyzed retrospectively. year-old Chinese female with a cardiac murmur was initially diagnosed as having a ventricular septal defect (VSD) in the local hospital. She was asymptomatic, had no di culty breathing, and displayed neither increased diaphoresis nor cyanosis, but she developed upper respiratory infections more often than her peers and had reduced exercise capacity compared to her peers. On physical examination, she had the following vital measurements: 24 kg weight, 121 cm height, blood pressure 115/51 mm·Hg, heart rate 92/min, respiratory rate of 22/min, and transcutaneous oxygen saturation (SpO 2 ) 96%. e results of physical examination were normal when compared with the same age of females within same race. On cardiac examination, her pulse and S1 and S2 were normal, but she had a grade 2/6 holosystolic murmur at the second left intercostal space.

Case Report
ECG displayed normal sinus rhythm and no signs of myocardial ischemia. Chest X-ray revealed an enlarged cardiac silhouette. Echocardiography demonstrated ALCAPA, right coronary artery to right ventriclar stula, right coronary artery aneurysm, collateral coronary circulation formation, severe mitral regurgitation (MR), left ventricular ejection fraction (LVEF) of 61%, and left ventricular fractional shortening (LVFS) of 33% ( Figure 1).
Subsequently, cardiac catheterization and left ventricular angiography demonstrated a dilated right coronary artery (RCA) and with delayed lling of a dilated left coronary artery (LCA).
ere was no shunt across the interventricular septum. en, aortic root angiography showed the dilated RCA originating from the right coronary cusp (RCC), and delayed enhanced-imaging demonstrated the LCA lling via extensive intercoronary collateral circulation. Finally, PA angiography showed immediate lling of the LCA, which originated from the PA; then abundant collateral circulation and delayed RCA were imaged (Figure 2), con rming the diagnosis of ALCAPA. e patient underwent direct reimplantation of the abnormal LCA into the aorta with general anesthesia under extracorporeal circulation through a median sternotomy. During the procedure, origin of the LCA from the PA trunk, a dilated and tortuous RCA from the RCC, extensive intercoronary collaterals, and anterior mitral valve prolapse were con rmed ( Figure 3). Postoperative bedside echocardiography showed LCA connected to aorta sinus, bilateral coronary artery aneurysms (Figure 4), and moderate-to-severe MR with LVEF of 71%, LVFS of 39%. e chest was closed on postoperative day 2, and the patient was discharged on postoperative day 11 with an uneventful recovery. Postoperative chest X-ray showed in ammation and exudation in the lung and mild cardiomegaly. We followed the patient on the rst month (bilateral coronary artery aneurysms and moderate MR with LVEF of 61%, LVFS of 32%), sixth month (right coronary artery aneurysms/dilated left coronary artery and mild-to-moderate MR with LVEF of 65%, LVFS of 35%), and rst year (bilateral dilated coronary arteries and mild MR with LVEF of 67%, LVFS of 34%) after the surgery by echocardiography ( Figure 5), and the patient showed good functional recovery.

Discussion
ALCAPA is also named Bland-White-Garland syndrome. Clinically, ALCAPA has been divided into adult and infant types according to intercoronary collateral circulation extent. Infant type usually survives only a few months for the reason of myocardial ischemia and heart failure, and only about 10% to 15% of patients survive to adolescence or adulthood [3]. On the other hand, extensive intercoronary collateral circulation usually exists in adult type, forming the "left to right shunt" and "coronary artery steal blood" phenomenon, which could induce to abnormal perfusion of myocardium and sudden death [4]. Our case was de ned as the adult type, with relatively abundant collateral circulation and minimal symptoms and a heart murmur. e incidence of adult type of ALCAPA is very low and often be asymptomatic, so it is usually being misdiagnosed, especially when ECG shows no obvious ST-T change and V waves. Echocardiography is usually the initial diagnostic tool; when the echocardiographer found the imaging feature of the dilation and dysfunction of left ventricular with severe mitral regurgitation, abnormal ow-pattern in the ventricular septum and dilatation of the right coronary artery, and the wide enhancement and thickening of the endocardium, the echocardiographer should not only pay attention to idiopathic endocardial broelastosis (EFE) [5] and/or idiopathic dilated cardiomyopathy (DCM) [6] but also should check the origination of the coronary arteries to avoid being misdiagnosed. e typical and direct echocardiographic imaging feature is to show the LCA originating from the pulmonary artery when diagnosing ALCAPA and should also reveal the origin, size, and course of coronary arteries clearly. In addition, the reversal of blood ow in the left coronary artery and abundant collateral circulation are approval to the diagnosis of ALCAPA. Visibly, echocardiography is an indispensable diagnostic tool because of its noninvasive repeatability, low cost, and ability to clearly show the origin of the coronary artery. It can not only determine real-time hemodynamic change, but also can measure heart function in subclinical stage and postoperative follow-up, including the index of heart, resilience, myocardial wall motion, and strain rate [7]. e patient reported in this report was misdiagnosed as having a VSD in the local hospital mainly due to two reasons: rst and most importantly, the stula in the ventricular septum was diagnosed as a VSD; second, the echocardiographer may not have comprehensive knowledge of ALCAPA.
However, DSA with CAG is considered as the gold standard diagnosis of ALCAPA. e use of the contrast agent in severe infant patients remains controversial with regard to ionization radiation and potential allergic reaction [8]. Magnetic resonance angiography (MRA) and computed tomography angiography (CTA) have been increasingly employed for the diagnosis of ALCAPA. CTA is a noninvasive imaging technique with good density and spatial resolution, which has certain advantages to evaluate small blood vessels such as the coronary artery, but it cannot evaluate an intravascular blood ow condition. MRA can be used to diagnose postoperative left ventricular morphology and function in patients with suspected myocardial ischemia; its image quality can be easily in uenced by heart rate.

Conclusion
ALCAPA is a rare congenital heart disease that carries a high mortality rate and may lead to sudden death if left untreated. Typical echocardiographic features and comprehension of ALCAPA are helpful for diagnosis and di erential diagnosis. e echocardiography can diagnose ALCAPA accurately and give su cient information for heart function and operation.

Conflicts of Interest
e authors declare that they have no con icts of interest.