Anomalous Origin of the Left Coronary Artery

Patient 1

A 1-year-old male infant was referred to our department for evaluation of a heart murmur. He was healthy and asymptomatic with normal growth and development. Cardiac examination revealed a grade 1–2/6 mostly soft systolic murmur with a minimal diastolic component at the left sternal border. The rest of his physical examination yielded normal results. An electrocardiogram was normal. Two-dimensional and color-flow Doppler echocardiograms (Fig. 1) revealed that the infant had an anomalous left coronary artery that originated from the main pulmonary artery. The left ventricular size, wall thickness, and function were normal. At surgery, the anomalous left coronary artery was transplanted successfully from the main pulmonary artery to the aortic root. The postoperative echocardiogram revealed excellent filling of the left coronary artery from the aorta, with normal left ventricular systolic function. The electrocardiogram remained normal.

Fig. 1 Patient 1: A) An echocardiogram shows the origin of the left coronary artery arising from the main pulmonary artery. B) Color-flow Doppler echocardiogram shows the left coronary artery draining into the main pulmonary artery. Note: Unless careful attention is paid, this color flow might be mistaken for pulmonary valve regurgitation.

Patient 2

A 1-day-old asymptomatic male neonate was referred by the hospital nursery pediatrician for evaluation of a heart murmur. The infant was the product of a normal full-term pregnancy. On physical examination, the heart murmur (grade 2/6, harsh, early systolic murmur at the left lower sternal border) was consistent with a small, muscular, ventricular septal defect with a left-to-right shunt. A complete 2-dimensional Doppler echocardiogram confirmed the presence of a septal defect of this description. In addition, an anomalous origin of the left coronary artery from the main pulmonary artery (Fig. 2) was revealed. The left ventricular systolic function was normal. At surgery, the left coronary artery was transplanted from the main pulmonary artery to the aortic root with excellent results.

Fig. 2 Patient 2: Echocardiogram shows the anomalous origin of the left coronary artery (arrow) from the main pulmonary artery (PA).

Ao = aorta

Lessons to Be Learned

Generally, an infant born with an anomalous origin of the left coronary artery from the main pulmonary artery has clinical manifestations of severe congestive heart failure (mimicking dilated cardiomyopathy) as a result of myocardial infarction. Symptoms are evident at 2 to 3 months of age, when the pulmonary vascular resistance drops to normal and the left coronary artery is unable to perfuse the myocardium. In rare cases, older children present with chest pain or die suddenly on exertion.

A complete 2-dimensional Doppler echocardiogram should show the origin of both coronary arteries and the bifurcation of the left coronary artery. Early recognition and treatment of an anomalous origin of the left coronary artery before the occurrence of myocardial damage provides the patient with an excellent long-term prognosis.