An 8 1/2-month-old female, the product of a normal pregnancy and delivery, presented to her private physician with a 3-day history of coughing, wheezing, nasal congestion, and diaphoresis. Vital signs were a heart rate of 170 beats/min, a respiratory rate of 50 breaths/min, a temperature of 100.8°F, a blood pressure of 60/40 mm Hg, and a weight of 6.51 Kg (fifth percentile for age). She appeared seriously ill with respiratory distress, dusky mucus membranes, a sweaty forehead, bilateral otitis media, and cardiomegaly by palpation. Laboratory data indicated a hematocrit of 33%, a hemoglobin of 10.5 g/dL, and a white blood cell count of 8,400/mm ³ with 66% lymphocytes, 20% neutrophils, and no bands.

The electrocardiogram (ECG) showed sinus tachycardia (166 beats/min), left atrial enlargement as manifested by large negative terminal P-wave forces in lead V ₁ , and broad, deep S waves in leads V ₂ to V ₄ suggestive of left ventricular hypertrophy (LVH). Abnormal Q waves in leads I, aVL, and V ₃ to V ₆ with ST elevation in leads I, V ₅ , and V ₆ and T-wave inversion in leads I, aVL, and V ₆ indicated anterolateral myocardial infarction ( Figure 1 ). This ECG in an infant strongly suggests anomalous left coronary artery arising from the pulmonary trunk.

ECG of an 8 1/2-month-old female on admission to hospital. See text for discussion.

An echocardiogram (M-mode and 2D) revealed a markedly dilated left ventricle with an ejection fraction of 25% to 30% and mild mitral regurgitation. The left coronary artery was visualized by 2D and originated from the pulmonary trunk.

Digitalis and diuretics effected modest improvement, and then through a median sternotomy, the origin of the left coronary artery was translocated from the pulmonary trunk to the ascending aorta. Unfortunately, owing to poor left ventricular (LV) function, the infant could not be weaned from cardiopulmonary bypass.

Necropsy revealed a heart weight of 133 g (expected, 41 g), a 7 cm × 5 cm anteroseptal infarct, and marked LV dilatation with aneurysm formation.

Anomalous origin of the left coronary artery from the pulmonary trunk is generally considered the most common clinically relevant congenital coronary arterial malformation. In utero high pulmonary arterial pressure results in anterograde left coronary arterial blood flow. Because soon after birth pressure in the pulmonary artery falls considerably below that in the aorta and its branches, the blood in the left coronary arterial system, which gets there through collaterals from the right coronary artery, for the most part flows retrogradely into the pulmonary trunk, that is, is stolen from the LV myocardium. This was suggested at necropsy as early as 1885 and has been documented by radioisotopic study. Because of their excellent clinical and first electrocardiographic description in this condition, it is often referred to as the Bland-White-Garland syndrome.

Infants with this malformation often appear to be normal for the first few months of life but then develop irritability, especially with feeding, similar to infantile colic. This is soon followed by dyspnea, wheezing, pallor, sweating, and growth retardation. Only some 20% survive the first year, and death may be sudden. A few live to adulthood and present with dyspnea, chest pain, syncope, ventricular dysrhythmias, mitral regurgitation, or cardiomyopathy with cardiac failure. A rare patient survives ≥60 years. Patients with the less common congenital malformation of origin of the right coronary artery from the pulmonary trunk are more likely to reach adulthood, probably because the right coronary artery supplies less blood to the myocardium than the left.

Because the results of medical management of anomalous origin of the left coronary artery from the pulmonary trunk are abysmal, operation is virtually always necessary. Operative treatment has evolved from ligation of the anomalous artery near the pulmonary trunk, which eliminates the steal, to ligation plus saphenous vein bypass grafting from aorta to the anomalous artery near the heart, which also provides anterograde coronary arterial flow, to translocation of the coronary arterial origin from the pulmonary trunk to the ascending aorta, which adds the potential for greater longevity of the corrected circulation. This last technique has become the standard.

Critical is the early recognition of anomalous left coronary artery from the pulmonary trunk before widespread infarction and adverse LV remodeling have essentially eliminated the chances of a favorable result. The history provides the first clue, and the ECG is excellent at distinguishing anomalous origin of the left coronary artery from the pulmonary trunk from myocarditis or dilated cardiomyopathy. Johnsrude et al found Q-wave depth >3 mm, Q-wave width >30 ms, and a QR pattern in at least one of the leads I, aVL, or V ₅ to V ₇ to be present in the ECGs of 100% of patients with anomalous origin of the left coronary artery from the pulmonary trunk. The absence of Q waves in II, III, and aVF was also universal. The ECG in the figure fulfills each of these criteria.