Anomalous Origin of Left Coronary Artery from the Pulmonary Artery (ALCAPA)
In this condition, the left coronary comes off the pulmonary artery, while
the right continues to come off normally from the anterior aortic sinus.
In the fetus , myocardial perfusion is normal.
Soon after birth, however, the pulmonary artery pressure falls, perfusion pressure to the left coronary artery (LCA) becomes inadequate; myocardial ischemia, infarction, and fibrosis result.
In some cases, interarterial collateral anastomoses develop between the right coronary artery (RCA) and LCA. Blood flow in the LCA is then reversed, and it empties into the pulmonary artery, , a condition known as the “myocardial steal”.
This results in ischemia of the
(anterolateral )wall of the LV.
The left ventricle becomes dilated, and its performance is decreased. Mitral insufficiency is afrequent complication
Infants present at 2 weeks to 6 months of age with heart failure from Ml or ischemia. Poor feeding, tachypnea
and respiratory symptoms are most common, although some have episodes of restlessness/crying, as though in pain.
Cardiomegaly is prominent, ECG shows (anterolateral) infarct pattern with abnormal Q waves in I, aVL, and the left anterior chest leads (V5 and V6); additionally, ST and T wave changes often occur.
Echo is often diagnostic, but occasionally cardiac catheterization is required.
Untreated, death often occurs from heart failure within the 1st 6 mo of life.
Those who survive require reconnecting the aberrant coronary artery to the aorta.
Nelson 21, Medstudy pediatrics 2018