Anomalous origin of left coronary artery from the pulmonary artery

What it means

Left main coronary artery begins (branches off from) the pulmonary artery rather than as normal from the root of the aorta, above the left cusp of the aortic valve.

In this anomaly the function of the LMCA territory often requires extensive collateral formation from the RCA, which is often dilated. In the first month of life, physiologic pulmonary hypertension tends to preserve anterograde flow within the left coronary artery, and infants are usually asymptomatic. As pulmonary pressure drops, left-to-right shunting from the higher pressure left coronary arterial system to the lower pressure pulmonary arterial system occurs, and patients become symptomatic. Imaging findings may include markedly dilated collateral arteries and coronary veins.

Rare diseases that can present with this2

The range is how often this sign appears among people diagnosed with each disease — it is not a probability of having any of them. Many of these signs also occur in common, non-rare conditions. A sign on this page is a conversation to have with a clinician, not a conclusion.

Part of the broader category

Also called: ALCAPA · Anomalous left coronary artery from the pulmonary artery · Bland-Garland-White syndrome