Anomalous left coronary artery is a heart defect in which the left coronary artery, which usually carries blood to a large portion of the heart muscle, does not form correctly. This causes the heart to not receive enough oxygen for it to pump correctly. This heart defect is present at birth and happens during the development of the baby's heart and vessels.
Update Date 5/14/2014
Updated by: Neil K. Kaneshiro, MD, MHA, Clinical Assistant Professor of Pediatrics, University of Washington School of Medicine, Seattle, WA. Also reviewed by David Zieve, MD, MHA, Isla Ogilvie, PhD, and the A.D.A.M. Editorial team.