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.
Review Date 7/7/2020
Updated by: Thomas S. Metkus, MD, Assistant Professor of Medicine and Surgery, Johns Hopkins University School of Medicine, Baltimore, MD. Also reviewed by David Zieve, MD, MHA, Medical Director, Brenda Conaway, Editorial Director, and the A.D.A.M. Editorial team.