Hypoplastic left heart syndrome is a congenital heart condition that occurs during the development of the heart in the mother's womb. During the heart's development, parts of the left side of the heart (mitral valve, left ventricle aortic valve, and aorta) do not develop completely. In patients with this condition, the left side of the heart is unable to send enough blood to the body.
Review Date 10/10/2021
Updated by: Michael A. Chen, MD, PhD, Associate Professor of Medicine, Division of Cardiology, Harborview Medical Center, University of Washington Medical School, Seattle, WA. Also reviewed by David Zieve, MD, MHA, Medical Director, Brenda Conaway, Editorial Director, and the A.D.A.M. Editorial team.