Underdevelopment of the left side of the heart. may include atresia of the aortic or mitral orifice and hypoplasia of the ascending aorta. [https://orcid.org/0000-0002-0736-9199, pmid:22192721]

Hypoplastic left heart syndrome (HLHS) is a rare congenital heart defect in which the left side of the heart is severely underdeveloped and incapable of supporting the systemic circulation. It is estimated to account for 2-3% of all congenital heart disease...