Hypoplastic left heart syndrome, or HLHS, is a complex congenital heart defect in which the structures on the left side of the heart, including the mitral valve, left ventricle, aortic valve, and ascending aorta, are severely underdeveloped and unable to support the body’s circulation. On fetal echocardiography, HLHS can be detected by the markedly abnormal four-chamber view showing a small, non-functional left ventricle, and by the diminutive ascending aorta visible in outflow tract views. Prenatal diagnosis is crucial because it allows for planned delivery at a center with the expertise to perform the complex series of open-heart surgeries, typically the Norwood procedure, that these infants require to survive.
Sonography Term