Just look at that smile! π This baby underwent an open heart surgery! π±ππΌ Reason was due to a rare congenital syndrome known as Hypoplastic Left Heart Sydrome which is characterized by the underdevelopment of the left side of the heart. . . Hypoplastic left heart syndrome (HLHS) is a rare congenital heart defect in which the left side of the heart is severely underdeveloped. It may affect the left ventricle, aorta, aortic valve, or mitral valve