Acyanotic congenital heart defects (non blue baby lesions) may be due to obstructive lesions (stenosis) or left-to-right shunts. Lesions with left-to-right shunts include atrial septal defect, ventricular septal defect, and patent ductus arteriosus. Obstructive lesions include pulmonary stenosis, aortic stenosis, and coarctation of the aorta. These babies are “pink” and present with symptoms of congestive heart failure, which may include poor weight gain, feeding or exercise intolerance (baby sweats when he/she eats), or prolonged recovery from simple respiratory infections. These defects should be dealt with prior to the development of Eisenmenger syndrome, irreversible pulmonary vascular damage (elevated pulmonary vascular resistance), which causes a reversal of the shunt (left to right becomes right to left).
Cyanotic congenital heart defects are a series of defects where a baby may have periods of being “blue”. They share the common characteristic of causing right sided to left sided shunting of blood within the heart or lungs and include tetralogy of Fallot, Transposition of the Great Arteries, Tricuspid Atresia, Total Anomalous Pulmonary Venous Connection, Truncus Arteriosus, Hypoplastic Left Heart Syndrome, Double-Outlet Right Ventricle, Interrupted Aortic Arch, Pulmonary Atresia with or without Intact Ventricular Septum, Double-Inlet Left Ventricle, and Absent Pulmonary Valve Syndrome. (Note that most of the cyanotic heart defects start with a “T”). These children present with varying degrees of cyanosis and until the late 1940s, were all destined for early death. Dr’s Alfred Blalock and Helen Taussig and lab assistant Vivian Thomas performed the first surgery for “blue babies” in 1946 at Johns Hopkins (see below, Modified Blalock-Taussig Shunt).