Which syndrome is associated with central cyanosis in infants?

The syndrome associated with central cyanosis in infants is Eisenmenger syndrome. This condition is primarily a consequence of long-standing left-to-right shunting of blood (due to congenital heart defects like ventricular septal defect), leading to pulmonary hypertension. Over time, the increased pressure in the pulmonary circulation can cause a reversal of the shunt, resulting in right-to-left shunting of blood through the defect. When this occurs, deoxygenated blood bypasses the lungs and enters the systemic circulation, leading to cyanosis, particularly noticeable in the central areas of the body (such as the lips and trunk), which is characteristic of central cyanosis.

In contrast, conditions like atrial septal defect and ventricular septal defect generally cause left-to-right shunting in infants, which usually does not lead to central cyanosis unless significant pulmonary hypertension develops over time. Coarctation of the aorta may lead to upper body hypertension and lower body ischemia, but it typically does not cause central cyanosis. Thus, Eisenmenger syndrome distinctly links prolonged uncorrected congenital heart defects with the emerging clinical presentation of central cyanosis in infants.