Scimitar syndrome with absence of the right pulmonary artery: a case with volume-induced, reversible, left-sided pulmonary hypertension.

An infant with scimitar syndrome, absent right pulmonary artery, and systemic blood supply to the right lung presented in severe cardiac failure. Cardiac catheterization revealed suprasystemic pressure of the left pulmonary artery and a high pulmonary vascular resistance. Right-sided pneumonectomy abolished cardiac failure and normalized both pulmonary artery pressure and resistance. Pure volume load affecting one lung--as in this case through absence of the right pulmonary artery plus additional left-to-right shunt from a systemic collateral--can lead to pulmonary hypertension. Early operative intervention can reverse this process and prevent pulmonary vascular disease.