Castaldi B, et al. - This inquiry was pursued to determine the potential impact of pulmonary vasodilators on pulmonary vasculature in Fontan patients. Findings of this retrospective, single-centre, non-randomised study demonstrated that in Fontan patients, attenuated pulmonary artery resistance and increased vascular compliance, pulmonary artery diameter and cardiac output were seen following treatment with pulmonary vasodilators, hence, pulmonary vasodilators may be used before the Fontan procedure in patients at high risk of Fontan procedure failure.