Pulmonary hypertension is among the causes of low cardiac output syndrome after neonatal and pediatric cardiac surgery. In the setting of transient postoperative myocardial dysfunction, even a moderate elevation of pulmonary pressure can result in heart dysfunction and circulatory collapse. Although, specific pharmacological manipulation of pulmonary vascular resistance is frequently required in the perioperative period, there is no widely standardized management. In this review, a systematic literature search of PubMed and MEDLINE databases using relevant terms was performed. All clinical trials and relevant manuscripts, along with important physiological, pharmacological, and evidence-based considerations involving the use of pulmonary vasodilators in the management of low cardiac output syndrome after cardiac surgery were reviewed. This article addresses the fifth of eight topics comprising the special issue entitled "Pharmacologic strategies with afterload reduction in low cardiac output syndrome after pediatric cardiac surgery".