Rationale: Levosimendan, a calcium-sensitizer, is a relatively new inotropic drug with the benefit over conventional inotropes that it does not increase myocardial oxygen demand or lead to arrhythmias. Levosimendan has a relatively unique pharmacokinetic profile, after a 24 hour infusion its clinical effects remain for several days. This is achieved through the continuing haemodynamic effects of its active metabolites, which have a half life of approximately 80 hours compared to 1 hour of Levosimendan itself. Levosimendan has been extensively studied in adults and is used in ischemic heart disease, acute heart failure, chronic heart failure, following cardiac surgery, and in septic shock. Due to the inotropic properties and its strong pulmonary vasodilatory effect, Levosimendan could also be very useful as perioperative therapy in children with congenital heart disease, low cardiac output, or pulmonary artery hypertension.