Myocardial contractile function following cardiac surgery often requires inotropic support. Traditionally, phosphodiesterase inhibitors and catecholamines are used [ 1 , 2 ]. Levosimendan is a novel inotropic agent–calcium sensitizer that enhances myocardial contractility without increasing intracellular calcium and myocardial oxygen demand [ 3 ]. The aim of our study was to evaluate circulation following levosimendan infusion, to find out the efficiency of tissue oxygen supply and to evaluate other inotrope dosage rates during levosimendan infusion.