The impact of administration of the calcium sensitizer levosimendan on hemodynamic parameters, dose of intraoperative and postoperative cardiotonic maintenance, length of intensive care unit stay, and hospital mortality was studied in cardiosurgical patients with dilated cardiomyopathy, second-fourth degree mitral valve insufficiency, or NYHA Class IV circulatory insufficiency. Levosimendan was administered to 25 patients 3-5 days prior to surgery. A control group of 22 patients did not receive levosimendan. The use of the agent caused statistically significant reductions in pulmonary artery pressure and pulmonary wedge pressure and increases in cardiac index and left ventricular ejection fraction. The levosimedan-treated patients needed smaller doses of sjmpathomimetics, less length of intensive care unit stay and showed lower mortality rates (p < O.05 for all indices).