Abstract: Levosimendan, a new calcium sensitizer agent, increases myocardial contractility and peripheral and coronary blood vessel vasodilation and reduces preload and afterload via increasing calcium sensitization of cardiac troponin and opening ATPsensitive potassium channels on cell membranes. Levosimendan is currently used mainly in the treatment of decompensated heart failure (HF). The guidelines both at home and abroad have classified it as Class IIa (level of evidence B) for treatment of acute HF in drug selection.