Numerous adverse effects and an increased mortality are the reasons why many clinicians are often unsuccessful with the inotropic agents presently in use. New therapeutic agents have been developed in the last few years to assist the clinician in the stabilization, support and treatment of cardiovascular disease.
One of the newest groups of inotropic agents is a group of agents, which increase the affinity of myofibrils for calcium and are called calcium sensitizers. Calcium sensitizers are the newest heterogeneous group of inotropic agents. The best known representatives of this group are levosimendan and pimobendan. Positive inotropic effects of levosimendan are achieved by its binding to troponin C and calcium, thereby stabilizing the tropomyosin molecule and prolonging the duration of actinmyosin overlap without a change in the net concentration of intracellular calcium. The vasodilatory effect of levosimendan is reached through activation of ATP-dependent potassium channels. This leads to a decrease in both afterload and preload, increased coronary blood flow and a resultant anti-ischemic effect. Levosimendan is therefore categorized as an antiischemic inotropic agent. Furthermore, experiments have confirmed that levosimendan as an opener of KATP – channels in the mitochondria and the sarcolemma of myocites may have an effect on the myocardium preconditioning
Key words: levosimendan, inotropic state, preconditioning, low cardiac output syndrome