[The characteristics of the inotropic effects of Levosimendan on the isolated myocardium of patients with ischemic heart disease].
Effect of the new cardiotonic agent levosimendan on the inotropic response parameters of the isolated myocardium of patients suffering from ischemic heart disease (IHD) was studied in the 0.01-1.00 mumole/liter concentration range. The inotropic response was measured in an isometric mode (electric stimulation frequency, 0.5 Hz; temperature, 37 degrees C; perfusion rate, 10 ml/min). In the range of 0.01-0.1 mumole/liter, levosimendan preferentially increases the rate of stress growth (+dP/dt) and the relaxation time. At concentrations above 0.1 mumole/liter, levosimendan produces a pronounced increase (56%) in the amplitude of single contraction. The mechanogram exhibits the signs of Ca-overload, including the post-contraction wave. It is concluded that the inotropic action of levosimendan on the isolated myocardium of IHD patients is related predominantly to increasing calcium uptake from outside. This circumstance is apparently caused by the initially high calcium content in sarcoplasmic reticulum, which is an important feature of the entire intracellular homeostasis in cardiomyocytes during IHD.
Afanas'ev
S A
SA
Department of Experimental Cardiology, Tomsk Scientific Center, Siberian Division, Russian Academy of Medical Sciences, Russia.
Timofeev
V Iu
VIu
D000328:Adult; D002316:Cardiotonic Agents / Q000494:pharmacology*; D002908:Chronic Disease; D004305:Dose-Response Relationship, Drug; D006321:Heart / Q000187:drug effects* / Q000503:physiopathology; D006325:Heart Atria / Q000187:drug effects / Q000503:physiopathology; D006801:Humans; D006835:Hydrazones / Q000494:pharmacology*; D066298:In Vitro Techniques; D008297:Male; D008875:Middle Aged; D009200:Myocardial Contraction / Q000187:drug effects*; D017202:Myocardial Ischemia / Q000503:physiopathology*; D011724:Pyridazines / Q000494:pharmacology*; D000077464:Simendan; D018709:Statistics, Nonparametric; D013268:Stimulation, Chemical
D002316:Cardiotonic Agents; D006835:Hydrazones; D011724:Pyridazines; D000077464:Simendan