[Mechanism of postextrasystolic potentiation of the myocardium].
Combined effects of poststimulation and postextrasystolic potentiation (PESP) were studied in the rat papillary muscles. The constant PESP augmentation of isometric force triggered by extrasystolic stimulus was shown for 2-8 poststimulatory potentiated contractions. The PESP was not dependent upon the Ca2+ concentration within the 0.5-1.2 mM range. The findings corroborate the postulate that the PESP in cardiomyocytes is associated with special Ca2+ store which is triggered by two APs: regular and extrasystolic ones.
D000818:Animals; D005117:Cardiac Complexes, Premature / Q000503:physiopathology*; D004558:Electric Stimulation; D006339:Heart Rate; D066298:In Vitro Techniques; D009200:Myocardial Contraction; D051381:Rats
K mekhanizmu postékstrasistolicheskoĭ potentsiatsii v serdechnoĭ myshtse.