[Instantaneous alteration of the dog heart contractility under instantaneous change in the stimulation rhythm].
Isolated canine heart has an expressed ability for an instantaneous alteration in the sense of re-tuning, of contractility (of the speed of mechanical restitution in diastolic period) under instantaneous change of stimulation rhythm. Postextrasystolic potentiation reflects instantaneous rising of the speed of mechanical restitution under the influence of extrasystole in the condition of instantaneous transition to a higher rhythm. Depression of contractility reflects instantaneous decreasing of the speed of mechanical restitution under the influence of delayed stimulus in the condition of instantaneous transition to a slower rhythm. Alteration (re-tuning) of heart contractility occurred irrespective of the influence of neurohumoral factor and Frank-Starling law on the work of the heart. Alteration (re-tuning) of contractility occurs at an organ (cell) level.
Gur'ianov
M I
MI
Tobolsk Biological Research Station, Severtsov Institute of Ecology and Evolution, Russian Acad. Sci., 626150, Tobolsk, 15 Voikov St., Russia.
D000818:Animals; D005117:Cardiac Complexes, Premature / Q000503:physiopathology; D003971:Diastole; D004285:Dogs; D004558:Electric Stimulation; D006339:Heart Rate; D009200:Myocardial Contraction
Mgnovennaia perestroĭka sokratimosti serdtsa sobak pri mgnovennom perekhode na novyĭ ritm.