[Effect of the pacing interval and extrasystole on amplitude and damping of diastolic oscillations in the rabbit papillary muscle].
Diastolic mechanical oscillations of right ventricular rabbit papillary muscles investigated at 15 degrees C in the perfusion chamber were analysed using a relaxation model with 6 parameters. From this analysis follows that the first diastolic oscillation amplitude plotted against the driving interval ("interval amplitude curve" of the first diastolic oscillation) shows tow maxima thus differing from the shape of the interval strength curve of the preceding driven contraction. It is concluded that the amplitude of diastolic oscillations is less determined by the Ca-amount released from the sarcoplasmic reticulum during the action potential than by the frequency of processes which effect the Ca release and the Ca-sequestration. The damping ratio varies within the range of tested driving intervals (0.36 to 10 s). After an extrasystole damping ratio and period of diastolic oscillation are diminished compared with the values after regularly driven contractions.
D000818:Animals; D002118:Calcium / Q000494:pharmacology; D005117:Cardiac Complexes, Premature / Q000503:physiopathology; D003971:Diastole; D066298:In Vitro Techniques; D008955:Models, Cardiovascular; D009200:Myocardial Contraction; D009991:Oscillometry; D010210:Papillary Muscles / Q000502:physiology*; D010477:Perfusion; D011817:Rabbits; D013696:Temperature
D002118:Calcium
Einfluss von Treibintervall und Extrasystole auf Amplitude und Dämpfung diastolischer Oszillationen am Kaninchenpapillarmuskel.