Comparison of the inotropic action of digitalis and isoproterenol in younger and older individuals.
The positive inotropic effects of digitalis (deslanoside C, 1.2 mg. intravenously) and isoproterenol (2 microgram/minute intravenously) were compared in two groups of younger and older individuals using the systolic time interval method. Both groups responded in a completely comparable way to deslanoside C. However, after isoproterenol administration, the LVET of the older group was significantly shortened. Consequently, the PEP/LVET ratio did not change significantly. This difference is attributed to a lesser increase of the stroke volume in the older group.
D000293:Adolescent; D000328:Adult; D000368:Aged; D000375:Aging; D004071:Digitalis Glycosides / Q000627:therapeutic use*; D004562:Electrocardiography; D005260:Female; D006801:Humans; D007545:Isoproterenol / Q000627:therapeutic use*; D008297:Male; D008875:Middle Aged; D009200:Myocardial Contraction / Q000187:drug effects*
D004071:Digitalis Glycosides; D007545:Isoproterenol