Left ventricular diastolic filling and cardiovascular functional capacity in older men.
We investigated anaerobic threshold (< theta(L)) gas exchange kinetics and maximal oxygen uptake (VO2,max) among older men with reduced left ventricular end-diastolic filling (LVDF). Ten men (mean age, 73 years) with LVDF impairment and low fitness, but without other cardiovascular dysfunction were studied. Treatments compared to control included: 5 days, high intensity exercise training protocol; 5 days, calcium channel blockade (240 mg verapamil); 21 days, detraining/washout; and 5 days, combined treatments. Results indicated no changes in resting left ventricular systolic function with any treatment. Significant resting diastolic function changes included increased early:late flow velocity (control, 0.87; training, 1.28; verapamil, 1.32), and a decreased isovolumic relaxation time (control, 0.10 s; training, 0.08 s; verapamil, 0.08 s). The combined treatments were not additive. Sub-threshold oxygen uptake kinetics (tauVO2, s) were significantly faster following either training or verapamil (tauVO2,control, 62+/-12; tauVO2,training, 44+/-9; tauVO2,verapamil, 48+/-10) and combined treatments (tauVO2, 41+/- 8). V O2,max (ml kg(-1) min(-1)) was significantly increased (control, 21.8+/-2.2; training, 27.3+/-2.2; verapamil, 25.2+/-3.4; combined treatments, 26.9+/-2.3). Increasing ventricular preload with either exercise training or calcium channel blockade was coincident with faster tauVO2 and increased VO2,max.
Petrella
R J
RJ
Departments ofFamily Medicine, Physical Medicine and Rehabilitation, Physiology and School of Kinesiology, The University of Western Ontario, London, Ontario, Canada N6A 5C1.
Cunningham
D A
DA
Paterson
D H
DH
D000368:Aged; D000375:Aging / Q000502:physiology*; D015308:Anaerobic Threshold / Q000502:physiology; D001783:Blood Flow Velocity / Q000187:drug effects; D001794:Blood Pressure / Q000187:drug effects; D002121:Calcium Channel Blockers / Q000494:pharmacology; D015444:Exercise / Q000502:physiology*; D006339:Heart Rate / Q000187:drug effects; D006801:Humans; D008297:Male; D010100:Oxygen / Q000097:blood / Q000378:metabolism; D010953:Plasma Volume / Q000187:drug effects; D016277:Ventricular Function, Left / Q000187:drug effects* / Q000502:physiology*; D014700:Verapamil / Q000494:pharmacology*
D002121:Calcium Channel Blockers; D014700:Verapamil; D010100:Oxygen