TY - JOUR
T1 - Changes in left ventricular function during recovery from upright bicycle exercise in normal persons and patients with coronary artery disease
AU - Plotnick, Gary D.
AU - Becker, Lewis C.
AU - Fisher, Michael L.
N1 - Funding Information:
From the Divisions of Cardiology, Veterans Administration Medical Center, University of Maryland School of Medicine, and the Johns Hopkins Medical Institutions, Baltimore, Maryland. This study was supported by the Veterans Administration, Washington, DC. Manuscript received October 30,1985; revised manuscript received March 4.1986, accepted March 21,1986.
Copyright:
Copyright 2014 Elsevier B.V., All rights reserved.
PY - 1986/8/1
Y1 - 1986/8/1
N2 - To characterize the hemodynamic changes during recovery after upright bicycle exercise, 56 normal subjects (group I) and 30 patients with documented myocardial ischemia (group II) were studied. Heart rate, blood pressure and radionuclide angiographically determined absolute left ventricular (LV) volumes were measured at baseline, peak exercise and 2 to 4.5 minutes and 4.5 to 7 minutes after upright bicycle exercise. Whereas ejection fraction and end-systolic volume responses at peak exercise differed between groups I and II, these parameters showed similar trends in both groups during recovery. Mean ejection fraction increased during 2 to 4.5 minutes in both groups, but remained elevated during 4.5 to 7 minutes only in normal subjects (group I)- Elevation of cardiac output after exercise was accounted for predominantly by increased heart rate rather than increased stroke volume. Despite significantly decreased end-diastolic volume during recovery, stroke volume was maintained in both groups by a substantial decrease in end-systolic volume, suggesting the impact of decreased afterload or increased sympathetic tone during recovery. Thus, the Frank-Starling mechanism does not appear to be playing a major role during recovery after upright bicycle exercise, whereas enhanced contractility is evident in both normal subjects and patients with documented myocardial ischemia.
AB - To characterize the hemodynamic changes during recovery after upright bicycle exercise, 56 normal subjects (group I) and 30 patients with documented myocardial ischemia (group II) were studied. Heart rate, blood pressure and radionuclide angiographically determined absolute left ventricular (LV) volumes were measured at baseline, peak exercise and 2 to 4.5 minutes and 4.5 to 7 minutes after upright bicycle exercise. Whereas ejection fraction and end-systolic volume responses at peak exercise differed between groups I and II, these parameters showed similar trends in both groups during recovery. Mean ejection fraction increased during 2 to 4.5 minutes in both groups, but remained elevated during 4.5 to 7 minutes only in normal subjects (group I)- Elevation of cardiac output after exercise was accounted for predominantly by increased heart rate rather than increased stroke volume. Despite significantly decreased end-diastolic volume during recovery, stroke volume was maintained in both groups by a substantial decrease in end-systolic volume, suggesting the impact of decreased afterload or increased sympathetic tone during recovery. Thus, the Frank-Starling mechanism does not appear to be playing a major role during recovery after upright bicycle exercise, whereas enhanced contractility is evident in both normal subjects and patients with documented myocardial ischemia.
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U2 - 10.1016/0002-9149(86)90056-1
DO - 10.1016/0002-9149(86)90056-1
M3 - Article
C2 - 3739912
AN - SCOPUS:0022525018
VL - 58
SP - 247
EP - 251
JO - American Journal of Cardiology
JF - American Journal of Cardiology
SN - 0002-9149
IS - 3
ER -