Evaluation of effects of aging, training and myocardial ischemia on cardiac reserve by exercise echocardiography.
Exercise tolerance and heart response were examined by cross-sectional echocardiography before and during exercise tests to assess the effects of aging, training and myocardial ischemia on the cardiac reserve of 40 healthy men, 20 athletes and 25 patients with angina on effort. The cardiac response to exercise can be divided into 4 types according to parameters derived from a short axis section echocardiogram. Type A: The left ventricular end-diastolic volume (LVEDV) increased slightly in the early stage of exercise, and thereafter, the cardiac response was maintained by a gradual increase of myocardial contractility and heart rate. Type B: Initial response to exercise was similar to Type A, but cardiac output was maintained only by an increase of heart rate under additional exercise load. Type C: LVEDV, LVESV (left ventricular end-systolic volume) and contractility remained virtually unchanged throughout the exercise. Type D: The contractility decreased from the early stage of the exercise, and LVEDV and LVESV increased. Most young subjects and all athletes showed Type A response, while in the aged healthy subjects the Type B response was more frequent. Anginal cases tolerating 125-watt load responded as Type B or C, and those tolerating only 75 watts showed Type C or D. All patients in Type D had multi-vessel disease.
D000328:Adult; D000368:Aged; D000375:Aging; D000787:Angina Pectoris / Q000503:physiopathology; D003327:Coronary Disease / Q000503:physiopathology*; D004452:Echocardiography / Q000379:methods; D005080:Exercise Test; D005260:Female; D006321:Heart / Q000503:physiopathology*; D006801:Humans; D008297:Male; D008875:Middle Aged; D005082:Physical Exertion; D013599:Systole