Hemodynamic changes in response to exercise training in patients with coronary artery disease

Abstract

The specific contributions of cardiac output (Q), stroke volume (SV), and arterio-venous oxygen (AVO(,2)) difference to improve functional capacity in patients with coronary artery disease (CAD) were determined in nine male subjects (age = 36 to 53 years) prior to and following a standard 12-week cardiac rehabilitation exercise training program. Cardiac output, SV and AVO(,2) difference were determined at approximately 85% of maximum heart rate (HR) using Collier's CO(,2) rebreathing technique. Maximal and submaximal ((TURNEQ) 85% HR) values for VO(,2) were also determined, using standard open circuit techniques. The mean value for VO(,2) max increased 15% from 25.6 ml/kg/min prior to training to 29.45 ml/kg/min post-training. Hotellings T('2) multivariate test for paired observations was applied to test the hypothesis that no differences would exist between pre- and post-training Q, SV, AVO(,2) difference and VO(,2). It appears that the exercise program had no significant effect on the variables (p > .05). Mean changes in Q and SV were small ((TURNEQ) 1% increase) while the change in AVO(,2) difference showed a 9.7% (1.42 ml/100 ml) improvement. These data support the theory that the major physiological response to training in CAD patients is a widening of the AVO(,2) difference.