Effects of a 1-year exercise training program on myocardial ischemia in patients after myocardial infarction

To determine the effects of exercise training on exercise-induced ischemia in patients following myocardial infarction, the experience of 13 patients with exercise-induced ST depression, who were moderate-to-high intensity trained for 1 year, has evaluated. After training, the maximum ST depression was significantly less (1.9 +/- 0.8 vs. 1.1 +/- 0.8 mm; p < 0.01), despite an increased maximal rate-pressure product (RPP; heart rate x blood pressure/100; 241.3 +/- 44 vs. 262.0 +/- 58; p < 0.01). For the onset of 0.1 mV of ST depression, we found a significant increase in RPP from 204.1 +/- 34.7 to 234.1 +/- 49.4 (p < 0.01) and also in heart rate (117.1 +/- 15.1 vs. 125.1 +/- 21.7 b.p.m.; p < 0.05), blood pressure (167.6 +/- 18 vs. 180.3 +/- 18 mm Hg; p < 0.01) and workload (93.8 +/- 17.4 vs. 121.1 +/- 23.2 W; p < 0.01). The relationship between ST depression and RPP (RPP/STmax) was favorably modified after training. The ratio RPP/STmax improved significantly from 143.6 +/- 49.4 to 209.1 +/- 69.5 (p < 0.0001). These findings support the hypothesis that a 1-year moderate-to-high training program in some patients following myocardial infarction can elicit adaptations that may well be attributed, at least in part, to an improvement in coronary blood flow.