Exercise hemodynamics 1 month, 2 months and 1 year after myocardial infarction: prognostic considerations

Sequential electrocardiographic and hemodynamic changes were studied at rest and during symptom-limited bicycle exercise in oligo-asymptomatic patients after myocardial infarction (MI). The exercise tests were performed after the acute episode on days 29 +/- 4 (E1) and 62 +/- 6 (E2) in 128 patients; on days 37 +/- 5 (E1) and 380 +/- 4 (E3) in 97 patients; on days 37 +/- 4 (E1), 72 +/- 6 (E2) and 394 +/- 30 (E3) in 44 patients. All patients underwent an intensive physical training during the second month after the MI. All groups showed a significant increase in work capacity and reduction in heart rate and rate-pressure product at similar work load (E2 and E3 vs. E1). These changes were independent from the level of exercise pulmonary wedge pressure (E-PWP). On the average a reduction of PWP was observed in more compromised patients after training, which became more marked at 1 year. At similar work load 1 year after MI the cardiac index reduced in less compromised patients (E1-PWP greater than 30 mm Hg) while it remained unchanged in patients with E1-PWP less than or equal to 30 mm Hg. Continuation or interruption of the physical training did not seem to affect the hemodynamic evolution. The incidence of ST-segment depression did not change from 1 month to 2 months and 1 year after MI, while both incidence and amount of ST-segment elevation significantly decreased and the sum of R-wave voltages in 12 lead ECG increased at 1 year. In conclusion, oligo-asymptomatic patients, trained and treated by drugs, trend to improve in the first year post-infarct.