Effects of different types of exercise training followed by detraining on endothelium-dependent dilation in patients with recent myocardial infarction.

BACKGROUND: In coronary artery disease, exercise training (ET) is associated with an improvement in endothelial function, but little is known about the relative effect of different types of training. The purpose of this study was to prospectively evaluate the effect of different types of ET on endothelial function in 209 patients after a first recent acute myocardial infarction. METHODS AND RESULTS: Endothelial function was evaluated before and after 4 weeks of different types of ET and after 1 month of detraining by measuring flow-mediated dilation and von Willebrand factor levels at baseline and after ET. Patients were randomized into 4 groups: group 1, aerobic ET (n=52); group 2, resistance training (n=54); group 3, resistance plus aerobic training (n=53); and group 4, no training (n=50). At baseline, flow-mediated dilation was 4.5+/-2.6% in group 1, 4.01+/-1.6% in group 2, 4.4+/-4% in group 3, and 4.3+/-2.3% in group 4 (P=NS). After ET, flow-mediated dilation increased to 9.9+/-2.5% in group 1, 10.1+/-2.6% in group 2, and 10.8+/-3% in group 3 (P<0.01 versus baseline for all groups); it also increased in group 4 but to a much lesser extent (to 5.1+/-2.5%; P<0.01 versus trained groups). The von Willebrand factor level after ET decreased by 16% (P<0.01) similarly in groups 1, 2, and 3 but remained unchanged in group 4. Detraining returned flow-mediated dilation to baseline levels (P<0.01 versus posttraining). CONCLUSIONS: In patients with recent acute myocardial infarction, ET was associated with improved endothelial function independently of the type of training, but this effect disappeared after 1 month of detraining.

The role of work simulation tests in a comprehensive cardiac rehabilitation program.

BACKGROUND: One of the goals of a comprehensive cardiac rehabilitation (CR) program is the patient's return to his or her usual activities. The aims of this paper were to implement an occupational evaluation protocol in a CR and to assess patients' hemodynamic responses and ventricular arrhythmias during work simulation tests. METHODS: After an 8-week outpatient CR, 132 patients performed work simulation, lifting (MH-L) and carrying (MH-C) tests. ECG, heart rate and blood pressure were constantly monitored. RESULTS: The comparison of physiological responses during work simulation and a standard exercise testing provided the following results: 1) maximal heart rate, blood pressure and double product values during WS and MH tests were significantly lower (p < 0.001) than those measured during exercise testing; 2) higher (p < 0.001) double product values were achieved during MH-C as compared to MH-L and work simulation; 3) arrhythmias were more frequent during MH-L as compared to exercise test (p < 0.001). The increment of double product was reached much faster during work simulation and MH tests as compared to exercise testing: according to the multivariate analysis this was a predictor of a greater incidence of arrhythmias. The incidence of arrhythmias during work simulation tests and MH was significantly higher in patients with reduced tolerance to effort, valvular replacement, arrhythmias during holter monitoring, low ejection fraction and effort silent ischaemia. CONCLUSIONS: Work simulation test provide a more personal functional assessment, complementary to the exercise testing. It appears particularly useful in patients with higher functional impairment who are at a higher risk of arrhythmias.