Effects of exercise training on ventricular function in patients with recent myocardial infarction.

Abstract

SUMMARY We evaluated the effects of 6 months of exercise training (bicycle ergometry, walking and jogging) on exercise performance and ventricular function in patients with recent myocardial infarction. Fifteen patients were selected on the basis of myocardial infarction at least 6 weeks but not more than 6 months before the study and age younger than 65 years. The patients were evaluated by maximal treadmill exercise testing and radionuclide angiography at rest and exercise before and after training.Before exercise training, maximal treadmill exercise time ranged from 1.5 to 11 minutes, ejection fraction at rest from 18% to 67% and end-diastolic volume from 108 to 208 ml. The mean EF was 48 ± 5% (± SD) at rest and did not change at maximal exercise (48.5 ± 5%). All 11 patients who completed the exercise training program achieved a significant training effect, as defined by a reduction in heart rate at 50% maximal pretraining effort or an increase in maximal treadmill time. The mean ejection fraction and end-diastolic volume and wall motion abnormalities at rest and at comparable pretraining exercise work loads and heart rates were not significantly different after training.Despite a wide range of rest and exercise ventricular function, patients with recent uncomplicated myocardial infarcts significantly increased their exercise performance. Because rest and exercise ventricular function were comparable before and after training, improvement in exercise performance probably resulted from training effects on the peripheral vasculature.PATIENTS with coronary artery disease demonstrate a wide range of impaired cardiovascular adjustments during exercise.' Although exercise performance in certain patients with coronary artery disease may not be different from that in age-matched normal subjects, most patients have lower maximal cardiac output and maximal oxygen consumption,lA a decreased heart rate response to exercise and a decreased stroke volume at submaximal work loads. 1-' During mild supine exercise, left ventricular filling pressures are often elevated$'0 and systolic ejection rate and the rate of rise of pressure at a given ventricular pressure are reduced."1-3 Noninvasive evaluation of ventricular function using radionuclide angiography has shown that the left ventricular ejection fraction frequently decreases and regional wall motion abnormalities appear during exercise in patients with coronary disease.I-'7 These findings indicate that left ventricular dysfunction commonly occurs in patients with coronary artery disease during exercise stress.Exercise training improves exercise tolerance in most patients with coronary disease.2' 5, 18-22 Clausen' summarized the central and peripheral effects of exercise training and pointed out that the effects are qualitatively similar in subjects with and without coronary artery disease. In patients with coronary disease and no chest pain, training may improve maximal exercise

Influence of Aerobic Exercise Training on Brain Natriuretic Peptide Secretion in Patients in the Chronic Phase of Myocardial Infarction

“…26 Cobb et al reported that left ventricular function at rest and during exercise revealed no significant change after exercise training, though improvement in exercise performance was observed. 27 We found that the plasma BNP level of the training group with anterior MI did not tend to decrease over the study period while that of the nontraining group with anterior MI decreased significantly.…”

Effects of Rehabilitation in Patients with Cardiac Disease

“…Peripheral adaptations similar to those seen in healthy subjects are thought to occur in this patient group (Clausen 1976;Detty et ale 1971), although there is some debate concerning the presence of central changes (Cobb et al 1982;Ehsani 1987;Franklin et ale 1992;Hagberg 1991;Hung et al 1984). The latter may be partially attributable to the different methods used to determine changes in stroke volume.…”

Evaluation of changes in perfusion defect and left ventricular systolic function using Tc-99m Tetrofosmin single photon emission computed tomography over 3 month period in patients of Acute Myocardial Infarction undergoing primary angioplasty

“…The perfusion in the distribution of dilated artery has been shown to improve progressively until 3 months [4]. Many authors have not found any difference in LV ejection fraction values in the third and sixth month following AMI [5][6][7]. This makes us hypothesize that majority of the improvement occurs in the first 3-4 months.…”