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[Four-week training of patients with large anterior wall infarct: comparison with a randomized untrained control
R Heller1, G Blümchen, J Zurmann
1Klinik Roderbirken der LVA Rheinprovinz, Leichlingen/Rhld. 1.
Insights
This study on male patients with heart attacks found that exercise training improved work capacity but did not significantly change ejection fraction or heart volume. Cardiac output decreased at rest.
Area of Science:
- Cardiology
- Exercise Physiology
- Rehabilitation Medicine
Background:
- Patients with myocardial infarction often experience left-ventricular dysfunction.
- Cardiac rehabilitation programs aim to improve outcomes in these patients.
- The impact of specific exercise training protocols on cardiac function requires further investigation.
Purpose of the Study:
- To evaluate the effects of a 4-week exercise training program on cardiac function and exercise capacity in male patients post-myocardial infarction.
- To assess changes in left-ventricular ejection fraction, heart volume, and hemodynamic parameters.
Main Methods:
- Thirty-nine male patients with anterior myocardial infarction and left-ventricular dysfunction (ejection fraction <50%) were randomized into training and control groups.
- The training program involved 3-4 daily sessions, 5 days/week, at an intensity of up to 1 W/kg body weight (4-5 METS) for 4 weeks.
- Evaluations included echocardiography, heart volume measurements, and right-heart catheterization at rest and during exercise.
Main Results:
- No significant changes were observed in relative heart volume, end-diastolic volume, or ejection fraction.
- Work capacity significantly increased in the training group (15 W) and particularly in the subgroup with ejection fraction <30% (28 W).
- Resting cardiac output decreased by 10%, while stroke-volume index increased in patients with ejection fraction >30%.
Conclusions:
- The 4-week exercise program improved exercise capacity and certain hemodynamic parameters in post-myocardial infarction patients.
- The training did not lead to significant improvements in left-ventricular ejection fraction or heart volume.
- Further research is needed to optimize exercise protocols for cardiac rehabilitation.
Abstract:
Thirty-nine male patients (average age 50.8 years +/- 8.4 years) with a large anterior myocardial infarction (average 45.6 days +/- 10.5 days ago) and with moderate to severe left-ventricular dysfunction (RNVA EF less than 50%) participated in the study. The patients were randomly assigned to either a training group or to a control group. They were also subdivided into training/control groups (EF less than 30% and EF = 30-50%). The training program consisted of three to four sessions per day, 5 days a week, at an intensity of up to 1 W/kg body wt. (approximately 4-5 METS). The following evaluations were recorded prior to and following the 4-week training program: relative heart volume (x-ray), echocardiographic data (enddiastolic diameter, ES-distance, and shortening fraction), and exercise stress test (work capacity, heart rate). Filling pressures, cardiac outpout, and stroke volume index were calculated from right-heart catheterization (Swan-Ganz) at rest and during exercise. Results indicate that there were no significant changes in relative heart volume, end-diastolic volume, ES-distance, resting heart rate, PCP at rest, and ejection fraction during exercise as a result of the training program. Shortening fraction showed a tendency to improve (not significant). Work capacity increased by 15 W (p less than 0.05) in the training group and by 28 W (1.5 METS, p less than 0.05) in the EF less than 30% training-group as compared with the control group. Cardiac output at rest decreased by 10% (p less than 0.05). Stroke-volume index increased in the EF greater than 30% training-group, while heart rate was reduced.(ABSTRACT TRUNCATED AT 250 WORDS)