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Relation between left ventricular diastolic function and exercise tolerance in patients with left ventricular
Insights
Left ventricular diastolic function, specifically exercise peak filling rate, predicts exercise tolerance in patients with left ventricular dysfunction. Patients with better exercise capacity showed a higher exercise peak filling rate.
Area of Science:
- Cardiology
- Cardiovascular Physiology
Background:
- Resting systolic function (ejection fraction) does not correlate with exercise tolerance in patients with left ventricular dysfunction.
- Left ventricular diastolic function is a potential determinant of exercise capacity in this population.
Purpose of the Study:
- To investigate the relationship between left ventricular diastolic performance and exercise tolerance.
- To identify predictors of exercise capacity in patients with left ventricular dysfunction and coronary artery disease.
Main Methods:
- Sixty-three patients with left ventricular dysfunction (ejection fraction < 50%) underwent symptom-limited bicycle ergometry.
- Left ventricular diastolic function was assessed, focusing on peak filling rate at rest and during exercise.
- Patients were stratified into groups based on exercise tolerance: normal, mild intolerance, and severe intolerance.
Main Results:
- No significant differences were observed in age, ejection fraction, or resting peak filling rate among exercise tolerance groups.
- Exercise peak filling rate was significantly higher in patients with normal exercise tolerance compared to those with intolerance (p = 0.03).
- Multivariate analysis identified exercise peak filling rate as the sole predictor of exercise tolerance (F = 6.0).
Conclusions:
- Exercise peak filling rate is a significant predictor of exercise tolerance in patients with left ventricular dysfunction.
- Diastolic function, assessed by exercise peak filling rate, plays a crucial role in determining exercise capacity in this patient group.
Abstract:
Previous studies show no correlation between resting systolic left ventricular performance assessed as the ejection fraction and exercise tolerance. This study examined the relation between left ventricular diastolic performance and exercise tolerance in 63 patients with left ventricular dysfunction (ejection fraction less than 50%) due to known or suspected coronary artery disease. The 51 men and 12 women, aged 54 +/- 8 years (mean +/- standard deviation), underwent symptom-limited upright exercise testing on a bicycle ergometer. The exercise end-points were angina (n:5), dyspnea (n:16), and fatigue (n:42). The patients were divided into three groups: group 1 (n:28) with normal exercise tolerance (9.5 +/- 2.4 minutes), group 2 (n:18) with mild exercise intolerance (5.8 +/- 0.5 minutes), and group 3 (n:17) had severe exercise intolerance (3.7 +/- 0.9 minutes). The three groups did not differ in age, ejection fraction, end-diastolic volume, exercise end-point, exercise heart rate, and left ventricular peak filling rate at rest. The exercise peak filling rate was, however, significantly higher in group 1 (p = 0.03). Stepwise multivariate discriminant analysis of important variables identified the exercise peak filling rate as the only predictor of exercise tolerance (F = 6.0). Thus, variation in exercise peak filling rate may in part explain the variability of exercise tolerance in patients with left ventricular dysfunction; patients with preserved exercise capacity have higher exercise peak filling rate than those with exercise intolerance.