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Determinants of the changes in left ventricular end-diastolic volume during upright exercise in patients with
Insights
Left ventricular dilation during exercise in coronary artery disease patients is linked to smaller resting volumes and reduced ejection fraction. These factors, not disease extent, predict dilation during physical activity.
Area of Science:
- Cardiology
- Exercise Physiology
Background:
- Left ventricular (LV) end-diastolic volume (EDV) changes during exercise are crucial in assessing cardiac function.
- Understanding factors influencing LV dilation during exertion is vital for managing coronary artery disease (CAD).
Purpose of the Study:
- To investigate the relationship between resting cardiac parameters and exercise-induced LV dilation in patients with CAD.
- To identify predictors of LV dilation during symptom-limited upright exercise.
Main Methods:
- 160 CAD patients were categorized into groups based on exercise-induced LV dilation (none, mild, moderate/severe).
- Resting LV end-diastolic volume (EDV), LV ejection fraction (EF), and delta EF (change in EF with exercise) were analyzed.
- Multivariate discriminant analysis was employed to identify predictive variables.
Main Results:
- Patients with exercise-induced LV dilation exhibited smaller resting EDV and higher resting EF.
- A significant inverse correlation was observed between resting EDV and the degree of LV dilation.
- Resting EDV, resting EF, and delta EF were the strongest predictors of LV dilation during exercise.
Conclusions:
- The degree of LV dilation during upright exercise in CAD patients is primarily determined by resting cardiac characteristics.
- Age, gender, and extent of coronary artery disease do not significantly predict exercise-induced LV dilation.
- Resting EDV, resting EF, and the EF response to exercise are key determinants of LV dilation.
Abstract:
We examined the changes in left ventricular (LV) end-diastolic volume (EDV) during symptom-limited upright exercise in 160 patients with coronary artery disease. Patients were divided into three groups based on the degree of exercise-induced LV dilation: group I (n = 66) had no increase in EDV (less than 10% change), group II (n = 38) had mild increase (10% to 24%), and group III (n = 56) had moderate or severe increase (greater than or equal to 25%). The patients with exercise-induced LV dilation had smaller resting EDV (p = 0.0001), higher resting LV ejection fraction (EF) (p = 0.008), and a greater decrease in EF with exercise (delta EF) (p = 0.007). A significant correlation was found between resting EDV and the degree of LV dilation with exercise (r = -0.45, p less than 0.001), and a weaker correlation between the degree of LV dilation and delta EF (r = -0.28, p less than 0.01). Multivariate discriminant analysis of important clinical, anatomic, and exercise descriptors identified three variables that best predicted the presence or absence of LV dilation during exercise: resting EDV (F = 38.2), resting EF (F = 24.2), and delta EF (F = 21.5). Thus, the degree of LV dilation during upright exercise is not related to age, gender, and extent of coronary artery disease, but is determined by the resting EDV, the resting EF, and the EF response to exercise.