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Influence of resting left ventricular function on the left ventricular response to exercise in patients with coronary
Insights
Resting left ventricular ejection fraction (LVEF) significantly predicts how the left ventricle functions during exercise in coronary artery disease (CAD) patients. Normal resting LVEF indicates greater changes and dysfunction during exercise.
Area of Science:
- Cardiology
- Cardiovascular Physiology
- Diagnostic Imaging
Background:
- Coronary artery disease (CAD) impacts left ventricular (LV) function.
- Understanding LV response to exercise is crucial for patient management.
Purpose of the Study:
- To determine if resting left ventricular ejection fraction (LVEF) predicts hemodynamic response to exercise in CAD patients.
- To investigate factors influencing changes in LVEF during exercise.
Main Methods:
- First-pass radionuclide angiocardiography in 150 CAD patients.
- Submaximal exercise testing to assess LV response.
- Multiple linear regression analysis to identify predictors of delta LVEF.
Main Results:
- Resting LVEF was a highly significant predictor of delta LVEF (p=0.0001).
- Patients with normal resting LVEF exhibited greater decreases in LVEF and new regional dysfunction during exercise.
- Reduced resting LVEF correlated with smaller delta LVEF and less dysfunction.
Conclusions:
- Resting LVEF is a key determinant of LV functional changes during exercise in CAD.
- The degree of resting LV dysfunction influences the magnitude and direction of exercise-induced changes.
Abstract:
First-pass radionuclide angiocardiography was used to access the left ventricular response to submaximal exercise in 150 patients with coronary artery disease (CAD). To test the hypothesis that resting systolic left ventricular function as determined by left ventricular ejection fraction (LVEF) was a predictor of the hemodynamic response to exercise, the study group included patients with a wide range of resting LVEF (0.12-0.82). The influences of resting LVEF, resting end-diastolic volume, the number of diseased vessels, exercise end point and exercise double product on the change in LVEF (delta LVEF) during exercise were tested using multiple linear regression analyses. Resting LVEF was a highly significant predictor of the delta LVEF (p = 0.0001). Exercise duration was not related to either the resting LVEF or the delta LVEF. For the 112 patients in whom coronary anatomy was known, resting LVEF retained its significance as a predictor of delta LVEF (p = 0.002) even after adjustment for the significance of the extent of CAD (p = 0.0007) and the exercise end point (p = 0.06). Patients with normal resting LVEF showed the most profound decreases in LVEF, the highest frequency of new regional dysfunction and the largest relative increase in end-diastolic volume during exercise. As rest LVEF decreased, the magnitude of the delta LVEF and the frequency of new regional dysfunction decreased. Therefore, left ventricular function at rest is an important determinant of the direction and magnitude of change in left ventricular function during exercise.