Abstract 13402: Left Ventricular Relaxation is a More Important Determinant of Exercise Capacity than Left Atrial Reservoir Function in Patients With Preserved Left Ventricular Ejection Fraction
Purpose: Left ventricular (LV) abnormal relaxation has been recognized as a parameter of exercise intolerance. Whereas left atrial (LA) reservoir function has been recognized as a determinant of LV stroke volume and exercise capacity. Accordingly, we investigated which of them is a prime determinant of exercise capacity in patients with preserved LV ejection fraction.
Methods: Fifty-six patients with chronic coronary artery disease who had LV ejection fraction >50% were studied. All the patients were examined echocardiography at rest before cardiopulmonary exercise testing. We obtained LV ejection fraction (LVEF), transmitral E wave velocity (E), early diastolic mitral annular velocity (e’). We also measured peak longitudinal LA strain during systole (S-LAs), a parameter of LA reservoir function, and peak LA strain rate during early diastole (SR-LAe), a parameter related to LV relaxation, using two-dimensional speckle tracking imaging at the anterior, posterior, lateral, and septal LA walls. The averaged values were used for analyses. Peak oxygen consumption during exercise was obtained by cardio-pulmonary exercise testing.
Results: The e’ and SR-LAe (surrogate markers of LV relaxation) were significantly correlated with the pVO2 (r=0.71, p<0.0001; r=0.63, p<0.0001). The S-LAs, a surrogate of LA reservoir function, was also significantly correlated with the pVO2 (r=0.58, p<0.0001). In multivariate regression analysis for the pVO2, only e’ was selected as determinant of exercise capacity (r=0.71, p<0.0001).
Conclusions: LV relaxation, not an LA reservoir function, is a prime determinant of exercise capacity in patients with chronic coronary artery disease and preserved LV ejection fraction.
- © 2013 by American Heart Association, Inc.