Left atrial volume is an independent predictor of exercise capacity in patients with isolated left ventricular diastolic dysfunction

Abstract

Left atrial (LA) volume reflects left ventricular (LV) diastolic properties. The latter is an important determinant of exercise capacity in patients with normal LV systolic function. We hypothesized that LA volume predicts exercise capacity in patients with isolated LV diastolic dysfunction. Echocardiography and treadmill exercise testing were performed in 256 patients with normal LV systolic function (ejection fraction≥50%). Diastolic dysfunction was defined using standard Doppler criteria. LA volume was measured using the ellipsoid method and indexed to the body surface area. 119 patients had LV diastolic dysfunction. They had higher indexed maximum LA volume (LA Vol(max), p=0.004) and lower exercise capacity (p<0.001). Univariate predictors of exercise capacity were age, mitral E/A, E wave deceleration time, ratio of early diastolic mitral inflow velocity to early diastolic mitral annular velocity (E/Ea), and indexed LA Vol(max). On multivariate analysis, only age, mitral E/A and indexed LA Vol(max) were independent predictors of exercise capacity. Notably, the combination of LV diastolic dysfunction and enlarged LA Vol(max) predicted worse exercise intolerance. In conclusion, indexed LA volume is an independent and reliable predictor of exercise capacity in patients with isolated LV diastolic dysfunction.