An Integrated Measure of Left Ventricular Diastolic Function Based on Relative Rates of Mitral E and A Wave Propagation

Abstract

Background and objectives: The mitral E wave propagation inside the left ventricle is slowed in patients with abnormal left ventricular (LV) relaxation with a prolongation of its transit time to the LV outflow tract (T e). On the contrary, the mitral A wave propagation is faster in those with elevated LV end-diastolic stiffness, resulting in a shortening of its transit time (T a). We hypothesized that the T e/T a ratio may serve an integrated measure of global LV diastolic function. Methods and results: The T e/T a ratio was measured with Doppler echocardiography in 94 subjects: 25 normal subjects, 38 patients with LV hypertrophy (18 with secondary LV hypertrophy and 20 with hypertrophic cardiomyopathy), and 31 patients undergoing left heart catheterization for clinical indications. The T e/T a ratio was 1.98 ± 0.61 in the normal subjects, 3.32 ± 0.93 in patients with secondary LV hypertrophy ( P < .0001 vs normal), and 3.18 ± 1.36 in patients with hypertrophic cardiomyopathy ( P = .0003 vs normal). In the invasive group the T e/T a ratio (range 0.56 to 3.60) correlated significantly with Tau ( r = 0.76, P < .0001), peak negative dP/dt ( r = -0.46, P = .01), the LV late diastolic stiffness index ( r = 0.57, P = .0013), LV pre–A wave pressure ( r = 0.46, P = .0096), LV end-diastolic pressure ( r = 0.58, P = .0007), and the amount of LV pressure rise with atrial systole ( r = 0.52, P = .0032) but not with the heart rate. Tau and LV stiffness were its sole determinants by stepwise multiple regression (R = 0.82). Conclusions: The ratio of mitral E and A wave transit times inside the LV (T e/T a ratio) is closely related to LV relaxation, its late diastolic stiffness, and filling pressures and gives valuable insights into LV diastolic performance. (J Am Soc Echocardiogr 1999;12:811-6.)