Impact of Left Ventricular Diastolic Property on Left Atrial Function from Simultaneous Left Atrial and Ventricular Three-Dimensional Echocardiographic Volume Measurement

Abstract

Simultaneous left atrial (LA) and left ventricular (LV) 3-dimensional (3D) echocardiographic volume measurements enable the quantifying of precise LA function, by virtue of their independence on any geometric assumption and capability of measurement for net LA conduit volume. We sought to elucidate the impact of conventional Doppler LV diastolic property on LA volume and function derived from this method. Our study subjects consisted of 381 patients who underwent 3D echocardiography. From LA time-volume curve, maximum and minimum volume index (VI) and VI before atrial contraction (LAVIpre-c) were determined; subsequently, active emptying volume was calculated as LAVIpre-c- minimum LAVI. From LA and LV volume measurement, conduit volume was calculated as LV stroke VI- (maximum LAVI- minimum LAVI). LA volume increased depending on the severity of diastolic dysfunction. Compared with patients with normal diastolic function, LA booster pump function, as the contribution of active emptying volume to LV filling, was higher in those with mild diastolic dysfunction. Additionally, it gradually decreased as diastolic dysfunction was advanced from mild to moderate and moderate to severe degree (23.2 ± 15.5%, 29.5 ± 15.1%, 25.1 ± 16.2%, 14.9 ± 14.1%, respectively; p <0.001). Contrarily, conduit contribution was significantly higher in patients with severe diastolic dysfunction than in those with mild diastolic dysfunction; furthermore, conduit function tended to increase, reciprocally to booster pump function, as diastolic dysfunction grade was advanced (39.1 ± 28.8%, 36.8 ± 26.2%, 42.7 ± 25.6%, 52.9 ± 26.2%, respectively; p= 0.034). In conclusion, simultaneous LA and LV volumetric analyses through 3D echocardiography clearly demonstrate the characteristic LA functional alterations following LA dilation caused by LV diastolic dysfunction.