Abstract 8696: Assessment of Time-Left Atrial Volume Curve and Left Atrial Emptying Function by Speckle Tracking Echocardiography is Useful to Evaluate Left Ventricular Diastolic Function in Patients with Preserved Ejection Fraction

Abstract

Background: Left atrial (LA) volume is proposed to evaluate left ventricular (LV) filling pressure and E/e' is used to estimate LV diastolic function instead of invasive measurement. However, it is difficult to measure LA volume accurately and quickly using routine echocardiography and E/e' from 8 to 15 is classified as a gray zone to estimate LV filling pressure. Thus, we assessed the hypothesis that evaluation of time-LA volume curve and LA emptying function (EF) measured by speckle tracking may be more useful to estimate LV diastolic function as a noninvasive method in the clinical settings than E/e' . Methods : LA phasic volume and EF were measured in 34 patients (age 69±8, 14 men) with LV ejection fraction ≥50% by speckle tracking echocardiography that can provide time-LA volume curve automatically, and E/e' was also obtained just before cardiac catheterization, and these parameters were compared with pulmonary capillary wedge pressure (PCWP). Results : LA max. and min. volume had significant positive correlations with PCWP (r=0.72, P<0.01 and r=0.80, P<0.01, respectively). LA total, passive and active EF had significant negative correlations with PCWP (r=-0.82, p<0.01, r=-0.56, p<0.05 and r=-0.66, P<0.01, respectively). There was a significant but weak positive correlation between E/e' and PCWP (r=0.52, p<0.05). As PCWP was elevated, LA max. and min. volume were increased and pre-atrial contraction volume was closer to min. volume, and total and active EF were decreased (Figure). Using 33% of LA total EF as a cutoff, the sensitivity and the specificity in predicting elevated LV filling pressure >12mmHg were 89% and 88%, while using 15 of E/e' those values were 53% and 79%, using 40ml/m 2 of LA volume those values were 48% and 82%. Conclusions : In noninvasive estimation of LV diastolic function, assessment of time-LA volume curve and LA EF may be a novel and more useful method and have an incremental value compared with measurement of LA volume and E/e' in the clinical settings .