P2461The presence of L wave was associated with non-invasively estimated left atrial stiffness in heart failure patients

Abstract

Abstract Background The mid-diastolic L wave is recorded as mid-diastolic mitral forward flow with conventional Doppler echocardiography. L wave is occasionally detected in heart failure (HF) patients but its mechanism of occurrence is still unknown. It is hypothesized that L wave was induced by a positive atrioventricular gradient caused by left atrial filling via pulmonary veins, and the magnitude of the L wave is augmented by increasing ventricular stiffness. We speculate that also Left atrium (LA) function will relate with the presence of L wave because the L wave flow occurs passing LA. LA function has been known to have reservoir, booster pump and conduit function. It is reported that LA conduit function related to LA stiffness. The aim of this study is to clarify the association between LA functions and presence of L wave in HF patients. Methods and results Eighty two patients who admitted to our hospital for HF were enrolled in this study. We performed echocardiography before discharge. LA speckle-tracking strain was analyzed by an external software program using apical 4 chamber view. Reservoir function was measured as peak strain value at end systole, and booster pump function was measured as the value of atrial contraction. Conduit function was calculated as the difference of the peak value at end systole and atrial contraction. There were 23 patients who had L wave before discharge and 59 patients without L wave. Transmitral E wave (E) and left atrial volume index (LAVI) were higher in patients with L wave than in those without L wave. LA reservoir strain was not different in two groups, but poster pump strain was lower and conduit strain was higher in patients with L wave than those without. LA reservoir strain and booster pump strain weakly correlated with A wave velocity (r=0.39 p=0.004, r=46 p=0.001) and LAVI (r=−0.23 p=0.0383, r=−0.31 p=0.005), but conduit strain had no correlation with A wave (r=0.12 p=0.26) and LAVI (r=−0.04 p=0.67). In multivariate regression analysis for the presence of L wave with A wave velocity, LAVI and LA conduit strain, LA conduit strain remained independent predictors of the presence of L wave (HR 1.12 95% CI 1.04–1.23; p=0.004). Conclusion LA conduit function was not correlated with conventional echo parameters of LA function (A wave velocity and LAVI). The presence of L wave was associated with LA conduit strain.