Abstract 10708: Impact of Age on Diastolic Function and Left Atrial Volume and Function in Normal Subjects Assessed by Two-Dimensional Speckle Tracking Echocardiography
Background: Left atrial (LA) volume (V) and function (F) is a strong predictor of cardiovascular outcomes. Using speckle tracking echocardiography (STE), attention has focused on LAV and LAF, which are affected by both age and left ventricular (LV) diastolic function (LV stiffness).However, normal reference values of LAV and LAF at each age and the impact of age on LAV and LAF have not been established. We assessed LV structure, LAV and LAF per decade in normal subjects using STE and conventional echocardiography.
Methods: We used 2-dimensional STE to examine phasic LA emptying function (EF), LAV index (LAVI), peak strain and strain rate in 136 normal subjects without cardiovascular disease. We reported previously that the pulmonary capillary wedge pressure (ePCWP) is accurately estimated by the kinetics-tracking (KT) index which includes both LAEF and LAV. ePCWP was calculated as 10.7 - 12.4 x log KT index, where KT index = active LAEF / minimum LAVI. Moreover, we measured LV mass index (LVMI), ejection fraction, E/e’ and E/A. LA stiffness was estimated as ePCWP / LA strain x 100.
Results: There were no differences in LVMI and LV ejection fraction among ages. LA total and passive EF as well as SR at systole and early diastole decreased with age. LA active EF and SR at atrial contraction (AC) increased with age, and this was associated with increased pre-atrial contraction LAVI. LA stiffness increased with age, and this was associated with increased E/e’ and decreased E/A despite no difference in ePCWP.
Conclusions: LA reservoir and conduit function decreased in normal subjects with age and this was associated with impaired LV relaxation. LA booster pump function increased with age to compensate for decreased conduit function, and this was associated with increased pre-AC LAVI, suggesting that the Frank-Starling mechanism maintains normal PCWP until there is age-related impaired LV relaxation and increased LA stiffness.
- © 2013 by American Heart Association, Inc.