Real-Time Three-Dimensional Echocardiography in the Evaluation of Left Atrial Structure and Function in Normal, Aging, Hypertensive and Heart Failure Patients: New Insights into Left Atrial Adaptation and Remodeling

Abstract

Precise left atrial (LA) volume quantification, representative of LA function, is of extraordinary clinical prognostic value. However, a detailed description of pathophysiology in different disease populations and interactions with aging by real-time three-dimensional echocardiography (RT-3DE) is lacking. This study consisted of three protocols: (1) to test the impact of different LA cutting planes on LA volume quantification in different disease populations ( n = 61) by RT-3DE; (2) to examine the impact of aging, hypertension ( n = 145), the interaction on LA remodeling; and (3) to further depict the LA regional and global remodeling process in different disease entities ( n = 68), including heart failure (HF). Bias and percentage error in LA volume quantification tended to decrease significantly when compared with the automatic border detection method at eight cutting planes. A linear relationship was apparent between maximal LA volume and age in the hypertensive group ( r = 0.26, p = 0.03), but not in the normal aging group ( r = 0.16, p = 0.19). A significantly reduced pumping fraction and enlarged LA volume was observed in HF patients ( p < 0.01), with a trend toward less LA pumping volume ( p = 0.1). Eight cut planes provided sufficient accuracy in LA volume quantification using the RT-3DE method. Compared with normal aging, LA volume tends to increase with higher pumping volume to compensate for impaired left ventricular relaxation in hypertension. Relatively preserved total LA pumping volume may exist in heart failure patients at the expense of further adaptive volume expansion with a subsequently reduced total emptying fraction.