Comparison of left atrial function between hypertensive patients with normal atrial size and normotensive subjects using strain rate imaging technique

Abstract

Background: Patients with hypertension are at risk of structural and functional changes in the left atrium (LA). There are only a few studies on the impact of hypertension on LA function, especially in hypertensive patients with a normal LA size. We, therefore, designed this study to evaluate LA function in patients with a normal LA size via deformation imaging. Objectives: We assessed regional longitudinal strain rate imaging (SRI) profiles along with tissue velocity imaging (TVI) in the LA walls to quantify LA reservoir function and explore changes in LA function in hypertensive patients with a normal value of LA size. Patients and Methods: One hundred twenty-four subjects with normal angiography (mean age = 56.28 ± 8.91 years, 46% male), who were referred to the Echocardiography Laboratory of our institution, were enrolled in this study. These subjects were categorized into two groups: hypertensive (75 cases) and age-matched normotensive (49 cases) groups. All the cases of the patient and control groups had a normal LA size. SRI parameters included strain (ST, %) and strain rate (SR, s-1), and tissue imaging parameters such as peak systolic velocity (Sm, m/s) were measured in four septal, lateral, anterior, and inferior LA walls at the mid-level. Results: Compared with the controls, the patients with a history of hypertension showed significantly lower values of Sm, ST, and SR in each segment of the LA. There was no effect of age on these indices. Also, no differences regarding Sm, ST, and SR were found between the septal, lateral, anterior, and inferior LA walls in each group. By multivariate linear regression analysis, a history of hypertension was the only independent determinant of average LA strain rate in the all the individuals (P < 0.001). When this analysis was repeated in the patients with a history of hypertension, the only independent determinant of average LA strain rate was heart rate (P = 0.026). Conclusions: In our subjects, with a normal value of LA size, the effect of hypertension on LA reservoir function was independent of age, sex, heart rate, left ventricular mass index, and left ventricular ejection fraction. Additionally, heart rate independently correlated with reduced TVI and SRI parameters in the patients with hypertension.