Abstract MP68: The Correlation Between Left Atrial-left Ventricular-arterial Coupling And Circadian Rhythm Of Blood Pressure In Hypertension

Abstract

The Correlation between Left Atrial-Left Ventricular-Arterial Coupling and Circadian Rhythm of Blood Pressure in Hypertension Objective: Hypertension induces left atrial (LA) and left ventricular (LV) dysfunction, and arterial stiffness increased. In this study, we further investigated the association between LA-LV-arterial coupling and circadian rhythm of blood pressure (BP) in essential hypertension (HT). Design and Methods: We enrolled 289 HT patients which were evaluated by 2 dimensional speckle tracking echocardiography (2D-STE), ambulatory 24-hour BP monitoring (ABPM) and carotid-femoral pulse wave velocity (PWV). According to BP patterns, these patients were divided into two groups, which included dippers (n=109), patients with a >10% reduction in BP at nighttime; non-dippers (n=180), patients with a <10% reduction in BP at nighttime. 2D-STE based LA and LV strains were studied and the following parameters were measured, LV global longitudinal strain (GLS), LA reservoir strain (LA S-S ), LA conduit strain (LA S-E ), and LA booster pump strain (LA S-A ). LA stiffness index (LASI) defined as the ratio of E/e' to LA S-S , and PWV-to-GLS ratio (PWV/GLS) were calculated to reflect LA-LV-arterial coupling. Furthermore, we also explored the correlation between LASI (or PWV/GLS) and ambulatory blood pressure indexes. The related factors were evaluated by multivariate linear regression analysis to find the independent factors. Results: LASI was significantly higher in non-dippers (0.35±0.24) than dippers (0.29±0.12) ( p <0.05). PWV/GLS was significantly higher in non-dippers (-90.30±34.13) than dippers (-79.62±25.84) ( p <0.05). LA S-S , LA S-A and LV GLS were significantly lower in non-dippers than dippers ( p <0.05). Multivariate linear regression analysis revealed that LV mass index (LVMI), PWV/GLS, nighttime mean SBP (n-SBP) and nighttime mean DBP (n-DBP) were independently correlated with LASI; LASI and n-SBP were independently correlated with PWV/GLS. Conclusions: LA and LV myocardial mechanics, and LA-LV-arterial coupling were associated with circadian rhythm of BP. Nocturnal systolic BP was the independent risk factor of abnormal LA-LV-arterial coupling in HT.