Arterial-atrial coupling in untreated hypertension

Abstract

Recently, there has been growing interest in an interplay of vascular mechanics and heart function (arterial-ventricular-atrial coupling). The contribution of arterial stiffness (AS) to left atrial (LA) enlargement is unclear. The aim of this study was to verify whether the association between carotid AS and LA volume in untreated arterial hypertension is independent of such confounders as age, sex, body mass index (BMI), blood pressure, left ventricular hypertrophy (LVH), left ventricular (LV) diastolic and systolic function. The study included 133 patients, among them 107 individuals with hypertension (51 men and 56 women, mean age 56.8 ± 10.3 years) and 26 matched controls. Each patient was subjected to echocardiography, ultrasonographic measurement of mean carotid intima-media thickness (IMT) and echo-tracking assessment of AS and wave reflection. LA volume was calculated by ellipsoid method. The indexed LA volume showed significant linear correlations with age (r = 0.32; p < 0.05), BMI (r = 0.21; p < 0.05), pulse pressure (r = 0.26; p < 0.05), B-type natriuretic peptide (r = 0.64; p < 0.05), LV end-diastolic volume (r = 0.42; p < 0.05), LV mass index (LVMI; r = 0.58; p < 0.05), septum thickness (r = 0.40; p < 0.05), posterior wall thickness (r = 0.34; p < 0.05), early filling wave of mitral inflow (E; r = 0.30; p < 0.05), early diastolic myocardial velocity of mitral annulus (e'; r =-0.22; p < 0.05), E/e' ratio (r = 0.45; p < 0.05), IMT (r = 0.26; p < 0.05) and augmentation index (AI; r = 0.27; p < 0.05). Progressive multivariate analysis identified LVMI, age, AI and BMI as independent determinants of indexed LA volume in patients with arterial hypertension. The study showed the significant relationship between wave reflection expressed by AI and LA structural remodeling, which supports the hypothesis of arterial-atrial coupling in hypertension.