Impairment of atrial conduction time in hypertensive patients. A Doppler tissue imaging study

Abstract

Hypertension is the first cause of atrial fibrillation. Its onset is explained by intricate mechanisms such as atrial conduction impairment. The aim of our study was to evaluate atrial conduction by tissue Doppler imaging in hypertensive patients compared to a control group. This is a comparative prospective study performed in the cardiology department of the FSI hospital enrolling 55 patients with hypertension and 55 controls. All of them underwent a complete echocardiocardiography exam with Doppler tissue imaging. We measured intra-atrial and inter-atrial electromechanical delay by Pulsed Tissue Doppler. Statistical analysis was conducted using SPSS version 22.0. Comparison of means was made with t Student test. Left ventricular mass and septal thickness were more important in the hypertensive group. Mitral A wave was greater in hypertensive group compared to controls (7.1 cm/s vs. 5.6 cm/s; P < 0,0001; respectively). Left atrial volume was of 32.7 ± 6.8 mL/m 2 in hypertensives vs. 29.5 ± 4.3 mL/m 2 in controls ( P = 0.006). Doppler Tissue study sowed homogeneous statistically significant elongation of atrial conduction times in hypertensive patients compared to controls: inter-atrial time (16.8 ± 7.8 ms vs. 12.4 ± 4.2 ms, P < 0.0003) and left intra-atrial (27.6 ± 8.6 ms vs. 19.0 ± 4.3 ms, P < 0.0001) and right intra-atrial time (10.8 ± 6.0 ms vs. 6.6 ± 2.9 ms, P < 0.0001; respectively for hypertensive and control subjects. There was a significant correlation between measured intra-atrial and inter-atrial electromechanical delays and duration of hypertension, indexed left atrial volume and indexed left ventricular mass ( r = 0.27–0.41, P < 0.001). Atrial conduction time is significantly longer in hypertensive patients. Impairment of atrial conduction may be predictive of atrial fibrillation and should prompt closer surveillance to detect this arrhythmia in these patients.