Assessment of atrial conduction time by Doppler tissue imaging in hypertensive patients

Abstract

Background: Hypertension is the first cause of atrial fibrillation. Its onset is explained by intricate mechanisms such as atrial conduction impairment.
Aim: To evaluate atrial conduction by tissue Doppler imaging in hypertensive patients compared to a control group.

Methods : 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 intraatrial and interatrial electromechanical delay by Pulsed Tissue Doppler.
Statical analysis was conducted using SPSS version 22.0. Comparison of means was made with t student test.

Results: Left ventricular mass and septal thikness were more important in the hypertensive group. Mitral A wave was greater in hypertensive group compared to controls (7,1cm/s vs 5,6cm/s; p<0,0001; respectively). Left atrial volume was of 32,7±6,8mL/m² in hypertensives vs 29,5±4,3 mL/m² in controls (p=0,006).
Doppler Tissue study showed homogeneous statistically significant elongation of atrial conduction times in hypertensive patients compared to controls: interatrial time (16.8±7.8ms vs 12.4±4,2ms, p<0.0003) and left intraatrial (27.6±8.6ms vs 19.0±4.3ms, p<0.0001) and right intraatrial time (10.8±6.0ms vs 6.6±2.9ms, p<0.0001; respectively for hypertensive and control subjects.
There was a significant correlation between measured intraatrial and interatrial electromechanical delays and duration of hypertension, indexed left atrial volume ans indexed left ventricular mass (r 0.27-0.41, p<0.001).
   
Conclusion : 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.