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

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.

Assessment of left atrial mechanical function by two-dimensional echocardiography in hypertensive patients.

INTRODUCTION: The left atrium (LA) have an important role in the normal functioning of the heart thanks to its three functions: reservoir, conduct and pump. Several pathologies lead directly or indirectly to morphological and functional modifications of the LA. AIM:   Investigate the effect of arterial hypertension on LA size and function. METHODS:   Prospective study including 50 hypertensive patients compared to 50 healthy controls. LA Volumes were measured using transthoracic echocardiography by biplane Simpson  method  at different times of cardiac cycle: at the end of systole (maximum LA volume (Vmax)), at mitral valve  closure (minimum LA volume (Vmin)) and immediately before LA contraction (Vp)). LA reservoir function (total emptying volume and expansion index), conduct function (passive emptying volume and passive emptying fraction) and pumping function (active emptying volume and active emptying fraction) have been calculated. RESULTS:   Hypertension was associated with an increase of all LA volumes: Vmax (p<0.001),  Vmin (p=0.001) and Vp (p<0.001). LA reservoir function evaluated by LA total emptying volume was higher in hypertensives than in control group (p=0.032). LA conduct function was impaired in hypertensive patients with a significantly lower passive emptying fraction in hypertensive group compared to control group (22 ± 12% versus 32 ± 11%, p <0.001, respectively). This decrease was greater in the presence of left ventricular hypertrophy (p = 0.02). LA pumping function was significantly higher in hypertensive patients than in controls with an increase of LA active emptying fraction (35±12% versus 30±12%respectively; p=0.037). The increase of LA pumping function was found to be higher in hypertensive patients with impaired diastolic function (p=0.029). CONCLUSION:   Hypertension was associated with an increase of pumping and reservoir functions and a decrease in left atrial passive emptying function. These changes appear to be related to left ventricular hypertrophy and the degree of left ventricular diastolic dysfunction.

Echocardiographic assessment of left ventricular dyssynchrony and correlation with QRS width in chronic heart failure.

BACKGROUND: Echocardiographic parameters of mechanical dyssynchrony may improve patients selection for cardiac resynchronisation therapy in chronic heart failure. AIM: This study aimed to define the prevalence of inter, intra and atrio-ventricular dyssynchrony in heart failure patients with different QRS duration and to evaluate inter and intra-observer variability in collecting different echocardiographic dyssynchony parameters. METHODS: Twenty patients with chronic heart failure of any origin, NYHA functional class II-III with LVEF < 40%, were evaluated by complete echocardiographic examination including tissue Doppler imaging (DTI) and Tissue Tracking. RESULTS: Three patients had an atrio-ventricular dyssynchrony with a mean left ventricular filling time to cardiac cycle of 33 +/- 5%. Six patients had an interventricular mechanical delay (IVMD) > or = 40 milliseconds, all of them had a QRS duration > or = 120 milliseconds. Overall, no statistically significant correlation was found between IVMD and QRS duration (r = 0.35, p = 0.4). The mean septal to posterior wall-motion delay (SPWMD) was 83 +/- 64 ms. 7 patients had SPWMD > or = 130 ms. The baseline QRS duration did not correlate with SPWMD (p = 0.7). The mean LV dyssynchrony determined by deltaS-peak was 74 +/- 42 ms. Seven patients had LV dyssynchrony. Linear regression did not demonstrate a relation between QRS width and intraventricular dyssynchrony (p = 0.34). There was no concordance between intra-ventricular spatial or longitudinal dyssynchrony determined by DTI method and by Tissue Tracking (p = 0.3 and 0.6 respectively). The intraobserver reproducibility of LVFT/RR, IVMD and deltaS-peak (ICC = 0.99, 0.98 and 0.99, respectively), as well as the interobserver reproducibility (ICC: 0.96, 0.94 and 0.92, respectively), were very high. However, we observed a high variability for SPWMD measure (ICC = 0.27, p = 0.31). CONCLUSION: Mechanical dyssynchrony did not correlate with QRS duration, despite the poor variability in collecting different echocardiographic parameters.