Left atrial function assessed by Doppler echocardiography rather than left atrial volume predicts recurrence in patients with paroxysmal atrial fibrillation

BACKGROUND

Paroxysmal atrial fibrillation (PaAF) may present as a single self-terminating episode of atrial fibrillation (AF) or a more persistent form after sinus conversion. We investigated predictors of recurrence in patients with PaAF.

HYPOTHESIS

Left atrial function would be an useful parameter for predicting PaAF recurrence.

METHODS

The study population included 228 PaAF patients (131 males, age 64±14 years) who underwent transthoracic echocardiography immediately after spontaneous sinus conversion at initial AF diagnosis. We followed the study patients for AF recurrence.

RESULTS

AF recurrence was demonstrated in 45 patients (20%, age 68±13 years) after spontaneous sinus conversion. Patients with recurrence had larger left atrial volume index (32±12 vs 25±10 mL/m2, P<0.001), left ventricle mass index (107±34 vs 93±25 g/m2, P=0.012), and left ventricle filling pressure (E/e'') (14±7 vs 12±5, P=0.012), whereas early diastolic mitral annular velocity (e') (5±2 vs 6±3 cm/s, P=0.021), late diastolic mitral annular velocity (A') (7±3 vs 9±2 cm/s, P<0.001), and peak systolic mitral annular velocity (7±2 vs 8±2 cm/s, P=0.045) were significantly lower. In multivariate Cox regression analysis detecting independent predictors of PaAF recurrence, lower A' (hazard ratio: 0.623, 95% confidence interval: 0.476-0.815, P=0.001) was a significant predictor of AF recurrence.

CONCLUSIONS

A', which indicates left atrial (LA) contractile function after sinus conversion, was the independent predictor of PaAF recurrence, whereas LA volume was not. LA function may be more important than LA volume in predicting recurrence particularly in patients with PaAF.

Impact of obstructive sleep apnea on left atrial functional and structural remodeling beyond obesity

BACKGROUND

To evaluate the left atrial (LA) volume and function of obese patients with/without obstructive sleep apnea (OSA) and its association with left ventricular (LV) diastolic function independent of obesity.

METHODS

LA volumetric and functional parameters were measured by 2-dimensional and strain echocardiography in 49 obese (body mass index ≥ 25 kg/m(2)) subjects (24 non-OSA and 25 OSA).

RESULTS

OSA group showed larger maximal LA volume indexed for body surface area, larger volume before atrial contraction, a reduction in the LA passive emptying fraction, and an increase in the LA active emptying fraction with no significant change in LA total emptying fraction. Mitral annular early diastolic velocity (Ea) was significantly reduced, whereas the ratio of mitral valve early diastolic velocity (E) to Ea (E/Ea) and late diastolic velocity (Aa) were significantly increased in OSA group. Although the mean peak late diastolic strain rate had not shown any differences, the LA mean peak systolic strain/strain rate, and mean peak early diastolic strain rate were significantly lower in the OSA group. Apnea-hypopnea index (AHI) of the OSA patients was significantly correlated with E/Ea (r=0.67, p<0.001). There is a significant correlation between LA active emptying volume index and E/Ea (r=0.77, p<0.001), and between LA passive emptying volume index and E/Ea (r=-0.51, p=0.009).

CONCLUSION

LA structural and functional remodeling was significantly correlated with the severity of OSA and LV diastolic filling pressure. OSA impaired LA wall compliance and passive contraction independent of obesity.

Impact of right ventricular apical pacing and its frequency on left atrial function

Background

Right ventricular apical (RVA) pacing induces left ventricular (LV) dyssynchrony, increases the risk of persistent atrial fibrillation in the long term. The aim was to investigate the effects of RVA pacing on left atrial (LA) function, which are unknown.

Methods

Echocardiographic evaluation including LV dyssynchrony based on conventional Doppler, tissue Doppler imaging and speckle tracking strain echocardiography was done before and after (12 months) single-chamber ventricular pacemaker implantation in 40 patients with sick sinus syndrome. Patients were divided to 2 groups, according to the RVA pacing frequency (group I had higher pacing rate of more than 50% and group II, less than 50%).

Results

There was no significant difference in LV ejection fraction, however, mean global LV strain, myocardial performance index, and parameters of LV dyssynchrony had shown significant changes after 12 months of RVA pacing. There were also significant increase in the LA volume index and the reduction of peak systolic LA strain and strain rate (SR), peak early and late diastolic SR after RVA pacing. Moreover, there was significant deterioration of LV dyssynchrony and both LA and LV longitudinal function in even group II. LA functional deterioration and LA volume was significantly correlated with the frequency of RVA pacing.

Conclusion

LV dyssynchrony, induced by RVA pacing, significantly impaired active LA contraction and passive stretching, and these findings were shown in the patients with even less than 50% of RVA pacing. Impairment of LA strain/SR was significantly correlated with the frequency of RVA pacing.

Echocardiographic assessments of left atrial strain and volume in healthy patients and patients with mitral valvular heart disease by tissue Doppler imaging and 3-dimensional echocardiography

Background and Objectives

The purpose of the current study was to assess left atrial (LA) physiology in relation to associations between LA volume change and regional tissue velocities and strains, and to extend this information to patients with mitral stenosis (MS) or mitral regurgitation (MR).

Subjects and Methods

Twenty-two healthy persons, 22 patients with moderate-to-severe MS, and 22 patients with moderate-to-severe MR were studied. Tissue velocities, strains, and time-volume curves of the LA were acquired using tissue Doppler imaging and 3-dimensional echocardiography.

Results

In healthy controls, the maximal LA volume was negatively correlated with the posterior wall longitudinal systolic strain (r=-0.45, p=0.03). The time-to-maximal LA volume was positively correlated with the time-to-posterior wall longitudinal peak strain (r=0.46, p=0.03) and the time-to-circumferential peak strain (r=0.59, p=0.004). The LA active emptying fraction (LAactEF) was positively correlated with the posterior wall longitudinal peak systolic and late diastolic tissue velocities. In patients with MS, the maximal LA volume was negatively correlated with the posterior wall radial peak systolic velocity and the longitudinal late diastolic velocity. In patients with MS, the LAactEF had an additional positive correlation with the anterior wall longitudinal and circumferential systolic velocities, whereas the patients with MR had an additional positive correlation between the LAactEF and the lateral wall longitudinal peak strain as compared with the healthy cantrols.

Conclusion

LA longitudinal and circumferential deformations are more related than radial deformation to determining LA volume and function. The LA of patients with MS revealed a greater pathologic physiology than those of patients with MR.