Left atrial dyssynchrony time measured by tissue Doppler imaging to predict atrial fibrillation recurrences after pulmonary vein isolation

The prognostic value of left atrial dyssynchrony measured by speckle tracking echocardiography in the general population

LA dyssynchrony is a predictor of cardiovascular morbidity in various patient populations. However, the prognostic value of LA dyssynchrony as evaluated by two-dimensional speckle tracking (2D-STE) in the general population is unknown. A cohort of 375 participants without atrial fibrillation (AF), ischemic heart disease (IHD), heart failure (HF) or previous ischemic stroke (IS) had an echocardiogram, including LA 2D-STE, performed. LA dyssynchrony was defined as the standard deviation of the time to peak regional LA reservoir strain values. The endpoints were all-cause mortality, a combined endpoint of AF and IS, and a combined endpoint of major adverse cardiovascular events (MACE) comprised of acute myocardial infarction (AMI), HF or cardiovascular death (CVD). During a median follow up of 16.1 years (IQR 15.0-16.3 years), 83 (22%) participants died, 60 (15%) reached the composite endpoint of AF and IS, and 38 (10%) reached the composite MACE endpoint. LA dyssynchrony was a univariable predictor of all-cause mortality (HR 1.07, 95% CI 1.02-1.11, p = 0.001) but was not significantly associated with the combined endpoint of AF and IS (HR 1.05, p = 0.064) nor MACE (HR 1.04, p = 0.22). However, when adjusted for age, LA dyssynchrony did not predict all-cause mortality (HR 1.03, p = 0.28). Similarly, after further adjustments for clinical and echocardiographic parameters LA dyssynchrony did not predict any of the study outcomes. In this general population study, LA dyssynchrony was not an independent predictor of all-cause mortality and did not predict MACE nor a composite outcome consisting of AF and IS.

Determinants of left intra-atrial electromechanical delay as evaluated by tissue Doppler imaging in candidates for coronary artery bypass graft surgery

OBJECTIVES

Inhomogeneity in the atrial conduction time is a predisposing factor for atrial fibrillation. The aim of our study was to determine the independent determinants of the left intra-atrial electromechanical delay (LIAEMD) as a marker of left atrial (LA) dyssynchrony in candidates for coronary artery bypass graft surgery (CABGS).

METHODS

This prospective cross-sectional study recruited 516 consecutive candidates for CABGS. Via the pulsed-wave tissue Doppler imaging modality in echocardiography, the times between the P wave and the peak of the a' wave at the septal and lateral mitral annuli were measured and the difference between these times was considered to be LIAEMD. Additionally, clinical and laboratory data on each patient were gathered. The odds ratio for an increased LIAEMD was calculated in patients with and without diabetes in univariate and multivariate analyses.

RESULTS

The multivariable analysis revealed that in the patients without diabetes, obesity, calcium-channel blocker usage, an increased maximal LA volume, and a decreased lateral e'/a' ratio and in the diabetic patients, diuretic usage and a decreased lateral e'/a' ratio were independently correlated with an increased likelihood of LIAEMD occurrence (P < .05).

CONCLUSIONS

In our study on CABGS candidates, in the patients without diabetes, obesity, an increased maximal LA volume, calcium-channel blocker usage, and a decreased lateral e'/a' ratio and in the diabetic patients, diuretic usage and a decreased lateral e'/a' ratio independently determined increased LIAEMD. The prevention or treatment of factors that are detrimental to the LA electromechanical function may be helpful for the preservation of the LA electromechanical integrity.

Left atrial structure and function predictors of recurrent fibrillation after catheter ablation: a systematic review and meta-analysis

BACKGROUND

Catheter ablation (CA) has become a conventional treatment for atrial fibrillation (AF), but remains with high recurrence rate. The aim of this meta-analysis was to determine left atrial (LA) structure and function indices that predict recurrence of AF.

METHODS

We systematically searched PubMed-Medline, EMBASE, Scopus, Google Scholar and the Cochrane Central Registry, up to September 2017 in order to select clinical trials and observational studies which reported echocardiographic predictors of AF recurrence after CA. Eighty-five articles with a total of 16 126 patients were finally included.

RESULTS

The pooled analysis showed that after a follow-up period of 21 ± 12 months, patients with AF recurrence had larger LA diameter with weighted mean difference (WMD: 2·99 ([95% CI 2·50-3·47], P<0·001), larger LA volume index (LAVI) maximal and LAVI minimal (P<0·0001 for both), larger LA area (P<0·0001), lower LA strain (P<0·0001) and lower LA total emptying fraction (LA EF) (P<0·0001) compared with those without AF recurrence. The most powerful LA predictors (in accuracy order) of AF recurrence were as follows: LA strain <19% (OR: 3·1[95% CI, -1.3-10·4], P<0·0001), followed by LA diameter ≥50 mm (OR: 2·75, [95% CI 1·66-4·56,] P<0·0001), and LAVmax >150 ml (OR: 2·25, [95% CI, 1.1-5·6], P = 0·0002).

CONCLUSIONS

Based on this meta-analysis results, a dilated left atrium with diameter more than 50 mm and volume above 150 ml or myocardial strain below 19% reflect an unstable LA that is unlikely to hold sinus rhythm after catheter ablation for atrial fibrillation.