Identifying patients at high risk of atrial fibrillation (AF) recurrence remains challenging. This study aimed to evaluate total atrial conduction time (TACT) and left atrial (LA) asynchrony as predictors of AF recurrence. Consecutive patients after the first AF episode, terminated either spontaneously or with cardioversion, underwent transthoracic echocardiography. TACT, estimated by the time delay between the onset of P-wave and the peak A'-wave on the Tissue Doppler Imaging (PA-TDI duration), atrial volumetric and functional parameters, and biatrial strain were assessed. We calculated mean PA-TDI-the average of PA-TDI measurements in all left atrial (LA) walls-and the difference between the longest and the shortest PA interval (DLS) and the standard deviation of 4 PA intervals (SD4) to assess the LA global remodeling and asynchrony, respectively. The primary endpoint was AF recurrence. Patients with recurrent AF had significantly prolonged PA-TDI intervals in each LA wall-and thus mean PA-TDI-than those without recurrence (mean PA-TDI: 157.4 ± 17.9 vs. 110.2 ± 7.7 ms, p < 0.001). At univariate analysis, LA maximum volume index, total LA emptying fraction, right atrial maximum volume index, PA-TDI, DLS, and SD4 were predictors of AF recurrence. At multivariable analysis, PA-TDI intervals in all LA walls remained strong predictors with mean PA-TDI (odds ratio 1.04; 95% confidence interval 1.03-1.06) having an optimal cutoff of 125.8 ms in receiver operator characteristics curve analysis providing 98% sensitivity and 100% specificity for AF recurrence (area under the curve = 0.989). PA-TDI was an independent predictor of AF recurrence and outperformed established echocardiographic parameters.
Keywords: Atrial asynchrony; Atrial fibrillation; PA interval; Tissue Doppler imaging; Total atrial conduction time.