Left atrial asynchrony is a major predictor of 1-year recurrence of atrial fibrillation after electrical cardioversion

BACKGROUND: The level of atrial mechanical asynchrony may vary within the atrial fibrillation population and this may have pathophysiological relevance. OBJECTIVE: We sought to verify whether the degree of left-atrial mechanical asynchrony associated with atrial fibrillation is a predictor of arrhythmia recurrence after restoration of sinus rhythm with electrical cardioversion. METHODS AND RESULTS: Left atrial volume was calculated, whereas two-dimensional (2D) strain (speckle tracking technique) was used to estimate peak and standard deviation (SD) of time-to-peak of deformation of six segments arbitrarily identified along the perimeter of the cavity, imaged in apical four-chamber view. Left atrial mechanical asynchrony was quantified according to quartiles of time-to-peak SD assuming that larger values would identify higher grades of asynchrony. A total of 130 patients undergoing cardioversion for atrial fibrillation were prospectively enrolled. Time-to-peak SD was inversely related with peak strain (P < 0.001). No differences were observed among groups in terms of clinical, therapeutical and additional echocardiographic variables. At 1-year atrial fibrillation was observed in 53% of patients, with time-to-peak SD linearly related to atrial-fibrillation recurrence (P = 0.014). At multivariate analysis only time-to-peak SD (P = 0.032), but not atrial volume (P = 0.075), was identified as an independent predictor of fibrillation recurrence. CONCLUSION: This is the first study showing that left atrial asynchrony, quantified as time-to-peak SD of regional atrial strains before electrical cardioversion, is a major independent predictor of fibrillation recurrence in patients back to sinus-rhythm postprocedure.