Atrial conduit function quantitation precardioversion predicts early arrhythmia recurrence in persistent atrial fibrillation patients.

Abstract

Atrial fibrillation incidence is increasing due to ageing population and electrical cardioversion (ECV) is overused because of atrial fibrillation recurrences. Study's aim was to evaluate value of novel three-dimensional echocardiographic-derived left atrial conduit (LAC) function quantification in predicting early atrial fibrillation recurrence after ECV. We included 106 patients [74 (64-78) years] who underwent ECV for persistent nonvalvular atrial fibrillation. For all clinical data and simultaneous left atrial and left ventricular (LV) three-dimensional full-volume data sets were available before ECV. We computed LAC as: [(LV maximum - LV minimum) - (left atrial maximum - left atrial minimum) volume], expressed as % LV stroke volume. Atrial fibrillation recurrence was checked with Holter monitoring. One month after ECV 66 patients were in sinus rhythm and 40 experienced atrial fibrillation recurrence. Pre-ECV patients with atrial fibrillation recurrence showed higher LAC contribution to LV filling (P < 0.0001) and noninvasively estimated left atrial stiffness (P < 0.0001) compared with sinus rhythm patients. There were no other differences, neither in clinical characteristics nor in LV properties. At multivariate LAC (P < 0.001), left atrial stiffness (P = 0.002) and volume (P = 0.043) predicted early atrial fibrillation relapse, even when compared with other confounding factors. Receiver-operating characteristics area (ROC) analysis confirmed LAC as best atrial fibrillation recurrence predictor (0.84, P < 0.0001), cut-off value more than 54% exhibiting reasonable sensibility-specificity (76-75%). Atrial fibrillation makes LV filling dependent on reciprocation between left atrial reservoir/conduit phases. Our data suggest that LAC larger contribution to filling in persistent atrial fibrillation patients reflects left atrial and LV diastolic dysfunction, which skews atrio-ventricular interaction that leads to atrial fibrillation perpetuation, making LAC a powerful atrial fibrillation recurrence predictor after ECV.