Aims: 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.
Methods: 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.
Results: 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%).
Conclusion: 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.