Blood Flow Volume Of Left Atrial Appendage Measured By Magnetic Resonance Imaging Is Improved After Radiofrequency Catheter Ablation Of Atrial Fibrillation

Introduction: Hemodynamics of left atrial appendage (LAA) is an important factor for future risk of ischemic stroke in atrial fibrillation (AF) patients. Velocity encoded cardiac magnetic resonance imaging (VENC-MRI) can evaluate blood flow volume of LAA without any invasive procedures. We aimed to evaluate the association between radiofrequency catheter ablation (RFCA) and LAA hemodynamics measured by MRI.Methods and Results: Consecutive RFCA cases in a single arrhythmia center were retrospectively analyzed. A total of 3120 AF patients who underwent first RFCA were analyzed. Among these patients 360 patients had both pre- and post-RFCA VENC-MRI evaluation. Atrial fibrillation was non-paroxysmal in 174 (48.3%) patients. Mean VENC-MRI (ml/sec) was significantly improved after RFCA with 49.93 +/- 32.92 and 72.00 +/- 34.82 for pre- and post-RFCA, respectively. Patients with non-paroxysmal AF ( increment VENC-MRI = 14.63 +/- 40.67 vs. 30.03 +/- 35.37; p < .001) and low pre-RFCA VENC-MRI ( increment VENC-MRI = 17.19 +/- 38.35 vs. 50.35 +/- 29.12; p < .001) had significantly higher improvement in VENC-MRI. Those who experienced late recurrence before post-RFCA MRI had significantly less improvement in LAA flow volume (increment VENC-MRI = 15.55 +/- 41.41 vs. 26.18 +/- 36.77; p = .011). Late recurrence and pre-RFCA VENC-MRI were significantly associated with increment VENC-MRI after adjusting covariates. Patients who were AF before RFCA but maintained sinus rhythm after RFCA showed greatest improvement in VENC-MRI.Conclusion: Effective rhythm control through RFCA can be associated with significant improvement in LAA hemodynamics. Low pre-RFCA VENC-MRI and absence of late recurrence were associated with greater improvement in LAA hemodynamics.