Contraction of Left Atrial Appendage before and after Radiofrequency Catheter Ablation: Assessment with 320-Slice Computed Tomography

Abstract

Background: Radiofrequency catheter ablation (RFCA) has been used to treat patients with atrial fibrillation (AF). Previous studies have assessed the effect of RFCA on left atrial (LA) volume and function. Especially, LA appendage (LAA) has high contractility and is important for booster pump function. However, the effect of RFCA on LAA has not been fully clarified. Methods: Twenty-one patients (63.5±8.9 years, 15 males) with paroxysmal Af (PAF) and 21 patients (64.3±7.6 years, 20 males) with persistent or chronic AF (CAF) were enrolled. Computed tomography was performed before and after RFCA with a 320-slice scanner. Images were reconstructed at 10 phases of one cardiac cycle (from 5% to 95% of the R-R interval). Accurate LAA volumes were obtained using either a paintbrush or a cutting technique. The ejection fraction of LAA (EF-LAA) was calculated before and after RFCA in PAF and CAF patients. Results: Before RFCA, EF-LAA were 27.4±15.9% for PAf patients and for 15.0±9.9% for CAf patients. After RFCA, EF-LAA were 38.3±22.2% for PAF (p=0.08) and 38.7±13.8% for CAF (p<0.0001). Conclusions: EF-LAA significantly improved after RFCA in CAF patients. Our study suggested that LAA function is disturbed more severely in CAF patients and that RFCA can recover booster function of LAA.