Changes in left atrial structure and function after catheter ablation and electrical cardioversion for atrial fibrillation

Background: The aim of this study was to assess whether the morphological and functional changes of the left atrium (LA) differ after catheter ablation (ABL) from those after electrical cardioversion (ECV) in atrial fibrillation (AF). Methods and Results: AF patients who had maintained sinus rhythm for 3 months after either ECV (n=30) or ABL (n=33) were studied. Both 2-dimensional and Doppler echocardiography were performed at baseline, 1 week, 1 month, and 3 months after these procedures. LA dimensions, mitral inflow velocity, and tissue Doppler imaging of the mitral annulus were examined. LA dimensions decreased in both groups. The mean late mitral annulus velocity increased from 1 week to 3 months in both groups, but the mean late transmitral peak velocity increased only in the ECV group (42.1±14.4 cm/s to 56.7±14.8 cm/s, p<0.001 vs 38.7±12.5 cm/s to 44.8±16.7 cm/s, p=NS). Conclusion: Reverse morphological remodeling of the LA occurred after successful ABL and ECV for AF. However, because LA function was lower in the ABL group than in the ECV group and did not recover to the baseline levels until 3 months after ABL, a meticulous anticoagulation program should be considered.