2.2 Assessment of LV function
Two-dimensional echocardiography was performed before catheter ablation and then at 3 ~ 6 months after the procedure. Echocardiograms were performed by experienced ultrasonographers. A standard imaging protocol was used based on apical 4-chamber views according to the recommendations of the American Society of Echocardiography Two independent observers analyzed echocardiograms.17 Three cycles were measured for each assessment, avoiding post-ectopic beats, and the average volumes were obtained.