The Effect of Left Anterior Line on Left Atrial Appendage Contraction in Chronic Atrial Fibrillation

Left anterior line (LAL) has been reported to be more efficient than mitral isthmus line for Catheter ablation of chronic atrial fibrillation (AF). The aim of this study was to investigate whether LAL delays LA appendage contraction.This study included 33 patients (73% men, mean age 58.3 ±9.1 years) who underwent Catheter ablation for persistent AF. Ablation procedure included antral isolation of pulmonary veins, roof line, LAL, and right atrial isthmus block. LAL block was confirmed by bidirectional pacing. Transthoracic and transesophageal echocardiography with Doppler tissue imaging was performed. A peak velocity of appendage outflow (ApVmax) and a time delay from QRS onset to appendage outflow (TDqa) were analyzed.The appendage outflow was delayed after the QRS onset in 8 patients (24%). The average values of ApVmax and TDqa after the ablation were 45±19cm/s and -62±81ms, respectively. Paired T-test was possible in 15 patients who showed sinus rhythm before the ablation. The ApVmax and TDqa did not change significantly after the ablation (58±26cm/s vs. 49±20, p=0.23 and -7±34ms vs.-46 ± 74, p=0.14).LAL ablation did not change the onset of appendage outflow time significantly. It is likely that LAL does not compromise the benefit of AF ablation in terms of LA systolic function.