Impact of left anterior line on left atrial appendage contractility in patients who underwent catheter ablation for chronic atrial fibrillation

Abstract

Background: Left anterior line (LAL) has been used as a substitute for mitral isthmus line for catheter ablation of chronic atrial fibrillation (AF). However, it results in left anterolateral conduction delay and might affect left atrial (LA) contractility. We aimed to investigate whether LAL decreases LA appendage function.

Methods: This study included 46 patients (30 men, mean age 58 ± 9 years, group 1) with persistent AF who underwent catheter ablation including LAL. Thirty patients with paroxysmal AF who received no additional LA ablation were compared as control group (21 males, mean age 56 ± 8 years, group 2). Transthoracic and transesophageal echocardiography with Doppler tissue imaging was performed in sinus rhythm before and after the ablation. We compared the following variables: (1) E/A ratio of the mitral flow velocity, (2) ratio of early mitral inflow and mitral septal annulus velocity (E/Em), (3) peak velocity of appendage outflow (ApVmax), and (4) time delay from QRS onset to appendage outflow (TDqa).

Results: LA diameter was significantly reduced after ablation in both groups. In group 1, parameters for diastolic function (E/A ratio, 1.7 ± 0.5 vs 2.0 ± 0.6, P = 0.197; E/Em, 11.7 ± 4.8 vs 11.6 ± 5.1, P = 0.883) and appendage flow (ApVmax, 55.2 ± 19.9 cm/s vs 50.3 ± 19.3 cm/s, P = 0.203; TDqa, -77.3 ± 30.1 ms vs -66.1 ± 60.8 ms, P = 0.265) did not change significantly after ablation. Changes of ApVmax and TDqa after ablation were not significantly different between two groups (P = 0.409 and P = 0.195, respectively).

Conclusions: LAL ablation did not aggravate mitral flow pattern or change appendage outflow. LAL could be used without concern over worsening LA diastolic and appendage function.

Keywords: atrial fibrillation; catheter ablation; diastolic function; echocardiography; left atrial appendage; pulmonary vein.