Left atrial function assessed by trans-thoracic echocardiography in patients treated by ablation for a lone paroxysmal atrial fibrillation

Abstract

Aims: Atrial fibrillation (AF) may induce three kinds of atrial remodelling: morphological, contractile, and electrical. Maintain of sinus rhythm is usually associated with left atrial (LA) volume decrease, but little is known about the evolution of its mechanical properties. We sought to explore LA mechanical and morphological remodelling in patients with lone paroxysmal-AF treated by catheter ablation (CA).

Methods and results: We prospectively included 31 patients (56.4 ± 10 years). We also followed 15 age- and gender-matched controls to get normal values. Each patient had a complete echocardiography at baseline and at 3-month and 1-year follow-up. LA-anatomical reverse remodelling was documented: indexed LA volume decreased from 39 mL/m(2) at baseline to 31 mL/m(2) at 1 year (P < 0.001). However, it remained larger than controls (31 vs. 23 mL/m(2), P = 0.001). LA compliance improved (LA lateral systolic peaks of strain = 50 vs. 31%, P < 0.05) without reaching controls values as estimated by 50 vs. 81%, P < 0.05). LA contractility increased as highlighted by A'-peak velocity (10 cm/s at 1Y-F/up vs. 7.5 at baseline, P = 0.01) and LA late diastolic peaks of strain rate (septal: -3 vs. -1 s(-1), lateral: -3 vs. -1.4 s(-1), P < 0.05). We show a functional remodelling at 1 year, with most contractile parameters being comparable to controls, whereas LA compliance remains significantly altered.

Conclusion: AF-CA could reverse LA anatomical and functional remodelling. Despite improvement, LA compliance remains altered after 1 year, probably reflecting irreversible fibrosis.