Biatrial remodelling in atrial fibrillation: A three-dimensional and strain echocardiography insight

Background Atrial remodelling has been poorly investigated in atrial fibrillation (AF), and few studies have focused on biatrial remodelling. Aim To evaluate right atrial (RA) and left atrial (LA) remodelling in AF using global atrial reservoir strain and three-dimensional (3D) atrial volumes, according to rhythm outcome at mid-term follow-up. Methods Two-dimensional and 3D transthoracic echocardiography (TTE) were performed within 24 hours after admission (M0) and at 6-month follow-up (M6) in patients admitted for AF. RA and LA variables were assessed: body surface area-indexed maximum 3D volume (Max 3D RA Vol i , Max 3D LA Vol i ) and minimum 3D volume (Min 3D RA Vol i , Min 3D LA Vol i ); atrial emptying fraction (3D RAEF, 3D LAEF); atrial expansion index (3D RAEI, 3D LAEI); and global RA and LA reservoir strain. Results Forty-eight consecutive patients were included prospectively. Three groups were identified depending on rhythm at M0 and M6: AF at M0 and sinus rhythm (SR) at M6 (AF-SR) in 25 (52.1%) patients; AF at M0 and AF at M6 (AF-AF) in 13 (27.1%) patients; and SR at M0 (spontaneous cardioversion before first TTE) and SR at M6 (SR-SR) in 10 (20.8%) patients. Between M0 and M6 in the AF-SR group, we found: significant decreases in Max 3D RA Vol i ( P = 0.020), Min 3D RA Vol i ( P = 0.0008), Max 3D LA Vol i ( P = 0.001) and Min 3D LA Vol i ( P = 0.0021); significant increases in 3D RAEF ( P = 0.037) and 3D RAEI ( P = 0.034); no significant differences in 3D LAEF and 3D LAEI; and significant increases in global RA and LA reservoir strain (both P < 0.0001). There was no significant difference with regard to these variables in the AF-AF and SR-SR groups. Conclusion 3D volume and strain analyses were useful in the evaluation of RA and LA reverse remodelling in successfully cardioverted patients with AF.