Electrophysiological Features of Atrial Tachyarrhythmias After the Creation of a Left Atrial Roof Line During Catheter Ablation of Atrial Fibrillation

Left atrial roof line (LARL) can prevent the perpetuation of atrial fibrillation (AF) by delineation of the arrhythmogenic substrate, but it may be associated with an increased incidence of atrial tachycardia (AT). This study was performed to evaluate the characteristics and clinical implications of inducible AT after LARL.A total of 139 consecutive patients with AF who underwent catheter ablation were prospectively enrolled in this study. LARL was required to prevent the perpetuation of AF in 98 of 139 patients (71%). LARL significantly reduced the incidence of inducible AF (before versus after: 100% versus 44%, respectively, P < 0.01), whereas it significantly increased the incidence of AT (18% versus 63%, P < 0.01). ATs were observed after LARL in 62 of 98 patients (63%), and these circuits were determined in 99 of 112 stable ATs (88%), including tricuspid isthmus-dependent (n = 35), mitral annulus (n = 22), septal (n = 15), surrounding right pulmonary veins (PVs) (n = 12), coronary sinus (CS) ostium (n = 4), upper loop (n = 4), surrounding left PVs (n = 4), and LA anterior wall (n = 3). Catheter ablation (CA) successfully terminated 111 of 122 stable ATs (91%) during CA. The occurrence of AT after CA was significantly higher in patients with than in those without residual AT (26% versus 2%, P < 0.05).Induced AT with a stable circuit after LARL creation could be mapped, and delineation of the induced AT may lead to a favorable outcome.