Ablation of atrial tachycardia after surgery for congenital and acquired heart disease using an electroanatomic mapping system: Which circuits to expect in which substrate?

Abstract

The purpose of this study was to compare atrial tachycardia circuits after a range of cardiac operations. Knowledge of circuits occurring in a given postsurgical substrate should help to ablate these challenging tachycardias and develop potential preventive strategies. We analyzed tachycardia circuits in 83 consecutive patients (60 males; median age 47 years, range 9-73) after atrial incisions undergoing ablation of atrial tachycardias. A combined strategy of electroanatomic (CARTO) and entrainment mapping was used. Fifty-two patients (63%) underwent operation for congenital and 31 (37%) for acquired heart disease. Patients were divided into subgroups based on the intervention performed in the atria: right lateral atriotomy (39 patients), left atrial (11) and superior transseptal (10) approach to the mitral valve, biatrial heart transplantation (8), Mustard (8) and Fontan (4) procedure, and other interventions (3). Most of the 119 tachycardias mapped were isthmus-dependent atrial flutter (66) and incisional tachycardia (30). Isthmus-dependent atrial flutter was the most frequent arrhythmia in all subgroups except for Fontan patients, in whom incisional tachycardia was most frequent. The distribution of tachycardia circuits did not differ significantly among groups. The observed circuits did not differ among the postsurgical substrates. Isthmus-dependent atrial flutter should be the first circuit considered in patients after atrial incisions.