Multiple atrial macro-re-entry circuits in adults with repaired congenitalheart disease: Entrainment mapping combined with three-dimensional electroanatomic mapping

OBJECTIVES We sought to characterize re-entry circuits causing intra-atrial re-entrant tachycardias (IARTs) late after the repair of congenital heart disease (CHD) and to define an. approach for mapping and ablation, combinin g anatomy, activation sequence data and entrainment mapping. BACKGROUND The development of IARTs after repair of CHD is difficult to man age and ablate due to complex anatomy, variable re-entry circuit locations and the frequent co-existence of multiple circuits. METHODS Forty-seven re-entry circuits were mapped in 20 patients with recur rent IARTs refractory to medical therapy. In the first group (n = 7), ablat ion was guided by entrainment mapping. In the second group (n = 13), entrai nment mapping was combined with a three-dimensional electroanatomic mapping system to precisely localize the scar-related boundaries of re-entry circu its and to reconstruct the activation pattern. RESULTS Three types of right atrial macro-re-entrant circuits were identifi ed: those related to a lateral right atriotomy scar (19 IARTs), the Eustach ian isthmus (18 IARTs) or an atrial septal patch (8 IARTs). Two IARTs origi nated in the left atrium. Radiofrequency (RF) lesions were applied to trans ect critical isthmuses in the right atrium. In three patients, the combined mapping approach identified a narrow isthmuses in the lateral atrium, wher e the first RF lesion interrupted the circuit; the remaining circuits were interrupted by a series of RF lesions across a broader path. Overall, 38 (8 1%) of 47 IARTs were successfully ablated. During follow-up ranging from 3 to 46 months, 16 (80%) of 20 patients remained free of recurrence. Success was similar in the first 7 (group 1) and last 13 patients (group 2), but fl uoroscopy time decreased from 60 +/- 30 to 24 +/- 9 min/procedure, probably related to the increasing experience and ability to monitor catheter posit ion non-fluoroscopically. CONCLUSIONS Entrainment mapping combined with three-dimensional electroanat omic mapping allows delineation of complex re-entry circuits and critical i sthmuses as targets for ablation. Radiofrequency catheter ablation is a rea sonable option for treatment of IARTs related to repair of CHD. (J Am Cell Cardiol 2001;37:1665-76) (C) 2001 by the American College of Cardiology.