P1007Efficacy and safety of atrial ablation procedures in patients with complete d-TGA and atrial switch at a Swiss tertiary center

Abstract

Abstract Introduction Patients with complete transposition of the great arteries (d-TGA) and atrial switch face a high lifetime risk of arrhythmias. Interventions in these patients are challenging because of their particular anatomy. Reports on ablation procedures in this patient population are scarce and missing for Switzerland. Method We retrospectively analyzed all ablation procedures performed in the above-mentioned population at a Swiss tertiary care center. Results Among 73 d-TGA pts. (71% male; N=37 Senning; N=36 Mustard) followed at our center, 17 ablations were performed in 11 pts. (15%; one ablation in 8 pts., two in 2 pts. and five in 1 patient). Median age at first ablation was 34 years (range 15–49 years). A total of 17 different intra-atrial reentry tachycardias (IART) and 3 AVNRT were targeted. Of the IART, 10 were cavotricuspid isthmus (CTI)-dependent and 7 were not. In two procedures (12%) only the systemic venous (SV) baffle was accessed for ablation. In 15 procedures (88%), ablation was performed within the pulmonary venous (PV) baffle. Access to the PV baffle was retrograde via the aorta in 6 cases (35%), via a baffle leak in 3 (18%) and via baffle puncture in 6 (35%). All procedures with retrograde approach to the PV baffle or with SV baffle only ablation were performed up to January 2012 and all remaining procedures afterwards. The 3 pts. requiring repeat procedures had retrograde or SV baffle approaches initially, and one additional ablation via baffle puncture was successful. The CTI was targeted in 10 pts. (91%) and ablation was finally successful in all with bidirectional block demonstrated in 8 pts. The coronary sinus was found to drain into the SV baffle in 5 pts. (46%) and useful for assessment of CTI block. The seven CTI-independent IART were scar-related micro-reentries. Ablation of all 3 AVNRTs was successful after one procedure without recurrence. Slow pathway ablation was performed in the SV baffle in two and in the PV baffle in one case (Figure). After a median follow-up of 7 months (range 2–186 months) 9 pts. are without recurrence and in 2 pts. rare self-limited arrhythmias still occur. No procedural complications occurred. Conclusion Arrhythmias in patients with complete d-TGA and atrial switch are mainly CTI-dependent IART or scar-related micro-reentries, and a few patients also have AVNRT. Ablation of these arrhythmias is safe and successful if PV baffle access is achieved via a baffle leak or baffle puncture.