"Transseptal" technique through atrial baffles for 3-dimensional mapping and ablation of atrial tachycardia in patients with d-transposition of the great arteries.

Access to targets for radiofrequency ablation in patients with congenital heart disease may be limited by anatomy and by surgically placed obstacles. In patients with atrial switch anatomy for d-transposition of the great arteries, the critical isthmus for maintenance of intraatrial macroreentry circuits is found often on the pulmonary venous side of the atrial baffle. A retrograde approach is extremely difficult for these arrhythmias. Use of transseptal techniques for diagnostic catheterization in these patients has been reported. We report the use of a transseptal technique in two cases in conjunction with 3-dimensional electroanatomic mapping for the successful ablation of atrial reentry tachycardias in patients with Mustard and Senning anatomy.