Ablation of incisional atrial tachycardias using a three-dimensional nonfluoroscopic mapping system

Incisional atrial reentrant tachycardias are macroreentrant arrhythmias in which surgical scars or prosthetic material constitute one of the constrain ing barriers of the circuit. Accurate reconstruction based on fluoroscopy-g uided endocardial mapping of the reentrant circuit is often incomplete and time consuming explaining, at least in part, the modest long-term results o f this technique. Mapping and ablation of these arrhythmias using a three-d imensional nonfluoroscopic mapping system that allows electroanatomic recon struction of the reentrant circuit could help in identifying the ablation t argets and improve long-term outcome. The study included 20 patients (12 me n, mean age 45 +/- 18 years) with corrected congenital heart disease (4 pat ients), coronary artery bypass surgery (7 patients), mitral or aortic valve replacement or reconstruction (6 patients), valve replacement and coronary revascularization (2 patients), and mitral valve replacement with maze pro cedure for atrial fibrillation (1 patient). Endocardial mapping with this n ovel system was complemented by standard electrophysiological techniques us ed to identify a critical isthmus of conduction. Two or more nonconductive areas of atrial tissue or surgical prosthetic material delimiting a critica l isthmus of conduction were identified in every patient, Radiofrequency li near applications spanning two to more boundaries successfully eliminated t he tachycardia in every patient. At a follow-up of 11.5 +/- 5.1 months (ran ge 17-5 months), two (10%)patients developed a new clinical arrhythmia, The remaining 18 had no recurrences off medical therapy. Mean fluoroscopy time was 45.7 +/- 15.2 minutes for patients with a single scar and 89 +/- 41.2 minutes in patients with two or more scars. In conclusions, this new nonflu oroscopic mapping system offers the opportunity to achieve a high rate of c ure of complex macroreentrant atrial tachycardias by facilitating reconstru ction of the macroreentrant circuit and its boundaries.