Left atrial linear ablation to modify the substrate of atrial fibrillation using a new nonfluoroscopic imaging system.

Linear left atrial ablation is performed in combination with pulmonary vein (PV) isolation to improve the clinical results of atrial fibrillation (AF) ablation. These procedures require long procedures and fluoroscopic exposure. The aim of the present study was to evaluate the performance of a new, nonfluoroscopic, real-time, three-dimensional navigation system for linear ablation at the left atrial roof and mitral isthmus. The study included 44 patients (54 +/- 10 years of age, 5 women) with drug-refractory AF, who underwent roof line or mitral isthmus linear ablation after 4-PV isolation. In 22 patients, ablation was performed with the navigation system (test group), and in the remainders linear ablation was performed with fluoroscopic guidance alone (control group). Conduction block was achieved in 20 patients (91%) in test group, and 21 patients (95%) in the control group (ns). Use of the navigation system was associated with a shorter fluoroscopic exposure for roof line (5.6 +/- 3.0 minutes vs 8.7 +/- 5.0 minutes, P < 0.05), and a trend for mitral isthmus ablation (7.8 +/- 7.8 minutes vs 12.1 +/- 5.9 minutes). It was also associated with a trend toward shorter procedure times for roof line (15.3 +/- 8.6 minutes vs 22.9 +/- 16.8 minutes) and mitral isthmus line (20.2 +/- 15.8 minutes vs 32.0 +/- 7.6 minutes) but no difference in duration of radiofrequency delivery. There was no procedural complication. The use of this new nonfluoroscopic imaging system was associated with a shorter fluoroscopic exposure as well as a trend toward shorter duration of linear ablation procedures for AF.