PURPOSE: The optimal radiofrequency (RF) power and lesion duration using contact force (CF) sensing catheters for atrial fibrillation (AF) ablation are unknown. We evaluate 50 W RF power for very short durations using CF sensing catheters during AF ablation.
METHODS: We evaluated 51 patients with paroxysmal (n=20) or persistent (n=31) AF undergoing initial RF ablation.
RESULTS: A total of 3961 50 W RF lesions were given (average 77.6±19.1/patient) for an average duration of only 11.2±3.7 s. As CF increased from <10 to >40 g, the RF application duration decreased from 13.7±4.4 to 8.6±2.5 s (p<0.0005). Impedance drops occurred in all ablations, and for patients in sinus rhythm, there was loss of pacing capture during RF delivery suggesting lesion creation. Only 3% of the ablation lesions were at <5 g and 1% at >40 g of force. As CF increased, the force time integral (FTI) increased from 47±24 to 376±102 gs (p<0.0005) and the lesion index (LSI) increased from 4.10±0.51 to 7.63±0.50 (p<0.0005). Both procedure time (101±19.7 min) and total RF energy time (895±258 s) were very short. For paroxysmal AF, the single procedure freedom from AF was 86% at 1 and 2 years. For persistent AF, it was 83% at 1 year and 72% at 2 years. There were no complications.
CONCLUSION: Short duration 50 W ablations using CF sensing catheters are safe and result in excellent long-term freedom from AF for both paroxysmal and persistent AF with short procedure times and small amounts of total RF energy delivery.