Usefulness of ablation of complex fractionated atrial electrograms using nifekalant in persistent atrial fibrillation

Abstract

Background: Additional ablation of complex fractionated atrial electrograms (CFAE) after pulmonary vein isolation (PVI) has been shown to improve the success of ablation of persistent atrial fibrillation (AF). However, extensive ablation is often necessary to eliminate all CFAE or to terminate AF. We assessed the usefulness of the administration of an antiarrhythmic drug (AAD) before CFAE ablation. Methods and results: One-hundred and ten patients with persistent AF first underwent PVI, roof and floor linear ablation (box isolation). One hundred patients who remained in AF after box isolation were then randomized to either receive (AAD group, n=. 50) or not receive (no-AAD group, n=. 50) intravenous nifekalant (0.3. mg/kg) followed by a CFAE ablation. In the AAD group, nifekalant terminated AF in 19 (38%) patients and ablation of localized CFAE was performed in 31 patients who remained in AF after nifekalant, and terminated AF in 11 (35%) patients. In the no-AAD group, ablation of CFAE terminated AF in 13 (26%) patients. The AAD group had a significantly lesser number of radio frequency applications at CFAE sites (18±12 versus 36±10, p<0.0001) and shorter procedure time (162±34 versus 197±29. min, p<0.0001) compared with the no-AAD group. However, there was no significant difference in success rate at 12. months after a single ablation procedure between the two groups (AAD group, 74% versus no-AAD group, 76%). Conclusions: An approach to ablation using nifekalant may be useful in localizing areas of CFAE, reducing the number of applications at CFAE sites and procedure time. Ablation of only CFAE localized with nifekalant may be sufficient for clinical outcome. © 2012 Japanese College of Cardiology.