Abstract
Purpose
When atrial fibrillation (AF) is initiated by a single or several non-pulmonary vein (PV) trigger ectopic beats, mapping the ectopy is often difficult, requiring a number of electrical cardioversion applications. Nifekalant is a rapidly activating delayed rectifier potassium channel (IKr) blocker which may suppress AF initiation without inhibiting ectopy development, thereby allowing the target ectopy to be mapped. To assess the efficacy of nifekalant in the ablation of non-PV ectopies that are unmappable due to easily initiated AF.
Methods
Eleven consecutive patients were administered nifekalant to map a non-PV ectopy that was unmappable using a conventional method due to easily initiated AF. Nifekalant was intravenously administered as a bolus dose of 0.2 mg/kg, and electrical cardioversion was delivered. Additional boluses of 0.2 mg/kg were repeatedly administered until AF initiation was prevented or until the appearance of significant prolongation of QT interval.
Results
AF suppression without inhibition of ectopy development was achieved in 7 patients. These patients had a higher rate of acute elimination of the ectopy than the remaining 4 patients without AF suppression (7 [100%] vs. 1 [25%] patients, p = 0.024). In addition, patients with suppression of AF initiation had a higher AF recurrence-free rate than those without (7 [100%] vs. 1 [25%] patients, p = 0.024).
Conclusion
Nifekalant administration appears useful in the ablation of non-PV ectopies that easily initiate AF.
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This study complied with the Declaration of Helsinki. Written informed consent for the ablation and participation in the study was obtained from all patients
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Masuda, M., Konishi, S., Asai, M. et al. Usefulness of an IKr blocker for ablation of non-pulmonary vein ectopies that are unmappable due to easily initiated atrial fibrillation. J Interv Card Electrophysiol 58, 203–208 (2020). https://doi.org/10.1007/s10840-019-00590-3
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DOI: https://doi.org/10.1007/s10840-019-00590-3