Abstract 10356: Intravenous Niferidile, a New Class III Antiarrhythmic Agent, for Termination of Persistent Atrial Fibrillation and Flutter
Niferidile (NF) is a new III class antiarrhythmic agent. It's electrophysiological profile is characterized by increasing atrial refractoriness and less significant influence on ventricle effective refractory period. The primary objective of this study was to evaluate the efficacy and safety of i.v. administered NF in doses up to 30 µg/kg in termination of persistent atrial fibrillation (AF) and flutter (AFL). 50 patients (33 male) without structural heart diseases were included in the study. Mean age was 55±12 years (29-76), arrhythmia duration was 4,4±4,2 months (2 weeks- 24 months). 39 of the patients had AF and 11 had AFL. Left atrium size was 4,26±0,5 cm and LV ejection fraction was 58±4%. Niferidile was administered as 3 bolus injections (10 µg/kg each) performed with the 15-min interval. If sinus rhythm was restored within 15 min after injection, the next injection was canceled. Efficacy, which was controlled in each case by Holter ECG monitoring, was measured as the percentage of patients converting to SR within 24 hours. SR was restored successfully in 44 of 50 patients: conversion to sinus rhythm was achieved in 54% patients with single dose of NF, cumulative cardioversion rate in dose of 20 µg/kg was 70%, and in dose of 30 µg/kg reached 88%. NF restored SR in all 11 patients with AFL and in 33 of 39 patients (85%) with AF. Among patients with restored SR interval QTc, measured during first 5 min after conversion, exceeded value of 500 mc in 16,8 % (7 of 44). No pro-arrhythmia was noticed in the study patients. Sinus bradycardia was registered in 17 of 44 (39%) patients. Bradycardia was symptomatic only in one of them and was treated successfully by atropine injection.
Conclusion: i.v. niferidil in doses up to 30 µg/kg demonstrated high efficacy (up to 88%) and safety in conversion of patients with persistent AF and AFL.
- © 2011 by American Heart Association, Inc.