Use of nifekalant in cardioversion of patients with atrial flutter treated with or without class I antiarrhythmic agents

Background: Nifekalant(NIF) is pure class III antiarrhythmic agent (Ikr blocker) and proved to be effective in the treatment of ventricular arrhythmias. However whether or not it has effectiveness on atrial flutter(AFL) or class I antiarrhythmic agents induced AFL(I-AFL) converted from atrial fibrillation(AF) has not been understood well.