Flecainide is effective against premature supraventricular and ventricular contractions during general anesthesia.

The effect of intravenously administered flecainide on premature supraventricular (PSCs) and ventricular contractions (PVCs) which developed under general anesthesia was evaluated. Flecainide was infused intravenously at a rate of 0.2 mg/kg/min until the efficacy of this drug appeared or for 10 min; thus, the maximum dose was determined to be 2 mg/kg. Flecainide was administered to 10 patients who experienced more than 5 supraventricular and/or ventricular contractions/min for a period of more than 5 min (PVCs, 4 patients; PSCs, 6 patients). PVCs in 4/4 cases and PSCs in 5/6 cases disappeared following administration of flecainide. The average dose of flecainide was 1.08±0.17 mg/kg (SE). This dose of flecainide did not affect the heart rate and QRS interval, but caused a transient decrease in systolic blood pressure from 127±6 mmHg (SE) to 114±6 mmHg, a 14% increase in the PQ interval, and a 6.3% increase in the QT interval. These results suggest that flecainide is a promising drug for the treatment of PSCs and PVCs which develop during general anesthesia. Transient hypotension and cardiac conduction disturbances immediately after injection may occur when flecainide is used intravenously.