Evaluation of flecainide acetate in rapid atrial fibrillation complicating wolff‐parkinson‐white syndrome

Abstract

Summary: Flecainide is reported to be effective in patients with paroxysmal tachycardias, but its effect on rapid ventricular response over accessory atrioventricular pathway during atrial fibrillation is not known. The influence of flecainide on various electrophysiological properties of the accessory pathway with special emphasis on ventricular rate during atrial fibrillation was investigated in 9 patients with severe symptomatic Wolff-Parkinson-White syndrome. The shortest ventricular response during atrial fibrillation increased from 218 (190-270) to 320 (240-block) ms. In 4 patients sustained rapid atrial fibrillation converted to sinus rhythm. The rate of circus movement tachycardia decreased from 166/min to 130/min after flecainide, due to a lengthening of retrograde ventriculoatrial conduction time over the accessory pathway. Flecainide caused a significant prolongation of the effective refractory period of the accessory pathway in our subgroup with extremely fast AV conduction during atrial fibrillation and induced a depressant effect on retrograde accessory pathway conduction. This makes the drug very promising for the emergency treatment of dangerous rapid tachyarrhythias complicating this syndrome.

ACC/AHA/ESC 2006 Guidelines for the Management of Patients With Atrial Fibrillation

“…Flecainide can slow the ventricular rate in patients who have AF associated with a very rapid tachycardia due to an accessory pathway and may terminate AF [861][862][863][864] by prolonging the shortest preexcited cycle length during AF. Propafenone seems less effective in this respect.…”

“…Propafenone seems less effective in this respect. 861 For patients with preexcitation syndromes and AF who have syncope (suggesting rapid heart rate) or a short anterograde bypass tract refractory period, immediate direct-current cardioversion followed by catheter ablation of the accessory pathway is the preferred therapy. 865 Ablation of the bypass tract does not necessarily prevent AF, however, especially in older patients, and additional pharmacological therapy may be required.…”

2011 ACCF/AHA/HRS Focused Updates Incorporated Into the ACC/AHA/ESC 2006 Guidelines for the Management of Patients With Atrial Fibrillation

“…Beta blockers are ineffective in this situation, and their administration via the intravenous route may have adverse hemodynamic effects. Flecainide can slow the ventricular rate in patients who have AF associated with a very rapid tachycardia due to an accessory pathway and may terminate AF [861][862][863][864] by prolonging the shortest preexcited cycle length during AF. Propafenone seems less effective in this respect.…”

“…Propafenone seems less effective in this respect. 861 For patients with preexcitation syndromes and AF who have syncope (suggesting rapid heart rate) or a short antero-grade bypass tract refractory period, immediate direct-current cardioversion followed by catheter ablation of the accessory pathway is the preferred therapy. 865 Ablation of the bypass tract does not necessarily prevent AF, however, especially in older patients, and additional pharmacological therapy may be required.…”

Effects of flecainide and quinidine on human atrial action potentials. Role of rate-dependence and comparison with guinea pig, rabbit, and dog tissues.

“…We chose flecainide as the prototype class IC drug for study because it has been the IC agent most extensively evaluated in the treatment of atrial fibrillation. [10][11][12][13][14][15][16][17][18][19] Quinidine was chosen as a reference class IA compound because of its widespread and longstanding use in the treatment of atrial fibrillation. 31 We compared the effects of flecainide with those of quinidine on atrial action potentials as a function of activation rate, using tissue from patients undergoing coronary artery bypass surgery, as well as from three animal species (guinea pigs, rabbits, and dogs).…”