Moreover all the anti-arrhythmic agents that are used in treatment of AF were potentially pro-arrhythmic especially in patients with coronary artery disease and structurally abnormal heart .
Although atrial fibrillation ( AF ) is the most common sustained arrhythmia seen during daily cardiovascular physician practice , its management remained a challenge for cardiology physician as there was no single anti-arrhythmic agents proved to be effective in converting atrial fibrillation and kept its effectiveness in maintaining sinus rhythm over long term .
Some of these drugs also have serious non cardiac side effects that limit its long term use in the management of atrial fibrillation .
Several new and investigational anti-arrhythmic agents are emerging but data supporting their effectiveness and safety are still limited .
Efficacy and safety of intravenously administered dofetilide in acute termination of atrial fibrillation and flutter: a multicenter, randomized, double-blind, placebo-controlled trial. Danish Dofetilide in Atrial Fibrillation and Flutter Study Group.
BACKGROUND This study was design ed to assess the efficacy and safety of intravenous dofetilide in acute termination of atrial fibrillation ( AF ) and flutter ( AFL ) .  Dofetilide , an investigational class III antiarrhythmic agent , selectively inhibits the rapid component of the delayed rectifier potassium current , thus prolonging the effective refractory period and duration of the action potential . Dofetilide can be administered intravenously and has a rapid onset of electrophysiologic action . METHODS AND RESULTS Ninety-six patients with AF ( n = 79 ) or AFL ( n = 17 ) with a median arrhythmia duration of 62 days ( range 1 to 180 ) were r and omized to placebo ( n = 30 ) or 8 micrograms/kg IV dofetilide ( n = 66 ) over 30 minutes . Conversion was defined as termination of the atrial arrhythmia within 3 hours from the start of infusion . The conversion rate was 30.3 % after dofetilide and 3.3 % after placebo ( P < .006 ) . Conversion rate was higher in AFL than in AF : 64 % versus 24 % ( P = . 012 ) . In nonconverters , there was no statistically significant difference between the change in heart rate among the dofetilide-treated compared with the placebo-treated patients ( P = . 42 ) . Torsade de pointes ventricular tachycardia developed in 2 patients ( 3 % ) . In both patients , drug infusion was discontinued before the event because of prolongation of the QT interval . CONCLUSIONS Intravenous dofetilide is effective in acute termination of AF and AFL of medium duration , with a particularly high efficacy rate in AFL . A small but serious risk of proarrhythmia must be anticipated
Moreover all the anti-arrhythmic agents that are used in treatment of AF were potentially pro-arrhythmic especially in patients with coronary artery disease and structurally abnormal heart .
Although atrial fibrillation ( AF ) is the most common sustained arrhythmia seen during daily cardiovascular physician practice , its management remained a challenge for cardiology physician as there was no single anti-arrhythmic agents proved to be effective in converting atrial fibrillation and kept its effectiveness in maintaining sinus rhythm over long term .
Some of these drugs also have serious non cardiac side effects that limit its long term use in the management of atrial fibrillation .
Several new and investigational anti-arrhythmic agents are emerging but data supporting their effectiveness and safety are still limited .