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 .
Clinical efficacy of antazoline in rapid cardioversion of paroxysmal atrial fibrillation -- a protocol of a single center, randomized, double-blind, placebo-controlled study (the AnPAF Study)
Background Rapid conversion of  atrial fibrillation ( AF ) to sinus rhythm may be achieved by the administration of class IA , IC and III antiarrhythmic drugs or vernakalant hydrochloride . However , that treatment may be related to potential pro-arrhythmia , lack of efficacy or the exceptionally high cost of a compound used . Antazoline is a first generation antihistaminic agent with chinidin-like properties . When administered intravenously , antazoline exerts a strong antiarrhythmic effect on supraventricular arrhythmia , especially on AF , facilitating rapid conversion to sinus rhythm . Despite a relative lack of published data antazoline has been marketed in Pol and and widely used in cardiology wards and emergency rooms for many years due to its efficacy , safety and rapid onset of action within minutes of administration . Methods / design A r and omized , double blind , placebo-controlled , superiority clinical trial was design ed to assess clinical efficacy of antazoline in rapid conversion of AF to sinus rhythm .  Eligible patients will present AF lasting less than 43 hours , will be in stable cardio-pulmonary condition and will have no prior history of advanced heart failure or significant valvular disease . Long-term antiarrhythmic therapy is not considered an exclusion criterion . Subjects who fulfill selection criteria will be r and omly assigned to receive intravenously either antazoline or placebo in divided doses and observed for 1.5 hours after conversion to sinus rhythm or after the last i.v . bolus . Primary end point will be the conversion of AF to sinus rhythm confirmed in an electrocardiogram ( ECG ) during the observation period . Secondary end points will be comprised of time to conversion and return of AF during the observation period . Special consideration will be given to the observation of any adverse events . A sample size of 80 patients was calculated based on the following assumptions : two-tailed test , a type I error of 0.01 , a power of 90 % , efficacy of placebo 5 % , efficacy of antazoline 50 % and 20 % drop-out rate to fulfill the criteria of intention-to-treat analysis . Due to the presumed lack of statistical power , the secondary end points and safety endpoints will be considered exploratory . Clinical trials registry Clinical Trials.gov ,
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 .