No other antiarrhythmic showed a significant effect on mortality compared with controls .
Class IA , IC , and III drugs are effective in maintaining sinus rhythm but increase adverse effects , and class IA drugs may increase mortality
BACKGROUND A variety of antiarrhythmic drugs have been used to prevent recurrence of atrial fibrillation after conversion to sinus rhythm .
We performed a systematic review to determine the effect of long-term treatment with those drugs on death , embolisms , adverse effects , and atrial fibrillation recurrence .
Mortality and morbidity in patients receiving encainide, flecainide, or placebo. The Cardiac Arrhythmia Suppression Trial.
BACKGROUND AND METHODS In the Cardiac Arrhythmia Suppression Trial , design ed to test the hypothesis that suppression of ventricular ectopy after a myocardial infa rct ion reduces the incidence of sudden death , patients in whom ventricular ectopy could be suppressed with encainide , flecainide , or moricizine  were r and omly assigned to receive either active drug or placebo . The use of encainide and flecainide was discontinued because of excess mortality . We examined the mortality and morbidity after r and omization to encainide or flecainide or their respective placebo . RESULTS Of 1498 patients , 857 were assigned to receive encainide or its placebo ( 432 to active drug and 425 to placebo ) and 641 were assigned to receive flecainide or its placebo ( 323 to active drug and 318 to placebo ) . After a mean follow-up of 10 months , 89 patients had died : 59 of arrhythmia ( 43 receiving drug vs. 16 receiving placebo ; P = 0.0004 ) , 22 of nonarrhythmic cardiac causes ( 17 receiving drug vs. 5 receiving placebo ; P = 0.01 ) , and 8 of noncardiac causes ( 3 receiving drug vs. 5 receiving placebo ) . Almost all cardiac deaths not due to arrhythmia were attributed to acute myocardial infa rct ion with shock ( 11 patients receiving drug and 3 receiving placebo ) or to chronic congestive heart failure ( 4 receiving drug and 2 receiving placebo ) . There were no differences between the patients receiving active drug and those receiving placebo in the incidence of nonlethal disqualifying ventricular tachycardia , proarrhythmia , syncope , need for a permanent pacemaker , congestive heart failure , recurrent myocardial infa rct ion , angina , or need for coronary-artery bypass grafting or angioplasty . CONCLUSIONS There was an excess of deaths due to arrhythmia and deaths due to shock after acute recurrent myocardial infa rct ion in patients treated with encainide or flecainide .  Nonlethal events , however , were equally distributed between the active-drug and placebo groups . The mechanisms underlying the excess mortality during treatment with encainide or flecainide remain unknown
No other antiarrhythmic showed a significant effect on mortality compared with controls .
Class IA , IC , and III drugs are effective in maintaining sinus rhythm but increase adverse effects , and class IA drugs may increase mortality
BACKGROUND A variety of antiarrhythmic drugs have been used to prevent recurrence of atrial fibrillation after conversion to sinus rhythm .
We performed a systematic review to determine the effect of long-term treatment with those drugs on death , embolisms , adverse effects , and atrial fibrillation recurrence .