Antiarrhythmic treatment of atrial arrhythmias.

Atrial premature beats seldom require an antiarrhythmic treatment; reassurance and suppression of coffee, alcohol, and tobacco generally suffice. Acute atrial fibrillation is best treated by electrical cardioversion if it induces acute cardiovascular decompensation. If it is not poorly tolerated, the arrhythmia may be treated with digitalis at doses sufficient to keep the ventricular response rate at 70-90/min. This therapy may restore sinus rhythm, but conversion to sinus rhythm often requires the combined use of digitalis with a beta-blocker or class I antiarrhythmic drug (quinidine, disopyramide, procainamide, propafenone, or flecainide). Digitalis must be avoided in the presence of a preexcitation, and class IA agents, which facilitate atrioventricular (AV) nodal transport, must never be used without digitalis. Chemical cardioversion may also be achieved by i.v. amiodarone. Long-term prevention of recurrences after cardioversion or in the presence of recurrent paroxysmal atrial fibrillation requires digitalis combined with a class I agent, or a beta-blocker, preferably sotalol. Amiodarone is also very efficacious. Special mention should be made of atrial fibrillations of vagal or sympathetic origin, which are best treated by amiodarone, or beta-blockade (nadolol), respectively. In the presence of chronic established atrial fibrillation, digitalis in combination with a beta-blocking agent or a calcium antagonist, such as verapamil or diltiazem, may be useful to slow the ventricular response rate. If successful control cannot be obtained, catheter ablation of the AV node with implantation of a rate-responsive pacemaker must be contemplated. The therapeutic approach in patients with chronic atrial fibrillation, whether or not associated, is similar to atrial flutter.(ABSTRACT TRUNCATED AT 250 WORDS)