Rhythm control: antiarrhythmic drugs

Atrial fibrillation (AF) is the most common chronic arrhythmia and a major cause of cardiovascular morbidity and mortality. The rhythm control strategy involves the use of antiarrhythmic drugs (AADs) to (1) facilitate the cardioversion of recent-onset AF (<7 days) to sinus rhythm in symptomatic patients without haemodynamic instability. Pre-treatment with AADs facilitates direct current cardioversion and their use for 1–2 months prevents immediate/early recurrences of AF after direct current cardioversion or catheter ablation; and (2) maintain sinus rhythm and prevent recurrences of AF. AADs reduce rather than eliminate AF recurrences. However, a recurrence is not equivalent to treatment failure if AADs render AF less symptomatic, briefer, and less frequent. A significant reduction in AF burden with an improvement in quality of life represents a therapeutic success for many patients. However, AADs present a limited efficacy and can produce serious adverse effects, mainly proarrhythmia and organ toxicity. Therefore, the benefit/risk ratio of the rhythm control should be carefully considered before starting the treatment, and safety, rather than efficacy, should be the primary guide to the final choice of AADs. Combination of AADs with non-pharmacological strategies and upstream therapies and optimal management of co-morbidities which promote AF should be pursued to reduce AF burden and facilitate maintenance of sinus rhythm.