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How is Sinus Rhythm Maintained in Paroxysmal Atrial Fibrillation?

While the choice of appropriate treatment of all varieties of atrial fibrillation (AF) can be difficult, when the disorder occurs as self-terminating paroxysms some problems particular to this variety of AF arise. For permanent AF, only rate-control therapy and warfarin are required, and with persistent AF the term of prophylactic therapy can expire after one or two years. With paroxysmal AF, long-term treatment with arrhythmia-suppressing treatment is envisaged in a patient population that is younger and more likely to be free of other heart disease than those with persistent or permanent AF (50% have ‘lone’ paroxysmal AF, versus 20% and <10% for persistent and permanent AF respectively).A clinical perception exists that paroxysmal AF is a precursor, by months or a few years, of permanent AF. Many patients, however, continue to suffer from purely paroxysmal AF for many years and, in any case, paroxysmal AF needs consideration for prophylactic antiarrhythmic drug therapy in the meantime. Current drug therapy is limited by side-effects and incomplete efficacy, and persisting medical concerns regarding proarrhythmic potential of drugs. Given the limited efficacy of current treatments, the possibility that, had effective treatment been offered at an early stage, the eventual outcome would have been different cannot be excluded. Attractive non-pharmacological strategies are emerging, and these may be more effective and cheaper in the long-term than antiarrhythmic drug therapy, but so far systematic evidence is too sparse and follow-up too short for definitive recommendations to be made from these trials. This article is a systematic review of what is currently established regarding the efficacy of both pharmacological and interventional treatments for and regression of atrial fibrillation. Where AF continues for more than 48 hours, or recurs after first onset has terminated, it has by definition become chronic AF. This is sub-classified as paroxysmal, persistent and permanent, and with time a patient may move between these types of AF.