Paroxysmal atrial fibrillation

Abstract

There has been a tendency to treat paroxysmal atrial fibrillation (PAF) in a similar way to sustained AF, but treatment objectives may be very different. We discuss current definitions, epidemiology, pathophysiology and natural history of PAF, and review evidence for its treatment and management. PAF comprises between 25% and 62% of cases of AF, with similar underlying causes to those in sustained AF. The main objective of management is prevention of paroxysms and long-term maintenance of sinus rhythm, and Class 1c drugs are highly effective, although beta-blockers are useful alternatives. If patients have severe coronary artery disease or poor ventricular function, amiodarone is probably the drug of choice. Although randomized controlled trials of thromboprophylaxis in patients with paroxysmal AF per se are lacking, the approach to patients with paroxysmal AF should be similar to that in patients with sustained AF, with warfarin for 'high risk' patients and aspirin for those at 'low risk'. Non-pharmacological therapeutic options, including pacemakers, electrophysiological techniques and the implantable atrial defibrillator, show great promise. Despite paroxysmal AF being a common condition, management strategies are limited by evidence from small randomized trials, with inconsistencies over the definition of the arrhythmia and the inclusion of only symptomatic subjects. Evidence for antithrombotic therapy is also based on epidemiological studies and subgroup analyses of the large randomized trials.