Paroxysmal atrial fibrillation after ischemic stroke: how should we hunt for it?

Paroxysmal atrial fibrillation (PAF) is a consideration in patients presenting with ischemic stroke despite sinus rhythm on admission ECG. Once PAF is identified, secondary prevention with anticoagulation prevents further stroke. Various methods are available to detect PAF, which is often asymptomatic. The evidence to guide our choice of detection strategies in stroke patients is weak. Current data suggest that prolonged monitoring increases the likelihood of PAF detection. Further research is required to establish the utility of various detection methods and identify their optimum timing, duration and cost-effectiveness. Newer technologies allow extremely brief paroxysmal episodes of AF to be detected, shorter than the traditional 30 s threshold required for diagnosis. However, risk associated with these very brief and hard to detect PAF episodes may be low. Here, the authors provide a broad review of the comparative utility and practicality of available detection methods, discuss ways to optimize outcome and highlight the current and future implications for detecting PAF in stroke patients.