To Monitor or to Not Monitor for Paroxysmal Atrial Fibrillation After Transient Ischemic Attack or Stroke

See related article, p 520.Approximately 25% of ischemic strokes cannot be classified as large-vessel disease, cardiac embolism, or small-vessel disease.1 This remaining entity is called cryptogenic stroke. Cryptogenic in this context can mean that the cause of the transient ischemic attack (TIA) or stroke could not be elucidated during the stay of the patient in the stroke unit or that there was incomplete or insufficient diagnostic testing. Several patients with so-called cryptogenic stroke might have paroxysmal atrial fibrillation (AF), which is not detected with standard 24-hour Holter monitoring on the stroke unit. The detection of AF has major implications for effective secondary stroke prevention. In patients with AF, anticoagulation with warfarin is clearly superior to aspirin,2 and the novel anticoagulants are at least as effective as warfarin if not superior with a comparable or lower rate of major bleeding complications.3Kishore et al4 in this issue of Stroke present results from a systematic literature review and meta-analysis investigating the detection rate of different ECG monitoring techniques to detect AF in patients who had a TIA or an ischemic stroke. They were able to analyze 32 observational or randomized studies with 5038 participants. The detection rate for AF was 11.5%, with a wide variation of methods used, observation time, and …