1. R2. 최태웅 / Pf. 김진배

2. BACKGROUND  Ischemic stroke : leading causes of death and disability : cause remains unexplained after routine evaluation → Cryptogenic stroke  Atrial fibrillation : well-recognized cause of ischemic stroke → stroke risk reduced by anticoagulation : paroxysmal & asymptomatic nature (may not be detected with traditional monitoring techniques)

3. BACKGROUND  Strategies for detection of atrial fibrillation serial ECG, Holter monitoring monitoring with use of external event or loop recorders, long-term outpatient monitoring monitoring by means of insertable cardiac monitors (ICMs)  Current guidelines recommend → at least 24 hr of ECG monitoring after an ischemic stroke to rule out atrial fibrillation → most effective duration and type of monitoring not established

4. Material and Method  The Cryptogenic Stroke and Underlying AF(CRYSTAL AF) trial → parallel-group trial(randomized, controlled study) → comparing ICM vs conventional (24hr Holter, ECG, event recorder) f/u in patients with cryptogenic stroke or transient ischemic attack (TIA)  The primary end point time to first detection of A-fib at 6 months of f/u  Secondary end points time to first detection of A-fib at 12 months of f/u, recurrent stroke or TIA, and change in use of oral anticoagulant drugs

5. Material and Method

6. RESULTS

8. Detection of A-fib (6 months) 8.9% vs 1.4% (HR 6.4) Detection of A-fib (12 months) 12.4% vs 2.0% (HR 7.3)

9. RESULTS Detection of A-fib (36 months) 30% vs 3.0% (HR 8.8)

10. RESULTS

11. CONCLUSION  ECG monitoring with an ICM was superior to conventional follow- up for detecting atrial fibrillation after cryptogenic stroke  A-fib after cryptogenic stroke was most often asymptomatic and paroxysmal → unlikely to be detected by strategies based on symptom-driven monitoring or intermittent short-term recordings