Detection of paroxysmal atrial fibrillation by an implantable subcutaneous holter in patients with non-lacunar cryptogenic ischemic stroke

Atrial Fibrillation (AF) is often paroxysmal and asymptomatic, and yet associated with a high risk of stroke. Finding AF after an ischemic cerebral event needs prescription of oral anticoagulants to reduce the risk of stroke recurrence. A 24-hour ECG monitoring has poor sensitivity for detection of paroxysmal AF (PAF) but the optimum duration of ECG monitoring is not known. Study: We hypothesized that asymptomatic PAF may be an under-recognized mechanism for cryptogenic ischemic stroke. So that, ECG monitoring by an implantable subcutaneous Holter and remote transmission may find episodes of PAF in patients with non-lacunar cryptogenic ischemic stroke. Inclusion criteria were sinus rhythm on 12-lead ECG on admission, no evidence of PAF in a 24 h ECG monitoring and freedom of structural heart disease. Embolism was further suspected by transcranial Duplex ultrasound and/or neuroimaging features. Results: One hundred and one patients have been followed up for a median 262 days (IQR: 119-471). Mean age was 67±13 years and 46% were male. Cardiovascular risk factors were: hypertension (56%), dislipidemia (32%), diabetes (18%) and smoking habit (37%). Median CHA2DS2-VASc Score was 2.5 (IQR: 1-4). Twenty-seven patients (27%) were previously on antiplatelet agent treatment. PAF (lasting more than 2 minutes) was present in 29 patients (28.7%). The first PAF episode was detected after 131 days (IQR: 50-240) of remote monitoring. PAF episodes were mainly at night in 9 patients, longer than 1 hour in 11 patients and the heart rate was below 100 bpm in 9 patients. The table shows the different profile of patients with PAF vs PAF free patients. View this table: Profile of patients with PAF vs PAF free patients Conclusions: In patients with ischemic cryptogenic stroke long ECG monitoring by an implantable subcutaneous Holter and remote transmission detects a significant rate of asymptomatic PAF. The actual pathological relevance of this finding is still unknown, so that wider controlled studies may be appropriate.