Follow-up of Kryptogenic Stroke Patients With Implantable vs. Non-invasive Devices to Detect Atrial Fibrillation.

Atrial fibrillation often is paroxysmal and asymptomatic and, therefore, often not detected. Because atrial fibrillation is the leading risk factor for ischemic stroke, and oral anticoagulation is very efficacious for both primary and secondary stroke prevention in atrial fibrillation patients, detection of atrial fibrillation is essential to prevent stroke and stroke-induced disability and death. The incidence of atrial fibrillation and paroxysmal atrial fibrillation is particularly high in stroke patients. Short duration monitoring identified new atrial fibrillation in only about 5% to 10% of stroke patients. Estimates of missed paroxysmal atrial fibrillation in stroke patients go up to 40 000 patients in Germany per year.

Due to the known poor sensitivity of a 24h-ECG, all patients with stroke of unknown cause will undergo the above mentioned non-invasive and invasive ECG monitoring. Based on the data of these extended ECG-analyses, the rate of missed AF in conventionally diagnosed stroke unit patients could be determined by comparison to the 24h-ECG results. Additionally, a cost-benefit equation of the different ECG analysis tools will be calculated by comparison of the respective detection rates and the known follow-up costs.

Inclusion criteria: Patients years with acute ischemic stroke of unknown cause, monitored on a stroke unit undergoing routine diagnostic procedures (conventional 12-lead-ECG, 24h-ECG, echocardiography, cranial computed tomography or cranial magnetic resonance tomography, Transcranial Doppler and carotid duplex ultrasound, long-term blood pressure monitoring, standard laboratory investigations) Exclusion criteria: Stroke with known etiology, Stroke caused by intracranial hemorrhage

Diagnosis-as-usual:

• Standard 24h-ECG on stroke units according to existing guidelines