The primary goal of the study is to determine, whether or not an extended heart monitoring program with an ILR will identify more patients with AF as the underlying cause of TIA. This can have enormous advantages for the patient, because the treatment with oral anticoagulation therapy reduces the risk of subsequent stroke by approximately 40% compared to conventional antiplatelet therapy. Secondly, the study means to identify patients at high risk for developing AF assessed with ultrasound, computed tomography and novel biomarkers.