In 25-40% of patients with thromboembolic stroke, current diagnostics fail to identify a cause. It has been shown that prolonged heart rhythm monitoring can detect atrial fibrillation (AF) as the underlying cause in one-third of these patients. Even though an implantable loop recorder detects AF in 37% of cases up to four years after stroke, several studies show no reduction in the number of recurrent strokes with anticoagulation treatment. It seems that a high degree of AF around the stroke, so-called high burden, has a more likely causal link, than AF detected months or years after stroke. Anticoagulation treatment may be more effective in high AF burden stroke patients. A less expensive, non-invasive detection method, applicable immediately after stroke, may be more suitable in practice. Furthermore, recent research shows promising results in the importance of determining electrocardiographic, anatomical and blood biomarkers indicative for an atrial myopathy and better detection AF.