The world’s largest atrial fibrillation study with continuous long-term ECG recording, NORSCREEN (norscreen.org), has now included 50,000 participants. The purpose of the study is to find «unknown» atrial fibrillation in people >65 years of age before the condition causes symptoms and complications (including stroke and heart failure). The study has included patients from all over Norway and is conducted as digital self-testing with ECG247.