Silent atrial fibrillation is an important cause of unnecessary strokes. If diagnosed and treated in time with anticoagulants, many disabling strokes can be prevented. In order to improve the diagnosis of atrial fibrillation the MyDiagnostick is developed; a user friendly and easy to use stick that diagnoses atrial fibrillation in one minute. During influenza vaccination, many patients who are also at risk for atrial fibrillation visit the general practice. This offers an ideal opportunity for screening for atrial fibrillation. The study investigates the yield of screening for atrial fibrillation with the MyDiagnostick during influenza vaccination (newly detected atrial fibrillation with corresponding CHA2DS2-Vasc score).