Registration process: Patients will be included in the registry at start of NOAC treatment. Exclusion criteria are an expected survival of less than two years and an additional indication for anticoagulation besides atrial tachyarrhythmia's. At baseline general patient characteristics will be registered. Standard echocardiography and laboratory assessments for follow-up in adult CHD patients will be recorded during the registration period. Quality of life and therapy adherence will be assessed with questionnaires. Registry follow-up will be warranted by telephone contact or during outpatient clinic visits. At each follow-up point the occurrence of pre-defined events will be recorded. A detailed description of each variable used by the registry is provided in the protocol. Anonymized data will be collected at each investigational site and entered in a central database at the main investigational site (Academic Medical Center, Amsterdam, The Netherlands).