1. Arrhythmia Clinic; Skåne University Hospital; Lund Sweden
2. Department of Cardiology, Clinical Sciences; Lund University; Lund Sweden
3. Department of Clinical Physiology and Nuclear Medicine; Skåne University Hospital and Lund University; Lund Sweden
4. Heart Research Follow-Up Program; University of Rochester; Rochester NY USA
5. Department of Clinical Physiology; Karolinska Institutet, and Karolinska University Hospital; Stockholm Sweden
6. Duke Clinical Research Institute; Durham NC USA
7. Office of Science and Engineering Laboratories; Center for Devices and Radiological Health; US Food and Drug Administration; Silver Spring MD USA