1. Clinic of Cardiology, Military Medical Academy of Belgrade, 11000 Belgrade, Serbia
2. School of Medicine, University of Defense, 11000 Belgrade, Serbia
3. Clinic of Emergency Internal Medicine, Military Medical Academy, 11000 Belgrade, Serbia
4. Clinic of Cardiology, Clinical Center Nis, 18000 Nis, Serbia
5. School of Medicine, University of Nis, 18000 Nis, Serbia
6. Institute of Pulmonary Diseases Vojvodina, Novi Sad, 21204 Sremska Kamenica, Serbia
7. School of Medicine, University of Novi Sad, 24000 Subotica, Serbia
8. Clinic of Cardiology, Clinical Center Banja Luka, 78000 Banja Luka, Bosnia and Herzegovina
9. School of Medicine, University of Banja Luka, 78000 Banja Luka, Bosnia and Herzegovina
10. General Hospital Pancevo, 26000 Pancevo, Serbia
11. Intensive Care Unit, University Cardiology Clinic, 1000 Skopje, North Macedonia
12. Clinic of Cardiology, Clinical Center Kragujevac, 34000 Kragujevac, Serbia
13. School of Medicine, University of Kragujevac, 34000 Kragujevac, Serbia
14. Clinic of Cardiology, University Clinical Center Zemun, 11080 Belgrade, Serbia
15. School of Medicine, University of Belgrade, 11000 Belgrade, Serbia