1. Department for Cardiovascular Diseases, Clinical Center Nis, Nis, Serbia
2. Faculty of Medicine, University of Nis, Nis, Serbia
3. Institute for Treatment and Rehabilitation Niska Banja, Nis, Serbia
4. Clinic for Internal Diseases Intermedica, Nis, Serbia
5. Clinical Center of Serbia, Department of Cardiology, Belgrade, Serbia
6. Department of Cardiology, Dedinje Cardiovascular Institute, Belgrade, Serbia
7. Health Center Kladovo, Kladovo, Serbia