1. Medical Faculty, University of Nis, Bulevar Dr. Zoran Djindjic 8, 18000 Nis,Serbia
2. Clinical Center Nis, Bulevar Dr. Zoran Djindjic 48, 18000 Nis,Serbia
3. Uniklinik Rostock, Kardiologie, Schillngallee 35, 18057 Rostock,Germany
4. Clinic for Internal Diseases Intermedica, Singidunum University Nis, Jovana Ristica 20/III-2, 1800 Nis,United States