1. 1 University of Kragujevac, Faculty of Medical Sciences , Department of Internal medicine , Kragujevac , Serbia
2. 2 Clinic for Cardiology , University Clinical Center Kragujevac , Kragujevac , Serbia
3. 3 University of Kragujevac, Faculty of Medical Sciences , Department of Physiology , Kragujevac , Serbia
4. 4 Clinic for Pulmology , University Clinical Center Kragujevac , Kragujevac , Serbia