Department of Internal Medicine, Faculty of Medicine, University of Belgrade, Dr Subotica 8, 11000, Belgrade, Serbia. Department of Cardiology, Cardiovascular Institute "Dedinje", Heroja Milana Tepica 1, 11000, Belgrade, Serbia. Department of Physiology, Faculty of Medical Sciences, University of Kragujevac, Svetozara Markovica 69, 34000, Kragujevac, Serbia. drvladakgbg@yahoo.com. Department of Human Pathology, 1st Moscow State Medical, University IM Sechenov, Trubetskaya Street 8, Moscow, 119991, Russia. drvladakgbg@yahoo.com. Pharmaceutical Company "Pharmanova", Generala Arnija 6, 11010, Belgrade, Serbia. Department of Cardiology, Clinical Center Nis, Bulevar dr Zorana Djindjica 48, 18108, Nis, Serbia. Department of Cardiology, Clinical Center "Dr Dragisa Misovic", Heroja Milana Tepica 1, 11000, Belgrade, Serbia. Department of Cardiology, Health Center Uzice, Milosa Obrenovica 17, 31000, Uzice, Serbia. College of Health Studies, Podgorica, Montenegro. Department of Physiology, Faculty of Medical Sciences, University of Kragujevac, Svetozara Markovica 69, 34000, Kragujevac, Serbia. Department of Human Pathology, 1st Moscow State Medical, University IM Sechenov, Trubetskaya Street 8, Moscow, 119991, Russia. Department of Pharmacy, Faculty of Medical Sciences, University of Kragujevac, Svetozara Markovica 69, 34000, Kragujevac, Serbia.