1. Students’ Scientific Group at II Department of Cardiology in Zabrze, Faculty of Medicine with Dentistry Division, Medical University of Silesia, Katowice, ul. Skłodowskiej 10, Zabrze 41–800, Poland
2. II Department of Cardiology in Zabrze, Faculty of Medicine with Dentistry Division in Zabrze, Medical University of Silesia, Katowice, ul. Skłodowskiej 10, Zabrze 41–800, Poland