1. Department of Electrocardiology and Heart Failure , Medical University of Silesia , Katowice , Poland
2. Department of Histology and Embryology , Medical University of Silesia , Katowice , Poland
3. Department of Cardiac and Vascular Diseases , John Paul II Hospital, Jagiellonian University Medical College , Kraków , Poland
4. Department of Cardiac Surgery , Medical University of Silesia , Katowice , Poland
5. Department of Cardiac and Vascular Diseases John Paul II Hospital , Jagiellonian University Medical College , Kraków , Poland