[1] Silesian Ctr Heart Dis Zabrze, Dept Cardiol Congenital Heart Dis & Electrotherap, PL-41800 Zabrze, Poland
[2] Psychol & Pedag Counseling Ctr 3 Katowice, PL-40096 Katowice, Poland
[3] Cracow Univ Econ, Dept Labor Resource Management, PL-31510 Krakow, Poland
[4] Med Univ Silesia, Fac Med Sci Zabrze, Dept Cardiol 3, PL-40055 Katowice, Poland