1 Department of Electrocardiology, Upper Silesian Heart Centre, Katowice, Poland; Department of Electrocardiology and Heart Failure, School of Health Sciences, Medical University of Silesia, Katowice, Poland. rafal_mlynarski@mp.pl
2 Department of Electrocardiology, Upper Silesian Heart Centre, Katowice, Poland; Department of Gerontology and Geriatric Nursing, School of Health Sciences, Medical University of Silesia, Katowice, Poland
3 Unit of Noninvasive Cardiovascular Diagnostics, Upper Silesian Medical Centre, Katowice, Poland; 3rd Division of Cardiology, Medical University of Silesia, Katowice, Poland