2nd Department of Medicine-Department of Cardiovascular Medicine, First Faculty of Medicine, Charles University in Prague and General University Hospital in Prague, II. interni klinika VFN a 1. LF UK, U nemocnice 2, 128 08, Praha 2, Czech Republic. tomas.kovarnik@vfn.cz. Department of Electrical & Computer Engineering and Iowa Institute for Biomedical Imaging, The University of Iowa, Iowa City, IA, USA. Cardiovascular Research Foundation, New York, USA. 2nd Department of Medicine-Department of Cardiovascular Medicine, First Faculty of Medicine, Charles University in Prague and General University Hospital in Prague, II. interni klinika VFN a 1. LF UK, U nemocnice 2, 128 08, Praha 2, Czech Republic. Institute for Research and Development of Education, Faculty of Education, Charles University in Prague, Prague, Czech Republic. Cardiology Department, Na Homolce Hospital, Prague, Czech Republic. Loyola University Stritch School of Medicine, Maywood, IL, USA.