1. Gottsegen György Hungarian Institute of Cardiology, Budapest, Hungary.
2. Neumann János Faculty of Informatics, Physiological Controls Research Centre, University of Óbuda, Budapest, Hungary.
3. Zala County St. Raphael Hospital, Zalaegerszeg, Hungary.
4. Semmelweis University's Heart and Vascular Centre, Budapest, Hungary.
5. State Hospital for Cardiology, Balatonfüred, Hungary.
6. Jósa András Szabolcs-Szatmár-Bereg County Hospitals and University Teaching Hospital, Nyíregyháza, Hungary.
7. University of Pécs–Heart Institute, Pécs, Hungary.
8. Pándy Kálmán Békés County Central Hospital, Gyula, Hungary.
9. Department of Cardiology, Petz Aladár County Teaching Hospital, Győr, Hungary.