1. School of Social Sciences, Hellenic Open University, Parodos Aristotelous 18, 26 335 Patra, Greece
2. Third Department of Cardiology, Hippokration General Hospital, Aristotle University Medical School, 49 Konstantinoupoleos Road, 54642 Thessaloniki, Greece
3. Second Department of Cardiology, Hippokration General Hospital, Aristotle University Medical School, 49 Konstantinoupoleos Road, 54642 Thessaloniki, Greece