Okudan, Yunus Emre, Cardiology Department Suleyman Demirel University Medicine Faculty, Isparta, Turkey Okutucu, Sercan, Department of Cardiology, Hacettepe University Faculty of Medicine, Ankara, Turkey Okutucu, Sercan Okutucu, Sercan Okutucu, Sercan, Department of Cardiology, Memorial Ankara Hospital, Ankara, Turkey (Türkiye) Okutucu, Sercan, Memorial Ankara Hospital, Department of Cardiology, Ankara, Turkey Olabu, Beda O. Olano, Daniel, Hospital Universitario Austral Olarewaju, Timothy Olasińska, Anna, I Klinika i Katedra Kardiologii Akademii Medycznej im. Karola Marcinkowskiego w Poznaniu Olasińska-Wiśniewska, Anna Olasinska-Wisniewska, Anna Olczykowska-Siara, Elżbieta Olczykowska-Siara, Krystyna Paruch i Elżbieta Olde Nordkamp, Louise R., Heart Center, Department of Clinical and Experimental Cardiology, Academic Medical Center, Amsterdam, The Netherlands Oldridge, Neil Bryan, School of Medicine and Public Health, University of Wisconsin , Wisconsin, USA Aurora Cardiovascular Services, Aurora Medical Center, Milwaukee, Wisconsin, USA Olejnik, Agnieszka Olejnik, Aleksander Oleksiak, Anna Oleksy, Tomasz, Department of Electrocardiology and Heart Failure. Medical University of Silesia, Katowice Oleszczak, Krzysztof Olgar, Yusuf, Akdeniz University Olinic, Dan Mircea, Iuliu Hatieganu University of Medicine and Pharmacy Cluj-Napoca Departament of Interventional Cardiology at Cluj County Emergency Hospital Olinic, Maria, Iuliu Hatieganu University of Medicine and Pharmacy Cluj-Napoca Departament of Interventional Cardiology at Cluj County Emergency Hospital Olivo, Giuseppe