1 First Department of Cardiology, National and Kapodistrian University of Athens, Hippokrateion Hospital, Athens, Greece.
2 First Department of Cardiology, National and Kapodistrian University of Athens, Hippokrateion Hospital, Athens, Greece. Electronic address: kgatzoul@med.uoa.gr.
3 Athens Heart Center, Athens Medical Center, Athens, Greece.
4 State Department of Cardiology, Hippokrateion Hospital, Athens, Greece.