1. Nikos Protonotarios Medical Centre; Naxos; Greece
2. 1 Department of Cardiology; University of Athens Medical School; Athens Greece
3. Department of Cardiology; Nicosia General Hospital; Nicosia Cyprus
4. 2 Department of Cardiology; Evangelismos General Hospital; Athens Greece
5. Institute of Cardiovascular Science; University College London and The Heart Hospital, University College London Hospitals Trust; London UK