1. Department of Cardiology, Birmingham City Hospital, Birmingham, UK
2. Department of Cardiology, Birmingham City Hospital, Birmingham, UK; Aston Medical School, University of Aston, Birmingham, UK
3. Department of Cardiology, Leeds General Infirmary, Leeds, UK
4. Department of Cardiology, Birmingham City Hospital, Birmingham, UK; Aston Medical School, University of Aston, Birmingham, UK; University of Birmingham, Birmingham, UK
5. Department of Cardiology, Birmingham City Hospital, Birmingham, UK; University of Birmingham, Birmingham, UK