1 Department of Cardiology, Doncaster Royal Infirmary, Doncaster and Bassetlaw Teaching Hospitals NHS Foundation Trust, Thorne Rd, Doncaster, UK, DN2 5LT.
2 Department of Cardiology, Northern General Hospital, Sheffield Teaching Hospitals NHS Foundation Trust, Herries Road, Sheffield, UK, S5 7AU.
3 Department of Infection, Immunity & Cardiovascular Disease, The University of Sheffield, Western Bank, Sheffield, UK, S10 2TN.
4 Department of Adult Congenital Cardiology, Leeds General Infirmary,Leeds Teaching Hospitals NHS Trust, Great George St, Leeds, UK, LS1 3EX.