[1] Royal Brompton Hosp, Cardiol Dept, London, England
[2] Northumbria Healthcare NHS Fdn Trust, Northumbria Specialist Emergency Care Hosp, Dept Acute Internal Med, Cramlington, England
[3] Mid Yorkshire Hosp NHS Trust, Pinderfields Gen Hosp, Dept Cardiol, Wakefield, England
[4] Northern Gen Hosp, Dept Cardiol, Sheffield, S Yorkshire, England
[5] Univ East Anglia, Dept Cardiol, Norwich, Norfolk, England
[6] Norfolk & Norwich Univ Hosp, Dept Cardiol, Norwich, Norfolk, England
[7] Northumbria Healthcare NHS Fdn Trust, Northumbria Specialist Emergency Care Hosp, Dept Cardiol, Cramlington, England