1 BHF Clinical Research Fellow and Cardiology Specialist Registrar, Augustus Waller Department of Electrophysiology, Hammersmith Hospital, Imperial College Healthcare NHS Trust, London W12 0HS.
2 Consultant in Interventional Cardiology, Hammersmith Hospital, Imperial College Healthcare NHS Trust, London.
3 Consultant in Cardiology and Cardiac Electrophysiology, Augustus Waller Department of Electrophysiology, Hammersmith Hospital, Imperial College Healthcare NHS Trust, London.