1. Department of Cardiology, Essex Cardiothoracic Centre, Basildon, United Kingdom (G.V.K., S.R.M., F.A.-J., R. Jones, R. Jagathesan, R.K.A., G.J.C., K.H.T., P.A.K., J.R.D., T.R.K.).
2. School of Medicine, Faculty of Medical Science, Anglia Ruskin University, Cambridge and Chelmsford, United Kingdom (G.V.K., S.R.M., F.A.-J., G.J.C., J.R.D., T.R.K.).
3. Department of Cardiology, Royal Sussex County Hospital, Brighton, United Kingdom (A.S.K.).
4. Medizinische Klinik I (Cardiology & Intensive care), Klinikum Darmstadt GmbH, Darmstadt, Germany (G.S.W.).