1. From the Bristol Heart Institute CardioNomics Research Group, Bristol Clinical Research and Imaging Centre, School of Physiology, Pharmacology and Neuroscience, University of Bristol, United Kingdom (T.C.H., Z.H.A., R.P.B., K.A.H., J.F.R.P., E.C.H., A.K.N.)
2. Department of Cardiology, Bristol Heart Institute, University Hospitals Bristol NHS Foundation Trust, United Kingdom (T.C.H., R.P.B., A.K.N.).
3. Department of Physiology, Faculty of Medical and Health Sciences, University of Auckland, New Zealand (J.F.R.P.)