1 MRC Centre for Neuromuscular Diseases, UCL Institute of Neurology and National Hospital for Neurology and Neurosurgery, Queen Square, London, WC1N 3BG, UK. Electronic address: [email protected].
2 MRC Centre for Neuromuscular Diseases, UCL Institute of Neurology and National Hospital for Neurology and Neurosurgery, Queen Square, London, WC1N 3BG, UK.
3 Cardiology Clinical Academic Group, St George's University of London, London, UK; St George's University Hospitals NHS Foundation Trust, London, UK.