1 Andersen-Tawil Syndrome presenting with complete heart block Karen Suetterlin a , Roope Männikkö a , Enrico Flossmann b , Richa Sud c , Doreen Fialho a , Vino Vivekanandam a , Natalie James a , Thomas D Gossios d , Michael G Hanna a , Kostas Savvatis d , and Emma Matthews, a,e a Queen Square Centre for Neuromuscular Diseases, National Hospital for Neurology and Neurosurgery, and Department of Neuromuscular Diseases, UCL Institute of Neurology, Queen Square, WC1N 3BG, London, UK b Royal Berkshire Hospital Reading and Nuffield Department of Clinical Neurosciences, University of Oxford, UK c Neurogenetics Unit, Institute of Neurology, Queen Square, London, UK d Inherited Cardiovascular Diseases Unit, Barts Heart Centre, Barts Healthcare NHS Trust, EC1A 7BE, London, UK e Atkinson Morley Neuromuscular Centre, Department of Neurology, St George's University Hospitals NHS Foundation Trust, SW17 0QT, London, UK Corresponding Author: Emma Matthews Email: emma.matthews8@nhs.net Atkinson Morley Neuromuscular Centre, Department of Neurology, St George's University Hospitals NHS Foundation Trust, SW17 0QT, London, UK Tel: 0203 108 7513 Fax: 020 3448 3633 Manuscript: 785 words Title: 60 characters References: 7 Figures: 1 Abbreviations: Andersen-Tawil syndrome (ATS) Running title: ATS with heart block