Up to 1 in 5 patients hospitalised by COVID-19 have evidence of heart muscle injury as measured from a blood test. This is associated with a high death rate. Using an MRI scan of the heart we aim to investigate how often, and in what way, the heart becomes damaged, and how the heart recovers 6 months later. We need to know how heart muscle damage and recovery is affected by age, sex, ethnicity and other medical conditions (such as diabetes, high blood pressure, heart disease and narrowing of blood vessels), as these are also known to be associated with high death rates. We also want to see if we can improve the diagnosis of viral heart damage from a simple ECG, which may save patients having invasive heart tests which can be uncomfortable, are expensive and carry a small risk of serious complications and may put healthcare staff at increased risk of exposure to COVID-19.