5. Conclusions The present multicenter study identifies patients with cardiac arrhythmia during hospitalization for COVID-19 as a high-risk subgroup characterized by severe course of disease and adverse outcomes. Underlying pathomechanisms may be related to a hyperinflammatory state and myocardial injury, particularly in patients with cardiac comorbidities. Due to the high incidence of arrhythmic events in COVID-19 and their potential prognostic implications, arrhythmias should be screened for in affected patients with respective risk factors.