In accordance with prior results, AF was the most common incident arrhythmia both in the entire cohort and in the subgroup of patients without any previous history of arrhythmia. An elevated risk for AF has been described in association with other respiratory virus infections, in particular influenza [21], however, with a lower incidence compared to our cohort of COVID-19-patients [22]. The present analyses of the patient subgroup with newly diagnosed AF revealed not only a relevant increase in cardiac biomarkers hinting at myocardial injury but also significantly elevated inflammatory biomarkers. This may point to an association between the degree of inflammatory state caused by COVID-19 and susceptibility to AF, which is in line with previous findings regarding inflammatory mechanisms promoting the development of atrial fibrillation [23].