ABSTRACT
Background and Aims: Subclinical atrial fibrillation (SCAF) is an asymptomatic, short and fast atrial arrhythmia observed during long-term monitoring. SCAF incidence ranges between 5-15% in critical illness and is associated to an increased risk of one-yeardeath, while its role in thromboembolism is debated. With this pilot study, we assessed SCAF incidence in a longitudinal cohort of moderate-to-severe CoViD-19, evaluating its association with inhospital death, major bleeding or thromboembolism. Methods: We considered all the subjects admitted to our subintensive medicine department for moderate-to-severe CoViD-19 undergoing to continuous ECG monitoring for at least seven consecutive days, evaluating the occurrence of SCAF daily. We also collected history, ECG, age, sex, occurrence of in-hospital death, thromboembolism and major bleeding. Results: Of 34 consecutive patients, 4 were excluded for pre-existing atrial fibrillation. We analysed 30 subjects who completed ECG monitoring: mean age was 66±14.8 years, 47% were females. SCAF incidence was 20% in 7 days. During the admission we observed 6(20%) deaths, 2(6%) thromboembolic events and 2(6%) major bleedings, with no relationship with SCAF occurrence. SCAF was more frequently observed in severe than in moderate CoViD-19 (p=0.0001). Conclusions: SCAF shows high incidence in CoViD-19, especially within a severe disease. This pilot study did not underline an association with short-term events: we are expanding our cohort and performing a longer follow-up to validate our data and to assess associations with post-CoViD events.