ABSTRACT
BACKGROUND: Cardiac arrhythmias, mainly atrial fibrillation (AF), is frequently reported in COVID-19 patients, more often in Intensive Care Unit (ICU) patients, yet causality has not been virtually explored. Moreover, non-Covid ICU patients frequently present AF, sepsis being the major trigger. We aimed to examine whether sepsis or other factors-apart from Covid-19 myocardial involvement-contribute to elicit New Onset AF (NOAF) in intubated ICU patients. METHODS: Consecutive intubated, Covid-19ARDS patients, were prospectively studied for factors triggering NOAF. Demographics, data on Covid-19 infection duration, laboratory findings (troponin as well), severity of illness and ARDS were compared between NOAF and control group (no AF) on admission. In NOAF patients, echocardiographic findings, laboratory and secondary infection data on the AF day were compared to the preceding days and/or ICU admission data. RESULTS: Among 105 patients screened, 79 were eligible; nineteen presented NOAF (24%). Baseline characteristics did not differ between the NOAF and control groups. Troponin levels were mildly elevated upon ICU admission in both groups. Left ventricular global longitudinal strain was impaired (<16.5%) in 63% vs 78% in the two groups, respectively. The right ventricle was mildly dilated, and pericardial effusion was present in 52 vs 43%, respectively. NOAF occurred on the 18 ± 4.8 days from Covid-19 symptoms' onset, and the 8.5 ± 2.1 ICUday. A septic secondary infection episode occurred in 89.5% of the patients in the NOAF group ( vs 41.6% in the control group (p < 0.001). In fact, NOAF occurred concurrently with a secondary septic episode in 84.2% of the patients. Sepsis presence was the only factor associated to NOAF occurrence (OR 16.63, p = 0.002). Noradrenaline, lactate and inflammation biomarkers gradually increased in the days before AF (all p < 0.05). Echocardiographic findings did not change on NOAF occurrence. CONCLUSION: Secondary infections seem to be major contributors for NOAF occurrence in Covid-19 patients, probably playing the role of the "second hit" in an affected myocardium from Covid-19.