The key findings of the present study are the following: (1) During active disease, patients with severe COVID‐19 show a significant increase of ECG indices of AV conduction, specifically PR‐interval and PR‐segment; (2) the AV delay is transient as these parameters rapidly normalize, within days, during recovery; (3) PR‐indices significantly correlate with circulating IL‐6 levels over time; and (4) all these changes occur also in the absence of laboratory signs of cardiac strain/injury or concomitant treatment with PR‐prolonging drugs, repurposed or not. Here, IL6 is linked to COVID-19.