LAUSR

We have recently read with great interest the article entitled Fragmented QRS pattern in patients with COVID-19: Further insights into its temporal and mechanistic features. The paper is an invaluable mini-review on the possible patho-physiological mechanisms and clinical implications of fragmented QRS (f-QRS) in patients with novel coronavirus disease (COVID-19). 1 We thank the authors for their interest and thoughtful comments on our study. 2 We would like to answer 2 questions that the authors wonder about our paper. First, we agree with the authors that it is important to determine whether f-QRS is reversible or irrevers-ible in order to have clearer evidences about long-term outcomes. However, our study was designed retrospectively. Therefore, we did not perform a prospective follow-up of survivors. Secondly, as the authors mentioned, coronary slow flow (CSF) may be an important indicator of hyperinflammation. On the other hand, there was no patient who underwent emergent coronary angiogram in our study population. Therefore, it was not possible to perform CSF analysis in patients with ST-segment depression on an electrocardiogram.