Reply to Letter to the Editor: “How Does SARS-CoV-2 Fragment the QRS?”

To the Editor,

We have recently read with great interest the article entitled “How does SARS-CoV-2 fragment the QRS?.” The article is on the possible pathophysiological mechanisms 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 some questions that the authors wonder about our paper. First, in our study, we did not have a hypothesis that f-QRS occurred due to SARS-CoV-2. The message we want to convey is that the presence of f-QRS is associated with poor prognosis in severe COVID-19 patients. Second, it was stated in our article that patients with f-QRS had QT prolongation. However, we agree that sufficient information is not provided about arrhythmias. Our study was designed retrospectively. For this reason, information was not given due to the lack of electrocardiogram (ECG) findings of arrhythmias that may have developed in our patients. We did not do a prospective follow-up of survivors, so we do not have data on long-term ECG results. Third, when the anamnesis of the patients was examined, no patient who developed autonomic dysfunction or had Guillain-Barre syndrome was found. Fourth, as the authors stated, cardiac involvement in SARS-CoV-2 infections may occur with endocarditis, myocarditis, or pericarditis. However, we do not have cardiac magnetic resonance imaging, endocardial biopsy, and transesophageal echocardiography data. Finally, the ECG parameters of the patients were evaluated by 2 different authors (analysis and/or interpretation – B.Ö., N.Ç), and optimal data were tried to be reached and artifacts were excluded. We thank the authors for their valuable comments and suggestions.