In another COVID-19 study with small sample size of 21 hemodialysis patients, no HQ-related arrhythmia was reported, but ECG monitoring revealed prolongation of corrected QT intervals [[1]]. Dear Editor, Shall we use hydroxychloroquine (HQ) in hemodialysis patients? Hypoxemia, thromboemboli, or cardiac complications may further blur the arrhythmia etiology in COVID-19 patients.