Research Article Effect of Hydroxychloroquine and Azithromycin on QT Interval Prolongation and Other Cardiac Arrhythmias in COVID-19 Confirmed Patients Seyed Parsa Eftekhar , 1 Sohrab Kazemi , 2 Mohammad Barary , 1 Mostafa Javanian , 3 Soheil Ebrahimpour , 3 and Naghmeh Ziaei 4 1 Student Research Committee, Health Research Center, Babol University of Medical Sciences, Babol, Iran 2 Cellular and Molecular Biology Research Center, Health Research Center, Babol University of Medical Sciences, Babol, Iran 3 Infectious Diseases and Tropical Medicine Research Center, Health Research Institute, Babol University of Medical Sciences, Babol, Iran 4 Department of Cardiology, Babol University of Medical Sciences, Babol, Iran Correspondence should be addressed to Naghmeh Ziaei; ziaiexn@yahoo.com Received 22 November 2020; Revised 8 February 2021; Accepted 19 February 2021; Published 2 March 2021 Academic Editor: Brian Tomlinson Copyright © 2021 Seyed Parsa Eftekhar et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. Background. Hydroxychloroquine with or without azithromycin was one of the common therapies at the beginning of the COVID- 19 pandemic. They can prolong QT interval, cause torsade de pointes, and lead to sudden cardiac death. We aimed to assess QT interval prolongation and its risk factors in patients who received hydroxychloroquine with or without azithromycin. Methods. This study was a retrospective cohort study. One hundred seventy-two confirmed COVID-19 patients were included in this study, hospitalized at Babol University of Medical Sciences hospitals between March 5, 2020, and April 3, 2020. Patients were divided into two groups: hydroxychloroquine alone and hydroxychloroquine with azithromycin. Electrocardiograms were used for outcome assessment. Results. 83.1% of patients received hydroxychloroquine plus azithromycin vs. 16.9% of patients who received only hydroxychloroquine. The mean age of patients was 59:2 ± 15:4.The mean of posttreatment QTc interval in the monotherapy group was shorter than the mean of posttreatment QTc interval in the combination therapy group, but it had no significant statistical difference (462:5 ± 43:1 milliseconds vs. 464:3 ± 59:1 milliseconds; p =0:488). Generally, 22.1% of patients had a prolonged QTc interval after treatment. Male gender, or baseline QTc ≥ 450 milliseconds, or high-risk Tisdale score increased the likelihood of prolonged QTc interval. Due to QTc prolongation, fourteen patients did not continue therapy after four days. Conclusions. Hospitalized patients treated by hydroxychloroquine with or without azithromycin had no significant difference in prolongation of QT interval and outcome. The numbers of patients with prolonged QT intervals in this study emphasize careful cardiac monitoring during therapy, especially in high-risk patients. 1. Introduction COVID-19 spread fast and infected millions of people world- wide until now from its beginning in Wuhan, China, and causes high mortality over the world, especially in patients with underlying diseases such as diabetes and congestive heart failure [1, 2]. Since enough clinical trials were unavail- able at the early stages of this pandemic, protocols suggested different treatments based on repurposing of medications, clinical trials, in vitro studies, and experiences from past cor- onaviruses like SARS and MERS. However, definite treat- ment and vaccine need more time and work [3–6]. Remdesivir, hydroxychloroquine sulfate, chloroquine phos- phate, and many other drugs showed antiviral efficiency in vitro. Even Yao and colleagues suggested hydroxychloro- quine is more potent than chloroquine [7, 8]. Shah et al. suggested prophylactic roles for chloroquine and hydroxy- chloroquine [9]. Nevertheless, clinical trials challenged Hindawi Cardiovascular erapeutics Volume 2021, Article ID 6683098, 7 pages https://doi.org/10.1155/2021/6683098