In their recent meta-analysis, Liao et al. concluded that the incidence of arrhythmia was higher in COVID-19 than in other community-acquired pneumonia (CAP) (16.8% vs. 4.7%, 95% CI 2.4–8.9) [1, 2], with 2 out of 10 COVID-19 patients dying after developing arrhythmia [3]. Higher incidence rates of conduction disorders and premature contractions were found in COVID-19 patients, compared to other types of arrhythmias [1]. The authors noted that possible mechanisms of arrhythmia may include cardiac damage from metabolic disarray, hypoxia, neurohormonal or inflammatory stress and infection-related myocarditis in the setting of COVID-19 [4]. However, in the vast majority of the studies included, a substantial number of patients were receiving hydroxychloroquine [1], and sometimes azithromycin, and lopinavir/ritonavir [3]. Currently, there is no robust clinical evidence for a benefit associated with these drugs in the treatment of COVID-19, though most, if not all, are associated with the potential to prolong the QT interval, and induce ‘Torsades de Pointes,’ with a consequent risk of drug-induced sudden cardiac death [3]. We felt it important to point out that treatment with hydroxychloroquine in particular may have contributed to these arrhythmias in COVID-19 patients [1]. Given an estimated prevalence of 1 per 2000 of congenital long QT syndrome (LQTS) in the general population [5] and given the fact that it is generally considered to be significantly underdiagnosed, administration of QT interval prolonging drugs in COVID-19 patients may go some way to explain the increased incidence of arrhythmia. [5].

Authors’ response

The authors appreciate Dr. Honore and his team’s valuable comments on our previous meta-analysis of arrhythmia in COVID-19 patients [1]. We agree with the viewpoint that higher incidence of arrhythmia in COVID-19 patients reported in prior literature could probably be explained by the complicated treatment [6]. However, the management strategies for COVID-19 are evolving quite rapidly, and some treatments with potential cardiac side effects, such as hydroxychloroquine, azithromycin and lopinavir/ritonavir, are not recommended under the current guidelines [7]. While existing systematic reviews and meta-analyses should be continually updated, our presented work maintains its emphasis on the clinical importance of monitoring arrhythmia to optimize patient outcomes during this pandemic [1, 8].