BACKGROUND Combination of hydroxychloroquine and azithromycin for the treatment of coronavirus disease 2019 (COVID-19) carries increased risk of corrected QT (QTc) prolongation and cardiac arrhythmias. OBJECTIVE To characterize the ventricular repolarization indexes which are associated with malignant ventricular arrhythmias in patients treated with hydroxychloroquine and concomitant azithromycin for COVID-19. METHOD A total of 81 patients who had hydroxychloroquine and azithromycin combination therapy because of possible or reverse-transcription polymertase chain reaction (RT-PCR) confirmed diagnosis of COVID-19 were included in the study. Baseline and control electrocardiograms (before and after treatment) were analyzed retrospectively. Tp-e interval, Tp-e/QT and Tp-e/QTc ratios, which are ventricular repolarization indexes, were calculated. RESULTS While there was no significant increase in QTc interval in patients receiving combination therapy, there was a significant increase in ventricular repolarization indexes. CONCLUSION The increase in ventricular replarization indexes is associated with the risk of arrhythmia. In patients using QTc prolonging medication for COVID-19 treatment, QTc monitoring alone may not be sufficient to follow-up for arrhythmia. Even if there is no prolongation in QTc, an increase in ventricular repolarization indexes may be seen (Tab. 5, Ref. 37).
Ventricular repolarization indexes in patients treated with hydroxychloroquine - azithromycin combination for COVID-19.