Chloroquine, hydroxychloroquine and azithromycin are medications used in the pandemic of COVID-19 as a treatment for confirmed and suspected cases of COVID 19 infection. QTc prolongation a side effect of these medication scan result intorsade’s de pointes leading to cardiac arrest [1]. Tisadale et al. developed a risk score to predict drug-associated QTc prolongation. The risk factors holding 1 point each include age above or equal to 68 years, female gender, use of loop diuretics. 2 points for the following risk factors; Admission QTc more than or equal to 450 msec, acute myocardial infarction and serum potassium of less than 3.5 mEq/L, and 3 points for each of the following risk factors; two or more QTc-prolonging drugs use, sepsis, heart failure or one QTc prolonging drug. A total score of 6 or less result in low risk, a score of 7 to10 results in a moderate risk and a score of 11 or more results in a severe risk [2].

In order to prevent complications especially for severe risk patients a recent publication from the American College of Cardiology contains an outline that can be used in monitoring COVID-19 patients who are to be started on hydroxychloroquine, chloroquine or azithromycin. The recommendation includes that all non-critical QTc prolonging agents to be discontinued, a telemetry to be placed prior to the start of the therapy, potassium to be monitored daily and an ECG to be done after the second dose of the medication which after a daily ECG to be performed. A relative contraindication for the medications is patients known to have long QTsyndrome or having a baseline QTc of more than 500 msec but more than 530 to 550 msec for those with QRS greater than 120 msec. Moreover, if the QTc increases more than 60msec or the absolute QTc is more than the previous relative contraindicated cutoff point azithromycin discontinuation is recommended if used in combination or reduction of the dose of hydroxychloroquine. After which, if the prolongation continues then revaluation of the risk and benefit of the medication is recommended [1].

Al-assaf O, AlHawai A (2020) When to stop COVID-19 Treatment? J Cardiol Clin Res 8(1): 1150.

COVID-19, QTc prolongation, Electrocardiogram

1. Simpson T, Kovacs R, Stecher E. Ventricular Arrhythmia Risk Due to Hydroxychloroquine-Azithromycin Treatment For COVID-19. Cardiology Magazine. American College of Cardiology. 2020.

2. Tisdale JE, Jayes HA, Kingery JR, Kingery JR, Mourad NA, Trujillo TN, et al. Development and validation of a risk score to predict QT interval prolongation in hospitalized patients. Circ Cardiovasc Qual Outcomes. 2013; 6: 479-487