Electrocardiograms of a COVID-19 patient treated with the combination of hydroxychloroquine and azithromycin

The study involved a 73-year old patient admitted to our hospital with moderate COVID-19 infection detected during acute coronary syndrome. The patient underwent revascularization using stenting of the circumflex artery eight hours after onset of chest pain. The patient had a history of type 2 diabetes treated with Metformin and high blood pressure treated with perindopril. At first he underwent ECG showing QTc level of 420 ms (corrected according to Bazett's formula). He received hydroxychloroquine 200 mg three times a day and azithromycin 500 mg/day according to Moroccan COVID-19 treatment protocol in addition to his post-infarct treatment (Clopidogrel 1 tablet of 75 mg once a day; aspirin 1 tablet of 75 mg once a day; atorvastatin 1 tablet of 80 mg once a day, bisoprolol 2.5 mg/day. On the 5th day of his hospitalization daily ECG monitoring showed QT interval prolongation of 547 ms (corrected according to Bazett's formula) with ventricular extrasystole (ECG A) justifying discontinuation of hydroxychloroquine/azithromycin treatment. Three hours after, another ECG was performed which showed focal atrial tachycardia with variable conduction and unchanged QTc (ECG B). No hydroelectrolyte imbalance associated with serum potassium 4.1 mmol/l and magnesemia 22mmol/l was detected. Outcome was favorable with QT returning to normal values, patient's transition to paroxysmal atrial fibrillation requiring oral anticoagulation therapy and discharge after 21 days of hospitalization.