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Arrhythmic profile and 24-hour QT interval variability in COVID-19 patients treated with hydroxychloroquine and
Alberto Cipriani1, Alessandro Zorzi1, Davide Ceccato2
1Department of Cardio-Thoraco-Vascular Sciences and Public Health, Padua, Italy.
Insights
Hydroxychloroquine and azithromycin increase corrected QT-interval (QTc) in COVID-19 patients. QTc duration is stable throughout the day, meaning multiple daily ECGs are not necessary for monitoring these patients.
Area of Science:
- Cardiology
- Infectious Diseases
- Pharmacology
Background:
- Hydroxychloroquine and azithromycin are commonly used for COVID-19.
- Both drugs can prolong the corrected QT-interval (QTc), necessitating electrocardiographic (ECG) monitoring.
- The diurnal variation of QTc interval in COVID-19 patients on this therapy is not well-established.
Purpose of the Study:
- To assess the impact of hydroxychloroquine and azithromycin on QTc interval in COVID-19 patients.
- To determine the diurnal variability of QTc interval in these patients.
- To evaluate the need for frequent ECG monitoring during combination therapy.
Main Methods:
- 12-lead ECGs and 24-hour Holter monitoring were performed on COVID-19 patients (<80 years) on hydroxychloroquine and azithromycin.
- A control group of healthy individuals matched for age and sex was included.
- QTc intervals and heart rhythm abnormalities were analyzed.
Main Results:
- Combination therapy significantly prolonged QTc interval compared to baseline (450 vs 426 ms).
- Four patients with QTc ≥ 480 ms had elevated liver transaminases (AST and ALT).
- 24-hour QTc dynamics showed higher QTc in COVID-19 patients but no significant hourly variability; no serious arrhythmias were observed.
Conclusions:
- Hydroxychloroquine and azithromycin therapy prolongs QTc interval in COVID-19 patients, especially those with elevated transaminases.
- QTc duration is stable over 24 hours, suggesting that multiple daily ECGs are not recommended.
- This finding aids in optimizing patient monitoring protocols during COVID-19 treatment.
Background:
Hydroxychloroquine and azithromycin combination therapy is often prescribed for coronavirus disease 2019 (COVID-19). Electrocardiographic (ECG) monitoring is warranted because both medications cause corrected QT-interval (QTc) prolongation. Whether QTc duration significantly varies during the day, potentially requiring multiple ECGs, remains to be established.
Methods:
We performed 12‑lead ECGs and 12‑lead 24-h Holter ECG monitoring in all patients aged <80 years admitted to our medical unit for COVID-19, in oral therapy with hydroxychloroquine (200 mg, twice daily) and azithromycin (500 mg, once daily) for at least 3 days. A group of healthy individuals matched for age and sex served as control.
Results:
Out of 126 patients, 22 (median age 64, 82% men) met the inclusion criteria. ECG after therapy showed longer QTc-interval than before therapy (450 vs 426 ms, p = .02). Four patients had a QTc ≥ 480 ms: they showed higher values of aspartate aminotransferase (52 vs 30 U/L, p = .03) and alanine aminotransferase (108 vs 33 U/L, p < .01) compared with those with QTc < 480 ms. At 24-h Holter ECG monitoring, 1 COVID-19 patient and no control had ≥1 run of non-sustained ventricular tachycardia (p = .4). No patients showed "R on T" premature ventricular beats. Analysis of 24-h QTc dynamics revealed that COVID-19 patients had higher QTc values than controls, with no significant hourly variability.
Conclusion:
Therapy with hydroxychloroquine and azithromycin prolongs QTc interval in patients with COVID-19, particularly in those with high levels of transaminases. Because QTc duration remains stable during the 24 h, multiple daily ECG are not recommendable.
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