Skip to main content


Swipe om te navigeren naar een ander artikel

29-04-2020 | Original Article | Uitgave 7-8/2020 Open Access

Netherlands Heart Journal 7-8/2020

Chloroquine-induced QTc prolongation in COVID-19 patients

Netherlands Heart Journal > Uitgave 7-8/2020
M. P. H. van den Broek, J. E. Möhlmann, B. G. S. Abeln, M. Liebregts, V. F. van Dijk, E. M. W. van de Garde



In the battle against the SARS-CoV‑2 pandemic, chloroquine has emerged as a new potential therapeutic option for the treatment of infected patients. A safety consideration for the application of chloroquine is its QTc-prolonging potential. Thus far, no data are available on the QTc-prolonging potential of chloroquine in COVID-19 patients.


To assess the degree of chloroquine-induced QTc prolongation in hospitalised COVID-19 patients.


A baseline electrocardiogram (ECG) and ECGs recorded during chloroquine treatment were retrospectively collected in patients suspected of having COVID-19. The QTc interval was calculated by computerised and manual interpretation. Baseline and follow-up QTc intervals were compared using the paired samples t-test.


A total of 95 patients had a baseline ECG recording and at least one ECG recording during chloroquine therapy. Chloroquine treatment resulted in a mean QTc prolongation of 35 ms (95% CI 28–43 ms) using computerised interpretation and 34 ms (95% CI 25–43 ms) using manual interpretation. No torsade de pointes was observed during chloroquine treatment. After manual review, 22 patients (23%) had a QTc interval exceeding 500 ms during chloroquine treatment. None of these patients had a prolonged QTc interval prior to the initiation of chloroquine treatment.


Chloroquine significantly prolongs the QTc interval in a clinically relevant matter. This highlights the need for ECG monitoring when prescribing chloroquine to COVID-19 patients.

Onze productaanbevelingen

Netherlands Heart Journal

Het Netherlands Heart Journal wordt uitgegeven in samenwerking met de Nederlandse Vereniging voor Cardiologie en de Nederlandse Hartstichting. Het tijdschrift is Engelstalig en wordt gratis beschikbaa ...

Over dit artikel

Andere artikelen Uitgave 7-8/2020

Netherlands Heart Journal 7-8/2020 Naar de uitgave