Researchers caution use of chloroquine therapy for patients at higher risk of heart r
 

A patient who met many of the published safety guidelines for chloroquine therapy against COVID-19 was observed to have a very abnormal ECG pattern after treatment began, leading to multiple episodes of torsade de pointes (TdP), a life-threatening arrhythmia in which the lower chambers of the heart beat out of sync with the upper chambers.

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