Abstract

QT prolongation refers to the prolonged QT interval in electrocardiography (ECG) which can even lead to life-threatening events such as ventricular arrhythmias, torsades de pointes, etc., several drugs can cause QT prolongation which includes sotalol, quinidine, arsenic, disopyramide, procainamide, amiodarone, haloperidol, etc., Arsenic trioxide (ATO) is used as an effective treatment option in promyelocytic leukemia (PML). Acute myeloid leukemia (AML) is a cancer that affects the blood and bone marrow. Acute promyelocytic leukemia (APL) is the M3 subtype of AML that affects mainly the white blood cells. In APL, immature granulocytes accumulate abnormally to form promyelocytes. ATO helps in the apoptosis of these cancerous promyelocytic cells. In patients on arsenic therapy, ECGs must be monitored to ensure QT prolongation as it a major side effect of the drug. Here is the case of a 58-year-old female patient and was newly diagnosed with APL. She developed QT prolongation with arsenic therapy. Other confounding factors such as electrolytes and presence of other QT-prolonging drugs were also corrected.