tretinoin and Bradycardia

The authors describe a 28-year-old woman with newly diagnosed acute promyelocytic leukaemia (APL), who developed junctional bradycardia after receiving the molecular-targeted therapy all-trans retinoic acid (ATRA) and the anthracycline-based chemotherapeutic agent idarubicin following sepsis and the APL differentiation syndrome. The patient was asymptomatic of the bradycardia. Electrolytes and cardiac imaging were unremarkable. No other cases have been reported in this context and the mechanisms of the sinus node dysfunction are unclear. The patient achieved normal sinus rhythm after ATRA was withheld. The patient recovered and went on to achieve complete remission after re-starting ATRA and idarubicin.

Topics: Antineoplastic Agents; Bradycardia; Cell Differentiation; Electrocardiography; Female; Follow-Up Studies; Granulocyte Precursor Cells; Humans; Leukemia, Promyelocytic, Acute; Remission Induction; Syndrome; Tretinoin

A case of acute promyelocytic leukemia (APL) complicated by sinus bradyarrhythmia during the course of all-trans retinoic acid (ATRA) administration is reported. A 3-year-old boy was admitted for evaluation of petechiae and APL was diagnosed. He was initially treated with 45 mg/m2 of ATRA without success, and a complete remission was achieved when the dose was increased to 135 mg/m2. Sinus bradyarrhythmia was first recognized 3 days after the induction therapy with ATRA. It did not disappear even when the patient stopped taking the medication. However, the arrhythmia tended to be augmented whenever he received ATRA again. Close observation of his cardiac condition was mandatory to continue ATRA as an integral part of the therapy for APL, combined with multidrug chemotherapy including anthracyclines, which themselves are potentially toxic to myocardium. In conclusion, the present case revealed the possibility that ATRA therapy induces sinus node arrhythmia, or that it can potentiate preexisting node dysfunctions.

Topics: Arrhythmia, Sinus; Bradycardia; Child, Preschool; Humans; Leukemia, Promyelocytic, Acute; Male; Tretinoin