Acute arrhythmogenicity of first-dose chemotherapeutic agents in children

BACKGROUND: Chemotherapeutic agents have been reported to cause severe arrhythmias and sudden death in the first 24 hr after administration. In this prospective study, we determined the magnitude of acute arrhythmogenicity of those agents in children. PROCEDURE: Thirty-three patients with diverse malignancies (leukemia n = 16, Wilms tumor n = 3, brain tumor n = 3, lymphoma n = 3, others n = 8) were studied with Holter monitors 24 hr before, during, and in the first 24 hr following the first-dose therapy. RESULTS: Two patients experienced conduction disturbances (phases of 2nd degree sinuatrial and atrioventricular blocks) during a 4-hr period corresponding to a 30 mg/m(2) daunorubicin infusion. Eight patients experienced supraventricular extrasystole (SE), ventricular extrasystole (VE), and/or short salvos of supraventricular (SVT) and/or ventricular tachycardia (VT). Six had leukemia (therapy: daunorubicin + vincristine), one had a lymphoma (therapy: vincristine + cyclophosphamide), and the last one a brain tumor (therapy: carboplatin + procarbazine). Three patients with leukemia had pretreatment arrhythmias (1 VT, 2 SVT). One of them and the five other patients had arrhythmias during and after the first-dose therapy (2 VE, 2 SVT, 1 SVT + VE, 1 VE + SE + SVT). No patient had life-threatening arrhythmias and no prognostic value of those disturbances could be demonstrated. CONCLUSIONS: Conduction disturbances and arrhythmias are common in cancer children at the beginning of the therapy, but no acute or long-term adverse consequences are related to their appearance.