Acute cardiac toxicity associated with high-dose intravenous methotrexate therapy: case report and review of the literature.

A 36-year-old woman was hospitalized for preoperative chemotherapy for osteosarcoma. She received intravenous fluids for 12 hours for volume expansion, then methotrexate 24 g (12 g/m2) over 6 hours. This was followed by intravenous leucovorin 200 mg over 1 hour. Two hours after the methotrexate infusion the patient developed chest pain and bradycardia. An electrocardiogram revealed sinus pauses, and telemetry recordings indicated a 4-beat run of ventricular tachycardia. A cardiac work-up consisting of cardiac enzyme level determination, two-dimensional echocardiography, and an adenosine technetium-99m tetrofosmin stress test was negative for structural and ischemic heart disease. The patient recovered without treatment and, approximately 2 weeks later, received a second course of methotrexate at half the dose without complication. One month later the patient received treatment with doxorubicin and cisplatin; 2 days later she died unexpectedly at home. Clinicians should be aware that high-dose methotrexate can cause cardiac symptoms and arrhythmias in previously healthy adults. This complication warrants attention and needs additional clinical investigation.