RESUMO
BACKGROUND: Fluoropyrimidines have been linked to cardiovascular toxicity. CASE PRESENTATION: A woman in her forties with locally advanced rectal cancer received curative-intent treatment according to the RAPIDO protocol. Shortly after starting the first 5-fluorouracil infusion she developed chest/epigastric pain, nausea and vomiting. Electrocardiogram showed mild ST elevation in multiple contiguous leads. Troponin I was elevated. Transthoracic echocardiogram (TTE) displayed signs suggestive of myocardial infarction. Coronary angiogram indicated no obstructive coronary artery disease. Ventriculography demonstrated apical hypokinesia and basal hyperkinesia. MRI revealed no signs of myocardial infarction or myocarditis. The patient was diagnosed with Takotsubo syndrome, possibly induced by 5-fluorouracil. Follow-up TTE three weeks later was normal. Subsequently, she received treatment with tegafur/gimeracil/oteracil (Teysuno®) in place of 5-fluorouracil, combined with oxaliplatin. No further cardiotoxicity was observed during three cycles. INTERPRETATION: The patient was diagnosed with Takotsubo syndrome following 5-fluorouracil infusion, likely to represent 5-fluorouracil-induced cardiotoxicity. Following replacement of 5-fluorouracil with Teysuno®, she experienced no signs of cardiotoxicity.