Ventricular fibrillation cardiac arrest due to 5-fluorouracil cardiotoxicity

Abstract

The antimetabolite chemotherapeutic agent 5-fluorouracil is used to treat a variety of cancers. Although 5-fluorouracil is generally well tolerated, its toxicity profile includes potential cardiac ischemia, vasospasm, arrhythmia, and direct myocardial injury. These actual or potential toxicities are thought to resolve upon cessation of the medication; however, information about the long-term cardiovascular effects of therapy is not sufficient. We present the case of a 58-year-old man who had 2 ventricular fibrillation cardiac arrests, with evidence of coronary vasospasm and myocarditis, on his 4th day of continuous infusion with 5-fluorouracil. External defibrillation and cessation of the 5-fluorouracil therapy resolved the patient's electrocardiographic abnormalities. In addition to reporting the clinical manifestations of 5-fluorouracil-associated cardiotoxicity in our patient, we discuss management challenges in patients who develop severe 5-fluorouracil-induced ventricular arrhythmias.

Keywords: Arrhythmias, cardiac/chemically induced; coronary vasospasm/chemically induced; fluorouracil/adverse effects; heart diseases/drug therapy; heart/drug effects; myocarditis/chemically induced; treatment outcome.

Fig. 1 Electrocardiograms show A) sinus bradycardia, a normal ST segment, and a normal QT interval (at baseline); B) ventricular fibrillation (upon emergent presentation); C) atrial fibrillation with a rapid ventricular response and ST-segment elevation in the anterior and inferior leads (after first defibrillation); and D) sinus rhythm with resolution of the ST-segment elevation (upon the patient's discharge from the hospital).

Fig. 2 Coronary angiograms show no obstructive lesions in A) the left anterior descending coronary artery, the left circumflex coronary artery, or B) the right coronary artery.

Fig. 3 Cardiac magnetic resonance with a myocarditis protocol. Spin-echo T1-weighted images show increased global early myocardial enhancement A) before and B) after gadolinium contrast, yielding an elevated ratio of 6.1 (normal, <4). C) Fast-spin-echo T2-weighted image shows global myocardial edema with an elevated ratio (2.1) of T2 signal in the myocardium compared to skeletal muscle (normal, <2). D) Late-gadolinium-enhancement image shows no focal myocardial fibrosis or injury.