Symptomatic 5-fluorouracil-induced sinus bradycardia.

Area of Science:

• Oncology
• Cardiology
• Pharmacology

Background:

• 5-Fluorouracil (5-FU) is a cornerstone antineoplastic agent for various cancers.
• Cardiotoxicity is a recognized, albeit not fully understood, adverse effect of 5-FU therapy.
• Establishing the precise mechanisms of 5-FU-induced cardiotoxicity remains an active area of research.

Observation:

• A 61-year-old male, undergoing treatment for advanced rectal cancer with 5-FU infusion and radiotherapy, presented with symptomatic sinus bradycardia.
• This cardiac dysrhythmia represents an uncommon manifestation of 5-FU toxicity.
• This is the second reported case of 5-FU-associated sinus bradycardia in medical literature.

Findings:

• The patient's sinus bradycardia developed during continuous infusion of 5-FU.
• The findings suggest a potential link between 5-FU administration and the development of bradycardia.
• Further investigation into the pharmacological actions of 5-FU is warranted to elucidate causative pathways.

Implications:

• This case underscores the importance of monitoring cardiac function in patients receiving 5-FU.
• Understanding the mechanisms of 5-FU cardiotoxicity can lead to improved patient management strategies.
• Further research may identify specific patient populations at higher risk for 5-FU-related cardiac adverse events.