Chemotherapy-Associated Atrial Fibrillation Triggered by Electrolyte Imbalance: Mechanistic Insights and Anticoagulation Challenges in Cardio-Oncology

Backgroundm : Atrial fibrillation (AF) is increasingly recognized in patients with cancer and is associated with significant morbidity due to thromboembolic and hemorrhagic complications. The pathophysiology is multifactorial, involving inflammation, autonomic dysregulation, and treatment-related toxicities. Electrolyte disturbances induced by chemotherapy remain an underappreciated trigger. Case Summary : A 78-year-old man with hypertension and diabetes, recently treated surgically for colorectal cancer and undergoing adjuvant chemotherapy, presented with acute dyspnea preceded by palpitations. Electrocardiography revealed rapid AF at 160 beats per minute. Transthoracic echocardiography showed left atrial enlargement with preserved left ventricular systolic function and elevated filling pressures. Laboratory testing demonstrated hypokalemia. The patient was treated with potassium and magnesium repletion, intravenous digoxin for rate control, and standard heart failure therapy. Anticoagulation strategy was individualized considering competing thrombotic and bleeding risks . Conclusions : This case highlights the critical role of chemotherapy-induced electrolyte imbalance in AF pathogenesis and underscores the complexity of anticoagulation in cancer patients. A mechanistic and multidisciplinary cardio-oncology approach is essential to optimize outcomes.