Unexpected turbulence: Ventricular tachycardia in a patient with lung cancer on Osimertinib

Background: Ventricular arrhythmias are an uncommon but clinically significant manifestation during targeted therapy of cancer patients. Their occurrence requires careful evaluation to differentiate between therapy-related cardiotoxicity and other cardiovascular causes, while balancing oncologic treatment needs. Case summary: Our case report presents a 63-year-old physically active man with metastatic lung adenocarcinoma on targeted therapy (osimertinib), who was admitted for recurrent non-sustained ventricular tachycardia (NSVT). He had no prior cardiovascular disease or arrhythmia. Initial echocardiography evaluation revealed preserved biventricular function without structural abnormalities. 24h Holter monitoring documented frequent supraventricular and ventricular ectopy, including NSVT. Malignant ventricular arrhythmias were registered in the recovery of treadmill stress echocardiography, and coronary angiography showed non-obstructive coronary artery disease. Antiarrhythmic therapy with amiodarone and bisoprolol led to complete arrhythmia suppression. Targeted therapy was temporarily withheld during cardiac work-up and subsequently resumed after multidisciplinary discussion. At six-month follow-up, the patient remained asymptomatic and arrhythmia-free under combined cardiology and oncology surveillance. Discussion: This case highlights the need for a careful and individualized approach to ventricular arrhythmias in patients undergoing EGFR-targeted therapy. In the absence of structural heart disease and with effective pharmacological control, oncologic treatment may be safely continued with close rhythm monitoring. A multidisciplinary approach is crucial to balance cancer control with cardiovascular safety.