Malignant Arrhythmias Caused by Pericardial Lipomas: Benign, Yet Deadly.

BACKGROUND: Cardiac lipomas are usually benign but can cause significant hemodynamic and arrhythmic complications, such as ventricular tachycardia, depending on size, location, and myocardial involvement. CASE 1 SUMMARY: An 18-year-old man presented with cardiac arrest during exercise. Following a normal coronary angiogram, a defibrillator was implanted. After recurrent shocks, imaging demonstrated a large cardiac lipoma. Surgical excision resulted in cessation of his recurrent ventricular tachycardia. CASE 2 SUMMARY: A 25-year-old woman presented with ventricular tachycardia, and imaging revealed a large cardiac lipoma with coronary artery encasement. Surgical resection led to resolution of ventricular arrhythmias, and permanent defibrillator implantation was avoided. DISCUSSION: These cases highlight how cardiac lipomas can lead to ventricular arrhythmias through mass effect and proximity to the coronary vasculature. Multimodal imaging was indispensable for the diagnosis and surgical planning for these cases. TAKE-HOME MESSAGES: Cardiac lipomas can cause life-threatening ventricular arrhythmias. A multimodal imaging approach combined with multidisciplinary team evaluation is essential for accurate diagnosis and management.