A 50-year-old woman was admitted with angina. Her past medical history included poorly controlled hypertension and mild Parkinson’s disease. A systemic examination was unremarkable apart from a slight resting tremor. Serial ECGs and 12-hour postadmission troponin levels were normal. Echocardiography confirmed normal biventricular function and no left ventricular hypertrophy. A 12-lead exercise stress ECG was stopped at stage 2 of the Bruce protocol because of shortness of breath. The patient had achieved 82% of her target heart rate with no ischemic ECG changes. Selective coronary angiography was performed and showed normal left anterior descending and circumflex arteries. However, the right ventricular branch of the right coronary artery appeared to supply a vascular mass (Figure 1 and Data Supplement Movie I). Subsequent computed tomography and magnetic resonance imaging demonstrated an intrapericardial mass with compression …