A 76 year old woman presented to our institution with shortness of breath. The initial evaluation included a computed tomographic (CT) scan to exclude pulmonary embolism. However, the CT scan demonstrated a large right atrial mass which was confirmed by echocardiography. The patient was referred for coronary angiography before resection of this mass. A right atrial angiogram showed a large mobile filling defect measuring 6 cm in diameter in the right atrium prolapsing into the right ventricle in diastole. Coronary angiography showed no significant coronary artery disease. The right coronary artery injection showed an atrial branch of the right coronary artery supplying this tumour producing a “tumour blush” (panel). The patient underwent surgical excision of the mass with patch reconstruction of the atrial septum. The final pathological diagnosis was atrial myxoma.