A 73-year-old patient with previously percutaneously treated coronary artery disease and a history of smoking was referred for routine preoperative screening in preparation for a transurethral tumour resection. He reported dyspnoea. Physical examination revealed normal cardiac auscultation without signs of heart failure. Echocardiography identified a mass of 56 by 32 mm in the left atrium (Fig. 1a) near the anterior leaflet of the mitral valve attached to the atrial septum (asterisk). Subsequently, MRI revealed that the mass was a myxoma. Preoperative coronary angiography showed no significant coronary artery stenoses. When contrast was injected into the right coronary artery a clear side branch (Fig. 1b) with contrast blush to a structure in the left atrium was seen, corresponding to a left atrial tumour (asterisk). As is known from the literature, left atrial myxomas are often vascularised by the circumflex artery, closely followed by the right coronary artery [1, 2]. Complete tumour resection followed, which left the patient in good health.