A 67-year-old man was admitted to hospital for the surgical treatment of a severe rheumatic mitral regurgitation. Preoperative coronary angiogram was unremarkable (A) The right coronary artery was dominant giving origin to large posterior descending and posterolateral arteries. In the left coronary system a single obtuse marginal originated from the circumflex artery which was of small caliber and exited the atrioventricular groove thereafter. The operation was carried through full median sternotomy and aorto-bicaval cardiopulmonary bypass. The mitral valve was exposed through a vertical transeptal bilateral atriotomy and replaced with a bileaflets mechanical prosthesis. The operative course was uneventful and the patient was transferred to the intensive care unit (ICU) on normal sinus rhythm and good cardiac function without inotropic support. Upon arrival in the ICU, a marked ST elevation became evident in inferior leads, while hemodynamic conditions remained stable. A transthoracic echocardiogram revealed hypokinetic inferior wall. A coronary angiogram was performed: a focal, subocclusive spasm was evident in the middle to distal segment of the right coronary artery (B Video 1). An intracoronary injection of nitrates resulted in a prompt resolution of the spasm (C Video 2) and of the electrocardiographic changes. Continuous intravenous infusion of nitroglycerin (4 mg/h) and oral administration of diltiazem 60 mg twice a day were started. On postoperative day 2, intravenous nitroglycerin was changed to transdermal patch (10 mg/day). Subsequent postoperative course was uneventful and the patient was discharged in good clinical conditions on postoperative day 7. Transthoracic echocardiogram on discharge showed no abnormalities of regional kinesis. Supplementry material related to this article found, in the online version, at.