'Missing' coronary arteries at urgent coronary angiography for ST-elevation myocardial infarction.

Coronary artery anomalies are a rare and often occasional finding at coronary angiography. When patients with ST-elevation myocardial infarction (STEMI) undergo angiography preliminary to a primary percutaneous coronary intervention, a 'missing' coronary artery is usually ascribed to the culprit occluded vessel.Two patients with inferior STEMI were admitted to our cath lab for a primary percutaneous coronary intervention; in both cases an anomalous origin of the left coronary system--partially in one, entirely in the another--from the opposite sinus was documented at urgent angiography. The knowledge and the identification of coronary artery anomalies have extreme clinical relevance in urgent angiography for STEMI patients.