An 82 year old woman with a history of high blood pressure and chronic atrial fibrillation without oral anticoagulation was admitted to the emergency department because of a syncopal episode followed by chest pain. Until that day she was totally asymptomatic.
On admission the patient was in cardiogenic shock; the ECG showed ST segment elevation from V4–V6, DI, and aVL. An urgent coronary artery angiogram was performed. An intra-aortic balloon counterpulsation was inserted. The first contrast injection was done in the right coronary ostium (panel A). The right coronary artery (RCA) was normal without any obstruction. During the same injection, a vessel arising from the proximal RCA was seen (*). Initial suspicion was an anomalous origin of left circumflex coronary artery (LCx), the most common coronary artery anomaly. The left coronary ostium was impossible to cannulate from the left aortic sinus, and aortography was performed (panel B; Ao, aorta): there was no left coronary ostium, suggesting that the vessel arising from the proximal RCA (*) was the left coronary artery. Two angioplasty guide wires (panel C) crossed the obstruction point (†). Balloon angioplasty was performed at the left main coronary artery (LMCA) bifurcation, displaying the whole coronary artery tree from a single injection in the right coronary artery ostium (panel D; LAD, left anterior descending coronary artery).
Anomalous LMCA takes an aberrant retroaortic course, as seen in panels A and B, which shows a left anterior oblique projection, where the LMCA goes backwards. This kind of anomalous coronary artery distribution is the most uncommon type.