In this case, a patient presents for pre-operative evaluation prior to a neuro-surgical spinal operation. He has a history of coronary heart disease and a known anomaly of the left coronary artery from the right coronary artery. Our patient underwent non-invasive PET perfusion imaging and coronary angiography. There was a discussion of the risk of coronary anomalies and potential strategies to mitigate that risk. Of interest, most patients with an anomalous left coronary artery have the left main arising from the right coronary cusp. In this patient, the LAD and circumflex arteries have separate ostia and separate courses – an unusual finding.

• To describe the three courses that are typical of an anomalous left coronary artery.
• To use coronary angiography to determine the course of an anomalous left coronary artery arising from the right coronary artery.
• To estimate the patient risk based on each of the potential anomalous courses of the left coronary artery.
• To describe the implication of an anomalous left anterior descending artery when the circumflex has a benign posterior course.