Summary

The authors report the case of a 49-year-old man with episodes of chest discomfort. Exercise/rest single-photon emission tomography (SPECT) with technetium-99m sestamibi (MIBI) revealed inferior and septal myocardial ischaemia, and MIBI anterior reverse redistribution, representing damaged myocardium. Cardiac tomography documented anomalous origin of the right coronary artery (ARCA) arising from the left sinus of valsalva coursing between the aorta and pulmonary artery. Myocardial ischaemia and myocardial damage revealed by SPECT are related to the transient coronary flow reduction elicited by the compression of the ARCA that is produced by the great arteries during exercise. The ARCA is a rare condition, but may cause myocardial infarction and sudden death. β-blockers and dihydropyridine calcium-channel blockers may provide cardioprotection from inducible myocardial ischaemia. However, in case of failure of medical cardioprotection, relocation of the ARCA to the appropriate aortic sinus and coronary bypass grafting could be considered as the best options.