Challenging situation of coronary artery anomaly associated with ischemia and/or risk of sudden death.

Coronary artery anomaly is known as one of the causes of angina pectoris and sudden death and is an important clinical entity that cannot be overlooked. The incidence of coronary artery anomalies is as low as 1%-2% of the general population, even when the various types are combined. Coronary anomalies are practically challenging when the left and right coronary ostium are not found around their normal positions during coronary angiography with a catheter. If there is atherosclerotic stenosis of the coronary artery with an anomaly and percutaneous coronary intervention (PCI) is required, the suitability of the guiding catheter at the entrance and the adequate back up force of the guiding catheter are issues. The level of PCI risk itself should also be considered on a case-by-case basis. In this case, emission computed tomography in the R-1 subtype single coronary artery proved that ischemia occurred in an area where the coronary artery was not visible to the naked eye. Meticulous follow-up would be crucial, because sudden death may occur in single coronary arteries. To prevent atherosclerosis with full efforts is also important, as the authors indicated admirably.