Abnormal coronary flow reserve in a 13-year-old girl with an absent left circumflex coronary artery

We measured the coronary flow reserve in a 13-year-old girl with the rare a nomaly of an absent left circumflex coronary artery. Although the coronary flow volume of the right coronary artery was at the same level as that of t he left anterior descending coronary artery, the coronary now reserve of th e patient's right coronary artery was depressed without stenotic lesion, an d it was less than the level of -2 standard deviation (SD) of the right cor onary artery preponderance cases.