Epicardial Coronary Spasm in Left Anterior Descending Artery and Coronary Microvascular Spasm in Right Coronary Artery

A 71-year-old woman presented with rest angina. A spasm provocation test (SPT) using acetylcholine (Ach) confirmed epicardial coronary vasospasm in the left anterior descending artery (LAD) and coronary microvascular spasm (MVS) in the right coronary artery (RCA), according to current guidelines. After nitrate administration, coronary function tests (CFTs) with adenosine were conducted on the RCA at 30-minute intervals, demonstrating significant improvement in coronary flow reserve (CFR) and the index of microcirculatory resistance (IMR). This case was first diagnosed as vasospastic angina (VSA) involving the LAD, MVS in the RCA, normal coronary function in the LAD, and coronary microvascular dysfunction (CMD) in the RCA, highlighting regional differences in vascular reactivity and microvascular function in the same patients. The improvement in CFR and IMR during the second CFT suggests longer persistence of MVS, indicating that post-SPT functional testing may overestimate microvascular dysfunction due to lingering MVS, even after nitrate administration.