Intracoronary ECG and Wave-Intensity Analysis Unmask Functional Coronary Microvascular Dysfunction in a Middle-aged Woman with ‘Normal’ Coronary Arteries: A Case Report

Background Angina and/or ischemia with nonobstructive coronary arteries (ANOCA/INOCA) is common, particularly in women, and is most frequently attributable to coronary microvascular dysfunction (CMD), rather than representing a benign finding after exclusion of epicardial stenosis. Case Summary A 55-year-old woman with cardiometabolic risk factors had recurrent angina and reversible ischemia on stress SPECT. Coronary angiography showed no obstructive disease. Doppler-based coronary function testing in the LAD demonstrated reduced CFVR (1.99) with normal HMR (1.31 mmHg·s·cm−1), suggesting functional CMD. Wave-intensity analysis showed high resting accelerating wave energy proportion without hyperemic augmentation, and intracoronary ECG during adenosine hyperemia revealed ischemic ST-segment shifts concordant with perfusion imaging. Discussion Multimodal invasive assessment can phenotype the INOCA endotypes and provide real-time ischemia confirmation. This case highlights the added value of combining intracoronary ECG with wave-intensity analysis for real-time ischemia verification in INOCA, supporting a shift from anatomical exclusion to integrated physiological diagnosis of coronary microvascular dysfunction. Vasoreactivity testing was not performed; therefore, a coexisting vasospastic endotype was not excluded.