microvascular dysfunction
Impaired function of coronary vessels smaller than 500 micrometers, not visible on standard angiography.
Full Definition
Microvascular dysfunction refers to abnormal function of the coronary microvasculature, including arterioles, capillaries, and venules with diameters less than 500 micrometers. This condition can cause anginal symptoms despite normal or near-normal epicardial coronary arteries on angiography. Microvascular dysfunction may result from structural abnormalities, endothelial dysfunction, or impaired vasodilation. Assessment requires specialized testing such as coronary flow reserve measurement, adenosine stress testing, or acetylcholine provocation. The condition is particularly common in women and patients with diabetes, hypertension, or heart failure with preserved ejection fraction.
Usage
Usage note: Requires specialized testing for diagnosis; distinguish from epicardial coronary artery disease.
In Context
- "Despite normal coronary angiography, the patient's symptoms were attributed to microvascular dysfunction." — Cardiology consultation note
- "Reduced coronary flow reserve suggested significant microvascular dysfunction in this diabetic patient." — Cardiac catheterization report