Stable Angina

A fixed ceiling on supply meeting a rising demand

A stable atherosclerotic plaque narrows a coronary artery but leaves an intact fibrous cap, so the lumen is fixed rather than acutely thrombosed. At rest, the narrowed vessel can usually still deliver enough blood. On exertion, heart rate and contractility rise, sharply increasing myocardial oxygen demand, but the stenosed segment cannot dilate enough to increase supply to match. The result is a predictable, reproducible mismatch between supply and demand once exertion crosses a threshold specific to that stenosis.