Coronary microvascular disease: Trouble from tiny vessels

Microvascular disease refers to problems in the network of tiny blood vessels in the heart. Doctors suspect this condition in people who have angina (chest) pain with no evidence of blockages in the heart’s larger arteries. In the most common form of microvascular disease, the inner walls of small arteries thicken, and the layer of cells closest to the blood lose their ability to expand and contract in response to the demand for increased blood flow, such as during exercise. In another form of the problem, vasospastic angina, muscles within the heart’s arteries suddenly clamp down, causing a temporary spasm that blocks blood flow to heart muscle.