Coronary microvascular disease is a type of heart disease that affects the tiny arteries in the heart, explains the National Heart, Lung and Blood Institute. With this disease, the tiny arteries of the walls of the heart have disease or damage.
Coronary microvascular disease is not the same as coronary heart disease, claims the NHLBI. With coronary heart disease, the large arteries in the heart become blocked with plaque, which can form blood clots and other deadly conditions. With coronary microvascular disease, however, plaque doesn't affect the small arteries, though many people diagnosed with this condition also have high blood pressure or diabetes. It is also possible that the condition is due to heredity.