Main Entry: unstable angina Function: noun : angina pectoris characterized by sudden changes (as an increase in the severity or length of anginal attacks or a decrease inthe exertion required to precipitate an attack) especially when symptoms were previously stable
unstable angina un·sta·ble angina (ŭn-stā'bəl) n. Angina pectoris characterized by pain of coronary origin that occurs in response to less exercise or other stimuli than usually required to produce pain.
