Hence, angina of this nature is called unstable angina and reflects a much more serious condition. If it occurs while sleeping, it can be called nocturnal angina, a variation of nocturnal angina is called Prinzmetal angina. Anaerobic metabolism cannot sustain the cell indefinitely. If it lasts briefly and oxygen is restored in time to the cell, the cell recovers without lasting damage. However, if conditions persist long enough, i.e. if a cell is deprived of adequate oxygen long enough, then ischemia and cell death occurs.
Ischemia quickly leads to necrosis.
When heart cells die they trigger off an inflammatory process in the surrounding tissue. Dead heart cells cannot be replaced. Clinically Few woman prior to menopause suffer from coronary artery disease. The reason for this is the protective actions of estrogen. Estrogen reduces LDL accumulation, inhibits platelet aggregation, inhibits foam cell formation, decreases collagen and elastin production and, generally, acts as an anti- oxidant.