Above: Incidence of heart attack hospitalization by age group in Oregon
Heart attacks (myocardial infarctions) are more common in men than women, and the incidence increases dramatically with age. During heart attacks, plaque on a coronary artery wall can rupture, causing fibrin deposition, platelet aggregation and thrombus (clot) formation that obstructs the flow of blood. The resulting deprivation of blood flow and oxygen kills cardiomyocytes (muscle cells of the heart), predisposing to life-threatening changes in heart rhythm. These electrical disturbances impair the heart’s pumping ability and cause blood movement to cease, resulting in death.
Question 1. Is the above a proximate or ultimate explanation of heart attacks?
Question 2. Are there evolutionary theories of aging that help explain the link between age and heart attacks seen in the graph above?
Additional Readings for class discussion: