What happens to myocardial tissue during ischemia?

During ischemia, myocardial tissue experiences a significant reduction in blood flow, which leads to a decrease in oxygen supply to the heart muscle. This lack of oxygen is critical because the heart cells require a constant supply of oxygenated blood to function properly and maintain their viability.

If this ischemic state persists for an extended period, the affected myocardial tissue begins to suffer irreversible damage and ultimately dies, a process referred to as necrosis. This necrotic tissue cannot recover and cannot function, leading to further complications such as heart failure or arrhythmias.

In contrast, hypertrophy refers to the increase in the size of heart muscle cells, which does not occur during ischemia but could occur as a long-term response to chronic heart conditions. Regeneration of myocardial tissue is limited in adults; the heart muscle does not regenerate rapidly following injury or ischemia, as opposed to some other tissues in the body. Finally, a decrease in size might be seen in terms of overall heart function or muscle mass in specific conditions, but it doesn’t accurately describe the direct and immediate response to ischemia itself. Hence, the key consequence of prolonged ischemia is the necrotic death of myocardial tissue.