What is the main consequence of untreated ischemia?

Untreated ischemia leads to tissue necrosis, which is the death of cells and tissue due to a lack of adequate blood supply. When ischemia occurs, the affected tissues do not receive sufficient oxygen and nutrients, which are critical for cellular metabolism and survival. If the blood flow is not restored, the cells in the ischemic area will begin to die, leading to irreversible damage, and ultimately, necrosis.

This process is particularly critical in organs such as the heart and brain, where prolonged ischemia can result in significant functional impairment, such as myocardial infarction (heart attack) or stroke. The progression from ischemia to necrosis highlights the importance of timely intervention to restore blood supply and prevent tissue death, as the longer the tissue remains ischemic, the greater the extent of necrosis that can occur.

In contrast, the other options imply positive outcomes that are not associated with untreated ischemia. Tissue regeneration would not occur in dead or dying tissue, increased cardiac output would not be a primary concern of ischemia, and improved blood circulation is the opposite of what occurs in ischemia. Therefore, the main consequence of untreated ischemia is indeed necrosis of tissue.