What is myocardial reperfusion?

Myocardial reperfusion refers to the process of restoring blood flow to the heart muscle, specifically the part of the heart muscle that has been deprived of oxygen during an acute myocardial infarction, commonly known as a heart attack. This restoration of blood flow is critical because it can limit the extent of the heart muscle damage and improve the chances of survival and recovery. In the context of acute myocardial infarction, the heart muscle experiences ischemia, which is a lack of blood flow and oxygen. This can lead to irreversible damage to the heart muscle cells. Reperfusion therapies aim to quickly reverse this ischemia by reopening the blocked coronary artery. The two primary methods of reperfusion therapy are primary percutaneous coronary intervention (PCI), which involves threading a catheter through the artery to the blockage and using a small balloon to open it, and fibrinolytic therapy, which uses medication to dissolve the blood clot causing the blockage. It's important to note that while reperfusion is essential to save as much heart muscle as possible, it can also cause additional injury to the heart muscle cells, known as reperfusion injury. This injury is due to the sudden reintroduction of oxygen and the rush of blood into the previously ischemic tissue, which can lead to oxidative stress and other cellular damage. Despite this potential for injury, the benefits of reperfusion in reducing infarct size and improving outcomes generally outweigh the risks.

Myocardial injury in the setting of an acute myocardial infarction is the result of ischemic and reperfusion injury. Reperfusion therapies, including primary percutaneous coronary intervention and fibrinolytic therapy, promptly restore blood flow to ischemic myocardium and limit infarct size.