Infarction

Infarction is tissue necrosis resulting from an interruption in blood supply, most often due to arterial occlusion that causes prolonged ischemia. The resulting cell death and tissue injury are called an infarct, and the area surrounding it may be inflamed and swollen. Infarcts can be pale or red, depending on the tissue involved and its blood supply.

Common sites include the heart (myocardial infarction), the brain (cerebral infarction or ischemic stroke), and other organs such as the kidneys, spleen, and intestines. Causes include arterial thrombosis, embolism, atherosclerotic occlusion, vasospasm, or severe hypoperfusion during shock or hypotension.

Pathophysiology: After arterial blockage, cells experience energy failure, loss of membrane integrity, and irreversible injury if perfusion is not restored. An inflammatory response follows, and microvascular obstruction can worsen tissue injury even after initial blood flow is reestablished. The infarct zone typically evolves into scar as it heals.

Diagnosis and treatment vary by organ. Myocardial infarction is suspected with chest pain, characteristic ECG changes, and elevated cardiac troponin; reperfusion with percutaneous coronary intervention or thrombolysis improves outcomes, supplemented by antiplatelet and statin therapy. Ischemic stroke is diagnosed by clinical deficit and brain imaging; timely thrombolysis or mechanical thrombectomy may restore perfusion.

Prognosis depends on infarct size and location; infarction can cause lasting functional impairment and, in some cases, death. Prevention focuses on controlling risk factors such as hypertension, diabetes, high cholesterol, smoking, and maintaining adequate organ perfusion.