Infarction: Definition, Causes, Types, and Key Features

Infarction is tissue death (necrosis) caused by prolonged ischemia—interruption of arterial blood supply.

Mechanism

• Arterial occlusion (thrombus, embolus, atherosclerosis, vasospasm, dissection)
• Loss of oxygen/nutrients → ATP depletion → failure of ion pumps → cellular swelling, enzyme release, necrosis.
• Irreversible after variable time (brain: minutes; heart: 20–40 min; kidney: hours).

Common Types

Infarct	Artery Involved	Clinical Syndrome
Myocardial infarction (MI)	Coronary artery	Chest pain, ECG changes, troponin rise
Cerebral infarction (ischemic stroke)	Cerebral artery (MCA common)	Focal neurologic deficit
Splenic infarction	Splenic artery	LUQ pain, fever, friction rub
Renal infarction	Renal artery	Flank pain, hematuria, AKI
Mesenteric infarction	SMA/IMA	Severe abdominal pain out of proportion to exam
Limb infarction	Peripheral artery	6 P's: pain, pallor, pulseless, paresthesia, paralysis, poikilothermia

Key Features

• Infarcts are typically wedge‑shaped (peripheral) or territorial (organ‑specific).
• Red (hemorrhagic) vs. pale (anemic) infarcts depending on tissue vascularity and reperfusion.
• Healing: inflammation → granulation → fibrosis (scar).

Rapid reperfusion (thrombolysis, PCI, thrombectomy) limits infarct size. Prevention targets atherosclerosis risk factors.