Infarts

Infarts, or infarcts, are areas of tissue necrosis caused by local tissue ischemia when blood supply is interrupted. They can develop in many organs, most commonly the heart, brain, lungs, kidneys, spleen, and intestines. The appearance of an infarct depends on the organ and its blood supply. Pale (white) infarcts occur in solid organs with a single arterial supply, such as the heart, spleen, and kidneys. Red (hemorrhagic) infarcts occur in organs with a dual blood supply or after reperfusion, such as the lungs and intestines, or when venous occlusion is involved.

Most infarcts arise from blockage of arterial blood flow by thrombosis or embolism, often related to atherosclerosis, atrial fibrillation, left ventricular thrombus, or other cardiac sources. Others include venous thrombosis, torsion, vasculitis, or external compression. Systemic hypotension or microvascular occlusion can contribute in susceptible tissues and may lead to multi-organ infarction in severe illness.

Clinical presentation depends on location. Myocardial infarction presents with chest pain and biomarkers of cardiac injury; cerebral infarction causes abrupt focal neurological deficits; pulmonary infarction typically presents with pleuritic chest pain and dyspnea; renal or splenic infarcts cause flank or abdominal pain. Diagnosis uses imaging and laboratory tests: ECG and troponins for heart; CT or MRI for brain; CT pulmonary angiography for lungs; Doppler ultrasound or CT angiography for other organs. Histology shows coagulative necrosis after a time.

Treatment aims to restore perfusion and address the underlying cause, including thrombolysis or thrombectomy for cerebral infarcts, reperfusion strategies for myocardial infarction, and anticoagulation when indicated. Prognosis varies with size and location, with recovery depending on the affected tissue.

Prevention focuses on cardiovascular risk reduction and management of contributing conditions such as atrial fibrillation, hypertension, diabetes, dyslipidemia, smoking, and dehydration.