iskemia

Ischemia, or iskemia, is a condition in which a region of tissue receives insufficient blood flow to meet its metabolic needs. This reduction in perfusion leads to reduced oxygen delivery (hypoxia) and nutrient supply, impairing cellular function. If blood flow is not restored promptly, ischemia can progress to tissue injury or death (infarction).

Causes and types

Ischemia results from obstruction or narrowing of arteries, disruption of microvascular circulation, or systemic hypotension. Common mechanisms include atherosclerotic narrowing, thrombosis, embolism, vasospasm, or compression. Ischemia can affect any tissue but is clinically significant in the heart (myocardial ischemia), brain (cerebral ischemia), intestines (mesenteric ischemia), and limbs (peripheral arterial disease). Acute ischemia is a medical emergency, whereas chronic ischemia develops gradually and may cause ongoing symptoms.

Pathophysiology

Reduced blood flow forces cells to rely on less efficient anaerobic metabolism, leading to acid buildup and energy failure. If perfusion is not restored, cell injury progresses, potentially causing irreversible damage and infarction. Reperfusion after ischemia can itself cause injury through inflammatory and oxidative mechanisms.

Clinical features

Myocardial ischemia may present as chest discomfort or dyspnea (angina). Cerebral ischemia can cause sudden focal neurological deficits or speech difficulties. Mesenteric ischemia often presents with severe abdominal pain after meals. Peripheral ischemia causes claudication, weakness, or a cold, pale limb. Diagnosis uses history, imaging (ECG, CT/MRI, Doppler), and laboratory markers such as troponins or lactate.

Treatment and prognosis

Management aims to restore perfusion, prevent further injury, and address underlying causes. This may include reperfusion therapies (percutaneous intervention or thrombolysis), anticoagulants, antiplatelets, statins, and risk-factor modification. Prognosis depends on tissue affected and duration of ischemia; timely treatment improves outcomes. Preventive strategies focus on controlling cardiovascular risk factors.