Iskemiaan

Iskemiaan, in Estonian medical usage, refers to ischemia, the condition in which tissue receives insufficient blood flow. Ischemia can be focal, affecting a specific organ or region, or global, reflecting systemic underperfusion. It leads to reduced oxygen and nutrient delivery and can cause cell dysfunction and death if perfusion is not restored.

Causes include arterial occlusion (thrombosis, embolism), severe atherosclerosis, vasospasm, low cardiac output, shock, and microvascular dysfunction. Time is critical: brain and heart tolerate ischemia only for minutes before irreversible injury occurs in many cell populations.

Pathophysiology: decreased perfusion causes hypoxia, switch to anaerobic metabolism, acidosis, ion imbalance, inflammation, and potential reperfusion injury upon restoration of blood flow.

Common forms: cerebral ischemia (transient ischemic attack, stroke); myocardial ischemia (angina, myocardial infarction); peripheral limb ischemia; mesenteric or renal ischemia. Symptoms vary with location: brain symptoms include sudden weakness, speech trouble; heart pain or shortness of breath; limb pain, pallor, or absent pulses; abdominal pain with GI ischemia.

Diagnosis: clinical assessment supported by imaging and tests. Brain ischemia: CT or MRI; carotid Doppler; vascular imaging. Myocardial ischemia: ECG, troponin, coronary angiography. Treatment: rapid restoration of blood flow when possible (thrombolysis, mechanical thrombectomy for stroke; nitrates, antiplatelets, anticoagulants for myocardial ischemia); management of underlying causes and risk factors; supportive care.

Prognosis varies by organ and duration of ischemia; brain injuries may be permanent; prevention focuses on risk factor modification, blood pressure and lipid control, smoking cessation, and controlling diabetes.