Ischemia

Ischaemia . Stopping or decreasing the circulation of blood through the arteries of a certain area, which involves a state of cellular suffering due to lack of oxygen and nutritional materials in the affected part.

This cellular suffering can be intense enough to cause cell death and the tissue to which it belongs ( necrosis ). One of the main functions of the blood is to make the oxygen taken by the lungs and nutrients circulate through the body and reach all the tissues of the body .

To survive, cells need to obtain energy . In general, there are two ways to generate it (both based on chemical processes ) that take advantage of the energy stored in one or more links: via fermentation or from oxygen. If the ischemia is very severe, it can lead to anoxia, which means that the tissues of that region will not have the energy necessary to survive. In this way, the tissue dies. Each tissue has a different level of tolerance to oxygen starvation.

Summary

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  • 1 Symptoms
  • 2 Myocardial ischemia (Angina pectoris)
  • 3 Cerebral ischemia
  • 4 Chronic ischemia
  • 5 Acute ischemia
  • 6 Renal ischemia
  • 7 Intestinal ischemia
  • 8 Acute limb ischemia
  • 9 Causes
  • 10 risk factors
  • 11 Prevention
  • 12 Treatment
  • 13 Pathophysiology
  • 14 Source

Symptoms

Ischemia can affect any organ or tissue area in the body, including the heart , brain, and legs . Ischemia in these areas of the body can lead to ischemic heart disease, dementia, and peripheral vascular disease, respectively.

Myocardial ischemia (Angina pectoris)

It is the decrease of the irrigation in the coronary arteries that go to the heart. It is generally identified with precordial pain with a choking sensation due to the low oxygen flow to the heart. If ischemia is prolonged long enough, a zone of necrosis or heart attack occurs .

Cerebral ischemia

The cerebral ischemia is the reduction of cerebral blood flow to levels that are insufficient to maintain the metabolism necessary for normal function and structure of the brain often resulting in death.

It occurs more frequently in older people with cardiovascular risk factors such as smoking , drug use like cocaine , high blood pressure , atherosclerosis, or diabetes . The affectation of specific areas of the brain generates focused manifestations such as paralysis or plegia of a hemibody (one half of the body), facial paralysis , aphasia (loss of ability to produce or understand language), among others.

Causes of vascular cerebral ischemia : lacunar infarction (in patients with vascular hypertension), carotid-dependent infarctions (by hemodynamic mechanisms), cerebral embolisms of cardiac origin. It can cause sudden death .

Chronic ischemia

Decreased arterial blood supply that occurs gradually and gradually. It can affect the upper and lower extremities, but much more often in the lower ones. That is, it decreases the circulation of blood in the affected area, occurring gradually. Lack of oxygen in the upper limbs can also easily cause oxygenation problems in the superior arteries such as the carotids , and can produce cerebral ischemia .

On the other hand, the lack of oxygenation in the upper limbs largely causes loss of functional mobility in various parts of these limbs (joint, muscle pain in the arms and especially the shoulders ) and it has also been found that in this type of ischemia only With movements in which the muscles need more oxygenation, they can be affected, such that they are tired, sore, and with other secondary problems related to lack of oxygen, such as in Leriche syndrome.

Acute ischemia

Decreased arterial blood supply that occurs suddenly. It is more frequent in the lower extremities than in the upper ones. This process can take place elsewhere in the body: in the kidney (acute renal ischemia), in the brain (acute cerebral infarction), in an artery in the cerebral territory ( paraplegia ).

Renal ischemia

It is the reduction of renal blood flow (uni or bilateral hypoperfusion) either by decrease in total blood volume, by redistribution of blood or by obstruction . Its causes are usually: surgical complications, hemorrhage , trauma , rhabdomyolysis with myoglobinuria, gram-negative sepsis, postpartum hemorrhage, pancreatitis , etc. It can condition acute kidney failure due to tubular necrosis. In cases of unilateral obstruction ( renal stenosis , embolism , etc.) they can lead to acute or renal atrophy (chronic ischemia).

Intestinal ischemia

Intestinal ischemia occurs when the blood vessels in the intestines become narrow or blocked, which reduces blood flow. Decreased blood flow can cause pain and can permanently damage your intestine.

Acute limb ischemia

Acute limb ischemia is a potentially serious condition that occurs when one leg or arm does not receive an adequate supply of new blood. Cholesterol buildup , blood clots in the main arteries, and other circulatory problems may be responsible.

 

Causes

Arterial ischemia is caused by a decrease in the blood supply to a tissue or organ . Blood flow can be blocked by a clot , an embolus , or an artery constriction . It can occur due to gradual thickening of the artery wall and narrowing of the artery, as in atherosclerosis. Trauma can also interrupt blood flow.

Risk factor’s

Not all people with risk factors will have ischemia. Risk factors for ischemia include:

  • Cholesterol or triglycerideshigh
  • Diabetes (a chronic disease that affects the body’s ability to use sugar for energy)
  • Hypertension
  • Obesity
  • Consumption of snuff
  • Physical inactivity
  • Stress
  • Advanced age
  • Trauma
  • Atrial fibrillation or other heart disease
  • Underlying vascular disease
  • Venous thromboembolism

Prevention

You can reduce your risk of ischemia by doing the following:

  • Control blood sugar
  • Have a healthy diet
  • keep a healthy weight
  • Give up smoking
  • Exercise regularly
  • Reduce your stress level
  • Taking medications for heart disease, cholesterol, diabetes, or high blood pressure.

Treatment

The goal of ischemia treatment is to restore blood flow and prevent further damage. Early treatment is essential to keep the affected limb viable. Treatment options include injection of a blood thinner , thrombolysis , embolectomy , surgical revascularization, or amputation .

Pathophysiology

Ischemia results in tissue damage in a process known as the ischemic cascade. The damage is the result of the accumulation of metabolic residues, inability to maintain cell membranes, and the leakage of enzymes into the cell and surrounding tissues.

 

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