Arterial embolism

Definition

Arterial embolism is a sudden interruption of blood flow to an organ or body part due to a clot (embolus).

Causes

An embolus is a blood clot or a piece of plaque that acts in the same manner as a clot. Emboli means more than one clot. If the clot travels from the site where it formed to another location in the body it is called an embolism.

An arterial embolism may be caused by one or more clots. The clots can get stuck in an artery and block blood flow. The blockage starves tissues of blood and oxygen, which can result in damage or tissue death (necrosis).

Arterial emboli often occur in the legs and feet. Some may occur in the brain, causing a stroke, or the heart, causing a heart attack. Less common sites include the kidneys, intestines, and the eyes.

Atrial fibrillation is a major risk factor for an arterial embolism. The risk of an embolism increases when factors that tend to form clots are increased. Such factors may include injury or damage to an artery wall and conditions that increase blood clotting (such as increased platelet count).

Another condition that poses a high risk for embolization (especially to the brain) is mitral stenosis. Endocarditis (infection of the inside of the heart) can also cause an arterial emboli.

Paradoxical embolization can take place when a clot in a vein enters the right side of the heart and passes through a hole into the left side. The clot can then cause blockage of blood flow to the brain (stroke) or other organs.

If a clot involves the arteries supplying blood flow to the lungs, it is called a pulmonary embolus

Symptoms

Symptoms may begin abruptly or slowly depending on the size of the embolus and the extent to which it blocks the blood flow.

Symptoms of an arterial embolism in the arms or legs may include:

• Muscle pain in the affected area
• Muscle spasm in the affected area
• Numbness and tingling in the arm or leg
• Pale color of arm or leg
• Decreased or absent pulse in the extremity
• Cold arm or leg
• Lack of movement of the extremity
• Weakness of arm or leg
• Fingers or hands feels cool
• Loss of muscle function

Later symptoms:

• Blisters
• Skin erosion (ulcer)
• Tissue death (necrosis; skin is dark and damaged)
• Sloughing of skin

Symptoms of a clot in an organ vary with the organ involved but may include:

• Pain
• Temporarily decreased organ function
• Ischemia (lack of oxygen)
• Infarction (tissue death)

Exams and Tests

There may be decreased or absent pulse, and decreased or absent blood pressure in the arm or leg. There may be signs of tissue death or gangrene.

Tests to diagnose arterial embolism or reveal the source of emboli may include:

• Doppler ultrasound exam of an extremity
• Transcranial Doppler
• Echocardiogram
• Transesophageal echocardiography (TEE)
• Myocardial contrast echocardiography (MCE)
• MRI
• Angiography of the affected extremity or organ
• Renal arteriography
• Extremity arteriography
• Plethysmography
• Duplex Doppler/ultrasound exam of extremity

This disease may also alter the results of the following tests:

• Isotope study
• Platelet aggregation test
• Factor VIII assay
• Euglobulin lysis time (ELT)
• Plasminogen activator inhibitor-1 (PAI-1) activity
• Tissue-type plasminogen activator (t-PA) levels

Treatment

Arterial embolism requires prompt hospitalization for treatment. The goals of treatment are to control symptoms and to improve the interrupted blood flow to the affected area of the body. The underlying cause of the clot, if identified, should be treated to prevent further problems.

Medications include:

• Thrombolytics (such as streptokinase)
• Anticoagulants (such as warfarin or heparin)
• Antiplatelet medications (such as aspirin, ticlopidine, and clopidogrel)
• Painkillers given by IV

Some people may need surgery. Procedures include:

• Thromboaspiration (clot aspiration)
• Embolectomy (clot removal through a balloon catheter or through open surgery)
• Angioplasty (dilatation of the artery with a balloon catheter) with or without implantation of a stent
• Blood vessel bypass

Outlook (Prognosis)

How well a patient does depends on the location of the clot and how much the clot has blocked blood flow. Arterial embolism can be serious if not treated promptly. There is a 25 - 30% death rate.

The affected area can be permanently damaged. Up to approximately 25% of cases require amputation.

Arterial emboli can come back (recur) even after successful treatment.

Possible Complications

• Infection in the affected tissue
• Tissue death (necrosis) and gangrene
• Septic shock
• Acute MI
• Transient ischemic attack (TIA)
• Stroke (CVA)
• Temporary or permanent kidney failure
• Temporary or permanent decrease or loss of other organ functions

When to Contact a Medical Professional

Go to the emergency room or call the local emergency number (such as 911) if symptoms indicate you may have an arterial embolism.

Prevention

Prevention begins with identifying the source of the blood clot. If your health care provider determines you have a high risk for blood clots, you may be prescribed blood thinners (such as Coumadin) to prevent their formation. Antiplatelet drugs may also be needed.

The risk for both atherosclerosis and clot formation increases in persons who smoke, are under stress, are overweight, or who are inactive and do no exercise. Taking steps to reduce hardening of the arteries (atherosclerosis) may reduce your risk of an arterial embolus forming from a piece of plaque.