Arterial Thrombosis

Overview

Arterial thrombosis is the formation of a blood clot (thrombus) inside an artery. Arteries carry oxygen-rich blood from the heart to the rest of the body, so when a clot blocks an artery, the tissue beyond it is suddenly deprived of oxygen. Depending on which artery is affected, this can cause a heart attack, a stroke, or a loss of blood flow to a limb or organ.

Most arterial clots form on top of fatty deposits called plaques, which build up in artery walls in a process known as atherosclerosis. When a plaque cracks or ruptures, the body forms a clot at that spot, which can quickly seal off the vessel. Because the consequences can be life-threatening or limb-threatening, arterial thrombosis is often a medical emergency requiring immediate care.

The specific danger depends on which artery is affected. A clot in a coronary artery causes a heart attack, one in an artery to the brain causes a stroke, and one in a limb artery threatens the arm or leg. In every case, the underlying message is the same: oxygen-rich blood is being cut off from tissue that needs it, and restoring that blood flow quickly is what limits the damage.

Symptoms

Symptoms depend entirely on which artery is blocked, but they usually come on suddenly.

• Heart (coronary arteries): Chest pain or pressure, shortness of breath, sweating, pain spreading to the arm or jaw, a heart attack
• Brain (cerebral arteries): Sudden weakness or numbness on one side, trouble speaking, facial drooping, vision loss, a stroke
• Limb (arm or leg arteries): Sudden pain, pale or cold limb, numbness, and loss of pulse
• Intestine or other organs: Sudden severe pain in the affected area

All of these are emergencies. Sudden chest pain, stroke symptoms, or a cold painful limb require calling emergency services right away.

Causes

Arterial thrombosis usually develops where an artery is already diseased.

• Atherosclerosis: Fatty plaques in the artery wall can rupture, triggering a clot that blocks the vessel. This is the most common cause.
• Clotting disorders: Conditions that make the blood more likely to clot.
• Irregular blood flow: Turbulence around narrowed or damaged areas promotes clotting.
• Injury or procedures: Damage to an artery from trauma, surgery, or catheter procedures.

An embolism, where a clot forms elsewhere and travels to lodge in an artery, can cause a similar sudden blockage.

Risk Factors

• Smoking
• High blood pressure
• High cholesterol
• Diabetes
• Obesity and physical inactivity
• Older age and a family history of heart or vascular disease
• Clotting disorders

Diagnosis

Diagnosis is guided by symptoms and the artery involved, and often needs to be made quickly.

• Physical examination and history: Checking pulses, blood pressure, and the affected area.
• ECG and blood tests: To diagnose a heart attack.
• Imaging of the brain: CT or MRI for suspected stroke.
• Ultrasound or angiography: To locate a blockage in the arteries of the heart, brain, or limbs.

Treatment

Treatment focuses on quickly restoring blood flow and preventing more clots.

• Clot-dissolving medication: Drugs that break up the clot, used promptly in heart attack and stroke when appropriate.
• Blood thinners and antiplatelet drugs: To stop the clot from growing and prevent new ones.
• Procedures to open the artery: Catheter-based techniques to remove the clot or place a stent, or surgery to bypass the blockage.
• Treating risk factors: Controlling blood pressure, cholesterol, and diabetes, and stopping smoking, to prevent recurrence.

The speed of treatment strongly affects the outcome, especially for the heart and brain.

Prevention

• Do not smoke
• Keep blood pressure, cholesterol, and blood sugar under control
• Eat a heart-healthy diet and stay physically active
• Maintain a healthy weight
• Take prescribed medications, such as antiplatelet or cholesterol-lowering drugs, as directed
• Attend regular check-ups if you have heart or vascular disease

When to See a Doctor

Arterial thrombosis can be life-threatening. Call emergency services immediately for sudden chest pain or pressure, shortness of breath, or pain spreading to the arm or jaw; for sudden weakness, numbness, trouble speaking, facial drooping, or vision loss (signs of stroke); or for a suddenly painful, pale, cold, or numb limb. Acting within minutes can save the heart muscle, brain tissue, or limb. Do not delay or try to drive yourself if symptoms are severe.

Related Topics

Frequently Asked Questions

References

1. National Heart, Lung, and Blood Institute (NHLBI). Heart Attack.
2. MedlinePlus, U.S. National Library of Medicine. Arterial embolism.
3. Centers for Disease Control and Prevention (CDC). Stroke.
4. Mayo Clinic. Atherosclerosis — Symptoms and causes.