Coronary thrombosis

Medical quality assurance by Dr. Albrecht Nonnenmacher, MD at June 28, 2016
StartDiseasesCoronary thrombosis

Coronary thrombosis is the formation of a blood clot within an artery of the heart, and it can lead to a myocardial infarction (more commonly known as a heart attack). Speedy emergency treatment with medication and surgery can safely dissolve the clot before a heart attack occurs. Treatment is lifelong and includes lifestyle changes as well as medication. 

Contents

Definition & Facts

Coronary thrombosis occurs when a blood clot forms within one of the heart's arteries, restricting blood flow. This type of ischemic heart disease occurs in combination with a narrowing of blood vessels following the clot.

Coronary thrombosis can lead to myocardial infarction which causes tissue death. If a clot develops in one of the two major coronary arteries supplying the heart with blood and oxygen, the blood supply to that area of the heart muscle stops. Drug-eluting stents may also cause coronary thrombosis. 

Symptoms & Complaints

Although there is a common set of symptoms that afflict most patients with coronary thrombosis, not all patients experience every symptom. Usually, the patient experiences more than one though. The symptoms of coronary thrombosis include: 

Although the symptoms may temporarily cease during hospital treatment, some symptoms like chest pain or angina may require lifelong medication to control.

Causes

Atherosclerosis, the accumulation of cholesterol and fat in the arterial walls, causes coronary thrombosis. When cholesterol and fat (also called plaque) collect, it causes the plaque to harden and narrow the arteries. This makes it hard for blood to flow through and a clot forms. The plaque can also rupture which also causes a clot.

A number or risk factors contribute to the build up of excess plaque in the artery walls. These risk factors include: smoking, inactivity/lack of exercise, obesity, high levels of psychological stress, family history of atherosclerosis, high cholesterol, high blood pressure, and diabetes type 1 or diabetes mellitus type 2. Ceasing negative impact activities (quitting smoking) while adopting lifestyle changes such as regular exercise can reduce risk as can careful management of related diseases.

Diagnosis & Tests

As part of the diagnostic process, the patient will undergo an electrocardiogram (ECG) which is a test that indicates a blocked coronary artery. Since the test can miss small clots, the doctor may run a second test about 30 minutes later.

During the first 24 hours in the hospital, the patient undergoes a series of blood tests to determine if the coronary thrombosis caused injury to the heart muscle. Follow up tests usually occur four to six weeks after leaving the hospital to determine long-term diagnosis and extent of heart damage.

A cardiac stress test reveals if areas of the heart lack oxygen supply. It's administered on either a treadmill or an exercise bike while a continuous ECG is administered. An echocardiography provides an ultrasound scan of the heart. This illustrates the heart's pumping efficiency and the extent of damage caused by the coronary thrombosis.

The doctor conducts a coronary artery examination called a coronary arteriography by injecting the patient with a contrast dye that is visible on X-rays. The dye's flow through coronary arteries reveals narrowing arteries and blockages.

Treatment & Therapy

As soon as a person experiences symptoms, they should call 911. The 911 operator may or may not tell the patient to take aspirin. Aspirin prevents platelets from sticking together around the blood clot.

Once at the hospital, treatment may include dissolving the blockage with medication or by surgery. Surgery involves an emergency catheter procedure called a balloon angioplasty that re-expands the artery. The earlier the surgery is performed, the better the outcome. Doctors use a variety of medications to treat coronary thrombosis over the long term. The most common prescribed medications include the following: 

  • Aspirin: A low-dose daily aspirin regimen is the most common. It helps thin the blood to prevent future clots. 
  • Clopidogrel: Clopidogrel is prescribed in combination with aspirin, usually during the first year following a heart attack.
  • Nitrovasodilators: Nitrates expand the arteries. While the quick-acting glyceryl trinitrate helps stop an episode of chest pain, long-acting oral nitrate works to prevent angina and shortens attack durations.
  • Beta blockers: Beta blockers help lower blood pressure, reduce the workload on the heart and increase blood flow in the coronary arteries by blocking the action of adrenaline hormones on the heart. 
  • Calcium channel blockers: Used in long-term angina management, calcium channel blockers work to reduce tension of the muscles in the heart's arteries by expanding them and relaxing the heart muscle slightly. This allows larger, more easy blood flow and reduces the heart's oxygen needs. 
  • Nicorandil: The potassium channel opener nicorandil dilates the body's blood vessels improving blood flow to the heart and reducing the heart's work to pump blood throughout the body. It also reduces muscle tension in the heart.

In addition to prescribing medications, the doctor may recommend participation in a cardiac rehabilitation program which helps the patient learn a more heart-healthy lifestyle and which addresses both psychological and physical wellness. Some patients suffer from depression after coronary thrombosis and professional counseling is recommended.

Prevention & Prophylaxis

Techniques to prevent coronary thrombosis include lifestyle modification and medication. Quitting smoking will reduce the risk of coronary thrombosis by immediately reducing wear and tear on the heart and lungs. One should also make attempts to reduce secondhand smoking. It is important to avoid environments where exposure to secondhand smoke is likely.

Regular exercise is crucial for preventing cardiovascular disease. Exercising for 30 minutes three to five times a week is often recommended. Cardio exercises like bicycling or walking can significantly reduce cholesterol levels and risk of disease.

Eating a healthy diet that is limited in saturated fats is important as well. Significantly reducing the amount of red meat and sweets consumed can also help. Enjoying a daily diet of oily fish; lean, skinless meats; five servings of fruits and vegetables; and reduced-fat versions of dairy items like milk and cheese may also be recommended. It is recommended to grill food when cooking instead of frying it.