Myocardial ischemia

Description

Myocardial ischemia occurs when blood flow to the heart is reduced, preventing the heart muscle from receiving enough oxygen. The reduced blood flow is usually the result of a partial or complete blockage of the heart arteries (coronary arteries).

Myocardial ischemia, also called cardiac ischemia, reduces the heart muscle's ability to pump blood. A sudden, severe blockage of one of the heart's artery can lead to a heart attack. Myocardial ischemia might also cause serious abnormal heart rhythms.

Treatment of myocardial ischemia involves improving the flow of blood to the heart muscle. Treatment may include medications, a procedure to open clogged arteries (angioplasty) or bypass surgery.

Heart-healthy lifestyle is important in the treatment and prevention of myocardial ischemia.

Symptoms

Some people who have myocardial ischemia has no signs or symptoms (silent ischemia).

When they do occur, the most common is the pressure in the chest or pain, usually on the left side of the body (angina pectoris). Other signs and symptoms that may be present more commonly by women, older people and people with diabetes include:

  • Neck or jaw pain
  • Shoulder or arm pain
  • A fast heartbeat
  • Difficulty breathing when you are physically active
  • Nausea and vomiting
  • Sweating
  • Fatigue

When to see a doctor

Get emergency medical help if you have severe pain in the chest or chest pain that does not go away.

Causes

Myocardial ischemia occurs when blood flow through one or more of the coronary arteries is reduced. The low blood flow decreases the amount of oxygen in the heart muscle receives.

Myocardial ischemia may develop slowly as the arteries become blocked over time. Or you can quickly occur when an artery is suddenly blocked.

Conditions that can cause myocardial ischemia include:

  • Coronary artery disease (atherosclerosis). The plaques are mainly composed of the accumulation of cholesterol in the walls of the arteries and restricts blood flow. Atherosclerosis is the most frequent cause of myocardial ischemia.
  • Blood clot. The plaques that develop in the atherosclerosis can rupture, causing a blood clot. The clot can block an artery and cause sudden, severe myocardial ischemia, which results in a heart attack. Rarely, a blood clot could travel to the coronary artery in another part of the body.
  • Spasm of the coronary artery. This temporary of the muscles in the wall of the artery may briefly reduce or even prevent the flow of blood to a part of the heart muscle. Coronary artery spasm is a rare cause of myocardial ischemia.

Chest pain associated with myocardial ischemia can be caused by:

  • The physical effort
  • The emotional stress
  • Cold temperatures
  • The consumption of cocaine
  • Eating a large or heavy meal
  • Sex

Risk factors

Factors that may increase your risk of developing myocardial ischemia include:

  • Tobacco. Smoking and long-term exposure to second-hand smoke can damage the inside of the walls of the arteries. The damage can allow deposits of cholesterol and other substances in order to collect and reduce the flow of blood in the coronary arteries. Smoking causes the coronary arteries to spasm and may also increase the risk of blood clots.
  • Diabetes. Type 1 and type 2 diabetes are linked to an increased risk of myocardial ischemia, heart attack and other heart problems.
  • The high blood pressure. Over time, high blood pressure can accelerate atherosclerosis, resulting in damage to the coronary arteries.
  • High blood cholesterol level. Cholesterol is an important part of the deposits that can narrow the coronary arteries. A high level of "bad" (low-density lipoprotein, or LDL) cholesterol in the blood may be due to a hereditary condition, or a diet high in saturated fats and cholesterol.
  • High level of triglycerides in the blood. Triglycerides, another type of fat in the blood, may also contribute to atherosclerosis.
  • Obesity. Obesity is associated with diabetes, high blood pressure and high cholesterol levels.
  • The circumference of the waist. A waist measurement of more than 35 inches (89 cm) for women and 40 inches (102 cm) in men increases the risk of high blood pressure, diabetes, and heart disease.
  • The lack of physical activity. Not getting enough physical exercise contributes to obesity and is linked to higher levels of cholesterol and triglycerides. The people who get regular aerobic exercise have better heart health, which is associated with a lower risk of myocardial ischemia and heart attack. Exercise also lowers blood pressure.

Complications

Myocardial ischemia can lead to serious complications, including:

  • Heart attack. If a coronary artery becomes completely blocked, the lack of blood and oxygen can lead to a heart attack that destroys part of the heart muscle. The damage can be severe and sometimes fatal.
  • Irregular heart rhythm (arrhythmia). An abnormal heart rhythm can weaken your heart and can be life-threatening.
  • Heart failure. Over time, repeated episodes of ischemia can lead to heart failure.

Prevention

The same habits of life that can help to treat myocardial ischemia can also help prevent it from developing in the first place. Leading a heart-healthy lifestyle can help keep your arteries strong, elastic and soft, and allow for the maximum flow of blood.

Myocardial ischemia

Diagnosis

Your doctor will start with questions about your medical history and a physical examination. After that, your doctor might recommend:

  • Electrocardiogram (ECG). Electrodes attached to your skin to record the electrical activity of your heart. Certain changes in the electrical activity of the heart can be a sign of heart damage.
  • Stress test. Your heart rate, blood pressure and breathing are monitored while you walk on a treadmill or ride a stationary bike. Exercise makes your heart pump harder and faster than usual, so that a stress test can detect heart problems that may not be noticeable otherwise.
  • The echocardiogram. The sound waves directed at your heart from a wand-like device that is held on your chest produce video images of your heart. An echocardiogram can help to identify whether an area of the heart has been damaged and not pumping normally.
  • Stress echocardiogram. A stress echocardiogram is similar to that of a regular echocardiogram, except the test is performed after exercise in the doctor's office on a treadmill or stationary bike.
  • Nuclear stress test. Small amounts of radioactive material is injected into the bloodstream. While you exercise, your doctor can see how that flows through the heart and the lungs, allowing the flow of blood to the problems identified.
  • The coronary angiography. A dye is injected into the blood vessels of your heart. Then, a series of X-ray images (angiograms) are taken, showing the tint of the route. This test gives your doctor a detailed look at the inside of the blood vessels.
  • Cardiac computed tomography. This test can determine if you have a calcium buildup in the coronary arteries — a sign of coronary atherosclerosis. The arteries of the heart you can also see the use of CT (coronary ct angiography).

Treatment

The objective of myocardial ischemia treatment is to improve the flow of blood to the heart muscle. Depending on the severity of your condition, your doctor may recommend medication, surgery, or both.

Drugs

Medications for the treatment of myocardial ischemia include:

  • The aspirin. A daily aspirin or other blood thinner can reduce the risk of blood clots, which can help to prevent the obstruction of the coronary arteries. Ask your doctor before you start taking aspirin, as it may not be suitable for you if you have a bleeding disorder or if you are already taking another blood thinner.
  • The nitrates. These medications expand the arteries, improving blood flow to and from your heart. Better blood flow means that your heart does not have to work so hard.
  • Beta-blockers. These medications help relax your heart muscle, slow your heartbeat and decrease blood pressure so that blood can flow to your heart more easily.
  • Calcium channel blockers. These medicines relax and dilate the blood vessels, increasing the flow of blood in your heart. Calcium channel blockers also slow down the speed of your pulse and reduce the workload of the heart.
  • Medications used for lowering cholesterol. These medicines decrease the main material that is deposited in the coronary arteries.
  • Angiotensin-converting enzyme (ACE) inhibitors. These medications help relax blood vessels and lower blood pressure. Your doctor may recommend an angiotensin-converting enzyme (ACE) inhibitors if you have high blood pressure or diabetes, in addition to myocardial ischemia. ACE inhibitors may also be used if you have heart failure, or if your heart does not pump blood effectively.
  • Ranolazine (Ranexa). This drug helps to relax the coronary arteries to relieve angina. Ranolazine may be prescribed with other angina medications, such as calcium channel blockers, beta blockers, or nitrates.

Procedures to improve the flow of blood

Sometimes, more aggressive treatment is necessary to improve the flow of blood. The procedures that can help are:

  • Angioplasty and stent placement. A long, thin tube (catheter) that is inserted into the narrowed part of the artery. A cable with a small balloon is inserted into the narrowed area and inflated to widen the artery. A small wire-mesh coil (stent) is usually inserted to keep the artery open.
  • Coronary artery bypass surgery. A surgeon uses a vessel from another part of your body to create a graft that allows blood to flow around the obstruction or narrowing of the coronary artery. This type of open-heart surgery is usually used for people that have multiple narrowing of the coronary arteries.
  • Enhanced external counterpulsation. This non-invasive, outpatient treatment may be recommended if other treatments have not worked. Cuffs that wrap around your legs gently inflated with air then deflated. The resultant of the pressure in the blood vessels can enhance the flow of blood to the heart.

Self-care

Lifestyle changes are an important part of the treatment. To follow a heart-healthy lifestyle:

  • Stop smoking. Talk with your doctor about stop-smoking strategies. Also, try to avoid second-hand smoke.
  • Manage the underlying health problems. The treatment of diseases or conditions that may increase your risk of myocardial ischemia, such as diabetes, high blood pressure and high cholesterol in the blood.
  • Eat a healthy diet. Limit saturated fats and eat lots of whole grains, fruits and vegetables. Know your cholesterol numbers and ask your doctor if you have reduced to the recommended level.
  • Exercise. Talk with your doctor about starting a safe exercise plan to improve the blood flow to your heart.
  • Maintain a healthy weight. If you are overweight, talk with your doctor about the weight loss options.
  • Reduce stress. Practice healthy techniques for managing stress, such as muscle relaxation and deep breathing.

It is important to have medical check-ups. Some of the main risk factors of myocardial ischemia — high cholesterol, high blood pressure and diabetes — do not have any symptoms in the early stages. The early detection and treatment can set the stage for a lifetime of better heart health.

Preparing for your appointment

If you are experiencing chest pain, it is likely that you are going to be examined and treated in the emergency room.

If you don't have pain in the chest, but has other symptoms, or are concerned about the risk of myocardial ischaemia, you may be referred to a heart specialist (cardiologist).

What you can do

  • Be aware of any pre-appointment restrictions, such as fasting before a blood test.
  • Write down your symptoms, including any that may seem unrelated to the reason for which you scheduled the appointment.
  • Make a list of all your medications, vitamins and supplements.
  • Write down your key medical information, including other conditions.
  • Write down key personal information, including any recent changes or stressors in your life.
  • Write questions to ask their doctor.
  • Ask a relative or friend to accompany you, to help you remember what the doctor says.

Questions to ask your doctor

  • What is the most likely cause of my symptoms?
  • What tests do I need? Is there any special preparation for them?
  • What type of treatments do I need?
  • Do I need to make lifestyle changes? What would be an appropriate diet and level of activity for me?
  • How often should I be screened for heart disease?
  • I have other health problems. How can I best manage these conditions?

In addition to the questions that you've prepared to ask your doctor, do not hesitate to ask questions during your appointment.

What to expect from your doctor

Your doctor may ask you a series of questions. Be prepared to answer them you can let go the more points you want to spend more time. You may ask:

  • What are your symptoms, and when they began?
  • How severe are the symptoms? Are occasional or continuous?
  • Is there something to improve or worsen your symptoms?
  • Do you have a family history of heart disease, high blood pressure or high cholesterol?
  • Do you or do you smoke?
Symptoms and treatment of Myocardial ischemia