Myocardial ischaemia

Myocardial ischaemia is a serious condition where your heart muscle doesn’t get enough oxygen-rich blood to work properly. This happens when the arteries that supply blood to your heart become narrowed or blocked, often by a buildup of fatty deposits called plaque.

cardiac ischemia

Table of contents

• What is myocardial ischaemia?
• Causes and risk factors
• Signs and symptoms
• How is it diagnosed?
• Treatment options
• Lifestyle changes and prevention
• Potential complications

What is myocardial ischaemia?

Myocardial ischaemia occurs when blood flow to your heart is reduced, preventing the heart muscle from receiving enough oxygen^[1]. The term myocardium refers to the heart muscle, and ischaemia means a lack of blood supply^[2].

The reduced blood flow is usually the result of a partial or complete blockage of your heart’s arteries, which are called coronary arteries^[1]. When your coronary arteries cannot deliver enough oxygen-rich blood to your heart muscle, the muscle becomes starved for oxygen^[2].

This condition reduces the heart muscle’s ability to pump blood effectively^[1]. If the lack of blood from your coronary arteries is severe or lasts for more than a few minutes, it can damage your heart muscle and then becomes a myocardial infarction, commonly known as a heart attack^[2].

Each year, more than 1 million people in the United States die from heart attacks caused by myocardial ischaemia, which represents a lack of blood flow and oxygen to the heart muscle^[2].

Causes and risk factors

The main cause of myocardial ischaemia is coronary artery disease, also called atherosclerosis. This is a buildup of plaque and cholesterol inside your coronary arteries, which supply blood to your heart muscle^[2]. The buildup narrows your artery so much that the oxygen-rich blood your heart needs cannot get through. This causes ischaemia and chest pain known as angina^[2].

Plaques are made up mostly of cholesterol and build up on your artery walls, restricting blood flow^[5]. Atherosclerotic plaque causes 70% of fatal heart attacks^[2].

Other causes of myocardial ischaemia include blood clots and coronary artery spasm. When plaque that forms in your narrow coronary artery breaks apart, it can attract a blood clot. When a blood clot settles in a coronary artery that is already narrow, it can cause a blockage^[2]. The plaques that develop in atherosclerosis can rupture, causing a blood clot that might block an artery and lead to sudden, severe myocardial ischaemia, resulting in a heart attack^[5].

A coronary artery spasm is a temporary tightening of the muscles in the artery wall that can briefly decrease or even prevent blood flow to part of the heart muscle. This is an uncommon cause of myocardial ischaemia^[5].

Certain factors can increase your risk of developing myocardial ischaemia. Often, a person has more than one cause or risk factor^[2]. People who get myocardial ischaemia often have high blood pressure, high cholesterol, diabetes, a family history of cardiovascular disease, and a history of tobacco product use^[2].

Several factors can increase your risk of developing this condition, including smoking and long-term exposure to secondhand smoke, diabetes, obesity, high blood pressure, high cholesterol and high triglyceride blood levels, and lack of physical activity^[5][6].

Chest pain associated with myocardial ischaemia can be triggered by physical exertion, emotional stress, cold temperatures, cocaine use, eating a heavy or large meal, and sexual intercourse^[5].

Signs and symptoms

Some people who have myocardial ischaemia don’t have any signs or symptoms. This is called silent ischaemia^[1]. It’s possible to have ischaemia or even a heart attack and not have any warning signs. Silent myocardial ischaemia is most common in people with diabetes, but it can happen to anyone with heart disease^[2].

When symptoms do occur, the most common is chest pressure or pain, typically on the left side of the body. This chest pain is called angina pectoris^[1]. The most common symptom of myocardial ischaemia is angina, which is chest pain similar to indigestion or heartburn^[2].

Angina can feel like chest discomfort, heaviness, tightness, pressure, aching, burning, numbness, fullness, or squeezing^[2]. Some people describe it as if a heavy object is sitting on the chest^[6].

There are two types of angina. Stable angina usually stops soon after you rest or take medication to manage it. Unstable angina can happen at any time, even when you’re relaxed or sleeping, and may not go away when you take medication^[2].

Other signs and symptoms, which might be experienced more commonly by women, older people, and people with diabetes, include neck or jaw pain, shoulder or arm pain, a fast heartbeat, shortness of breath when you are physically active, nausea and vomiting, sweating, and fatigue^[1].

Additional symptoms can include pain or discomfort in your upper body, including your arms, left shoulder, back, neck, jaw or stomach; trouble breathing or feeling short of breath; sweating or cold sweat; feeling full, indigestion, or a choking feeling (may feel like heartburn); feeling lightheaded, dizzy, very weak or anxious; and fast or irregular heartbeat^[2].

If you have angina or any of the symptoms of ischaemia that last for more than five minutes, call emergency services right away^[2]. Get emergency help if you have severe chest pain or chest pain that doesn’t go away^[1].

How is it diagnosed?

Your doctor will start by asking questions about your medical history and performing a physical exam^[8]. After that, your doctor might recommend several tests to diagnose myocardial ischaemia.

An electrocardiogram, also called ECG or EKG, uses electrodes attached to your skin to record the electrical activity of your heart. Certain changes in your heart’s electrical activity may be a sign of heart damage^[8].

A stress test monitors your heart rhythm, blood pressure, and breathing while you walk on a treadmill or ride a stationary bike. Exercise makes your heart pump harder and faster than usual, so a stress test can detect heart problems that might not be noticeable otherwise^[8].

An echocardiogram uses sound waves directed at your heart from a device held to your chest to produce video images of your heart. It can help identify whether an area of your heart has been damaged and isn’t pumping normally^[8].

A nuclear stress test involves injecting small amounts of radioactive material into your bloodstream. While you exercise, your doctor can watch as it flows through your heart and lungs, allowing blood-flow problems to be identified^[8].

Coronary angiography involves injecting a dye into the blood vessels of your heart. Then a series of X-ray images, called angiograms, are taken, showing the dye’s path. This test gives your doctor a detailed look at the inside of your blood vessels^[8].

A cardiac CT scan can determine if you have a buildup of calcium in your coronary arteries, which is a sign of coronary atherosclerosis. The heart arteries can also be seen using CT scanning^[8].

Blood tests may be performed to check for cardiac biomarkers such as cardiac troponins, which are proteins that help evaluate cardiac health^[6].

Treatment options

Treatment for myocardial ischaemia involves improving blood flow to the heart muscle^[1]. The goal is to increase blood circulation to the heart^[6]. Which treatment is suitable for you depends on the cause of ischaemia^[6].

Treatment may include medications, a procedure to open blocked arteries called angioplasty, or bypass surgery^[1]. Medications are the mainstay of treatment and may include antiplatelets, beta-blockers, calcium channel blockers, and nitrates^[6].

Angioplasty and stent placement is a procedure where a thin tube is inserted into a blocked artery to open it up. A small mesh tube called a stent may be placed to keep the artery open. You may need to spend a night at the hospital after this procedure^[6].

Coronary artery bypass graft, or bypass surgery, creates a new path for blood to flow around a blocked artery. After the procedure, the patient usually needs one week of hospitalization, followed by 6-12 weeks of recovery at home^[6].

Medications can help manage the condition. These may include baby aspirin, clopidogrel, cholesterol-lowering drugs, and ACE inhibitors, which may be beneficial^[6].

Lifestyle changes and prevention

Making heart-healthy lifestyle choices is important in treating and preventing myocardial ischaemia^[1]. Lifestyle changes play a crucial role in preventing the risk of developing myocardial ischaemia^[6].

Following a healthy diet is essential. You should eat more fruits, vegetables, and whole grains. Avoid saturated fat and keep your cholesterol at the recommended level^[1]. Follow a diet rich in fruits, vegetables, fish, and white meat. As far as you can, minimize your consumption of pastries, cured meats, fried foods, and red meats^[21]. Eat a diet low in saturated fats, trans fats, cholesterol, and salt. Eat lots of whole grains, fruits, and vegetables^[12].

Regular exercise is critical. Set aside a minimum of three hours per week, spread over several days, for exercise. The activity does not have to involve strenuous exercise, but you should notice your heart rate increase a little and your breathing become a bit heavier^[21]. Exercise regularly and maintain a healthy weight^[1]. Physical exercise is best at a level that is comfortable for the individual. This can help strengthen the heart muscle and improve overall health. Aerobic exercise is best, such as walking, biking, light jogging, or even swimming^[12].

Quitting smoking is undoubtedly the best thing you can do for your health^[21]. Stop smoking and avoid secondhand smoke^[1][6][12].

You should also manage your stress by practicing muscle relaxation and breathing techniques^[6]. Reduce stress and alleviate depression^[12]. Relaxation techniques, meditation, and finding time to look after yourself are all basic elements to help you adopt a more relaxed, positive attitude towards daily life^[21].

Limit alcohol intake or just stop drinking alcohol^[12]. Control your weight through an unhealthy diet and sedentary lifestyle changes^[21].

Manage your medical conditions, such as diabetes, high blood pressure, and high cholesterol, which can increase the risk of myocardial ischaemia^[6]. Take the prescribed medications for your heart condition and other diseases^[12]. It is important to follow your prescribed medication schedule very closely. Forgetfulness or inconsistency can lead to important complications^[21].

Have a regular medical checkup, which can help you detect the disease early^[6].

Potential complications

Myocardial ischaemia can lead to serious complications if not properly treated. A sudden, severe blockage of one of the heart’s arteries can lead to a heart attack^[1]. Myocardial ischaemia might also cause serious abnormal heart rhythms^[1].

As your condition gets worse, you can have symptoms of myocardial ischaemia with less and less activity. In time, it can be hard to go up a flight of stairs. Eventually, you can even have symptoms when you’re at rest^[2]. Myocardial ischaemia makes it difficult to exercise, especially in the cold^[2].

It’s important to manage this condition because ischaemia can lead to a higher risk of heart attack and heart disease, as well as a higher risk of death due to heart disease or heart failure^[12].

If myocardial ischaemia is not properly treated, serious complications include heart attack, heart failure, and irregular heart rhythm^[7].