Myocardial Ischemia

Myocardial ischemia (cardiac ischemia) is a lack of blood flow to your heart muscle. Without enough blood, the muscle doesn’t get the oxygen and nutrients it needs to work as it should. Myocardial ischemia isn’t the same thing as a heart attack, but it can lead to one.

If the lack of blood from your coronary arteries is severe or goes on for more than a few minutes, it can permanently damage your heart muscle and cause a heart attack (myocardial infarction).

If your symptoms last more than a few minutes or you think you may be having a heart attack, call 911 or emergency services immediately.

Myocardial ischemia is one of the main reasons heart attacks happen. It usually causes them due to plaque buildup in the coronary arteries. Each year, more than 1 million people in the United States die from a heart attack.

Symptoms of myocardial ischemia

The most common symptom of myocardial ischemia is angina (also called angina pectoris). Angina is chest pain or discomfort that can feel like:

• Heaviness
• Tightness
• Pressure
• Aching
• Burning
• Numbness
• Fullness
• Squeezing

Angina from cardiac ischemia lasts 10 minutes or fewer in most cases. It may be stable or unstable.

• Stable angina usually stops soon after you rest or take medication for it.
• Unstable angina can happen at any time, even when you’re relaxed or sleeping. It may not go away when you take medication and may increase in frequency and severity.

Some people, especially women, older adults and people with diabetes, may have symptoms other than chest pain. These can include:

• Pain or discomfort in your upper body, including your arms, left shoulder, back, neck, jaw or stomach
• Trouble breathing (shortness of breath)
• Sweating or “cold sweats”
• A feeling of being full or choking
• Nausea or vomiting
• Feeling lightheaded, dizzy, very weak or anxious
• Fast or irregular heartbeat

If you have angina or any of the symptoms of cardiac ischemia listed here that last for more than five minutes, call 911 or emergency services right away.

It’s possible to have ischemia ─ or even a heart attack ─ and not have any warning signs. This is called silent myocardial ischemia. This is most common in people with diabetes, but it can happen to anyone with heart disease.

Myocardial ischemia causes

Myocardial ischemia is most likely to happen when your heart needs more oxygen and nutrients than it’s getting. Often, more than one condition can contribute to myocardial ischemia, including:

• Coronary artery disease: Plaque (atheroma) builds up inside your coronary arteries, narrowing them and reducing blood flow to your heart muscle.
• Blood clot: When plaque in a narrowed coronary artery breaks apart, a blood clot can form. The clot further blocks blood flow, reducing oxygen to your heart muscle, which can cause myocardial ischemia and angina.
• Coronary artery spasm: Cocaine or an unknown cause can make coronary arteries spasm, which temporarily reduces or cuts off blood supply to your heart.
• Coronary artery embolism: A blood clot or other substance from elsewhere creates a blockage.
• Coronary artery dissection: This rare condition can keep blood from getting to your heart as a result of a tear in the lining of your coronary artery.
• Left ventricular hypertrophy: With this condition, your heart doesn’t work as efficiently as it should.

Other conditions, like autoimmune diseases, severe aortic stenosis or anemia, can also cause myocardial ischemia.

Risk factors

These conditions and other factors increase your risk because they can damage your arteries, promote plaque buildup or make it harder for enough oxygen-rich blood to reach your heart muscle:

• High blood pressure
• High cholesterol
• Diabetes
• Peripheral vascular disease
• Obesity
• A biological family history of cardiovascular disease
• A history of tobacco product use
• Lack of physical activity

How to lower your risk

Your healthcare provider may recommend medications or lifestyle changes to reduce your risk of cardiac ischemia.

Medications to lower your risk

Medicines that can lower your risk include:

• Baby aspirin
• Beta-blockers
• Cholesterol-lowering drugs
• ACE inhibitors
• Clopidogrel

Lifestyle changes to lower your risk

Physical activity is very helpful for improving your heart and blood vessel health. It gets more oxygen to your heart muscle, which helps with symptoms. Healthcare providers recommend getting at least 30 to 60 minutes of exercise five or more days a week (150 minutes/week), in addition to up to two sessions of resistance training. Starting small and gradually increasing will help keep you from putting strain on your heart.

Other things you can do include:

• Getting treatment for diabetes, high blood pressure and high cholesterol
• Eating less fat and lots of fruits, vegetables and whole grains
• Staying at a weight that’s healthy for you
• Not using tobacco products

Complications of this condition

The major complication of myocardial ischemia is a heart attack. Other possible complications include irregular heart rhythms (arrhythmias), heart failure and even death.

Cardiac ischemia also makes it hard to be physically active, especially in the cold. As your condition gets worse, you can have symptoms of myocardial ischemia 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.

How doctors diagnose this condition

In addition to getting your medical history and doing a physical exam, your healthcare provider may request the following tests:

• Electrocardiogram (EKG)
• Echocardiogram
• Holter monitor
• Exercise stress test
• Coronary angiogram
• Chest X-ray
• Heart MRI
• Nuclear stress test (PET scan)

Your provider may also do blood tests to check for:

• Proteins and enzymes from heart muscle damage
• Causes of ischemia
• High cholesterol

How is it treated?

Myocardial ischemia treatment aims to improve blood flow to your heart muscle and prevent permanent damage. Depending on the cause and severity of your condition, treatment may include medications, procedures and heart-healthy lifestyle changes.

Medications to treat myocardial ischemia

Medications can help improve blood flow, relieve symptoms and lower your risk of complications. Examples include:

• Nitroglycerin for quick relief of angina
• Beta-blockers
• Calcium channel blockers
• Thrombolytics (clot-busting drugs)
• Cholesterol-lowering medications

Procedures to treat myocardial ischemia

If medications aren’t enough or the blockage is severe, your healthcare provider may recommend a procedure to help improve blood flow, like:

• Angioplasty and stent placement
• Coronary artery bypass graft

After angioplasty or stent placement, you’ll probably spend the night in the hospital and go home the next day.

After a coronary artery bypass graft, you’ll need to spend about a week in the hospital. After that, you’ll need six to 12 weeks to recover at home.

When should I see my healthcare provider?

Contact your healthcare provider if your medicines aren’t helping you or if the side effects are severe. If you’ve had an angioplasty and stent placement or coronary artery bypass graft, you’ll most likely need to see your provider every six months during the first year after your procedure.

Call 911 or emergency services and chew an aspirin if you think you’re having a heart attack. If you have a clot in your coronary artery, aspirin can help make it smaller.

Seek emergency care right away if angina doesn’t improve with rest or medication. If a provider prescribed nitroglycerin for your angina and you’ve taken three doses of it (one dose every five minutes) and still have symptoms, call 911 or emergency services. Don’t drive yourself or have someone drive you to the hospital if you think you’re having a heart attack.

What can I expect if I have this condition?

It’s common for people with unstable angina to have a heart attack in the next three months. Heart attacks can be fatal in the first few hours.

Most people who get through the first few days after a heart attack recover completely. But some live less than a year after their heart attack.

How long you live with myocardial ischemia depends on many factors, like:

• Whether you have a heart attack
• How quickly you get a diagnosis and treatment
• How well you make and maintain lifestyle changes
• How well you manage conditions that cause myocardial ischemia