What is a myocardial bridge?

A myocardial bridge, or myocardial bridging, is a heart defect where part of a coronary artery travels through the heart muscle (the myocardium) rather than over it. Normally, the coronary arteries sit on top of the heart muscle, essentially going around it.

Myocardial bridging is a congenital condition, meaning it exists at birth. While a myocardial bridge can affect any of the coronary arteries, it most often occurs in the heart’s largest artery, the left anterior descending artery.

In many cases, a myocardial bridge doesn’t cause any noticeable symptoms, and doctors often find them during procedures or imaging scans for other conditions.

Types of myocardial bridges

Myocardial bridges are usually categorized by type after a doctor diagnoses you with the condition. There are three categories of myocardial bridges, based on how they were diagnosed, whether they cause symptoms and how severe the symptoms are. Identifying the type of myocardial bridge you have helps your doctor determine the most appropriate treatment.

The Schwarz classification for myocardial bridges defines the three types as:

  • Type A: This type of myocardial bridge isn’t causing symptoms and was discovered as an incidental finding on an unrelated test or imaging scan.
  • Type B: This type of myocardial bridge places pressure on the coronary artery, causing ischemia (limited blood flow to the heart).
  • Type C: This type of myocardial bridge causes significant ischemia, changing blood flow and pressure in the circulatory system.
anatomic model of heart

Symptoms of a myocardial bridge

Myocardial bridges don’t usually cause symptoms, but sometimes, the muscle over the misplaced coronary artery presses down on the artery, interfering with blood flow. When blood can’t travel through the heart as it should, you may develop symptoms.

Myocardial bridge symptoms may include:

  • Chest pain (angina), especially when your heart is working hard
  • Dizziness
  • Heart palpitations
  • Shortness of breath

When to see a doctor

You should see your doctor annually for regular checkups so they can monitor your heart health and identify problems early, especially as myocardial bridges don’t usually cause symptoms. If your doctor finds a myocardial bridge or you are experiencing symptoms, they can recommend next steps, including diagnostic testing.

Myocardial bridging can cause chest pain, dizziness and shortness of breath, which are also common signs of a heart attack. If you experience these, never hesitate to call 911.

Myocardial bridge causes

Myocardial bridging is a congenital condition, which means you are born with it. Myocardial bridging occurs as babies develop in the womb and their heart and coronary arteries form. Doctors don’t know why some people develop myocardial bridges, and there are no known causes or risk factors.

Complications

Myocardial bridges rarely cause complications, but complications can develop when a myocardial bridge puts excessive pressure on a coronary artery. The bridge of muscle can limit blood flow to the heart, causing the development of serious and even life-threatening heart problems.

Complications of a coronary myocardial bridge may include:

  • Acute coronary syndrome: This is an umbrella term for conditions that occur when blood flow to the heart muscle is suddenly diminished or stopped.
  • Atherosclerosis: Plaque containing fat, cholesterol and other substances builds up in the coronary artery near the myocardial bridge.
  • Broken heart syndrome: This condition, caused by extreme emotional stress, weakens the heart’s pumping ability.
  • Heart attack: Myocardial bridging can suddenly disrupt blood flow to the heart. Heart attacks can also occur as a result of atherosclerosis.
  • Myocardial ischemia: A result of restricted blood flow, myocardial ischemia is a condition in which the heart doesn’t get the oxygen it needs to function well.
  • Sudden cardiac death: Unexpected death can occur with the rapid onset of a heart problem.
  • Vasospasm: This is the sudden narrowing of a coronary artery caused by a contraction of the blood vessel.
  • Ventricular arrhythmias: These abnormal heart rhythms develop in the heart’s lower chambers and can be life-threatening.

Diagnosing a myocardial bridge

In many cases, myocardial bridging is detected during testing for another medical condition. If you have symptoms, your doctor will use several tools to determine a diagnosis and care plan. Once they diagnose the condition, they’ll determine which type you have to help decide which treatments you may need.

Myocardial bridge treatment

Not all myocardial bridges need to be treated, especially if they don’t cause symptoms. If your doctor thinks you need treatment, they’ll create a plan based on whether you have symptoms and, if so, how severe they are.

In general, adopting healthy lifestyle changes can protect your overall health and may help prevent complications of a myocardial bridge, but if you have symptoms, your doctor may suggest medications and, possibly, surgery.

Lifestyle changes

Having a myocardial bridge puts you at a higher risk of developing atherosclerosis, which is a buildup of fatty plaque in the coronary arteries. A heart-healthy lifestyle can help you lower your risk and protect your heart.

Habits such as exercising regularly, eating a diet filled with fruits and vegetables, losing weight if needed and not smoking can help. It’s also important to work with your doctors to manage any other medical conditions you have that can increase your risk, including high blood pressure and high cholesterol.

Locations for myocardial bridge care

At Baylor Scott & White, you’ll find heart teams with extensive experience in identifying and treating myocardial bridges. We can help you find care at a location in North and Central Texas best suited to your needs.

Frequently asked questions

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