Myocardial Bridge Unroofing

A myocardial bridge is a heart condition involving a segment of coronary artery trapped by a band of muscle (myocardium). Your coronary arteries carry blood to your heart muscle. These arteries typically lie on the surface of the heart muscle.

In this condition, when the heart beats and contracts, a muscle overlying the coronary artery also contracts. The contracting myocardial bridge can limit the flow of blood to the artery, causing chest pain.

Myocardial bridge on the left anterior descending (LAD) artery. When the heart is in distole/relaxation, it allows blood to flow freely through the LAD.

When the heart is in systole/contraction, the myocardial bridge overlying the LAD also contracts, trapping the artery by limiting blood flow and causing chest pain.

Evaluation of Who Needs Myocardial Unroofing

Schematic representation of the detailed evaluation performed for diagnosing a hemodynamically significant myocardial bridge suitable for surgical unroofing. (CT = computed tomography; dFFR = diastolic fractional flow reserve; IVUS = intravascular ultrasonography.)

Some people aren’t helped by standard medicine for angina—including medications like beta blockers, calcium channel blockers, statins, and aspirin. The first step in treatment options include long term medical management and use, under the care of your cardiologist.

One advanced option is “surgical myocardial bridge unroofing.” Doctors perform tests to identify if the myocardial bridge is affecting blood flow. The tests include stress echocardiograms, ultrasounds and angiograms.

Treating the problem directly

Previously, patients whose angina didn’t respond to medicine had few options. Many people with a myocardial bridge have lived with chest pain for many years by the time Stanford doctors see them.

Some other treatments that have been unsuccessfully tried for treatment of bridges include percutaneous coronary intervention (PCI) or coronary artery bypass graft (CABG) surgery. These procedures are not designed to treat structural abnormalities in the heart like myocardial bridges.

Studies have shown that these other procedures fail to provide lasting relief for people with myocardial bridges. The squeezing of the muscle in the bridge damages the stents used in PCI over time, and bypass grafts tend to close, due to competitive flow.

Surgical myocardial bridge unroofing is safe and effective. Stanford doctors use new imaging techniques to map the muscle bridge very precisely before surgery is considered.

Circle is location of the myocardial bridge. These are intravascular angiogram and ultrasound images used to map the length and blood flow patterns of the bridge before surgery.

Surgical Treatment Options

At Stanford, doctors can offer multiple options if you have chest pain from a myocardial bridge. When medical therapy is ineffective, a surgical procedure called a myocardial bridge unroofing can be considered.

During this procedure, the surgeon divides the band of the muscle that covers the artery.


- The imaging studies previously completed for diagnosis are used as a detailed road map for your surgical plan and approach.

- Nerve blocks can be placed to reduce pain after surgery.


- Surgical approach options will be discussed with you and your surgeon. The type of incision for this surgery depends on the length and location of the myocardial bridge. It also depends on the patient’s body type and preferences.

- A “minimally invasive” approach, also called a “mini-thoracotomy,” uses a smaller incision in your chest. This incision is roughly 3–4 inches, on the left front side of the chest, between the ribs.

- A “median sternotomy” approach, uses an incision through the breastbone to reach the heart.

- Stanford doctors perform the surgery “off-pump,” or without the heart-lung machine. The surgery is done on a beating heart. A stabilizer allows the surgeons to work on the bridge safely.

- Bridge muscle is divided in 1–2 millimeter increments.

- Surgery takes approximately 2 hours.

Left: Surgery to release the coronary artery from the myocardial bridge.
Right: Free-flowing coronary artery after myocardial bridge procedure.

“Numerous myocardial bridge patients, before they found care at Stanford, feel tired and hopeless from their search. Many of these patients have sought care all over the country, in an effort to find relief from their pain. It is deeply rewarding to have the opportunity to finally offer these patients the care and relief from pain that they have been seeking.”  —Jack Boyd

Post-Operative / Recovery

If you have myocardial unroofing surgery, you will likely have a very short stay in the hospital intensive-care unit.

Minimally invasive mini-thoracotomy approach recovery:

- You may expect to go home 2 to 3 days after surgery.

- Many people return to normal levels of activity in several weeks.

Sternotomy approach recovery:

- You may expect to go home 3 days after surgery.

- It may take 1–2 months for you to return to normal activity. You are restricted from lifting heavy objects. Restrictions last for 3 months, until the breast bone completely heals. However, you should be able to take care of yourself and walk independently.

Most patients have significant improvement in the quality of their lives. Stanford is one of just a handful of hospitals in the nation with a program for this surgery. Our cardiologists have pioneered the diagnosis of myocardial bridges and our cardiac surgeons are among the most experienced with myocardial bridge unroofing.

Seattle Angina Questionnaire scores before (preoperative [blue bars]) and after (postoperative [red bars]) surgical unroofing of a myocardial bridge. Data available for 38 patients; higher scores represent better outcome. The p value was less than 0.001 for all five categories.

Transfer Center and Referral Information

Patients and Families (Self-Referral)

The patient’s doctor will request an evaluation by the Stanford Advanced Lung Support team, who will review their previous medical records and determine if additional tests are necessary. After reviewing the patient’s information, the team will provide further details regarding patient transfer.   You can call the clinic number below to speak with one of our clinic staff about the status of your referral or self-referral.  They will help guide you through the process or next steps needed.  

We use a multi-disciplinary approach to diagnose and treat patients with valvular heart disease, offering repair and replacement for heart valves.

Stanford Referral Center and Clinics are staffed Monday through Friday from 8 am - 5 pm (PST)

We have several locations where our surgeons can see you for a consult, offering you convivence closest to your home.    

Our main Adult Heart Surgery Clinic & Surgery schedulers number to call for an appointment is: 650-724-7500

Our direct clinic contact information and locations are:

Heart Surgery in Palo Alto
Heart and Vascular Center
300 Pasteur Drive
3rd Floor, Clinic A31
Stanford, CA 94305
Phone: 650-724-7500
Map of Stanford Hospital

Aortic Disease Center
Heart and Vascular Center
300 Pasteur Drive
3rd Floor, Clinic A31
Stanford, CA 94305
Map of Stanford Hospital

Heart Surgery in Pleasanton 
5565 W. Las Positas Blvd.
Suite 320
Pleasanton, CA 94588
Phone: 925-278-7017

Heart Surgery in San Jose
751 S. Bascom Avenue
San Jose, CA 95128
Phone: 408-885-3838

Interested in an Online Second Opinion?

The Stanford Medicine Online Second Opinion program offers you easy access to our world-class doctors. It’s all done remotely and you don’t have to visit our hospital or one of our clinics for this service. You don’t even need to leave home! Visit our online second opinion page to learn more.

International Patient Referrals

Phone: +1 650-723-8561

International Medical Services (IMS) at Stanford Health Care provides information, interpretation and translation services, and other supportive services for patients and families who may be seeking care from out of country.  

For Physicians / Health Care Professionals

Transfer Center
Phone: 1-800-800-1551  (24 hours - 7 days a week)
Fax: 650-723-6505

Physician Helpline
Phone: 1-866-742-4811 
Fax: 650-320-9443
Monday – Friday  8:30 a.m. – 5 p.m. (PST)
After hours: Call the hospital page operator at 650-723-4000 and ask for the physician on call

FAX: Fax a referral to the Cardiothoracic Surgery Department at 650-736-0901  

Online Portal (PRISM)

Our online portal, known as PRISM (Physician Referral Information at Stanford Medicine), provides a streamlined platform for community physicians to send referrals, check on referral status, access medical records, and message Stanford providers.

If you have any questions about the referral process, please call us at 650-724-7500.


Angina: Chest pain that occurs when the heart doesn’t get enough blood

Coronary arteries: Arteries that carry blood to the heart

CT angiography or angiogram: An imaging test that looks at the arteries supplying blood to your heart, often done to diagnose chest pain

Diastole and systole: Two parts of a heartbeat

Diastole is the relaxation period when your heart muscle is relaxed.

Systole is the contraction period when heart muscle tightens.

Echocardiogram: A test that uses sound waves to produce images of your heart beating and pumping blood

Invasive hemodynamic test:A test that measures the movement of blood and its pressure in the veins, arteries, and chambers of the heart

Intravascular ultrasound: A test that uses sound waves to see inside blood vessels, often used to evaluate coronary arteries that supply blood to the heart

LAD artery: left anterior descending artery, a major artery bringing blood to the heart

Median sternotomy: Surgery that makes an incision in the breastbone to reach your heart

Minimally invasive surgery: Surgery that makes a small incision

Mini-thoracotomy: Surgery that makes a small incision in your chest

Myocardium: Heart muscle

Myocardial bridge: A band of heart muscle that lies on top of a coronary artery, instead of underneath it

Off-pump surgery: Done without a heart-lung machine, while the heart is beating

Unroofing: Surgery that splits the myocardial bridge so it no longer presses on (and squeezes) a coronary artery