Cardiac Resynchronization Therapy (CRT)

Cardiac resynchronization therapy (CRT), also known as biventricular pacing, uses electrical pulses to help the ventricles, or the lower chambers of the heart, beat correctly. Patients with damage to the heart muscle (due to a prior heart attack or cardiomyopathy) can sometimes have damage to the normal conduction system (or "wiring") of the heart. This results in the ventricles beating “out of sync” with each other. CRT is used for patients with moderate to severe heart failure and helps coordinate the beating of the ventricles.

The Heart Rhythm Disorders Program of the Brigham and Women’s Hospital’s (BWH) Heart & Vascular Center is devoted solely to the care of patients with irregular heart rhythms, heart palpitations and rapid heartbeat conditions. Treatment is provided by some of the world’s most experienced physicians in cardiac electrophysiology (the study of the heart’s electrical system), and many patients with complex cases, from around the country and the world, are referred to our program. Our cardiac electrophysiologists perform more than 3,000 procedures annually, utilizing the latest medications, devices and innovative care approaches.

With 47,000 outpatient visits each year, the Heart & Vascular Center is one of the largest in the United States, treating over 7,000 inpatients and performing more than 8,000 procedures annually at our state-of-the-art Shapiro Cardiovascular Center.

Cardiac Resynchronization Therapy (CRT)

What Happens During Cardiac Resynchronization Therapy?

Cardiac resynchronization therapy (CRT) involves implanting a pacemaker or implantable cardioverter defibrillator (ICD) attached to wires (leads) that are threaded into specific areas of the heart. Live X-ray (fluoroscopy) is used to guide the placement of these wires. The wires use pulses of electricity to help the left and right ventricles (lower chambers of the heart) beat together as they should. Unlike a typical pacemaker or ICD, a CRT device sends pulses to both of the heart’s lower chambers at the same time. This is sometimes called “biventricular pacing.”

Many, but not all, CRT patients also are at risk for potentially life-threatening irregular heartbeats. CRT devices can also be combined with ICDs that deliver electrical shocks to the heart to correct irregular heartbeats. This type of combination therapy is called CRT-D. CRT devices that only include a pacemaker are called CRT-P. The type of device you require will be determined in consultation with one of the cardiac electrophysiologists of the BWH Heart Rhythm Disorders Program.

Putting a CRT device in place requires minor surgery. Via a small incision made in the upper left or right chest, your electrophysiologist will thread the wires of the device through blood vessels into your heart and place them in their desired sites. The electrophysiologist will then insert the small metal device under the skin of the chest and connect the wires to it. The device will deliver the electrical impulses, which are painless and cannot be felt. The device and wires are completely under the skin.

You will likely stay in the hospital overnight to make sure the device is working properly. Most people return to their normal routine a few days to weeks after the procedure. Your doctor will give you specific instructions on what you can do after the device is in place.

The Day of Cardiac Resynchronization Therapy

The day of your procedure you will be asked to refrain from eating after midnight. After arriving at the hospital, blood tests will often be performed and you and your family will be brought to the cardiovascular recovery room (CVRR) for preprocedure preparation. This will include placement of an intravenous line (IV), and shaving of your chest if needed.  Your procedure will be reviewed and consent obtained. This is an opportunity for you and your family to ask any additional questions.   

You will then be brought back to the electrophysiology laboratory (EP Lab). You will be closely monitored throughout the procedure. Many electrodes and a blood pressure cuff will be placed. An experienced nurse will provide sedation during the procedure. Every effort will be made to keep you comfortable and anxiety-free during the procedure. The area where the incision will be made will be “numbed” with local anesthesia. During the procedure you may feel some pressure, but you should not experience any pain. At the end of the procedure the “pocket” under the skin where the device is placed will be closed with sutures and a dressing will be applied.

After your procedure, you will recover in the CVRR where you will receive comprehensive care by an experienced cardiac surgical and nursing staff. You may stay overnight in the hospital for monitoring. You will be provided with a remote monitor which can be used to check your device from home, ensuring it is working properly and reducing the number of visits to the hospital for follow-up. One of our staff members will educate you and your family on “living” with your new cardiac device and will answer any questions.

Why Have Cardiac Resynchronization Therapy?

Studies suggest that CRT—by helping the ventricles beat as they should—improves the survival, heart function, quality of life and exercise capacity for people with heart failure.  CRT therapy may also help avert the progression of the underlying heart condition, preventing the development of worsening heart failure. Read: Cardiac Resynchronization Therapy - A Patient’s Guide.

What You Should Expect

The Heart & Vascular Center is located in the Shapiro Cardiovascular Center, across the street from BWH’s main 75 Francis Street entrance. The Heart & Vascular Center brings together the full range of services in one location, fostering seamless and coordinated care for all cardiovascular patients.

If you are having surgery or a procedure, you will likely be scheduled for a visit to the Watkins Clinic in the Shapiro Cardiovascular Center for pre-operative information and tests.

During your procedure, family and friends can wait in the Shapiro Family Center where staff members will provide surgery updates.

Multidisciplinary Care

In addition to our cardiovascular medicine specialists, patients also benefit from the teamwork of interventional cardiologists, cardiovascular imaging experts and radiologists, and anesthesiologists, all experts in cardiac disorders. They work alongside nurses, physician assistants, physical therapists, dietitians and social workers to achieve outstanding outcomes for our patients.


Learn about the Heart & Vascular Center’s Heart Rhythm Disorders Program.

Visit the Kessler Health Education Library in the Bretholtz Center for Patients and Families.

Access a complete directory of patient and family services.

Learn about the Watkins Clinic in the Shapiro Cardiovascular Center.


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