Cardiac Resynchronization Therapy (CRT)

Cardiac Resynchronization Therapy (CRT) can relieve CHF symptoms by improving the timing of the heart’s contractions, or beats, which protects patients from abnormally slow and fast heart rhythms. While not all patients will qualify for or benefit from CRT, some patients may have features visible on their electrocardiogram (ECG or EKG) indicating that they may improve with CRT.

Millions of people worldwide suffer from congestive heart failure (CHF), a serious and common problem that is often due to weak pumping of the heart muscle. Poor heart pumping function can cause fatigue, leg swelling, trouble exercising, and difficulty breathing.

Lifestyle changes, medications, and heart surgery can sometimes help with symptoms, but because many people with CHF also have an arrhythmia, or heart rhythm problem, they need even more help to keep their hearts functioning properly.

What is Cardiac Resynchronization Therapy?

Cardiac Resynchronization Therapy (CRT) can relieve CHF symptoms by improving the timing of the heart’s contractions, or beats, which protects patients from abnormally slow and fast heart rhythms. While not all patients will qualify for or benefit from CRT, some patients may have features visible on their electrocardiogram (ECG or EKG) indicating that they may improve with CRT.

CRT uses a biventricular pacemaker (or defibrillator) with two wires in the lower chambers of the heart to overcome this slow or abnormal conduction. By delivering simultaneous or near simultaneous electrical impulses to both lower heart chambers (the right and left ventricles), it causes the heart to beat in a more synchronized, efficient manner. Biventricular pacing improves the symptoms of about two-thirds of the patients undergoing this procedure and also improves survival.

As people with heart muscle damage also may have dangerously fast heart rhythms, biventricular pacing is often combined with a defibrillator.

How does a CRT device work?

The procedure to put in a resynchronization device is a little more complicated than putting in a regular pacemaker or defibrillator. The extra or third wire required is usually positioned in a very small vein that goes to the left side of the heart. Although most people have a vein that can be used for this purpose, this is not true of everyone. Therefore, occasionally this extra wire is placed on the outside of the heart during a surgical procedure or at the time of another heart operation such as valve surgery or a coronary bypass operation.

Like all pacemakers and defibrillators, biventricular devices require monitoring to be certain that they are functioning in the best possible way. Their batteries also gradually wear down, and they need to be changed – generally a small operation – every 5-7 years.

Before Your Visit

Talking to your Doctor

By talking openly to your doctor, you will know what treatments are best for you. Your doctor can provide advice based upon your concerns, value and priorities; a process called shared decision-making. Even if you simply want to follow your doctor’s recommendations, it is important to have a conversation about what matters most to you.

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Heart Rhythm Disorders
Millions of people experience irregular or abnormal heartbeats, called arrhythmias, at some point in their lives. Most of the time, they are harmless and happen in healthy people free of heart disease. However, some abnormal heart rhythms can be serious or even deadly. Having other types of heart disease can also increase the risk of arrhythmias.
Pediatrics and Congenital Heart Disease (CHD)
This section is for pediatric patients and families living with heart rhythm disorders and heart rhythm disorders related to congenital heart disease (CHD).
Early Warning Signs
If you are experiencing a racing, pounding, rumbling or flopping feeling in your chest or if you have been fainting, having repeated dizzy spells, feeling lightheaded or you are extremely fatigued, it's time to see a doctor to discuss your heart health.
Common Treatments
Learning about the underlying cause of any heart rhythm disorder provides the basis for selecting the best treatment plan. Information and knowledge about care options, and their risks and benefits help you work with your health care provider to make the best choices.
Lifestyle
Since other heart disorders increase the risk of developing abnormal heart rhythms, lifestyle changes often are recommended. Living a “heart healthy” lifestyle can ease the symptoms experienced with heart rhythm disorders and other heart disorders, and can be beneficial to overall patient health.
The Normal Heart
The heart is a fist-sized muscle that pumps blood through the body 24 hours a day, 365 days a year, without rest. The normal heart is made up of four parts: two atria on the top of the heart (right atrium and left atrium), and two ventricles (right ventricle and left ventricle) which are the muscular chambers on the bottom of the heart that provide the major power to pump blood.