Cardiac Resynchronization Therapy

What is CRT?
How does CRT work?
Who is a good candidate for CRT?
About Medtronic CRT Systems

What is CRT?

Cardiac Resynchronization Therapy (much easier to remember as CRT) is a way of treating heart failure with an implantable device similar to a pacemaker. Basically, it is a heart failure pacemaker that helps both ventricles of the heart beat together again in a more synchronized pattern. This improves the heart’s ability to pump blood and oxygen to the body.

How does CRT work?

The heart failure pacemaker is implanted under the skin of the chest and connected to three leads (soft insulated wires) that are inserted through the veins into the heart. The device is battery-powered and delivers tiny electrical pulses to both ventricles which makes them beat in a synchronized way. These tiny impulses are small and usually not felt. Watch a video >>

CRT, in combination with a complete program of therapy, has proven to improve the quality of life for many patients by reducing symptoms of heart failure, increasing exercise capacity and allowing them to resume many daily activities. It is not a replacement for drug therapy. It is recommended that anyone choosing to receive CRT also continue taking medications as determined by a physician.

Who is a good candidate for CRT?

Your doctor may use the following criteria to determine if you are a potential candidate for CRT:

You have ventricular dysynchrony. That means the two lower chambers of your heart are not beating together and are unable to pump blood to the body effectively.
Your medications do not adequately treat your symptoms, and you continue to have a poor quality of life.
Your heart failure has been classified by your doctor as Class III or IV.
Your heart is not able to pump blood effectively (also called low ejection fraction).
You still have symptoms even though you have been taking the maximum amount of medication your doctor has prescribed.
You have a QRS duration of greater than or equal to 130ms.

There are several implantable systems available. The one appropriate for you will be determined by your physician based upon your medical history and whether you are at risk for ventricular arrhythmias.

Single therapy system – provides only CRT

Combined therapy system – provides CRT plus therapies to treat ventricular tachyarrhythmias (VT/VF)

For some patients, CRT has been shown in clinical trials to:

Improve the ability to exercise and perform other physical activities
Improve quality of life
Improve the New York Heart Association functional class (Class III, IV—the heart failure classification system developed by the New York Heart Association widely used in the diagnosis of heart failure).