Our hearts rely on perfectly timed contractions to squeeze and refill an average of 100,000 times a day. When the electrical impulses driving this process are not uniform, certain areas of the main pumping chamber of the heart (left ventricle) may contract earlier than others. This reduces the heart’s ability to pump effectively, causing fatigue, shortness of breath with exertion and other symptoms of heart failure.
Cleveland Clinic is a non-profit academic medical center. Advertising on our site helps support our mission. We do not endorse non-Cleveland Clinic products or services. Policy
Getting your heart in sync
For many people with this condition, a technique called cardiac resynchronization therapy (CRT) can put the heart’s contraction back on track.
“One-half to two-thirds of patients will have an improvement in symptoms, quality of life and endurance,” says electrophysiologist Walid Saliba, MD, co-director of the Ventricular Arrhythmia Center at Cleveland Clinic.
In patients who qualify for CRT, the procedure can help restore the shape of a stretched-out, weakened left ventricle and allow it to regain some function—in essence, reversing heart failure.
How this technique works
In CRT, a biventricular pacemaker is implanted below the collarbone in a simple procedure. One wire is placed into the right atrium (upper right chamber), one into the right ventricle (lower right chamber) and one into a vein around the left ventricle. These are connected to a pacemaker, which is then programmed with an external device to make the heart contract in synchrony.
Patients with minimal symptoms may qualify
You don’t have to have major symptoms of heart failure to benefit from CRT: Your symptoms can be minimal, so long as your heart function is weakened and the electrical signal to the ventricle is not working properly.
“Even in patients with no symptoms of reduced heart function, CRT may delay or prevent heart failure. In some studies, CRT has even been shown to improve survival,” says Dr. Saliba.
Is CRT right for you?
People with heart failure who have a poor ejection fraction (EF) (<35%) are at risk for fast, irregular and sometimes life- threatening heart rhythms.
CRT may be appropriate for people who:
- Have severe or moderately severe heart failure symptoms.
- Are taking medications to treat heart failure.
- Have delayed electrical activation of the heart (such as intraventricular conduction delay or bundle branch block).
- Have a history of cardiac arrest or are at risk for cardiac arrest.
Together, you and your doctor can determine if this treatment is right for you.