Cardiac resynchronization therapy (CRT) helps the ventricles contract normally. This treatment, also known as biventricular pacing, can be helpful for some patients with heart failure with reduced ejection fraction (EF).

About 30% of patients with heart failure have electrical problems in the ventricles that create delays when they contract/pump. When the ventricles don’t pump together, there is less oxygen-rich blood sent to your organs and muscles. Pumping delays cause heart failure to get worse and can increase your risk of death from heart failure.

Treatment with CRT involves implanting a pacemaker in your body. Three wires (leads) are attached to the pacemaker and keep the ventricles pumping together by sending small electrical impulses to the heart muscle. These impulses are not painful.

A CRT-D is a device that combines CRT and an ICD. It keeps the ventricles beating together. If they get out of synch because of ventricular tachycardia or fibrillation, the CRT-D sends a shock to restore a normal rhythm. About 75% of patients who do not get relief from symptoms with medication and have CRT, with or without an ICD, have improvement in their symptoms.

Cardiac resynchronization therapy helps improve survival, quality of life, heart function and your ability to exercise, and can lower your risk of hospitalization.