Overview

Cardiac resynchronization therapy is a procedure to implant a device in your chest to make your heart's chambers squeeze (contract) in a more organized and efficient way.

Cardiac resynchronization therapy (CRT) uses a device called a biventricular pacemaker (also called a cardiac resynchronization device) that sends electrical signals to both lower chambers of your heart (ventricles). The signals trigger your ventricles to contract in a more coordinated way, which improves the pumping of blood out of your heart.

Sometimes the device also contains an implantable cardioverter-defibrillator (ICD), which can deliver an electrical shock to reset your heartbeat if your heart rhythm becomes dangerously erratic.