WHAT IS A CARDIAC RESYNCHRONIZATION THERAPY IMPLANTABLE CARDIOVERTER DEFIBRILLATOR (CRT-D)?

An implantable cardioverter defibrillator (ICD) is a microcomputer that is implanted under the skin of your upper chest area. It is small enough to fit in the palm of your hand. It monitors your heart rate and delivers therapy in the form of small electrical pulses. A cardiac resynchronization therapy implantable cardioverter defibrillator (CRT-D) is a type of specialized ICD used to treat heart failure.

HOW A CRT-D WORKS

Once implanted, an ICD detects your heart rhythm through one or more thin, insulated wires called leads, which are placed on or inside the heart muscle and attached to the device. The leads transmit your heart rate information to the device. CRT-Ds are a type of ICD that have an additional lead that attaches to the left ventricle, the primary pumping chamber of the heart, which makes the left ventricle beat at the same time as the right. When an abnormal heart rhythm occurs, your CRT-D sends an electric shock to your heart muscle. Sometimes the defibrillating shock is uncomfortable. Whether you can feel it or not, your CRT-D is doing its work.

CRT-Ds can provide lower- or higher-energy therapy to treat heart failure, depending on the need.