Patient education: Cardiac resynchronization therapy (The Basics)

What is cardiac resynchronization therapy? — Cardiac resynchronization therapy (CRT) is a treatment for some people who have heart failure. Heart failure is a condition in which the heart does not pump as well as it should.

When the heart pumps, the walls of the main pumping chamber of the heart (called the "left ventricle") should pump at the same time (figure 1). But in some people with heart failure, the walls of the left ventricle do not pump at the same time. This can make heart failure worse.

CRT uses a special device called a biventricular pacemaker, also called a BiV pacemaker or BiV pacer. This device sends electrical signals to the heart to make the walls of the left ventricle pump at the same time.

What are the benefits of CRT? — CRT can:

●Improve symptoms of heart failure

●Keep people from needing to go to the hospital for their heart failure

●Help people with heart failure live longer

What does a BiV pacemaker look like? — A BiV pacemaker has 2 parts:

●A pulse generator – This is a thin metal case with a battery and tiny computer in it. It is put in the chest under the skin. The pulse generator creates and sends electrical signals. The doctor sets the computer to tell the pulse generator when to send electrical signals.

●Wires, also called "leads" – The wires connect the pulse generator to the heart. Electrical signals travel from the pulse generator through the wires to the heart. A BiV pacemaker usually has 3 wires (figure 2).

A BiV pacemaker is similar to other pacemakers that can help treat abnormal heart rates, but a BiV pacemaker has an extra wire. This extra wire helps make the walls of the left ventricle pump at the same time.

How is CRT done? — Your doctor will do a procedure to put the BiV pacemaker in your chest. They will make a small cut in your upper chest. They will put the wires in a blood vessel near the cut and thread them to your heart. Each of the 3 wires will sit in a different part of your heart (figure 2). Your doctor will then connect the wires to the pulse generator. They will program the pulse generator and put it under the skin in your chest.

Depending on your heart condition, your doctor might use a "combined" device. A combined device has a BiV pacemaker plus an implantable cardioverter-defibrillator (ICD). An ICD can sense and treat abnormal heartbeats that could cause sudden death.

What problems can happen with CRT? — Different problems can happen with CRT, either during the procedure or afterward:

●A wire can make a hole in a blood vessel, the heart, or the lungs.

●An infection can start around the pulse generator or wires.

●The wires might be put in the wrong place during the procedure or move out of place later on.

Other downsides of CRT include the following:

●You will need another surgery after about 8 to 10 years to replace the battery.

●There is a chance that CRT will not work and that the BiV pacemaker will not improve your heart failure. If your heart failure does not improve with CRT, your doctor might change the settings of your BiV pacemaker. They will also talk with you about other possible treatments.

Do I still need to take my heart failure medicines? — Yes. After CRT, you will still need to take your heart failure medicines. You will also need to follow your doctor's instructions about diet and exercise.

What else will I need to do if I have a BiV pacemaker? — If you have a BiV pacemaker, you will need to:

●Follow up with your doctor on a regular basis. They will make sure that your device is working the right way.

●Avoid certain electric or magnetic sources or equipment. Your doctor will tell you which electric or magnetic sources or equipment you can be near, and which ones you should avoid. For example, you can be near televisions and radios. But you should probably not use a welder or a chainsaw.

●Let all of your doctors and nurses know that you have a BiV pacemaker. You should carry a card telling people you have a BiV pacemaker. The card should say which type of BiV pacemaker you have and which company made it. Some procedures and tests are safe for people with a BiV pacemaker, but others are not. For example, you might not be able to have an imaging test called an MRI scan.

More on this topic

Patient education: Heart failure (The Basics)
Patient education: Medicines for heart failure with reduced ejection fraction (The Basics)
Patient education: Pacemakers (The Basics)
Patient education: Implantable cardioverter-defibrillators (The Basics)

Patient education: Heart failure (Beyond the Basics)
Patient education: Pacemakers (Beyond the Basics)
Patient education: Implantable cardioverter-defibrillators (Beyond the Basics)