How you prepare

Before your doctor decides if you need a pacemaker, you'll have several tests done to find out the cause of your irregular heartbeat. These could include:

• Electrocardiogram. In this noninvasive test, sensor pads with wires attached, called electrodes, are placed on your chest and sometimes your limbs to measure your heart's electrical impulses. Your heart's beating pattern can offer clues to the type of irregular heartbeat you have.

• Holter monitoring. Also known as an ambulatory monitor, a Holter monitor records your heart rhythms for an entire 24-hour period. Wires from electrodes on your chest go to a battery-operated recording device carried in your pocket or worn on a belt or shoulder strap.

  While you're wearing the monitor, you'll keep a diary of your activities and symptoms. Your doctor will compare the diary with the electrical recordings to try to figure out the cause of your symptoms.

• Echocardiogram. This noninvasive test uses harmless sound waves that allow your doctor to see your heart without making an incision. During the procedure, a small instrument called a transducer is placed on your chest. It collects reflected sound waves (echoes) from your heart and transmits them to a machine that uses the sound wave patterns to compose images of your beating heart on a monitor.

  These images show how well your heart is functioning, and recorded pictures allow your doctor to measure the size and thickness of your heart muscle.

• Stress test. Some heart problems occur only during exercise. For a stress test, an electrocardiogram is taken before and immediately after walking on a treadmill or riding a stationary bike. In some cases, an echocardiogram or nuclear imaging may be done.

  Other types of treadmill exercise tests also can be done to evaluate your heart, including an oxygen consumption test that measures how much oxygen your body is using.

Results

Once your pacemaker is implanted, the battery should last five to 15 years, which is the average battery life. When a pacemaker's battery wears out, the pacemaker's pulse generator is replaced. The leads of your pacemaker can be left in place — though they may need to be replaced eventually — and the procedure to change your pacemaker's battery is often quicker and requires less recovery time than the procedure to first implant your pacemaker.

Pacemakers are a standard treatment for many conditions affecting your heart's electrical system. By preventing a slow heart rate, pacemakers can treat symptoms, such as fatigue, lightheadedness and fainting. Because most of today's pacemakers automatically adjust your heart rate to match your level of physical activity, they can allow you to resume a more active lifestyle.

Pacemakers and end-of-life issues

If you have a pacemaker and become terminally ill with a condition unrelated to your heart, such as cancer, it's possible that your pacemaker could prolong the process of dying. Doctors and researchers have varied opinions on turning off a pacemaker in end-of-life situations.

Talk to your doctor if you have a pacemaker and are concerned about turning it off. You may also want to talk to family members or another person designated to make medical decisions for you about what you'd like to do in end-of-life care situations.

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.

Why it's done

Cardiac resynchronization therapy is a treatment for heart failure in people whose ventricles don't contract in a coordinated fashion.

If you have heart failure, your heart muscle is weakened and may not be able to pump out enough blood to support your body. This can be worsened if your heart's chambers aren't in sync with each other.

Cardiac resynchronization therapy may reduce your symptoms of heart failure and lower your risk of heart failure complications, including death.

Risks

All medical procedures come with some type of risk. The specific risks of cardiac resynchronization therapy depend on the type of implant and your overall health.

Complications related to cardiac resynchronization therapy and the implantation procedure may include:

• Infection
• Injury to a blood vessel
• Collapsed lung (pneumothorax)
• Compression of the heart due to fluid buildup in the sac surrounding the heart (cardiac tamponade)
• Failure of the device
• Shifting of device parts, which could require another procedure

What you can expect

Cardiac resynchronization therapy requires a minor surgical procedure to implant a device in your chest.

You'll likely be awake during the procedure, though the area where the pacemaker is implanted is numbed and you'll receive medication to help you relax (conscious sedation). The procedure typically takes a few hours.

During surgery, insulated wires (leads, or electrodes) are inserted into a major vein under or near your collarbone and guided to your heart with the help of X-ray images. One end of each wire is attached to the appropriate position in your heart. The other end is attached to a pulse generator, which is usually implanted under the skin beneath your collarbone.

Cardiac resynchronization therapy devices include:

• Cardiac resynchronization therapy with a pacemaker (CRT-P). The device used for cardiac resynchronization therapy has three leads that connect the pacemaker to the right upper chamber of your heart (right atria) and both lower chambers (ventricles).
• Cardiac resynchronization therapy with a pacemaker and an ICD (CRT-D). This device may be recommended for people with heart failure who also have a risk of sudden cardiac death. It can detect dangerous heart rhythms and deliver a stronger shock of energy, which is able to reset your heartbeat, than a pacemaker can deliver.

You'll usually stay overnight in the hospital after cardiac resynchronization therapy. Your doctor will test your device to make sure it's programmed correctly before you leave the hospital. Most people can return to their usual activities after a few days.