Pacemaker or ICD: Which Do I Need?

Medically Reviewed by James Beckerman, MD, FACC on April 06, 2023
Written by WebMD Editorial Contributors
5 min read

You may have heard of two little devices that doctors use to help treat heart problems: pacemakers and ICDs (implantable cardioverter defibrillators).

They use them when you have a type of heart problem called an arrhythmia. When you have it, your heart might beat too slowly, too fast, or with an irregular rhythm, depending on which kind you have.

While both devices work to help your heart beat better, these two devices are not exactly the same. Learn about what each one does, how they work, and when each would be used.

It’s a small device placed under your skin in your upper chest. The pacemaker has a computer that senses when your heart beats at the wrong speed or out of rhythm.

When that happens, it sends out electrical pulses to keep your heart at a steady rhythm and rate.

You might need a pacemaker if:

  • Your heart beats too slow or unevenly and other treatments haven't helped.
     
  • You have an ablation procedure. This burns off tiny areas of your heart that trigger abnormal electrical impulses. Sometimes the doctor will destroy a section of your heart called the AV node. This is where electrical signals pass from the atria to the ventricles. After this procedure, you will need a pacemaker to regulate your heart rhythm.
     
  • You take certain heart medicines. Beta-blockers and some other heart medications can slow your heartbeat. You might need a pacemaker to speed up the beat.

Before your surgery, you might need to take an antibiotic, a type of medicine that kills bacteria. Your doctor may ask you to stop taking certain other medications, such as blood thinners. You'll need to stop eating about 8 hours before your surgery.

You'll have the surgery at a hospital. You'll get medicine to relax you and prevent pain.

The doctor will thread the pacemaker wires (called “leads”) through a blood vessel into your heart. Then, they will make a small cut in your chest. They will insert the pacemaker just under your collarbone. It contains a small computer and a battery.

Usually, it will go on the side you don't use most of the time. If you're right-handed, it will go on your left side.

Leads will connect the pacemaker to your heart. Electrical signals will travel down the leads. These signals will adjust your heart rate if it gets too slow or too fast. Your doctor will test the device to make sure it works.

Any surgery can carry the chance of complications. With pacemaker surgery, you may have bleeding and bruising. Other possible problems include:

You may stay in the hospital overnight to make sure the pacemaker is working. You might have some pain and swelling in the area where it was placed for a few days afterward.

Most people can go back to their normal routine within a few days of getting a pacemaker. You might need to avoid lifting anything heavy for the rest of your life and playing contact sports that could damage it. Talk to your doctor about how much you can do.

Your doctor will check your pacemaker once every 6 months. During the checkup, they will make sure:

  • The battery works
  • The wires are still in place
  • The pacemaker is keeping your heart in rhythm

Batteries need to be replaced every 5 to 15 years. You'll have minor surgery to switch them.

You need to be careful around devices that have strong magnetic fields. They could mess up the pacemaker’s signal. Limit how long you’re around them and try not to get too close. Some of these devices are:

  • Cell phones and MP3 players
  • Electrical generators
  • High-tension wires
  • Metal detectors
  • Microwave ovens

Some medical procedures can also interfere with a pacemaker. If your doctor wants you to have an MRI scan or shockwave therapy for kidney stones, for instance, be sure they know you have a pacemaker and what kind you have. That information can be put on a card you carry with you.

Like a pacemaker, an implantable cardioverter defibrillator, or ICD, is a device placed under your skin. It also contains a computer that tracks your heart rate and rhythm.

The main difference is that if your heart beats way too fast or is very out of rhythm, the ICD sends out a shock to get it back into rhythm. Some also act like pacemakers. They send out a signal when your heart rate gets too slow.

You might need an ICD if the rhythm of your heart's lower chambers, called the ventricles, is dangerously abnormal.

You might also need one if you've had a heart attack or cardiac arrest, which is when your heart stops working. An ICD could save your life if your abnormal heart rhythm becomes life-threatening.

You may have to take an antibiotic before the surgery. And, your doctor might ask you to stop taking certain medicines, such as blood thinners. You’ll have to stop eating and drinking about 8 hours before your surgery.

You'll get medicine to relax you and so you don't feel pain. Also, you might be given something so that you won’t be awake during the surgery.

The doctor will place the ICD wires into a vein and thread them into your heart. They will place the device in your chest through a small cut. They will test the ICD to make sure it works.

You could have bleeding or bruising. Other possible problems from ICD surgery include:

  • Blood clots
  • Damage to a blood vessel, nerves, or your heart
  • Infection
  • Punctured or collapsed lung

Once your ICD is in place, it might shock your heart if it beats too fast. The shock can feel intense. You might get dizzy or faint when it happens.

Sometimes you can get shocked when you don't need it. If this happens, your doctor can reprogram your device to stop it from jolting you at the wrong time.

You'll stay in the hospital for 1 to 2 days. You won't be able to lift the elbow on the side of the ICD for 4 weeks after it's implanted. Your doctor will tell you how soon you can go back to your normal activities. You should avoid heavy lifting and contact sports that could damage the ICD.

Your doctor will check your ICD once every 3 months to make sure it works. Keep your distance from magnetic fields that could interfere with your ICD. These include:

  • Motorcycle engines
  • Power plants
  • Chain saws
  • Cell phones (hold to the ear opposite the ICD)
  • Airport security

Your pacemaker or ICD will help keep your heart in rhythm. You should be able to do most of your normal activities, including exercise.

Follow your doctor's instructions and go to all of your follow-up visits to make sure you get the most from your device.