Pacemakers and Defibrillators

Some arrhythmias are life-threatening and can increase the risk of heart failure, stroke, or death. Implantable pacemakers and defibrillator devices can help keep your heart in rhythm.

Experts at the AHN Cardiovascular Institute use the latest devices to treat abnormal heart rhythms.


Your physician may recommend a pacemaker if you have symptomatic bradycardia. If you have an abnormally slow heart rate and feel poorly as a result, a pacemaker can help regulate your heart rate

Types of pacemakers

Depending on your specific needs, your physician may recommend one of the following:

Transvenous pacemakers

Transvenous pacemakers use low-energy electrical pulses to stimulate a heartbeat. They are most often placed on the chest wall, below the collarbone, and wires connect to the heart. Depending on your specific needs, one, two, or three wires may be needed.

Leadless pacemakers

In certain situations, a leadless pacemaker may also be considered. Leadless pacemakers have more limited pacing capabilities but do not utilize wires because the contact point is built in. The device is so small that they are embedded entirely inside the heart. In fact, they are so compact that, when the battery is low and you require a new pacemaker, the old one may not need to be removed.

Implantable cardiac defibrillators (ICDs)

Implantable cardiac defibrillators, or ICDs, are similar to pacemakers but are modestly larger and have the ability to treat dangerously fast heart rhythms by delivering a high-energy shock to reset the rhythm. Sometimes a dangerously fast rhythm can be paced back into normal rhythm, with shocks reserved as backup. Most defibrillators are implanted similarly to transvenous pacemakers, on the chest below the collarbone, with leads attached inside the heart. Most defibrillators can also function as pacemakers and, depending on your medical situation, one, two, or three leads may be implanted. There is also a type of ICD called a subcutaneous ICD, with a single lead that is tunneled under the skin and placed around the heart. This type of device has limited pacemaker functionality, but it has other benefits. Deciding on the best type of device for you is an important discussion to be had with your cardiologist or electrophysiologist.

Pacemakers and defibrillators generally have two main components: the pulse generator, which houses the battery and computer circuitry, and the leads. The batteries in the pulse generator generally last seven to 10 years in an ICD and nine to 12 years in a pacemaker, though there is some variability depending on the specific device you have and how often it paces, or if you have any shocks. When the battery is low, another procedure is required to give you a new pulse generator. Leads are designed to last decades and, as long as they’re functioning well, they don’t need to be changed at the time of a new pulse generator. Technology is constantly improving, so the battery life on your next pulse generator will likely be even longer.

What to expect

How to prepare

Before having an ICD implanted, you’ll be asked to avoid food and drinks for at least eight hours before your procedure. Your doctor will provide other detailed instructions on how to prepare, including whether you should avoid specific medications.

How pacemakers are implanted

Pacemakers and ICDs are usually placed in the electrophysiology lab. In some cases, the catheterization lab or the operating room may also be used for implantation. You will be sedated by an anesthesiologist and local anesthesia will also be used over the incision site. Most people can be safely discharged to go home the same day as the implant procedure. However, some patients may be required to spend the night in the hospital to ensure the device is working properly.

To implant the device, a small incision is made in the skin below the collarbone. The lead or leads enter a vein near this location and follow that vein down to the heart. Once each lead is in place, it will be tested to ensure it’s working appropriately. The leads connect to a pulse generator, which includes the battery and computer circuitry, and the pulse generator is placed deep under the skin. The incision is closed with sutures. Immediately following the procedure, you’ll be advised to avoid certain activities for a few weeks while the skin and leads heal in place. After that, there are few long-term restrictions.

Once the pacemaker or ICD is implanted, the programming will be customized to your unique medical situation. If the programming needs to be adjusted in the future, the device can be reprogrammed wirelessly without another invasive procedure.

The battery life on most pacemakers is around eight to 12 years and, on most ICDs, around eight to 10 years. However, exactly how long your device battery will last depends on several factors, including how many leads are utilized, how often pacing is required, if an ICD must deliver shock therapy, etc. When the battery is low, another similar procedure is necessary to replace it. Keep in mind that technology is constantly evolving with battery life improving every generation.


Most patients will be released to go home the same day of their procedure. You will need to have someone drive you home afterward and have a support system at home during your recovery. You cannot safely drive within 24 hours after receiving anesthesia.

The incision where the device was implanted may be tender for a few weeks after the procedure, but most people do not require pain medication to alleviate the discomfort.

You should ask your health care provider about the following during recovery:

  • Appropriate medications to be taking.
  • Precautions and activity restrictions, including possible driving restrictions.
  • How and how often the device will be monitored. 
  • Symptoms that should be reported after device implant, such as fever, increasing pain or swelling, or any sort of bleeding.

Interference with implanted devices

Everyday devices rarely affect the function of a pacemaker or ICD; however, electromagnetic interference is possible. How that impacts you depends on the nature of the electrical interference, whether you have a pacemaker or defibrillator, and whether you’re dependent on its functionality.

Cellular phones and other mobile devices

Talking on a cellphone is safe and will not cause interference with your device. However, some cell phones have strong magnets built in to interact with accessories. Though these magnets will not cause permanent damage, they can temporarily affect the programming of your device if the magnets are sufficiently close. It’s important to note that this is by design, and your device will resume prior programming when the magnet is moved away. Nevertheless, it’s advised to keep cell phones and magnets away from both pacemakers and ICDs.

Security systems

After your procedure, you will receive a wallet card with the details of your pacemaker or ICD. Keep that card with you. Your device may or may not trigger security alarms commonly found in airports and other venues and, though security personnel are accustomed to seeing these devices, your wallet card may help explain the situation. Security screening systems are generally safe for pacemakers and ICDs, but we advise you request a manual search when possible.

Medical equipment

Modern pacemakers and ICDs are MRI compatible. However, an MRI utilizes a very powerful magnet that can affect the programming on your device. Be sure to inform your health care providers about your device so the appropriate precautions can be taken during the MRI procedure.

TENS (transcutaneous electrical nerve stimulation) therapy should be avoided. Discuss with your health care provider if you are considering TENS therapy.

Power generators

Stand at least two feet from welding equipment, high-voltage transformers, or motor-generator systems. If you work around such equipment, your doctor can schedule a test in your workplace to ensure the equipment doesn’t affect your device. This type of high voltage equipment can cause a pacemaker to inhibit pacing, which could be problematic if you’re dependent on your pacemaker, and could cause inappropriate shocks if you have an ICD. Your device will return to normal function upon moving away from the offending equipment.


Strong magnets can temporarily affect the programming on your pacemaker or ICD, but will not permanently damage your device. However, magnets can cause pacemakers to temporarily switch to a backup pacing mode and ICDs to temporarily inhibit therapies. While your device will resume normal programming when the magnet is moved away, it’s advised to avoid strong magnetic fields and the equipment that may produce them.

Diagnostic tests

Before you get a pacemaker or ICD, your doctor will likely need several tests, which may include:

Electrocardiography (ECG or EKG)

An ECG/EKG is a quick and painless test that measures the electrical signals that make the heart beat. This test will show whether your heart is beating too fast or too slow.


This noninvasive test uses sound waves to produce images of the heart in motion. It shows the size and structure of the heart and valves inside it, and measures the overall function of the heart.

Holter monitoring

A Holter monitor is a wearable device that records your heart rhythm for a longer period of time than an ECG can record. This monitor is used to spot irregular heart rhythms that an ECG/EKG may have missed. Patients may need to wear a Holter monitor for up to 30 days.

Contact us

Call (412) 359-8178 to request an appointment with AHN cardiovascular services.