So You Have an Arrhythmia: ICDs and Pacemakers

Cartoon of a pacemaker inside of someone

A cardiac arrhythmia is an abnormal heartbeat caused by a problem in the “wiring” of your heart muscle. Your heart could beat too slowly, too fast or irregularly. It could be such a subtle flutter or “skip,” you may not even feel it. But this does not mean it should be ignored, even if it’s not happening often. It’s true that some arrhythmias are benign, but others are not, and it's best to get yours checked by an expert. Dr. Saman Nazarian, electrophysiologist at the Hospital of the University of Pennsylvania, discusses cardiac arrhythmias and how they’re treated.

When the heart is beating irregularly, and its usual signals aren’t firing properly, it can affect how blood flows throughout your heart. This can have a negative impact on your entire body. If found early, these abnormal heartbeats can be treated and managed. The longer an arrhythmia goes untreated, the more damage it can do to your heart. Additionally, some arrhythmias may lead to catastrophic events, which could have been prevented. If you do not already have a cardiologist, ask your primary care doctor for a referral.

The First Step

At your first visit with a cardiologist, you will likely go over your past medical history and receive a series of noninvasive tests to see how your heart is functioning.

Electrocardiogram (EKG or ECG) - records the electrical activity of your heart.

Echocardiogram - uses sound waves to create pictures of the heart.

The electrocardiogram will not only determine if your heart is beating too fast (tachycardia) or too slow (bradycardia), but also provide an electrical picture of your heart’s health. The echocardiogram provides information about your hearts structural health and muscle strength. In some cases, the doctor will provide reassurance and send you back to the care of your primary care physician. If a more significant arrhythmia is present, you may only need to be followed by an electrophysiologist to ensure it does not worsen over time. However, if you begin to notice symptoms such as dizziness, lightheadedness, fainting, chest pain or shortness of breath, be sure to consult your care team. In some circumstances, additional tests or therapies may be necessary.

Pacemaker vs. Implantable Cardioverter Defibrillator (ICD)

First and foremost, if you receive advice that such a device is necessary, you should not ignore it. A second opinion is always reasonable if you feel the need to review the information with another expert. However, you should know that specialists do not make device implantation recommendations lightly.

Is there a difference between a pacemaker and an ICD? The answer is yes. While both are implanted into your body using a similar procedure, pacemakers and ICDs have different purposes. They are both battery operated devices implanted through a small incision in your chest. Thin, insulated wires or “leads” connect the device to your heart and keep it in check.


Your physician may recommend a pacemaker if you have a persistent, or brief, slow heartbeat that has caused symptoms, reduced the ability of your physician to treat you appropriately or altered your heart function. The pacemaker will sense if your heart is beating too slow and send a tiny electrical impulse through the wires to remind the heart to beat at a normal pace. You will not feel these tiny impulses, as the pacemaker functions in the background without your knowledge. A pacemaker allows your heart to maintain an adequate heart rate which in turn allows a normal, healthy blood flow throughout your body.


There are a few reasons your physician may recommend an ICD as the best course of treatment. It is likely you are at a very high risk for a malignant ventricular arrhythmia, i.e. a very fast heart beat that results in quivering rather than normal contraction of your heart’s muscles, thus resulting in a catastrophic loss of blood and oxygen supply to your brain and body parts. While a pacemaker is used to speed up your heart rate back to normal if it skips a beat or slows down, an ICD is capable not only of all pacemaker functions, but also of delivering a shock to reset too fast, deadly, heart rates thus restoring normal blood flow to your body.

You are at risk of having or have recently survived a heart attack or sudden cardiac arrest

Ventricular Tachycardia (VT or V-tach) – A typical normal heartbeat at rest is considered to be 50 to 90 beats per minute. When experiencing V-tach, your heart will beat very fast, sometimes even reaching heart rates above 200 times per minute. Although it cannot prevent V-tach from occurring, an ICD can stop it. Your electrophysiologist can discuss options to lower the chance of V-tach from occurring, but due to medication and procedures being incapable of completely eliminating the risk of V-tach, an ICD is necessary to provide protection.

Living with a Pacemaker or ICD

After recovering from the procedure, your life may change, but only slightly. Your care team will give you strict guidelines to follow to ensure you have the best recovery possible.

  • Take the medications prescribed by your doctor.
  • Ask your doctor questions so you truly understand how your device works.
  • Be prepared - The American Heart Association created an ICD Identification Card that you should print, fill out and keep with you at all times. You will also receive a card with device specific information from the manufacturer of your device.

In the event you have a medical emergency, having this documentation will ensure the person treating you is aware you have an ICD.

Your pacemaker or ICD is a potentially lifesaving tool. Be sure to avoid being in close proximity to the objects below for extended periods of time.

  • Electronics with strong magnetic fields (i.e. magnetic resonance scanners, high power electrical fields)
  • Metal detectors (inform the personnel at security screening stations that you have a cardiac device, they have been instructed to appropriately handle patients with these devices)
  • Do not place your cell phone, iPad or other electronic devices directly on your device implantation site
  • If you have any doubt about other electronic devices, contact your electrophysiologist or device manufacturer.

About this Blog

The Penn Heart and Vascular blog provides the latest information on heart disease prevention, nutrition and breakthroughs in cardiovascular care.

Date Archives


Author Archives

Share This Page: