Internal Cardiac Defibrillator

What is an implantable cardioverter-defibrillator?

Implantable cardioverter-defibrillators (ICD) are somewhat similar to pacemakers.  Pacemakers prevent the heart from beating to slowly by delivering a pacing stimulus to the heart to keep a patient’s heart rate above a determined number of beats per minute.  We often program a patient’s pacemaker to keep the patient’s heart at or above 60 beats per minute.  While pacemakers can prevent the heart from beating too slowly, a pacemaker cannot prevent the heart from beating too rapidly. 

An implantable defibrillator (ICD) is a special type of pacemaker that prevents the heart from beating too slowly just like a standard pacemaker.  However, an ICD has the added advantage of being able to prevent the heart from beating too rapidly from such abnormal fast heart rhythms as ventricular arrhythmias.  An ICD can stop these fast heart rhythms by shocking the heart back to normal rhythm.  

The defibrillator itself is about the size of a pager and is placed under the skin, generally on the left side of the chest.  The defibrillator is connected to one, two, or three leads depending upon the needs of the patient.  These leads travel from the defibrillator under the skin, into a vein and then down to the heart to the inside of the heart.  The leads stay connected to the heart by tiny screws at the tip of the leads that hold them to the muscle of the heart. These leads send information about every beat of the heart back to the defibrillator in the shoulder.  The defibrillator then knows whether to act as a pacemaker, a defibrillator, or to do nothing at all if the heart is beating normally.     

How is a defibrillator implanted?

Defibrillator implantation procedures are performed in the electrophysiology laboratory in the hospital.  First, the patient changes into a hospital gown and IV lines are started.  The patient is the given sedation through an IV in the arm.  The procedure begins with the administration of local anesthesia in the area where the defibrillator is being placed.  After the area is anesthesized, a 4 cm incision is made and the leads and defibrillator are placed in position.  This process may take anywhere from one o several hours depending upon how many leads are being placed in the heart.  At the end of the procedure, we generally have a member of the anesthesia department put the patient to sleep with medication for one minute while we deliver a test shock through the device. 

What is the recovery following the procedure?

Patients are observed overnight in the hospital and are generally discharged to home the next day.  There is usually a modest amount of pain in the shoulder area for one to two weeks following the procedure.  Patients are sent home with a prescription for pain medicine although most patients do not require it. 

What is the follow-up?

After discharge from the hospital, patients are scheduled to return to the Heart Center one week after the procedure so we can inspect the incision.  The patient is seen every three months in our office so we can check the defibrillator. 

What are the restrictions following the procedure?

The patient is instructed to keep the arm on the side of their defibrillator below the level of the shoulder for 6 weeks following the procedure and to avoid lifting anything more than 10 lbs with that are for the first 3 months.  After the first three months, patients are instructed to avoid lifting anything more than 30 lbs with that arm.

How is a defibrillator different from a pacemaker?

A pacemaker prevents slow heart rhythms by pacing the heart if it begins to slow down.  A defibrillator can do this as well.  However, a defibrillator has added capability of treating fast heart rhythms by pacing the heart rapidly or by shocking the heart. Because of this added capability, defibrillators are sometimes referred to as “special pacemakers” or a “pacemaker-plus”.  

Can I travel?

Once the incision is fully healed, it is usually safe for patients to travel. However, patients are encouraged to touch base with their cardiologist before making plans for long-distance traveling. 

With regard to passing through airports, we ask patients to present their defibrillator card to the airport security.  This card will be given to you after your defibrillator is implanted.  It will be important for the airport security to know that you have a defibrillator.  Patients may walk through the security booths but we ask that the security wand not be placed over the defibrillator. 

Can I use a microwave?

It is perfectly safe for patients with a defibrillator to use a microwave.

Can I use a cellphone?

Yes, we simply ask that you hold the cellphone to the ear on the side opposite of your defibrillator.  We also ask that you do not place the cellphone in a pocket immediately over the defibrillator.