What to know about variable heart rhythms and AFib
An Ohio State cardiac electrophysiologist shares what to know about heart rhythms and AFib.
An implantable cardioverter defibrillator (ICD) is a surgically implanted electronic device that detects and treats rapid heart rhythms coming from the ventricles (bottom chamber of the heart). These heart rhythm problems are called ventricular arrhythmias. They cause the pumping function of your heart to stop and you experience sudden cardiac arrest or death. (An ICD does not treat all heart rhythm abnormalities. In particular, it will not treat rapid heart rhythms from the top chamber of the heart, such as atrial fibrillation or atrial flutter. Treatments for these heart rhythm problems require different types of therapies.)
When your heart does not beat effectively, your brain does not get enough oxygen and serious, irreversible brain injury or death may occur. An ICD provides the best therapy by shocking your heart to eliminate these dangerous rhythms. The shock stops the rhythms, restores blood flow and delivery of oxygen to your brain and other organs and increases your chances of surviving.
There are three different types of ICDs but all have the same basic functions: continuous monitoring and prompt delivery of shock therapy. All ICDs also provide therapy to treat slow heart rhythms by pacing the heart. The monitoring function detects dangerous rhythm abnormalities from the bottom chambers of your heart and provides a prompt, electrical shock to restore normal rhythm. The pacing therapy is designed to treat excessively slow heart rhythms.
The three main types of ICDs are:
The best type of ICD for you will be determined by your physician.
Individuals who experience cardiac arrest rarely have symptoms beforehand. Your physician will evaluate you and determine your risk of developing these dangerous, rapid heart rhythms. If you are at high risk, your physician will recommend proceeding with the implantation of an ICD.
Factors that put you at high risk include already having experienced cardiac arrest, a low ejection fraction (weak pumping function of your heart called cardiomyopathy, an abnormal electrophysiology study or a unique heart condition, such as long QT syndrome or hypertrophic cardiomyopathy.
Ohio State’s Ross Heart Hospital has a dedicated staff of heart rhythm experts (called electrophysiologists), nursing staff, a device management team, research scientists and pharmacists that provides a complimentary team approach to evaluating patients who have experienced, or who are at risk to have, sudden cardiac death. We are the largest electrophysiology group in central Ohio and have one of the highest patient implantation experiences with devices in the United States.
Preparing for your procedure
The day before and morning of your procedure, you will need to use a special soap called CHG. It is sold by the brand name of Hex-A-Clens or Hibiclens and is available at most pharmacies. Please scrub from the neck down, avoiding your eyes and ears.
You will be asked to not eat or drink anything after midnight the evening before your procedure. Your physician will give you specific instructions on which medicines, if any, you should stop taking before the test. If you are not given specific instructions, please take your medicines as you normally would with a small amount of water. Please tell your doctor if you are diabetic and on medication.
Do not smoke or use tobacco products for 24 hours before your procedure.
During your procedure
The basic parts of an ICD are the ICD generator (battery pack) and lead (wire). The site of your ICD generator implantation will be just below your collar bone, typically on the left side of your chest. Your doctor will make an incision through your skin but not typically through the chest wall muscle. An ICD pocket is made underneath your skin and the ICD is placed inside.
After your procedure
After your ICD implantation, you will return to your hospital room and be monitored overnight. Patients usually only spend one night in the hospital. The day after your procedure, an X-ray of the device is completed and the device is tested by the Device Clinic staff. You will need to arrange to have an adult drive you home the day you are discharged.
The success rate for implanting an ICD is quite high (greater than 99 percent). However, when implanting a 3-lead ICD system, placement of the third lead may not be successful in about 2-4 percent of patients. This third lead is only required for pacing. The delivery of ICD shocks is still available.
The risk of complications with an ICD implantation is low (approximately 1-1.5 percent). Possible complications include injury to blood vessels, the heart wall or lung tissues, stroke, breathing complications, an infection that would require device removal and death. There is also the chance that your ICD device could have a random component failure. If this happens, the ICD or lead may need to be replaced.
Monitoring your defibrillator
Your ICD will need to be periodically evaluated. At these evaluations, the health of your ICD will be checked including the leads and the battery function. ICDs can also store information about your heart rhythm. This information will be reviewed as well.
Some ICDs can be evaluated with a home monitoring system. This system uses a unique monitor that sends the ICD information over the Internet. This information can then be reviewed by our staff at the Device Clinic. All information sent over the Internet is only reviewed during normal business hours.
If your ICD is capable of being monitored from home, the OSU Device Nurse will enroll you in the program. Home monitoring can not change or reprogram the ICD parameters but more information about the leads and heart rhythm can be obtained from the system. Home monitoring does not treat any medical condition.
What items can interact with my defibrillator?
There is no interaction between a microwave and an ICD. The likelihood of adverse interactions when using your cell phone is quite low. However, we do recommend talking on the opposite side from your defibrillator when using your cell phone.
When going through airport security, it is important to notify the security personnel that you have an ICD. They may ask you to show them the defibrillator card and we recommend that you ask to be hand-searched.
An ICD may be sensitive to anti-theft systems often found in stores and public libraries. These systems will not adversely affect the ICD if you walk through them in a normal manner without lingering.
Arc welding or other devices that can emit electronic magnetic signals can interfere with defibrillators. If you have hobbies or your work involves interaction with devices that can emit large magnetic fields or electromagnetic interference, it is best that you discuss this with your physician before returning to work.
What should I do if I notice any drainage, redness or swelling from the ICD site?
If you notice any of these changes, do not probe the incision with a cotton swab or apply any lotion or topical antibiotic. Please contact The Ohio State University Device Clinic staff at 614-293-8916. These changes may indicate that there is an infection.
What if I hear a beeping sound from my ICD?
Many ICDs have safety features to detect device problems. If a problem is detected, the ICD will periodically emit a beeping sound. If you hear this beeping, contact The Ohio State University Device Clinic, Monday through Friday from 8 a.m. to 5 p.m. at 614-293-8916.
When can I return to work?
The decision of when to return to work is based on several factors and should be discussed with your physician before you are discharged from the hospital. If you need return-to-work slips or paperwork completed, please do not hesitate to ask us.
Will I feel the shock from the ICD?
Your ICD is designed to detect and treat rapid heart rhythms from the bottom chamber of your heart. It takes approximately 15 seconds for the defibrillator to detect, charge up and deliver a shock. Your rapid heart rhythm may result in a very rapid drop in the blood pressure causing you to pass out. In this scenario, it is unlikely that you would feel a shock from your ICD. However, you may sustain an injury due to your loss of consciousness.
If your blood pressure does not drop rapidly and you remain conscious, you may feel the shock when it is delivered from the ICD. This may cause you to feel uncomfortable. However, all of your discomfort is temporary, typically lasting only a few minutes.
Can an ICD prevent a heart attack?
No, an ICD cannot prevent a heart attack. A heart attack is due to a blockage in the blood flow to the heart.
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