To determine whether you need an ICD, your doctor may perform any of these diagnostic tests:
- Electrocardiography (ECG). In this noninvasive test, sensor pads with wires attached (electrodes) are placed on your chest and, sometimes, limbs to measure your heart's electrical impulses. Your heart's beating pattern can offer clues to the type of irregular heartbeat you have.
- Echocardiography. This noninvasive test uses harmless sound waves that allow your doctor to see your heart without making an incision. During the procedure, a small, plastic instrument called a transducer is placed on your chest. It collects reflected sound waves (echoes) from your heart and transmits them to a machine that uses the sound wave patterns to compose images of your beating heart on a monitor. These images show how well your heart is functioning, and recorded images allow your doctor to measure the size and thickness of your heart muscle.
- Electrophysiology study (EPS). In this procedure, electrodes are guided through blood vessels to your heart and used to test the function of your heart's electrical system. This can identify whether you currently have or may develop heart rhythm problems.
- Holter monitoring. Also known as an ambulatory electrocardiogram monitor, a Holter monitor records your heart rhythms for an entire 24-hour period. Wires from electrodes on your chest go to a battery-operated recording device carried in your pocket or worn on a belt or shoulder strap. While you're wearing the monitor, you'll keep a diary of your activities and symptoms. Your doctor will compare the diary with the electrical recordings to try to figure out the cause of your symptoms.
- Event recorder. Your doctor may ask that you wear a pager-sized device that records your heart activity for a day or so. Unlike a Holter monitor, it doesn't operate continuously — you turn it on only when you feel your heart is beating abnormally.
Your doctor will give you specific instructions on what to do immediately before your surgery to prepare. It's likely you'll be asked not to eat or drink for at least eight hours before your surgery. Talk to your doctor about any medications you take, and whether you should continue to take them before your procedure to implant an ICD.
Jun. 04, 2013
- Implantable cardioverter defibrillator. National Heart, Lung, and Blood Institute. http://www.nhlbi.nih.gov/health/dci/Diseases/icd/icd_all.html. Accessed March 14, 2013.
- Epstein AE, et al. 2012 ACC/AHA/HRS focused update incorporated into the ACC/AHA/HRS 2008 guidelines for device-based therapy of cardiac rhythm abnormalities. Circulation. 2013;127:e283.
- Devices that may interfere with implantable cardioverter defibrillators (ICDs). American Heart Association. http://www.heart.org/HEARTORG/Conditions/Arrhythmia/PreventionTreatmentofArrhythmia/Devices-that-may-Interfere-with-Implantable-Cardioverter-Defibrillators-ICDs_UCM_448464_Article.jsp. Accessed March 14, 2013.
- Living with your implantable cardioverter defibrillator (ICD). http://www.heart.org/HEARTORG/Conditions/Arrhythmia/PreventionTreatmentofArrhythmia/Living-With-Your-Implantable-Cardioverter-Defibrillator-ICD_UCM_448462_Article.jsp. Accessed March 14, 2013.
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- Epstein AE, et al. Addendum to ''Personal and public safety issues related to arrhythmias that may affect consciousness: Implications for regulation and physician recommendations — A medical/scientific statement from the American Heart Association and the North American Society of Pacing and Electrophysiology" public safety issues in patients with implantable defibrillators. Circulation. 2007;115:1170.
- Eifling M, et al. The evaluation and management of electrical storm. Texas Heart Institute Journal. 2011;38:111.