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Should You Get an Implantable Defibrillator?


Updated November 12, 2011

Written or reviewed by a board-certified physician. See About.com's Medical Review Board.

Implantable defibrillators (ICDs) are highly effective at preventing sudden cardiac death from heart arrhythmias. Unfortunately, most of the more than 400,000 Americans who die suddenly each year never learn that their risk is high - and therefore, they never have the opportunity to consider an ICD.

If you have any type of heart disease, or several risk factors for heart disease, or a history of close family members who have had sudden death, you should talk to your doctor about evaluating your risk for sudden death.

Do You Have an Increased Risk of Sudden Death?

People who are at an increased risk for sudden death generally fall into four categories:

1) People who have significant coronary artery disease (CAD). The plaques associated with CAD can suddenly rupture, producing a spectrum of conditions that are called Acute Coronary Syndrome (ACS). One of the dire outcomes of ACS is cardiac arrest. This occurs because plaque rupture can acutely disrupt the cardiac electrical system, producing sudden ventricular tachycardia (VT) or ventricular fibrillation (VF). It is estimated that in about 30% of people who have significant CAD, sudden death is the very first sign that the disease is present.

Generally speaking, people who have CAD but who have not yet had a myocardial infarction (heart attack) are not candidates for ICDs. Rather, these individuals need to undertake aggressive measures at controlling the risk factors that are known to accelerate CAD and that make plaque rupture more likely. Good medical care and effective lifestyle modification can greatly reduce the risk of sudden death, heart attacks and angina.

2) People who have already had episodes of VT or VF, especially if the arrhythmia has caused cardiac arrest or loss of consciousness. These people have a very high risk of having another cardiac arrest - probably a 1 in 5 chance each year - and virtually all of them should be offered an ICD.

3) People who have heart failure with a significantly reduced left ventricular ejection fraction. It is estimated that almost 50% of patients with severe heart failure eventually experience a cardiac arrest. Current guidelines recommend that ICDs ought to be considered for people whose ejection fractions are reduced to 30 to 35% or lower.

This is why, if you have heart disease of almost any type, it is important to know your ejection fraction.

4) People who have inherited heart defects that make VT or VF more likely to occur. Such conditions include long QT syndrome, hypertrophic cardiomyopathy, and Brugada syndrome. ICDs can prevent sudden death in these inherited conditions, and should be strongly considered in many affected individuals. Anyone with a strong family history of sudden death should discuss their family history with their doctor and ask whether any special testing ought to be done. In most cases a simple ECG and perhaps an echocardiogram would be sufficient to rule out the most common inherited cardiac disorders that increase the risk of sudden death.

If you believe any of these four categories may apply to you, you need to have a serious conversation with your doctor about evaluating your risk for sudden cardiac death.

If Your Risk Is Elevated, Should You Have an ICD?

ICDs are not for everyone. There are risks with these devices as well as benefits. Whether to have one - even if your risk is elevated and you have a formal "indication" for an ICD - is always an individual decision. However, before you can even have the opportunity to make this decision, you need to be aware that your risk for sudden death is elevated. Unfortunately, many doctors are (understandably) reluctant to broach this topic with their patients. So, if you are concerned that you might be at increased risk, break the ice yourself - ask your doctor to talk with you about it.

Read More About ICDs:


Zipes, DP, Camm, AJ, Borggrefe, M, et al. ACC/AHA/ESC 2006 guidelines for management of patients with ventricular arrhythmias and the prevention of sudden cardiac death: a report of the American College of Cardiology/American Heart Association Task Force and the European Society of Cardiology Committee for Practice Guidelines (Writing Committee to Develop Guidelines for Management of Patients With Ventricular Arrhythmias and the Prevention of Sudden Cardiac Death). J Am Coll Cardiol 2006; 48:e247.

Epstein, AE, DiMarco, JP, Ellenbogen, KA, et al. ACC/AHA/HRS 2008 Guidelines for Device-Based Therapy of Cardiac Rhythm Abnormalities: a report of the American College of Cardiology/American Heart Association Task Force on Practice Guidelines (Writing Committee to Revise the ACC/AHA/NASPE 2002 Guideline Update for Implantation of Cardiac Pacemakers and Antiarrhythmia Devices): developed in collaboration with the American Association for Thoracic Surgery and Society of Thoracic Surgeons. Circulation 2008; 117:e350.

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