Should You Get an Implantable Defibrillator?

Implantable defribillator

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Implantable defibrillators (ICDs) are highly effective at preventing sudden cardiac death from heart arrhythmias. Unfortunately, most of the more than 350,000 Americans who die suddenly each year never learn that their risk is high — and therefore, they never have the opportunity to consider an ICD.

Anyone who has significant heart disease, or has close family members who have had sudden death, should talk to their doctor about their own risk of sudden death. If your risk is high, you should have a discussion about an ICD.

Do You Have an Increased Risk of Sudden Death?

People who are at an increased risk for sudden death generally fall into five categories. For many people in four of these categories, an ICD should be considered as an option.

1) People who have significant coronary artery disease (CAD). The presence of CAD itself increases a person's risk of having a life-threatening arrhythmia, but in general does not increase the risk high enough to require an ICD.

The plaques associated with CAD can suddenly rupture, producing a spectrum of conditions that are called Acute Coronary Syndrome (ACS).

One of the possible 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, however, the overall risk of sudden death in people who have CAD but who have not yet had a myocardial infarction (heart attack) is not high enough to require an ICD. 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 heart attacks, angina, and sudden death.

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. Unless some underlying cause for the cardiac arrest has been identified that is totally reversible, almost all of these people 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 many people with heart failure whose ejection fractions are reduced to 35% or lower. Many of these individuals benefit from an ICD that also includes cardiac resynchronization therapy.

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

4) People who have had heart attacks and have significantly reduced left ventricular ejection fractions. People who have had a heart attack which has left them with a left ventricular ejection fractions of 30% or lower have a substantially increased risk of cardiac arrest, and should be considered for an ICD.

5) People who have inherited heart defects that make VT or VF likely to occur. Such conditions include long QT syndromehypertrophic 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 the last four categories may apply to you, you need to have a serious conversation with your doctor about evaluating your risk for sudden cardiac death.

A Word From Verywell

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. 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.

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