The LifeVest by Zoll is a defibrillator that a person can wear. A cardiac life vest can send electrical pulses to the heart to attempt to restart it after cardiac arrest.

The LifeVest by Zoll received FDA approval in 2001. It is for people who are at risk for sudden cardiac arrest. It is a temporary solution for people awaiting surgery for a permanent implantable defibrillator.

In this article, we provide further information about LifeVest. We also provide a list of alternatives.

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LifeVest is a device that can detect abnormal heart rhythms. When it detects these abnormalities, it sends a shock or electrical pulse to the heart to restore it to the normal rhythm.

A LifeVest does not require another person to be present as a standard automated external defibrillator (AED) does.

LifeVest has several different components.

The garment

People wear this lightweight garment under their clothes, directly against the skin. People can put clothes over it, including undergarments.

The garment holds one of the other components, the electrode belt, in the correct places on the body.

The electrode belt

This is the part of the device which detects any abnormal heart rhythms and delivers the shocks.

This belt is made up of several components:

  • Therapy pads: These pads generate an electric shock to the heart.
  • ECG electrodes: These monitor the rhythm of the heart continuously.
  • Vibration box: This notifies a person if they are about to receive a shock.
  • Cable and connector: These connect the belt to the garment.


A person wears this monitor around their waist or over the shoulder using the provided holster. It monitors a person’s heart rhythm and has a display screen.


The alarm can clip onto an item of clothing, such as a belt or breast pocket.

The device will sound an alarm when it detects an abnormal heart rhythm. If it turns out the reading was incorrect and the wearer is conscious, the person has a short space of time to switch the alarm off.

Before the device administers the shock, the alarm warns people nearby not to touch the person. Once the person receives the shock and the heart rate goes back to normal, the alarm will stop by itself.

A person may need to use a LifeVest temporarily while waiting to see if LVEF improves or waiting to undergo placement of an implantable cardioverter defibrillator (ICD).

People with a reduced left ventricular ejection fraction (LVEF) may benefit from wearing a LifeVest. Reduced LVEF means the heart’s left ventricle a lower proportion of blood with each contraction.

According to the American Heart Association, a wearable cardiac defibrillator may be suitable for people who need an implantable cardioverter defibrillator (ICD) but are waiting to get one.

Typically, this includes people who waiting to see if LVEF is going to go away with medication. It can also be useful for those who might expect to see recovery from LVEF. This could happen if problems with LV function results from a reversible cause, such as thyroid disease.

Additionally, people may benefit from wearing the LifeVest if they:

  • are awaiting a heart transplant or heart surgery
  • have had a recent heart attack
  • have heart disease or failure
  • are starting to take medications for unusual heart rhythm

A person should not wear a LifeVest if they:

  • have an active implanted cardioverter defibrillator (ICD)
  • have mental, physical, vision, or hearing difficulties that would prevent them from hearing the alarm or pressing the buttons
  • cannot wear the device at all times
  • are pregnant or breastfeeding
  • are under the age of 18 with a body size less than that specified by the manufacturer
  • do not wish to be resuscitated

The main benefit of a LifeVest is that it can help to save a person’s life if they suddenly go into a cardiac arrest.

It does not require another person to operate it, so it can help even if a person is on their own.

It also may help provide peace of mind to a person while they are awaiting surgery or at risk for cardiac arrest.

LifeVest comes with a few risks.

One is that a person needs to be ready to respond to the alarm at all times if it goes off unnecessarily. If a person does not dismiss the alarm, the device will send a shock to the heart, which may be harmful if the heart’s rhythm is not truly abnormal.

There is also the potential for the device to malfunction. A person needs to ensure the batteries are always fully charged. Otherwise, the LifeVest may not work properly.

Additionally, wearing the LifeVest while bathing, showering, or swimming is unsafe.

The device may also pose a risk to people nearby if they touch the wearer while it sends out electrical shocks.

A 2018 meta-analysis of over 19,000 people using wearable defibrillators showed that dangerous arrhythmias were successfully stopped 95.5% of the time, and mortality from sudden cardiac death due was low at 0.2%.

A 2018 study found that people who wore the LifeVest and took medications in the 90 days following a heart attack reduced their likelihood of death by 35%. This is in comparison to people who only took medication.

In 2018, the VEST trial found that people who wore the LifeVest and took medications in the 90 days following a heart attack had no difference in mortality due to arrhythmias.

However, not everyone in the study who was assigned to wear the LifeVest wore it regularly. A subsequent analysis looking deeper into this issue found that those who wore the LifeVest had a 62% reduction in mortality due to sudden cardiac death.

However, another 2018 study examined 109 LifeVest users. They found that wearing a LifeVest can affect a person’s quality of life. Forty-three percent of participants reported mental health issues such as depression or anxiety, and 37% reported pain or discomfort.

The study also found that people had difficulties with day-to-day activities, self-care, mobility, and sleep.

People should be able to go about their usual everyday activities while wearing a LifeVest.

A person should not shower, bathe, or submerge themselves in water while wearing a LifeVest. People may want to shower while somebody else is present.

People should also avoid loud or high-vibration environments that may impair their ability to hear the alarm.

Automated external defibrillators (AEDs) are available in many public spaces. It is similar to LifeVest. However, another person will need to control it.

Emergency medical staff also have access to AEDs.

The FDA regulates and approves all AEDs before they can be displayed in a public place.

Alternatively, a doctor may suggest an ICD. This is a defibrillator device that a doctor implants under the skin, just below the collarbone. It works 24 hours a day and functions in a similar way AEDs and a LifeVest.

A LifeVest is a wearable defibrillator that a person may wear if at risk of sudden cardiac arrest. This may include people who have recently had a heart attack or are awaiting surgery.

It works by monitoring a person’s heart rhythm. If it detects anything abnormal, it can administer an electric shock to the heart. The LifeVest contains an alarm to warn the person or those around them that it is about to send a shock to the heart.

Several studies show that the device helps to extend life expectancy. However, it may make some daily tasks more difficult.