Ventricular arrhythmia is a rhythm irregularity in the heart’s lower chambers that can develop after a heart attack. For people with this condition, a cardioverter-defibrillator can be a lifesaver.

When a dangerous heart rhythm is detected, the cardioverter-defibrillator sends a mild electric shock to the heart to return it to a regular rhythm and prevent it from going into cardiac arrest.

Usually, the small, battery-powered device is implanted surgically in the chest near the heart. This is known as an implantable cardioverter-defibrillator (ICD).

But when a person is awaiting the procedure or has had an older ICD removed, a wearable cardioverter-defibrillator (WCD), also known as a vest defibrillator, can serve as a temporary bridge until a new ICD can be implanted.

A vest defibrillator is worn under the clothes. A band of fabric supported by shoulder straps fits around the torso, just under the chest. The vest includes electrodes that lie on the skin near the heart and a wire attached to a heart monitor that can be worn at the waist or over a shoulder.

The WCD may be a little uncomfortable at first, but the vest is lightweight and should not interfere with sleeping once you get used to wearing it.

A vest defibrillator constantly monitors the heart for irregular heart rhythms (arrhythmias).

Two of the more potentially dangerous arrhythmias include ventricular fibrillation, which is a quivering and ineffective beating of the ventricles, and ventricular tachycardia, which is an irregularly rapid heartbeat.

When a dangerous rhythm is detected, the WCD delivers a shock to the heart, usually within 60 to 90 seconds. The vests will usually sound an alert and vibrate prior to delivering the shock.

If the wearer is conscious and does not feel in distress, the alarm can be turned off and the shock diverted. If the individual is either unconscious from cardiac arrest or aware that the heart is beating irregularly, the shock can continue.

The goal is to shock the heart back into a steady, healthy rhythm and prevent a serious incident such as cardiac arrest. Cardiac arrest is the sudden stoppage of electrical activity in the heart. This is an often fatal event.

There are a few different types of vest defibrillators, but the parts are essentially the same in each. The vest includes two electrodes attached to a rechargeable generator and battery pack. These may be worn attached to a belt, in a fanny pack, or over the shoulder.

These electrodes monitor the rhythm of the heart. The vest also includes two defibrillation electrodes that administer electrical impulses from the generator.

Pros of vest defibrillators

  • cardiac arrest protection while waiting for an ICD or heart transplant
  • portable
  • low maintenance
  • less expensive and burdensome than a hospital stay

Cons of vest defibrillators

  • somewhat uncomfortable, especially at first
  • shocks can be painful
  • vest and electrodes must be worn properly to be effective
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A vest defibrillator may be prescribed to anyone at high risk for cardiac arrest who cannot currently have an ICD. Potential candidates include recent heart attack survivors regaining their strength and health to undergo ICD implantation.

Some people who have ICDs must have their devices removed because of infection, mechanical problems, or other reasons.

For these individuals who are awaiting a replacement ICD, a vest defibrillator can be a safe and effective temporary solution. It can also be less expensive than a longer hospital stay with constant heart monitoring, according to a 2021 study.

A 2018 analysis of more than 400 children who wore WCDs because of ventricular arrhythmias found that the devices are safe and effective for younger individuals who may not be old or healthy enough to receive an ICD.

A person with heart failure who is awaiting a heart transplant may be a good candidate for a WCD to avoid going through the invasive nature of ICD implantation.

If your cardiologist does not determine that your risk for cardiac arrest warrants an ICD, you should not wear a vest defibrillator. Other reasons for not having a vest defibrillator include:

  • having a life expectancy of less than 1 year
  • having an arrhythmia that cannot be managed by a device
  • having an arrhythmia that may be better managed with a procedure known as ablation

Along with monitoring your heart for dangerous arrhythmias and administering any needed shocks, a WCD also records your heart rate and information about any shocks that are given. The device can even record how long you wear it.

Depending on the type of WCD you have, this information may be recorded automatically or manually. Most vests let you send the data over a phone line directly to a doctor or a secure database your doctor can access.

A vest defibrillator is meant to prevent cardiac arrest, which is different from a heart attack. A heart attack occurs when there is a blockage in one of the heart’s arteries supplying blood to the heart muscle.

This can cause major damage to heart tissue. But generally, the heart keeps beating during a heart attack, though not very effectively.

Cardiac arrest is a condition where the heart’s electrical system stops, slows, or weakens to the point where it’s unable to pump enough blood out to the body. Defibrillators help keep the heart’s electrical activity running smoothly rather than keep blood vessels open.

The cost of a vest defibrillator, including the vest and hardware, as well as the recording and transmission of wearer data to the doctor’s office, averages around $3,000 a month.

Does insurance cover a vest defibrillator?

Most health insurance plans, including Medicare and Medicaid, will cover a vest defibrillator if it is medically necessary. Insurers have specific heart-health criteria that an individual must meet in order for a WCD to be considered medically necessary.

Coverage is also limited to a certain time period, usually 40 to 90 days, depending on a person’s cardiac health.

A vest defibrillator is one of a few different types of devices designed to shock a person’s heart back into a healthy rhythm. Others include:

  • Automatic external defibrillator (AED). AEDs use handheld pads to deliver shocks from outside the body.
  • Advanced life support defibrillators. These defibrillators are equipped with AED functions and technology that allow healthcare professionals to manage a person’s heart rate.
  • Implantable cardioverter-defibrillator (ICD). ICDs are placed in the chest near the heart with two wires or leads extending into the heart to deliver shocks.

The risk of going into cardiac arrest while not wearing a vest defibrillator outweighs most risks of wearing the device. However, there are some issues worth understanding if you have been advised to wear a WCD.

The primary concern is an improper shock. While this may not pose a serious health risk, it can be unnecessarily painful. However, ICDs pose the same risk.

Unlike an ICD, which operates 24 hours a day, a WCD must be removed when bathing. This presents brief periods where cardiac arrest is a risk.

For someone recovering from a heart attack, the risk of a dangerous ventricular arrhythmia that could lead to cardiac arrest is greatest in the days and weeks right after the heart attack.

But for many people, the risk lowers as their heart regains strength through cardiac rehabilitation, a heart-healthy lifestyle, and the heart’s natural healing process.

A 2019 study of more than 11,000 individuals who were recent heart attack survivors reported that in the first year following a heart attack, the death rate was lower among those who wore a WCD when compared to those who did not.

If you are eligible for the surgical implant of an ICD or for a heart transplant but cannot yet have either of those procedures, you may be a good candidate for a vest defibrillator.

The devices are usually meant for temporary use and are often covered by insurance. Though they may be somewhat uncomfortable at first, they can often be effective means of preventing or immediately treating cardiac arrest.