What is a Defibrillator?

What is a Defibrillator – Overview

A defibrillator is a medical device that provides an electric shock to your heart so it can adjust its abnormal rhythm (arrhythmia) which can often be otherwise fatal.

This device is also used in event of ventricular fibrillation and ventricular tachycardia. Both these problems develop in the ventricles, which are the two lower chambers of the heart.

Who Can Use a Defibrillator?

Anyone suffering from arrhythmias can use a defibrillator at a hospital or place that has an automated external defibrillator available. However, if you have high-risk arrhythmia then you may need to get your own defibrillator.

A shock from a defibrillator is painless or so hard that you feel like someone’s kicked your chest. People who suffer from potentially fatal arrhythmias can use the following types of personal defibrillators:

Wearable cardioverter defibrillator – This is an externally-worn device that can be used like a vest under your clothes. The sensors in the device are kept in contact with your skin so they can detect an abnormal rhythm and can send an electric shock to get the heartbeat under control.

Implantable cardioverter defibrillator – Also called ICD in short, this device is implanted near the collarbone, close to the heart with leads connected to the main arteries. It works similarly to a pacemaker as it keeps the heart beating at a steady, regular rate.

The defibrillator part kicks in when the sensors detect an abnormal rhythm and sends an electric pulse to adjust the heart rate back to normal levels.

How Does a Defibrillator Work?

What is a Defibrillator

What is a Defibrillator – How Does a Defibrillator Work

A defibrillator often proves essential to survive a sudden cardiac arrest, as CPR (cardiopulmonary resuscitation) provides only temporary relief. A person who already has a pacemaker or an ICD implanted can also use a defibrillator.

In the event of sudden cardiac arrest, it is advisable to keep providing CPR to the patient until you have access to a defibrillator.

Once you have the defibrillator in hand, make sure to shock the patient when no one is touching the patient’s body or bed.

If you are using an automated external defibrillator (AED), it can also check the heart’s rhythm and determine if an electric shock is needed. Once the AED gets fully charged, it also gives verbal instructions and warning on how to use it.

Usually, a defibrillator is used by a healthcare provider or first responder in the following manner:

  • Place the two sticky pads or paddles connected to the defibrillator on the patient’s chest. One paddle/pad should be placed just below the right shoulder and the other pad/paddle should be placed carefully below the left nipple. A special conducting material is applied to the pad/paddles of a defibrillator to prevent burns. Still, you will need to put conducting material on the patient’s chest before using the paddles/pad.
  • For sticky paddles, you will need to push a button on the defibrillator machine to give the shock. For handheld devices, you will need to push the button on each paddle simultaneously.

A defibrillator causes your heart muscles to stop moving for a few moments so that your heart can create an even rhythm using an electric impulse. In short, defibrillators restart your heartbeat.

What Happens After Using a Defibrillator?

Initially, the first responder or healthcare provider will start giving the patient CPR for around two minutes. Then they will check the patient’s pulse and see if the heart rhythm is back to normal. If needed, they will give more CPR and another electrical shock.

In case defibrillation does not work successfully, then the first responder or healthcare professional will administer medication, such as amiodarone or epinephrine to correct the abnormal rhythm.

If the blood flow is normal, but the patient is non-responsive the healthcare professional will attempt to bring the patient’s body temperature down to 89.6 to 96.8 degrees Fahrenheit (32 to 36 degrees Celsius) to protect and promote recovery of brain functions.

Once the patient’s condition is stabilized, the healthcare provider may choose to perform a cardiac catheterization.

What are the Benefits of using a Defibrillator?

A defibrillator is used for ventricular tachycardia where there is no pulse or for ventricular fibrillation. If you use a defibrillator for any other kind of arrhythmia, it could cause the patient to suffer a cardiac arrest or cause ventricular fibrillation.

Recovering after defibrillation following a cardiac arrest is a long-term process and may take several months to a few years, depending on the patient’s age, medical history, lifestyle, and other similar factors.

According to studies, around 40% of cardiac arrest survivors have some form of impairment following defibrillation, which prevents them from resuming work or doing some regular activities upon leaving the hospital.

It may take considerable time to recover from a rib fracture that may happen during CPR and to manage other related problems, such as difficulty in walking or seizures. You may need to undergo physical, speech or occupational therapy to recover from defibrillation.


If you see someone collapsing with chest pain, it is advised to immediately call the emergency medical services (EMT) number. if you are trained in CPR, then you may administer it, at your discretion.

However, it is always advisable to make the patient feel comfortable till the professional EMTs arrive on the scene and take charge.

Reference links




See Also

American Heart Association AED Grants

AED Grants for Police Departments

AED Grants for Fire Departments

AED for Schools Grant Money

Grants for AED

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