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Does a Defibrillator Stop or Start the Heart

Does a Defibrillator Stop or Start the Heart

A defibrillator is a medical device that delivers a therapeutic dose of electrical energy to the heart muscle. Most people think an AED shocks the heart causing the heart to beat normally. In reality, defibrillation actually shocks the heart to stop it so the natural pacemaker of the heart can hopefully reset. This energy helps to restore the heart’s normal rhythmic function. This article will outline what actually happens when a defibrillator is used on a sudden cardiac arrest victim.

Defibrillators: What They Are and How They Work

Defibrillators are medical devices that are used when the heart is beating irregularly or dangerously fast. This can happen in conditions called ventricular fibrillation (VF) or pulseless ventricular tachycardia (PVT). There are common misconceptions and arrhythmias are often confused with a heart attack, In reality, sudden cardiac arrest (SCA) is a totally different health concern. A heart attack is like having a plumbing problem in a person’s heart while SCA is an electrical problem.

Defibrillators What They Are and How They Work

In short, a defibrillator is used to reset the electrical system of the patient’s heart. This is done by delivering a therapeutic dose of electrical energy to the heart muscle. The shock actually stops the heart from beating so that the natural pacemaker of the heart can hopefully reset. Note that if a suspected victim of SCA is actually suffering from a heart attack, the AED may determine there is not a shockable rhythm (no electrical activity) and no attempt for a defibrillator restart will be attempted.

Ventricular Fibrillation is an arrhythmia when the heart’s ventricles (the lower chambers) quiver in a chaotic rhythm instead of contracting in a coordinated way. This means that oxygenated blood is not pumped out of the heart properly and doesn’t reach the rest of the body. Ventricular Tachycardia is when the heart’s ventricles beat too fast (usually more than 150 beats per minute). This is also known as a fast or rapid heart rate.

When these arrhythmias happen, the stopped heart cannot pump blood throughout the body properly. This can lead to collapse, unconsciousness, and death if not treated immediately.

Automated External Defibrillators (AEDs) work by delivering a shock through the chest to the heart. This shock actually stops the heart from beating erratically and allows it to resume the heart’s rhythm. The shock from an AED temporarily stops the heart from beating allowing it to reset its rhythm. The sinus node is the “pacemaker” of the heart and it sets the pace of the heartbeat. The electrical shock can help to reset the sinus node and restore the rhythm of the heart.

There are two types of defibrillators: external and implantable. External defibrillators or AEDs are used in emergency situations and are portable devices that can be carried by first responders. Implantable defibrillators are surgically implanted devices that are used for the long-term treatment of heart conditions.

Sudden Cardiac Arrest

Sudden cardiac arrest (SCA) is a medical emergency in which the heart suddenly stops beating. Sudden cardiac arrest occurs due to a variety of reasons, including an electrical malfunction in the heart, a blockage in the heart’s blood supply, or a build-up of fluid in the lungs. Treatment of sudden cardiac arrest occurs typically involves resuscitation with CPR and defibrillation. In some cases, a mechanical device may be used to support the heart. With prompt treatment, SCA can be reversible and often leads to a full recovery. However, if not treated immediately, it can lead to death.

Sudden Cardiac Arrest

There are many causes of SCA. The most common cause is an electrical malfunction in the heart, which can cause the heart to beat irregularly or stop altogether. Other causes include a blockage in the heart’s blood supply, a build-up of fluid in the lungs, and an imbalance of electrolytes in the blood. No matter the cause, SCA is a medical emergency that requires immediate treatment.

CPR is often the first line of treatment for sudden cardiac arrest. This involves chest compressions and rescue breaths. Chest compressions help to circulate the blood and keep the heart pumping. Rescue breaths provide oxygen to the lungs and help to prevent brain damage. Defibrillation is also often used to treat sudden cardiac arrest and to restart a stopped heart. This involves using a device to deliver an electric shock to the heart. This can often restart the heart and restore the heart’s natural rhythm. In some cases, a mechanical device may be used to support the heart. This includes devices that help to pump blood or provide oxygen to the lungs.

The Science Behind Defibrillation

When the heart stops beating, blood flow to the brain quickly decreases. This lack of oxygenated blood causes the victim to become unconscious within seconds. If not treated immediately with CPR and defibrillation, death will occur within minutes. Defibrillation is an electrical shock that is delivered to the heart through paddles or electrode pads placed on the chest. This defibrillation shock usually restores normal heart rhythms.

The Science Behind Defibrillation

When the heart stops, its electrical system is disrupted. This disruption prevents the heart from effectively pumping blood. Defibrillation works by delivering a shock that corrects this electrical problem and allows the heart to beat normally again.

The AED was invented in the 1960s, but it was not until the late 1990s that this life-saving device became widely available. Modern portable AEDs combined with deploying immediate CPR saves lives.

Today, AEDs are found in many public places, such as airports, office buildings, and schools. They are also carried by many first responders, such as police officers and firefighters.

How Defibrillators Are Used in treating Cardiac Arrest

When someone has a cardiac arrest, their heart stops beating. This means that blood is no longer able to pump around the body and oxygenated blood is not reaching the brain. A defibrillator is a device that gives a high-energy electric shock to the heart’s electrical system through the chest wall to try to restore a normal rhythm. This can be an external defibrillator (AED) which is a portable device that can be used by anyone, or an implantable cardioverter defibrillator (ICD), which is a surgically implanted device. A quick defibrillator restart of the heart’s normal rhythm immediately is extremely important to revive an SCA victim and to avoid brain damage due to lack of oxygen.

How Defibrillators Are Used in treating Cardiac Arrest

The American Heart Association prescribes defibrillation as an essential part of the chain of survival for someone who has a cardiac arrest. If it is delivered within the first few minutes, it can be successful in restoring a normal heart rhythm and increase the survival rates significantly for a person suffering from SCA. The average response time for emergency medical services (EMS) in the US is 7 to 12 minutes nationwide. This means you have very little time, 10 minutes or less to revive the SCA victim. Don’t wait for emergency services to arrive, act quickly with CPR and defibrillation.

An Automated External Defibrillator AED is typically found in public places such as supermarkets, sports stadiums, and airports. They are easy to use and will give clear instructions on how to deliver the shock. People who are trained in their use, such as first aiders and ambulance staff, will also be able to give advice.

Implantable cardioverter defibrillators are usually only considered for people who have had a cardiac arrest or who are at high risk of having one. These devices continuously monitor the heart rhythm and can deliver a shock if they detect an abnormal heart rhythm.

Defibrillation is a safe and effective treatment for cardiac arrest, and it can save lives. If you are trained in its use, or you have access to an AED, don’t be afraid to use it if someone has a cardiac arrest.

The Pros and Cons of Using a Defibrillator

Although defibrillators are very effective, there are some pros and cons to using them.

One of the biggest pros of using a defibrillator is that it can be the difference between life and death for a person in cardiac arrest. When used correctly, a defibrillator can shock the heart back into a normal rhythm, giving the person a much better chance of survival.

The Pros and Cons of Using a Defibrillator

Another pro of using a defibrillator is that it is relatively easy to use. Most defibrillators have clear instructions and are designed for use by laypeople. This means that anyone can potentially save a life by using a defibrillator, even if they have no medical training.

There are also some cons to using a defibrillator. One of the biggest cons is that defibrillators can be expensive and therefore not enough AEDs are available for public access. Modern AEDs are some of the most advanced medical devices in history and save lives. As more AEDs are deployed throughout the world, hopefully, the number of sudden cardiac arrest deaths will decrease.


Modern AEDs are so advanced today that they require almost no assistance from a responder to operate. Thankfully we don’t have to worry about if an AED stops or starts the heart and instead only make sure these remarkable life-saving devices are available.

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