Defibrillator Types

During sudden cardiac arrest, defibrillators are there to reset the heart's rhythm and potentially save a life. Defibrillators are medical devices that come in multiple forms each with its own uses and features. Defibrillators are a life-saving tool and are crucial to helping someone experiencing sudden cardiac arrest. The heart is the hardest working muscle in the body and it's important that regardless of the type of defibrillator response time is as quick as possible.


What is a Defibrillator?


A defibrillator is a medical device that sends an electrical shock to the heart of an individual experiencing sudden cardiac arrest. A defibrillator delivers an electric shock to reset the potentially fatal abnormal heart rhythm and restore the heart's normal rhythm. This device comes in multiple forms, but all provide a powerful shock to an individual experiencing a cardiac emergency. 


How does a Defibrillator Work?


A Defibrillator works by monitoring the heart's rhythm and determining if a shock is necessary. If a shock is advised, defibrillators deliver an electrical impulse to the heart. The electrical shock is used to rest the heart, sort of like turning a device on and off. This jolt of energy can restart the rhythm and set the heart back on track to its normal heart rhythm. 


What is a Defibrillator Used for?


A defibrillator is used when someone is experiencing sudden cardiac arrest. A defibrillator is needed when an individual is experiencing life-threatening arrhythmias like ventricular fibrillation or ventricular tachycardia, where the heart's ventricle contractions become abnormal.


Defibrillator Types


There are four different types of defibrillators each designed and used for specific situations. 


  1. Advanced life support defibrillators
  2. Automated external defibrillators  (AED)
  3. Implantable cardioverter-defibrillators  (ICD)
  4. Wearable cardioverter defibrillators (WCD)

Advanced Life Support Defibrillators


Advanced life support defibrillators or ALS defibrillators are used by medical staff in hospitals or during emergency medical transportation like in ambulances. Advanced life support defibrillators are the machines usually depicted in medical TV shows and movies. The ALS defibrillator can recommend shocks but also has the power to override and manually shock, this gives the doctor the ability to intervene and decide the voltage level and when to provide the shock. Advanced life support defibrillators have a wide range of features allowing them to also monitor blood pressure, carbon dioxide levels, temperature, and other vital medical information. 


Automated External Defibrillators


Automated external defibrillators or AED for short, are medical devices used during sudden cardiac arrest. AEDs are designed for civilians and trained individuals. AEDs are typically placed in public areas like schools, offices, gyms, and other public places. An AED can walk a user through a sudden cardiac emergency in hopes to save a life. An AED, once the electrode pads are placed, will detect and analyze the victim's heart rhythm, then determine whether or not a shock is advised. If it is, the device will then send a powerful electric shock to the individual. This shock of energy is used to treat abnormal heart rhythms in hopes to restart the rhythm and get the heartbeat back to normal. The AED will also give instructions on providing CPR, so the victim has the best chance of survival. AEDs come in both semi-automatic and fully automatic versions. The semi-automatic version has the rescuer press the shock button when advised, as to where the fully automatic will deliver the shock with no intervention from the rescuer needed. AEDs are a powerful tool allowing for quick response times from bystanders before a rescue team has arrived. 


Implantable Cardioverter Defibrillator


Implantable cardioverter-defibrillators or ICDs is a medical device implanted inside an individual's chest near the collar bone. Performed in a hospital, an ICD is placed in a patient's chest with wires threaded into the heart. ICDs are used for individuals at a high risk of sudden cardiac arrest and life-threatening arrhythmias, as well as those who have previously experienced ventricular fibrillation or ventricular tachycardia. An ICD monitors an individual heartbeat and heart rhythm. If a life-threatening heart rhythm is detected the ICD can deliver a powerful shock to the heart and hopefully reset the heart back to a normal state. ICDs give individuals peace of mind and an increased quality of life. In the event, the heart does experience an abnormal rhythm, the ICD is ready and the individual will get an electrical shock as quickly as possible increasing their chances of survival. 


The most common reason individuals get an ICD is 

  • Congenital heart defects
  • Heart failure 
  • Heart attack 

Wearable Cardioverter Defibrillators 


Wearable cardioverter defibrillators (WCD) are a vest-like device that is worn externally underneath clothing. The Wearable defibrillators will monitor the heart and in the chance, it detects a sudden cardiac event the device will provide an electric shock to reboot the heart and hopefully set a normal rhythm again. Wearable defibrillators can be used on individuals who are unable to get an ICD or can be used temporarily before the device gets placed. The WCD does not need outside intervention from a bystander or medical professional; the device is automatic and will act when it detects sudden cardiac arrest. 


The most common reasons individuals get a WCD are 


  • Individuals waiting to get or replace their ICD 
  • Individuals waiting for a heart transplant 

Types of Defibrillator


There are four main types of defibrillators: advanced life support defibrillators, automated external defibrillators (AED), implantable cardioverter defibrillators (ICD), and wearable cardioverter defibrillators (WCD). Each defibrillator has one thing in common - - the electric shock. Each of these devices provides powerful electric shocks in hopes to reset the heart and return it to normal function. These devices are crucial tools in the life-saving treatment of sudden cardiac arrest. With all cardiac emergency response time is key, and delivering treatment as quickly as possible will help increase the chances of survival.