How Does A Defibrillator Work?

A defibrillator is a medical device used to restore normal cardiac rhythm in a person who is suffering sudden cardiac arrest. Find out more on how they work here.

A defibrillator is a medical device used to restore normal cardiac rhythm in a person who is suffering sudden cardiac arrest. It works by delivering an electric shock to the heart in order to reset or restore its normal rhythm. In this blog post, we will explore how a defibrillator works and its importance in saving lives.

To begin with, it is essential to understand the heart’s electrical system to fully comprehend how a defibrillator works. The heart is controlled by electrical conduction that stimulates its rhythmic beating. This system starts in the sinoatrial (SA) node located in the right atrium, which acts as the heart’s natural pacemaker. The electrical impulses travel from the SA node to the atrioventricular (AV) node, stimulating the heart’s contractions. In cases of sudden cardiac arrest, this system malfunctions, causing irregular heartbeats or even stopping the heart from beating entirely.

A defibrillator is used in emergency situations when a person’s heart has stopped beating correctly, and they are not breathing. These devices work by generating an electric current that is delivered to the heart in order to ‘reset’ its rhythmic beating. A defibrillator can either be manual or automated external. An  automated external defibrillator (AED) can be either manual or fully automatic and can be used by a layman laypersons to deliver the electric shock in case of an emergency. The only difference between the two configurations is that the manual will require the operator to press the shock button on command, the fully auto will do this if required without operator intervention.

An AED has two electrodes/pads, which are placed on the chest of the patient, as displayed on their packaging. These pads work by detecting the heart’s electrical activity and transmitting it to the AED to analyse the rhythm. If the machine detects an abnormal heart rhythm, it will instruct the operator to deliver an electric shock to the heart by pressing a button on the device. If fibrillation is not detected, i.e. in a stroke, the unit will not shock.

One of the most important aspects of defibrillators is the amount of energy they can deliver. The energy can be adjusted depending on the patient’s age, size, and condition. For instance, an adult typically requires an energy level of 200 joules, while a child would need less – typically between 50 and 100 joules. It is important to note that the energy delivered by the defibrillator can cause the patient’s chest to rise as if they are taking a breath. This is normal and indicates that the delivery of energy was successful.

In conclusion, defibrillators are essential medical devices that are used in emergency situations to reset or restore the normal rhythmic beating of the heart. The automated external defibrillator delivers an electric shock to the heart to reset its rhythm and is commonly used by non-medical personnel. The importance of defibrillators in saving lives cannot be overstated, and it is crucial that they are available in various public places to ensure immediate response in the event of a cardiac arrest. With defibrillators, lives are saved every day, and it is a device that has revolutionised emergency medical care.

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