defibrillatorDefibrillation is a common method of treatment used by doctors for patients who are suffering from cardiac problems such as arrhythmia’s, pulseless ventricular tachycardia, and ventricular fibrillation. The process of defibrillation involves the utilization of a therapeutic dose of direct electrical energy to the affected part of the heart with an apparatus called a defibrillator. With the use of such a device, it will be able to depolarize a mass in the heart muscle, which can ultimately end an arrhythmia and aims to enable a normal sinus rhythm to take place by the sinoatrial node, (SA node), of the heart, which serves as a natural pacemaker.

These devices come in different forms each depending on the need and usage, they can be trans-venous, implanted, or external. The most common type is the automated external defibrillator (AED), which is shown in the picture above. This innovative device can automatically detect and diagnose treatable rhythms and is made so even bystanders can utilize them, even if they are not trained. Defibrillators that are implanted are known as, Implantable Cardio-Verter Defibrillators (ICD). This type of implantable device is able to send a current from a capacitor in the chest wall to the heart and can ultimately stop heart fibrillation.

What is the difference between a defibrillator and a pacemaker?

Pacemakers help attain a steady heartbeat, however defibrillators, pause the heart for a short moment with a shock in order to try and attain normal heart function. Pacemakers create electrical energy in the heart for patients who are diagnosed with specific cardiac arrhythmia’s. The defibrillator, however, is used to give the heart a very strong shock so that it stops the heart’s electrical activity. Physiologically in comparison to other muscles in the body, the heart can create its own electrical impulse so the shock administered by a defibrillator can ultimately restart the heart. External defibrillators are typically utilized for severe cardiac arrhythmia.

For instance, if an individuals heart rhythm slows down and cannot be treated with alterations in medications, then a pacemaker is required. As mentioned, the pacemaker allows the heart to beat at an appropriate rate and prevents it from beating at an irregular pace. On the other hand, ICD, is a much larger apparatus and it is used as a precaution to avoid possible death from cardiac arrest. This type of device is capable of shocking the heart when needed, and it can correct the hearts rhythm. Being that a pacemaker is built into this device, it has the potential to provide the same effects as a pacemaker.

A Chest X-ray showing the Implantation of an ICD
Diagram showing where an ICD is Implanted

Video Comparison of Pacemakers and Defibrillators