Defibrillators: The 'Heart Shock Machine'

Introduction

A 'heart shock machine' usually refers to a defibrillator, a medical device used to restore normal heart rhythm in life-threatening cardiac emergencies. Defibrillators work by delivering an electric shock to the heart to correct serious arrhythmias, most commonly ventricular fibrillation (VF) and ventricular tachycardia (VT).

Types of Defibrillators

There are several types of defibrillators, each serving a different purpose:

1. Automated External Defibrillator (AED):

   • Found in public places like airports, malls, and gyms.
   • Designed for use by untrained individuals.
   • Provides voice and visual prompts to guide the user.

2. Manual Defibrillator:

   • Used in hospitals by trained healthcare professionals.
   • Requires ECG reading interpretation before delivering a shock.

3. Implantable Cardioverter Defibrillator (ICD):

   • Surgically implanted in patients at high risk of sudden cardiac arrest.
   • Continuously monitors heart rhythm and automatically delivers shocks if needed.

4. Wearable Cardioverter Defibrillator (WCD):

   • Used for short-term protection in high-risk patients waiting for ICD implantation.

When Is a Defibrillator Needed?

Defibrillators are used in cases of sudden cardiac arrest (SCA), most commonly caused by VF or VT. During SCA, the heart stops pumping effectively, leading to loss of consciousness and, without intervention, death within minutes.

Symptoms of Cardiac Arrest:

• Sudden collapse
• No pulse
• No breathing
• Loss of consciousness

Importance of Early Defibrillation

The chances of survival decrease by 7-10% per minute of delay in receiving defibrillation. Early use of AEDs in public places has significantly improved survival rates in witnessed cardiac arrests.

Conclusion

Defibrillators save lives by restoring normal heart rhythm in critical situations. Understanding how they work and their timely use is crucial in emergencies. If you see someone collapse and suspect a cardiac arrest, call emergency services immediately and use an AED if available.

Source recommendations

1. American Heart Association Guidelines on CPR and Emergency Cardiovascular Care

1. https://cpr.heart.org/en/resuscitation-science/cpr-and-ecc-guidelines
2. https://professional.heart.org/en/science-news/2020-aha-guidelines-for-cpr-and-ecc
3. https://international.heart.org/en/courses/2020-handbook-of-emergency-cardiovascular-care-for-healthcare-providers
4. https://www.ahajournals.org/doi/10.1161/CIR.0000000000001194
5. https://pubmed.ncbi.nlm.nih.gov/33081530/

2. European Resuscitation Council Guidelines for Resuscitation

1. https://cprguidelines.eu/guidelines-2021
2. https://www.sciencedirect.com/science/article/pii/S0300957221000551
3. https://cprguidelines.eu/
4. https://www.erc.edu/
5. https://pubmed.ncbi.nlm.nih.gov/33773825/