Cardiac Defibrillator: What You Need to Know

Introduction

A cardiac defibrillator is a life-saving device used to treat serious heart rhythm disorders, particularly ventricular fibrillation (VF) and ventricular tachycardia (VT). These conditions cause the heart to beat erratically, which can lead to sudden cardiac arrest.

Types of Cardiac Defibrillators

1. Automated External Defibrillator (AED):
   • Found in public places
   • Used by non-medical personnel
   • Provides voice instructions for use
2. Implantable Cardioverter Defibrillator (ICD):
   • Implanted in patients at high risk of sudden cardiac arrest
   • Continuously monitors heart rhythm
   • Delivers a shock when life-threatening arrhythmias are detected
3. Wearable Cardioverter Defibrillator (WCD):
   • Worn externally by patients at temporary high risk
   • Provides protection until a permanent ICD can be implanted

How It Works

A defibrillator analyzes the heart’s electrical activity. If an abnormal rhythm is detected, the device delivers a controlled electrical shock to restore a normal heart rhythm.

Who Needs a Defibrillator?

A cardiac defibrillator is recommended for patients with: - History of cardiac arrest or serious arrhythmias - Severe heart failure (ejection fraction ≤ 35%) - Genetic arrhythmia syndromes (such as Long QT syndrome) - Following a heart attack with high risk of arrhythmia

Risks and Complications

Although defibrillators are effective, complications can include: - Inappropriate shocks (delivered when not needed) - Infection at implant site - Battery replacement needs over time - Psychological effects (anxiety & depression in some patients)

Conclusion

Defibrillators have significantly reduced sudden cardiac death rates. Patients at high risk should discuss options with a cardiologist to determine the best treatment plan.

Source recommendations

1. American Heart Association Guidelines on Sudden Cardiac Arrest

1. https://www.heart.org/en/health-topics/cardiac-arrest
2. https://www.ahajournals.org/doi/10.1161/CIR.0000000000000549
3. https://www.heart.org/en/health-topics/heart-attack/about-heart-attacks/heart-attack-or-sudden-cardiac-arrest-how-are-they-different
4. https://cpr.heart.org/en/resources/cpr-facts-and-stats
5. https://www.heart.org/en/health-topics/heart-attack/warning-signs-of-a-heart-attack

2. European Society of Cardiology Guidelines on Management of Ventricular Arrhythmias

1. https://www.escardio.org/Guidelines/Clinical-Practice-Guidelines/Ventricular-Arrhythmias-and-the-Prevention-of-Sudden-Cardiac-Death
2. https://academic.oup.com/eurheartj/article/43/40/3997/6675633
3. https://www.ahajournals.org/doi/10.1161/CIR.0000000000000549
4. https://pubmed.ncbi.nlm.nih.gov/36017572/
5. https://www.acc.org/Latest-in-Cardiology/ten-points-to-remember/2022/09/02/14/23/2022-ESC-Guidelines-for-VAs-ESC-2022