A defibrillator is a medical device that delivers an electric shock to the heart to restore a normal heart rhythm. It is used in life-threatening conditions such as:
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Sudden Cardiac Arrest (SCA)
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Ventricular Fibrillation
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Ventricular Tachycardia without a pulse
🔹 Purpose
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To stop abnormal heart rhythms
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To allow the heart’s natural pacemaker to reset and regain a normal rhythm
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Often used as emergency treatment in both hospitals and public places
🔹 History
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1899: Swiss scientists Jean-Louis Prévost and Frédéric Batelli first showed electric shocks could affect heart rhythm in animals.
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1947: Dr. Claude Beck performed the first successful defibrillation on a human patient.
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1960s: Development of external defibrillators for use outside operating rooms.
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1980s–1990s: Invention and use of Automated External Defibrillators (AEDs) made the device accessible to the general public.
🔹 Types of Defibrillators
| Type | Description |
|---|---|
| Manual External Defibrillator | Used by trained professionals; requires ECG reading before shock is delivered. |
| Automated External Defibrillator (AED) | Used by laypersons in public areas; gives voice and visual instructions. Automatically detects if shock is needed. |
| Implantable Cardioverter Defibrillator (ICD) | Surgically implanted in patients at high risk; automatically detects and corrects dangerous rhythms. |
| Wearable Defibrillator | A vest worn by patients temporarily; monitors heart activity and delivers shock if needed. |
| Manual Internal Defibrillator | Used during open-heart surgery; shock is delivered directly to the heart via paddles. |
🔹 How It Works
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The device detects abnormal electrical activity in the heart.
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It delivers a controlled electric shock through electrodes.
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The shock stops the abnormal rhythm, allowing the heart’s natural rhythm to resume.
🔹 Where It's Used
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Hospitals & Clinics
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Emergency Medical Services (ambulances)
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Public spaces like airports, malls, schools (AEDs)
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Home or wearable use for patients with known heart risk
🔹 Key Facts
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Time is critical: Using a defibrillator within 3–5 minutes of collapse can increase survival chances by up to 70%.
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AEDs are safe and provide step-by-step instructions.
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Training improves confidence, but untrained bystanders can still use AEDs effectively.
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Most modern AEDs automatically analyze heart rhythm, ensuring a shock is only given when appropriate.
🔹 Signs a Defibrillator May Be Needed
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Person collapses suddenly
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No pulse, not breathing
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Unconscious and unresponsive
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CPR alone is not reviving the person
🔹 Fun Fact
AEDs are now commonly found in sports stadiums, schools, airplanes, hotels, and even office buildings due to global efforts to reduce cardiac arrest fatalities.