What is the key difference between cardioversion and defibrillation?

What is the key difference between cardioversion and defibrillation?

• A. Cardioversion is synchronized to the R-wave; defibrillation is not synced
• B. Cardioversion is external; defibrillation is internal
• C. Cardioversion uses medications; defibrillation uses electrical shocks
• D. Cardioversion is for atrial fibrillation; defibrillation is for VT

Answer: (A)

The core idea is the timing of the shock relative to the heart’s rhythm. Cardioversion delivers a synchronized electrical shock, timed to the ECG—typically on the R-wave—to terminate organized tachyarrhythmias like atrial fibrillation or atrial flutter with a pulse, while minimizing the risk of triggering dangerous rhythms. Defibrillation, on the other hand, delivers an unsynchronized shock without regard to the ECG, used in life-threatening pulseless rhythms such as ventricular fibrillation or pulseless ventricular tachycardia to rapidly reset the heart. So the key difference is synchronization: cardioversion is synchronized to the heart’s cycle, defibrillation is not.

The core idea is the timing of the shock relative to the heart’s rhythm. Cardioversion delivers a synchronized electrical shock, timed to the ECG—typically on the R-wave—to terminate organized tachyarrhythmias like atrial fibrillation or atrial flutter with a pulse, while minimizing the risk of triggering dangerous rhythms. Defibrillation, on the other hand, delivers an unsynchronized shock without regard to the ECG, used in life-threatening pulseless rhythms such as ventricular fibrillation or pulseless ventricular tachycardia to rapidly reset the heart.

So the key difference is synchronization: cardioversion is synchronized to the heart’s cycle, defibrillation is not.