New York State Basic Emergency Medical Technician (EMT-B) Practice Exam

Which rhythms can be shocked by an AED?

1. Atrial fibrillation and sinus tachycardia

2. Asystole and bradycardia

3. Ventricular fibrillation and ventricular tachycardia

4. Normal sinus rhythm and atrial flutter

The correct answer is: Ventricular fibrillation and ventricular tachycardia

The ability of an Automated External Defibrillator (AED) to shock certain heart rhythms is critical for effective resuscitation. Ventricular fibrillation and ventricular tachycardia are the two rhythms that can be treated with a defibrillation shock. Ventricular fibrillation is a chaotic electrical activity in the heart that leads to ineffective pumping action, while ventricular tachycardia is an excessively fast rhythm originating from the ventricles that can also be life-threatening if it persists without conversion. Both conditions result in inadequate blood flow and can lead to cardiac arrest if not addressed promptly. The AED analyzes the heart's rhythm and will only deliver a shock if it detects one of these two life-threatening rhythms. This targeted shock can help restore a normal rhythm and increase the chance of survival. Other rhythms, such as asystole and bradycardia, do not respond to defibrillation; therefore, they are not candidates for AED shocks. Similarly, rhythms like sinus tachycardia or atrial flutter are not treated with defibrillation unless they progress to a more dangerous state. Thus, recognizing the specific rhythms that can be treated is crucial for effective emergency response training.