Advanced Patient Assessment Practice Exam

In the context of cardiopulmonary resuscitation (CPR), which rhythm is most likely to respond to defibrillation?

1. Asystole

2. Pulseless electrical activity

3. Ventricular fibrillation

4. Atrial flutter

The correct answer is: Ventricular fibrillation

Ventricular fibrillation is a chaotic and ineffective heart rhythm that prevents the heart from pumping blood effectively. This arrhythmia is characterized by disorganized electrical activity in the ventricles, leading to rapid and erratic contractions. Defibrillation is an electrical shock delivered to the heart to reset its electrical activity and restore a normal rhythm. In the case of ventricular fibrillation, defibrillation is a critical intervention, as it can successfully convert this life-threatening rhythm back to a viable one, such as a normal sinus rhythm. The other rhythms listed are less likely to respond to defibrillation. Asystole represents a complete absence of electrical activity in the heart, where there is no rhythm to correct. Pulseless electrical activity (PEA) occurs when there are electrical signals on the ECG but no effective mechanical heart action, and this also doesn’t typically respond to defibrillation. Atrial flutter, while abnormal, usually does not require defibrillation for treatment and instead may be managed pharmacologically or through other interventions. Hence, ventricular fibrillation is the rhythm most likely to respond to defibrillation in a cardiopulmonary resuscitation scenario.