Which condition requires immediate defibrillation?

Ventricular fibrillation is a condition where the heart's electrical activity becomes disorganized, leading to ineffective quivering of the heart muscle instead of coordinated contractions. This results in the inability of the heart to pump blood, leading to a lack of perfusion to vital organs, which makes it immediately life-threatening.

Immediate defibrillation is crucial because it aims to restore a normal rhythm by delivering an electrical shock to the heart. This shock can help to 'reset' the heart's electrical system, potentially allowing it to resume a normal rhythm. The effectiveness of defibrillation in this scenario is vital for survival and minimizing damage, as every moment counts in arrhythmias like ventricular fibrillation.

Other conditions listed do not require immediate defibrillation. For example, asystole represents a flatline on the ECG and does not benefit from defibrillation; instead, it is managed with advanced cardiac life support protocols. Bradycardia indicates a slow heart rate, which may require medication or pacing rather than defibrillation. Pulseless electrical activity involves a heart rhythm that appears organized but does not generate a pulse and typically necessitates addressing underlying causes rather than immediate defibrillation.