Final answer:
Ventricular fibrillation requires immediate defibrillation as it involves disorganized electrical activity in the heart, preventing effective blood pumping and posing immediate risk to life.
Step-by-step explanation:
Of the cardiac rhythms listed, ventricular fibrillation requires prompt defibrillation.
Ventricular fibrillation is described as a disorder where there is no normal electrical activity in the heart, causing the ventricles to quiver ineffectively instead of pumping blood (see Figure 19.25d).
This lack of effective ventricular contraction can quickly lead to brain death if not treated immediately.
Defibrillation is a medical intervention using specialized equipment to deliver a controlled electrical charge to the heart, with the aim of restoring a normal sinus rhythm.
It is a critical emergency procedure often described as a "code blue" situation in hospital settings.