Safety and work practicesQuestion 589 of 1506

Why does a defibrillator use a jolt of DC on a person whose heart is fibrillating?

  1. The DC jolt makes the heart flutter faster to move more blood around.
  2. The DC jolt halts the fibrillation so a normal beat can return.
  3. The DC jolt heats the chest to warm the heart muscle quickly.
  4. The DC jolt puts the diaphragm muscle into a state of tetanus.
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Correct answer: The DC jolt halts the fibrillation so a normal beat can return.

Stopping the disordered beating gives the heart a chance to start a normal pattern again.

Source: Lessons in Electric Circuits I: DC (Kuphaldt), 3.2: Physiological Effects of Electricity

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Questions last reviewed: 18 October 2026