Ventricular Fibrillation
Definition
Chaotic, ineffective cardiac electrical activity induced by alternating current (50-60 Hz) at 100-300 mA through the thorax. The primary mechanism of death in low-voltage domestic electrocution. Not self-terminating; requires defibrillation.
- Trigger
- AC current (50-60 Hz), 100-300 mA through the thorax
- Context
- Primary mechanism of death in low-voltage domestic electrocution
- Nature
- Chaotic, ineffective cardiac electrical activity
- Reversibility
- Not self-terminating; requires defibrillation
Common questions
Why is low-voltage AC particularly dangerous for triggering ventricular fibrillation compared with higher currents?+
The 50-60 Hz mains frequency sits in the range where the human heart is most susceptible to fibrillation, well below frequencies where tissue can no longer follow each cycle and well above frequencies that cause smooth tetanic contraction without disrupting cardiac rhythm. Direct current and very high-frequency AC are markedly less likely to induce fibrillation at comparable current levels.
How does the absence of self-termination affect a death investigation involving electrocution?+
Because fibrillation does not spontaneously resolve, a victim who is not promptly defibrillated will die from the arrhythmia itself even if the electrical contact was brief, which means investigators should not assume a short contact duration rules out electrocution as the cause of death.
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