Asked by: Finn Crozier, Oswestry
At low currents, AC electricity can disrupt the nerve signals from the natural pacemaker in your heart and cause fibrillation. This is a rapid fluttering vibration, too weak to pump blood. If the rhythm isn’t restarted with a defibrillator, it’s usually fatal. At higher currents, DC electricity can have the same effect by causing the entire heart muscle to contract at once, which also breaks the pacemaker rhythm.
The highest currents (more than one amp) cause burns through resistive heating as the current passes through the body. If this path crosses the heart or brain, then the burn may be fatal.