FYI: Defibrillators don't start the heart, they stop it.
The heart doesn't stop in many heart attacks. Instead it just beats erratically and in a way that doesn't pump blood well. Shocking the heart to stop it (what a defib does) causes the nerve cells to "reboot" and start beating regularly again.
Shocking a victim who's heart has stopped is useless and automatic defibrillators won't go off until they've detected the arrhythmia.
When I was a teenager my computer survived years of percussive maintenance. All I'm saying is, have doctors tried beating the shit out of their patients?
Yes, thank you, I'm glad you mentioned it here, it doesn't happen often enough. I mean, it's even in the name, right? Defibrillator gets rid of fibrillation - the erratic beating!