When a heart is functioning normally, all of the heart's muscle fibers contract at roughly the same moment in time, producing a heartbeat (or pulse). It's important that the muscle fibers contract in a coordinated fashion, or else the heart wouldn't be able to squeeze the blood out of the ventricles and into the arteries. The heart signals the muscle fibers to contract at the same time via an electrical impulse through a bundle of nerve fibers.
When a heart attack occurs, the muscle fibers are all contracting at different times and out of coordination. Even though the nerve bundle is sending the signal, the muscle fibers are ignoring it. This lack of coordination fails to produce a heartbeat, blood pressure drops substantially, and the victim of the heart attack will rapidly lose consciousness (from immediately to within 45 seconds). If corrective action isn't taken within a few minutes, the victim will suffer brain damage and eventually death. Brain damage begins in as little as 4 minutes, and brain death occurs after about 8 to 12 minutes.
A defibrillator is used to send a single electric shock through the entire heart muscle. This "resets" the muscle fibers into coordination again. It forces all of the muscle fibers to contract simultaneously, and hopefully all of the muscle fibers will sense the signal from the nerve bundle, and resume normal coordinated contraction once again. This shock is called "defibrillation" because the muscle fibers are said to be "fibrillating", or quivering, when a heart attack is in progress.
The sooner the shock is applied, the more likely the heart will reset to a normal beat. The longer the heart fibrillates, the less chance defibrillation will work.
It's important to note that fibrillation doesn't occur in all heart attacks; sometimes the heart's rhythm may be something else during a heart attack and a defibrillator will not shock the heart. For example, if a heart attack victim is conscious, it is unlikely their heart is in need of defibrillation. And, fibrillation is not in and of itself a disease. Rather, there is almost always a precipitating factor that caused the heart to begin fibrillating, such as a blocked coronary artery (most common), congestive heart failure, toxic amounts of certain drugs, lack of oxygen (hypoxia), or other causes. Rarely does a heart spontaneously begin fibrillation for no reason. Still though, a condition does exist for this and for people with this condition, they may have a defibrillator implanted within their chest.
Lastly, it is important to note that defibrillation does not "jump start" the heart. While this seems like a natural analogy (a defibrillator attached to a patient does somewhat look like jumper cables connected to a car), defbrillation is more akin to restarting a computer. Or, whipping a bunch of kids in line that have become unruly by announcing they won't get to go to Chuck E Cheese if they don't immediately start behaving.
There is not an agency that collects this information. There is a potential in the USA to save several hundred thousand lives a year using CPR.
This statistic is not known because there is not one agency that gathers this data.
3,613,435 and counting
by your blood
55,000
1
millions of lives are saved by animal testing
lots and lots of lives have been saved by airbags. its indeed very cool.
Yes, this futuristic invention they call a "four wheeler" has saved many lives.
he saved many lives by yelling the regulators are coming although he was captured he still saved many lives
he saved many lives by yelling the regulators are coming although he was captured he still saved many lives
many soo yeah many were saved like BILLIONS
3,613,435 and counting
not enough
lots
Yes it saved many lives
Quite a few ;)