The paddles for starting a heart in an open chest cavity are quite different from the big pads used to defib someone. Applied directly to opposite sides of the heart. And not just any heart, one that was deliberately stopped with the cause of the stoppage no longer (hopefully) in effect.
Because the cause of the flatlining is not just the heart malfunctioning. The heart is not getting a signal to beat from the brainstem. . . Or not enough oxygen is in the blood to sustain it. . . Or too much toxic waste has built up in the blood due to failure of some other organ . . Or a blood vessel is so blocked that the heart tissue is necrotic . . . such that the cells can’t function normally even if you could get a pacemaker in there on time.
Something else is happening, and so just getting the electrical signals to the heart back in order won’t fix the problem.
The heart doesn’t get its signal from the brainstem. If it did, heart transplants wouldn’t work since the nerves are severed during the process.
The heart gets its signal from the SA node at the top of the heart. This is the heart’s “pacemaker”, if you will. The atria (upper chambers) of the heart contract. A short time later, the electrical signals from the SA node reach the AV node further down in the heart, and the AV node fires off, causing the ventricles (lower chambers) to contract, completing the pumping cycle. The SA node keeps sending out pulses at the appropriate time, triggering each cycle.
The SA node controls everything, not the brain stem. The brain can send signals to the heart through nerves which can make the SA node speed up or slow down, and various hormones and chemicals (like adrenaline released from the adrenal glands) can also affect the SA node’s pace.
People who have had heart transplants have to be careful because the nerve connections to the heart have been severed, so that regulation method for the heartbeat no longer works. They might pass out if they exert themselves too much too quickly, since without those nerve connections the heart is much slower to respond to things like exertion and stress.
Ignorance fought. But it also supports my overall point.
Well, they’re smaller and use less power if that’s what you mean.
I’m not sure that’s true. From an old post by Cheif Pedant:
http://boards.straightdope.com/sdmb/showpost.php?p=13548555&postcount=37
It could be that all the above cases resulted in survival because what was reading on the monitor as asystole was incorrect, but I’m just guessing.
Maybe just a TV/movie thing but Sometimes (usually doing a transplant) start the blood flowing back and the heart just sitting there, then the surgeon "thumps " the heart with his finger and it starts beating. Real or not?
https://en.wikipedia.org/wiki/Precordial_thump
Supports the suggestion that surgeions defib after heart transplant or surgery. (I know lots of odd bits of medicine, but not about surgery )
I was on a bus once that stopped and off-loaded a teenager. One of my acquaintances had been sitting next to the guy, and applied a precordial thump when he went into fibrillation. I guess it worked, because the guy recovered consciousness and was med-evac’d.
One of my brothers (mountain guide) did it once successfully on one of his clients. The wikipedia article mentions however that it was apparently taught in the past in CPR training, and discarded later because it resulted more often in further damages than in restarting the heart (although I’ve always been told that when someone is fibrillating, you shouldn’t be too bothered about the damages you could cause, since you can hardly make the situation any worse).