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Medical When the heart stops beating

  1. May 4, 2013 #1
    From the moment a persons heart stops beating, stop functioning, how long does it take until the brain starts to shut down and how long until it's completely non functional and you're dead beyond the point of revival?

    It's probably hard to conduct such an experiement but have there ever been any tests done that compares a persons brain activity who is sleeping to that of someone who's heart has just stopped beating and if they're not revived they'll die?

    One last question for anyone who's a doctor or surgeon, when you've revived someone, what do they tell you later afterwards, once they've recovered. Is there anything that's patients tend to recall happening?

    I assume it would just be like being knockout?
  2. jcsd
  3. May 4, 2013 #2
    Most of your queries are easily found through googling...


    Neurons start to die after about 5-6 min. after oxygen denial, which is what would happen if your heart stopped and the blood could no longer carry O2 to your brain.

    I'm not a doctor, but I've heard that some have said something along the lines of "What the %#@& happened!?" Some tend to recall a bright light at the end of a tunnel...However, that conversation is off limits at PF so you're gonna have to google that yourself off-site.

    As far as your second question...

    I don't think so. I'm sure the ethics committee would think twice before authorizing a study like that. However, if they do, I'd be happy to participate with you if I'm the one doing the sleeping:smile:

    Since that probably won't happen, I can tell you that the sleeping brain goes through very specific sleep cycles that are regulated through brainstem biorhythms. Someone's who's just had a heart attack has a brain that is in a trauma state, and the brain rhythms would look nothing like that of a sleep state. I'm pretty sure you're not gonna find that answer through googling it, so there you have it.
  4. May 6, 2013 #3


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    Once your heart stops (or becomes ineffective at pumping blood, as in ventricular fibrillation), you will pass out within a couple seconds. In CPR classes, one statistic that we use is that for every minute that passes before you start CPR compressions, there is about a 10% increase in mortality rate.
  5. May 7, 2013 #4


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    Nothing so far in my experience, but I've only been on the chest compression train about 20 times for a code.
  6. May 27, 2013 #5
    What blows my mind is the difference between in vivo and in vitro low-oxygen responses. I mean, if I plate a dish of neuron and exposed them to no-oxygen no-glucose (oxygen glucose deprivation, OGD) conditions, it can take a long, long time before they start to die. I mean, we often deprive them of oxygen for hours just to get a 'stress' signal, let alone a 'death' signal.
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