better names for existing things...
Discussion
TwigtheWonderkid said:
That's good, but unfortunately, it's actually a hearty stoppy. When you have a heart attack, the heart doesn't initially stop, it goes into an irregular beat. The defib delivers a shock that momentarily stops the heart, allowing it to "reboot" and restart immediately on it's own, hopefully in the correct rhythm. If you've actually flatlined, the defib won't be any use at all. But on tv it looks more dramatic for the machine to flatline and the defib to shock you back to life, which is why they show it that way.
I never actually realised that, so thanks.In my job I've had to sit First Aid lessons every year (though don't now) and I never got told that, and I always wondered why the instructor mentioned their needed to be a heart beat before using one. I never questioned it as that would mean the lesson would last another couple of minutes whilst the instructor answered, which would mean the class would be 2 minutes late finishing work for the day.
Finishing work on time is more important than saving lives, obviously!!
Edited by The Gauge on Saturday 13th April 08:17
SpudLink said:
This thread actually reminds me of “The Meaning of Liff”.
Wow, you are as old as me it seems 
SpudLink said:
languagetimothy said:
Reminds of the radio live comedy show “I’m sorry I haven’t a clue” and the round named “oxbridge English dictionary” where words were given another meaning. The classic example being:
Countryside: the murder of Piers Morgan.
This thread actually reminds me of “The Meaning of Liff”. Countryside: the murder of Piers Morgan.
boxst said:
SpudLink said:
This thread actually reminds me of “The Meaning of Liff”.
Wow, you are as old as me it seems languagetimothy said:
Reminds of the radio live comedy show “I’m sorry I haven’t a clue” and the round named “oxbridge English dictionary” where words were given another meaning. The classic example being:
Countryside: the murder of Piers Morgan.
[pedant] Uxbridge English dictionary [/pedant]Countryside: the murder of Piers Morgan.
https://www.amazon.co.uk/Complete-Uxbridge-English...
boxst said:
SpudLink said:
This thread actually reminds me of “The Meaning of Liff”.
Wow, you are as old as me it seems DodgyGeezer said:
love listening to Jay and Dunc on The Rock Drive and heard the above on their podcast. A few to get you started...
This is the original twitter thread for credit, there's quite a few more...https://twitter.com/AdamCSharp/status/176728814289...
Mammasaid said:
languagetimothy said:
Reminds of the radio live comedy show “I’m sorry I haven’t a clue” and the round named “oxbridge English dictionary” where words were given another meaning. The classic example being:
Countryside: the murder of Piers Morgan.
[pedant] Uxbridge English dictionary [/pedant]Countryside: the murder of Piers Morgan.
https://www.amazon.co.uk/Complete-Uxbridge-English...
languagetimothy said:
Mammasaid said:
languagetimothy said:
Reminds of the radio live comedy show “I’m sorry I haven’t a clue” and the round named “oxbridge English dictionary” where words were given another meaning. The classic example being:
Countryside: the murder of Piers Morgan.
[pedant] Uxbridge English dictionary [/pedant]Countryside: the murder of Piers Morgan.
https://www.amazon.co.uk/Complete-Uxbridge-English...
The Gauge said:
TwigtheWonderkid said:
That's good, but unfortunately, it's actually a hearty stoppy. When you have a heart attack, the heart doesn't initially stop, it goes into an irregular beat. The defib delivers a shock that momentarily stops the heart, allowing it to "reboot" and restart immediately on it's own, hopefully in the correct rhythm. If you've actually flatlined, the defib won't be any use at all. But on tv it looks more dramatic for the machine to flatline and the defib to shock you back to life, which is why they show it that way.
I never actually realised that, so thanks.In my job I've had to sit First Aid lessons every year (though don't now) and I never got told that, and I always wondered why the instructor mentioned their needed to be a heart beat before using one. I never questioned it as that would mean the lesson would last another couple of minutes whilst the instructor answered, which would mean the class would be 2 minutes late finishing work for the day.
Finishing work on time is more important than saving lives, obviously!!
Edited by The Gauge on Saturday 13th April 08:17
Heart attack is cessation of blood flow to a section of the heart due to an occlusion of a coronary blood vessel. As a consequence of this, an area of cardiac muscle is stunned or dies, which is what causes the symptoms of a heart attack. Heart attack doesn't mean that the heart stops, since the affected area could be a tiny area of muscle with little consequence, or a huge area of muscle. A heart attack could cause a little pain, moderate pain or a lot of pain, it could cause shortness of breath, it could cause sudden death, or it could cause no symptoms whatsoever (called a silent MI). It is not treated with defibrillation unless a complication requiring it arises. It is treated with interventions or drugs aimed at restoring blood flow to the heart muscle at risk of death.
Cardiac arrest is cessation of blood flow/circulation in the body. That might be because the heart has stopped, or it might be because of another reason, e.g., circulation is obstructed in some manner, e.g. cardiac tamponade or a tension pneumothorax, or there's nothing left to circulate. More importantly, cardiac arrest is not a cause of death, it's the onset of death. You cannot have "1A Cardiac Arrest" as a cause of death on a 'medical certificate of cause of death' (the form a doctor fills in, which the Registrar of Births, Deaths and Marriages then uses to produce the death certificate) as it would be meaningless; everybody who dies has a cardiac arrest at the moment of their death.
If a cardiac arrest is going to be treated, the treatment depends on the underlying cause as well as the heart rhythm. If circulation has ceased because there's no circulating volume left following major trauma, you need to stop the loss of blood and restore volume. Pumping their chest and frying their chest with repeated shocks isn't going to do anything. Even somebody else is in VF, if they're hypothermic and their body temperature is too low, shocking will not achieve anything, so you need to warm them up first and keep going with chest compressions till they're warm ("you're not dead till you're warm and dead") as the heart's electrical activity requires a temperature of at least 33C to function reliably.
When it comes to defibrillation, all muscle activation, including my finger muscles as I type this, require an electrical stimulus. For heart muscle cells, this is very tightly regulated through a specialised network of cells because the muscle cells of each area of the heart must beat in coordination with the other parts in order to generate forward blood flow. Defibrillation only works when the heart is in ventricular fibrillation, also called VF, a rare rhythm called pulseless ventricular tachycardia (VT), and nothing else (I'm not including other therapeutic uses of defibrillation in non-cardiac arrest situations). Fibrillation is uncoordinated electrical activity in the heart where each muscle cell is beating totally independently of its neighbours and therefore no forward blood flow is being generated. Moderately problematic if it happens in the atria, total cessation of flow if it happens in the ventricles.
Defibrillation, as the name suggests, is an attempt at stopping the fibrillation and reinstituting coordinated electrical activity. It does not stop the heart because the heart has already stopped. What it does is use a DC current to give an external stimulus to every single heart muscle all at the same time in an attempt to restore coordinated activity. The short period of flat line after a shock, even when defibrillation works, isn't because the heart has been stopped, but because of the mechanism by which defibrillation and cardiac action potential work to generate the first post-shock activation. There's a refractory phase built into the cardiac action potential to allow heart muscle cells to recover between each beat, even when it's going at 150 bpm, and in essence, that's what you're seeing following a shock in the flatline phase.
Even this explanation is a very simplified version of what happens as I don't want to take too long.
TL:DR
'Defibrillator is a hearty stoppy': No, it isn't. Defibrillation doesn't stop the heart, just attempts to coordinate electrical activity.
Heart attack doesn't mean the heart has stopped.
Cardiac arrest doesn't mean the same thing as a heart attack, just means there's no circulation. It's the onset of death, nothing else.
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