Most, but we have no idea of exact numbers because most MCIs are asymptomatic. Over half of all people with permanent scarring of the heart tissue were never diagnosed and studies using enzymes released from damaged heart tissue suggest that something like 90% of all MCIs don’t cause any permanent damage and are completely undiagnosed.
And that’s one of the problems. If the MCI is undiagnosed it can lead to the formation of an ectopic pacemaker days later which results in sudden massive heart failure. And if it doesn’t lead to the formation of an ectopic pacemaker the heart disease can go completely unnoticed until severe heart tissue damage has resulted.
I can’t see why. Small MCIs are not harmful in and of themselves. They don’t damage significant amounts of heart tissue and they tend to be self-repairing. It’s only in those rare cases where they cause the death of large amounts of heart tissue or where they lead to the formation of an ectopic pacemaker that they are life threatening and need treatment.
In contrast heart failure requiring CPR is inherently deadly.
IOW for a MCI you’ll probably be alright unless something goes very wrong. In contrast when your heart fails and you are relying on CPR to stay alive you’ll probably be dead unless everything goes exactly right.
So I’d assume the survival rate for MCIs to be orders of magnitude better than the rate for CPR, and the stats pretty much bear that out.
Now that is very interesting. In fact the inverse of what I wrote. But it makes perfect sense - just counterintuitive to perhaps the more common ideas of heart failure.
So basically, if you have an MCI, you stand a reasonable chance, even with mediocre attention.
Other cases then.
Electrocution. I have always assumed that once the heart is restarted the subject will recover. (Assuming no serious tissue damage.)
But the other cases - like where I said neurotoxic envenomation was the cause - you really do need somone to get it right. Or at least just keep going.
One question on terminology. If heart failure is due to later damage or scarring that resulted from an MCI, what do you call the failure? Would the mortality statistics call it an MCI? I assume not.
Somewhere one would hope there might be some hard numbers. However I have learnt over the years that good stats in many such areas are harder to come by than one might hope.
You have much better than even odds with no attention whatsoever.
That’s pretty much true of any cause of heart failure: if there’s no tissue damage then once the rhythm is restored the patient is as good as new.
Fortunately most neurotoxins affect the somatic nervous system, so they don’t have any direct affect on the heart. They cause death by suppressing the activity of the muscles involved in ventilation. Any heart failure is due to the oxygen stress caused by not breathing. If you’re lucky enough to be with someone trained, they’ll begin EAR before you go into cardiac arrest so CPR isn’t normally required. And if you’re not with someone who knows EAR the chances of meeting someone who knows CPR between cardiac failure and brain death are pretty slim.
IANAD, but AFAIK it’s usually listed as something along the lines of “heart failure due to defibrilliation due to ectopic focus due to tissue damage due to MCI due to coronary artery occlusion due to sclerotic plaque movement due to exertion”.
AFAIK there is no universal attempt to categorise all those factors in any statistics.
Just a small issue that needs to be cleared up: a heart attack is NOT when your heart stops. A heart attack is when you have a blockage in one of the arteries that supply blood to your heart, and you get chest pain, sweatiness, and the rest of that stuff. The term for when your heart stops is CARDIAC ARREST, and can be caused by heart attacks, as well as a wide number of other things (lack of oxygen, drug overdoses, trauma, electrocution, heart failure, kidney failure, acidosis, hypothermia, etc.)
When Michael Jackson recently died, the news stations were saying he had a heart attack. That is absolutely false. Michael Jackson went into cardiac arrest and died, apparently due to a lack of oxygen to the heart (too much propofol - he went unconscoius and stopped breathing).
I need to clear up some terminology here. What do you mean by ‘heart failure’? If we’re on the same page, heart failure can certainly result after a heart attack, and often times it is the result of many small heart attacks which go undetected. This is called ischemic heart disease (ischemic refers to low bloodflow). However, the cause of heart failure is widespread, and can be caused by many other things such as disease in your heart valves, infections, genetic causes, and so forth. I’m not sure what the fellow means by an ectopic pacemaker leading to heart failure. In general, heart failure is a state where the heart is unable to keep pumping hard enough to meet the demands of the body’s blood and oxygen requirements. Often times, you can quantify heart failure by something called ejection fraction, which is the percent of blood sitting in the heart that gets pumped out with each heartbeat. Heart failure will lead to feelings of weakness, dizziness, shortness of breath, and also fluid backing up in places like the lungs, or in the legs.
On rereading what I wrote, I really meant “death” and cause thereof. If you were gathering statistics on causes of death, would we see a final symptom, or the causation? It has often been noted that almost all forms of death can be charaterised as “heart stops beating.” But clearly there is some room to maneuver here.
Guilty as charged on misuse of “heart failure.” Even worse, I do know what it means. Just not thinking straight.
IANAD. I’ve taken several CPR and First Aid classes, fire extinguisher training, and other emergency situational classes.
I think a big part of successful CPR (or any rescue action) depends on how practiced you are at the task, even if it’s mentally running through it repeatedly. Of course you’d rather have someone give you CPR who’s performed it (successfully) on other people. If you lack someone experienced in CPR on people, you’d prefer someone who has taken CPR once a year for 6 years rather than someone who has taken it once. And you’d prefer someone who has taken it once to someone who has just witnessed it on TV.
I’m bothered by TV CPR frequently, especially when they get it wrong in a medical drama.
TV CPR often shows people getting up and walking around after a few moments of CPR and a few rescue breaths.
You rarely see someone get tired from performing CPR - it’s a hugely tiresome activity to keep up for more than a few minutes.
TV CPR rarely shows people pumping fast enough. In my last CPR class, our instructor played the song “Staying Alive” and said the song is 100bpm, which is how fast you should pump someone’s heart.
On TV, I see people giving CPR to someone on a padded hospital gurney rather than dragging them onto the floor.
On TV, I’ve seen people give CPR while sitting on the person’s stomach, and rescue breaths while the person’s head is at the wrong angle.
On lifeguard shows, CPR brings about a person spitting up water, and then sitting up as if nothing had happened.
CPR is the cure on TV, not a technique to keep a body viable until someone arrives with advanced care.