How do you know you're not having an asymptomatic heart attack?

Factual Questions
1

And how bad is it, if you are?

IANAFMA - I am not asking for medical advice…Just looking to fight this area of ignorance within me.

Having read a couple of weeks ago about someone in the news who suffered one of these, I was wondering: What is it anyway? Does it hurt? If there are no symptoms, what makes if a heart attack?- a serious question, not meant to be facetious. Or does asymptomatic mean something like: lacking in some common symptoms. Unfortunately google was not that helpful. Any info appreciated.

2

I suppose the only way to be absolutely sure is if you start to show symptoms. Then you know it isn’t asympotmatic!

Tris

3

Oh god. When I worked the ER and the urgent care clinics, I always hated it when the TV would feature shows on “how to have a heart attack”. Folks would trek in with all sorts of bizarre symptoms, fearing they were infarcting their precious myocardium. Chest colds, constipation, even a mildly sprained wrist, all were interpreted in the context of “this could be the only symptom I get for my heart attack!” One guy was convinced his inflamed hemorrhoids were a result of heart failure from an MI.

And when the term “silent heart attack” got used, it was even worse. Folks would come in and complain of not having any chest pain and be worried that they were having MIs.

4

:eek: OH NO! I’m not having chest pains right now! What should I do?

5

The trouble is that ‘heart attack’ is one of those terms that can mean several possible things, from severe angina to an infarct to cardiac arrest.

Any time I’ve seen "asymptomatic heart attack” they have been referring to an infarct (basically a blocked blood vessel) and the associated tissue death. The heart is just a muscle, and like the other muscles it relies on arteries and arterioles to provide it with the blood to needs to function. It might seem odd that the organ that pumps blood needs a blood supply, but it’s a big organ that needs a lot of oxygen and energy to contract and blood doesn’t diffuse very well.

Occasionally one of the blood vessels that supply the heart muscle gets blocked. That’s normally form a fatty plaque but it can also be caused by a clot or other odd things. That guy that Cheney shot had one of his heart vessels blocked when a shotgun pellet got washed in there and jammed it up. When that happens the area of muscle that should be supplied by that vessel suffocates and dies. If it’s a major artery that is blocked a large mass of muscle will die. That can be enough to prevent the heart from working at all, and the person drops down dead within minutes. It is certainly enough to make you short of breath and/or feel serious pain as the heart muscle starts to ‘cramp’.

However if only a small artery is blocked only small area of muscle dies. That won’t be enough to stop the heart from working immediately. In fact you won’t even notice it happened in most cases. The heart tissue just quietly dies and the rest of the heart takes up the slack. That is a silent heart attack. You’ve got a blocked artery. You’ve got dead and dying heart tissue but you don’t feel anything.

But just because you don’t feel it doesn’t mean a silent heart attack is harmless. The tissue immediately around the blockage dies, but the tissue on the fringes that is supplied by two vessels just gets nutrient and oxygen starved and becomes ‘sick’. That is what causes the problems because the sick tissue basically doesn’t have then energy required to beat in time with the rest of the heart. You get a small area beating out synch with the rest of the heart. That causes problems of arrythmia and decreased heart function, and in the worst cases can lead to fibrillation, where the heart can’t make up its mind how to beat and simply starts twitching. That’s fatal within minutes.

So what makes it a heart attack? Well it’s a heart attack because because one of the blood vessels supplying the heart is blocked and non functional, and you have heart muscle dying as a result.

Does it hurt? Not at the time, hence the term asymptomatic. However within a few days it can cause irregular heart beat and that can often be felt, if only because of tiredness and shortness of breath. And of course if it leads to fibrillation you will certainly feel that.

How bad is it? It depends. I’ve seen evidence that suggested that most men over 20 and most women over 35 probably have one such event every year. So in that sense it’s not bad. However it can also lead to death within days. So in another sense its serious. Medical staff certainly treat such an event as serious.

More seriously blood tests will pick up chemicals released by dying heart tissue. And if it’s large enough an ECG will show the effect of the tissue damage on heart function.

Well? It makes sense. A silent heart attack is characterised by a total lack of symptoms, and I have a lack of symptoms. Ergo I am having a silent heart attack. The trouble is you doctors just don’t care.

6

Blake: can that kind of damage heal?

7

Not AFAIK. Once it’s dead it’s dead and you end up with an permanenet area of ‘scar’ tissue. The rest of the heart muscle will grow to take over any function caused by the tissue loss so you may not suffer any additonal symptoms in the long term, but the damage itself can’t heal.

The tissue that was just starved and ‘misfiring’ and not actually dead will gradually recover as other blood vessells grow into the gap and start feeding it again.

8

Thanks for the information and supportive humor so far. It sounds so far as if this is not a cut and dried kkind of thing. Thanks especially to Qadgop the Mercotan. The physicians I know are always working so many hours and I’m always impressed and appreciative that you take the time to write about these issues here.

9

Can I ride on these coattails and ask - is the “women have different heart attack symptoms than men - here are some of them” the same thing that Qadgop was talking about with “you may be having a silent heart attack right now!” - in other words, is that scare TV, or is it something I should really pay attention to? Our local news station did a bit on that awhile ago and I was really surprised.

10

Depending on the age of the population studied, about 20 to 45 percent of people over the age of 45 have had an asymptomatic but significant heart attack (myocardial infarction = MI).

Synonyms for the phenomenon are “silent MI”, “unrecognized MI”, and “asymptomatic MI”.

These silent, but significant, MI’s are diagnosed on the basis of an electrocardiogram showing heart muscle damage that extends completely through the wall of the heart (unlike the minor, probably trivial events that Blake was referring to above). These are called Q-wave MI’s or transmural MI’s.

Why are they silent? One common explanation (that can’t work in all cases, mind you) is that people with diabetes are more likely to have silent MI’s. This is because diabetes is often associated with nerve damage (which in this discussion would provide an explanation for a painless MI, i.e. nerve damage). Similar nerve damage can occur in other conditions and sometimes for now apparent reason at all (idiopathic)

It is also important to note that although a heart attack can be silent, painless, and “asymptomatic”, there are many symptoms of MI’s other than pain. For example, sudden unexplained sweating can be a prominent symptom. Likewise, sudden and otherwise unexplained nausea/vomiting, shortness of breath, or lightheadedness can all be “equivalent” symptoms to the pain of an MI.

Silent MI’s in age 45 to 65.

Silent MI’s in age 55 plus (a 2006 publication!).

FREE nice review article on the subject (pdf).

11

I was under the impresion that no MI was considered trivial because the possibility always exists that it will become an ectopic pacemaker and thus presents a real risk for arrythmia of fibrillation. The same reason that no physical damage to the heart is considered trivial even if it is just a scratch and doesn’t cause any fluid leakage into the pericardium.
I’m not a doctor but my impression was that any MI warrented at least 3 days close observation whether it extended all the way through the heart wall or not.

12

It should be noted that the fibrillation you’re talking about here is ventricular fibrillation, not atrial fibrillation, which is a different sort of beast, and reasonably common. There’s been a thread or two recently on the subject.

13

To insert some anecdotal evidence, my gradfather had an extended series of silent heart attacks over 2 months or so. He experienced them as short periods of breathlessness and it was only with 20/20 hindsight by his doctors that they were diagnosed. He wound up having a septuple bypass and died 3 years later.

14

Are you having impending feelings of doom? Might be a heart attack, might be a panic attack, might just be paranoid.

We can just point one of our orbital cardiac monitoring satellites at you…hmmm…nope, just paranoid.

:smiley:

15

I’m reminded of the old SNL commercial for the Early Home Headache Test. “I feel fine. But what if I have a headache and don’t know it?”