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  #1  
Old 09-07-2004, 09:03 PM
observer11 observer11 is offline
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How can you know you have heart blockages before you keel over?

Bill Clinton's clogged arteries have gotten a lot of attention this week. What is most surprising is that for at least 12 years, as President and former President, Clinton has probably been as closely monitored as anyone outside an ICU, he has had immediate access to the finest medical care in the world, and yet his problem wasn't discovered until he was apparently within days of a massive heart attack. What chance do the rest of us have? What medical tests are commonly used to assess arterial blockages, how unpleasant/complex/dangerous are those tests, how much are they likely to cost, and does medical insurance typically cover them as part of preventive care (as opposed to testing a patient who comes in clutching his chest and unable to breath)? Apart from diet and exercise, how can I avoid a quadruple bypass?
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  #2  
Old 09-07-2004, 09:22 PM
MLS MLS is offline
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IANAD.
Sometimes, you don't.
If you're lucky, you get warning signs, some of which may be vague and easily confused with other less serious problems. Much like Mr. Clinton's.

One diagnostic test is an angiogram, in which material that will show up on an xray is injected into the blood vessels that are headed directly for the heart. Then doctors can see if there are any serious blockages. However, according to one doctor I heard on the radio today, it's possible for a not-too-serious arterial plaque accumulation to "rupture" and become dangerous within a relatively short time. Like a few months.

I've never had an angiogram, but my father and my husband did. The test is, I'm told, not especially uncomfortable, but you have to lie very still for several hours afterward. There's not AFAIK an especially high rate of complications, but like most medical procedures, there's always some degree of risk. In my husband's case, for example, the angiogram showed a serious blockage in the main coronary artery, indicating a need for a bypass. The cardiologist said the test itself could have loosened up the blockage, and thus increased the risk. (The bypass was done within a few hours and he was home in 4 days. )

A less serious test is a stress test, in which the patient runs on a treadmill while monitoring is performed. Basically, if you can exercise strenuously without pain, you're deemed reasonably likely to be o.k. (A vast simplification, of course.)

The moral of the lesson is that the best possible health care available anywhere in the world today (whereever that is) can't guarantee you diddlysquat. At best it can give you an idea of the odds.
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  #3  
Old 09-07-2004, 09:28 PM
kniz kniz is offline
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It is called a "stress test". They take X-rays of your heart while you are rested then they put you on a jogging machine and get your heart rate up to a determined level, then more X-rays. If that comes out bad then you go in for the test where they go in around your crotch and look inside your arteries leading to the heart. If that doesn't go well, you end up on the table where Bill was.

In my case I kept having these bad feelings and finally went to the hospital. That night I had a heart attack, but they were there and gave me the latest medicine, which prevented heart damage. A week later they gave me the roto-router procedure which seems to have worked.
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Old 09-07-2004, 09:29 PM
MLS MLS is offline
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To take a shot at some of your other questions, I think most insurance companies will cover such tests within their rules. Of course, some restrict where you can have them done, "within network," etc. YMMV.

I think you already know the most sensible precautionary measures: a good diet, exercise, not smoking. Also, depending on your age, your doctor may take a blood sample for a test of your cholesterol and triglyceride levels, both of which can give a hint as to the state of your risk. If you are found to have high levels of the wrong stuff, and if it doesn't get reduced by diet and exercise, there are meds that can address both. These require regular evaluation and re-testing to be sure the meds are being effective and not causing undue side effects.
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  #5  
Old 09-07-2004, 09:54 PM
KarlGauss KarlGauss is online now
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Quote:
Originally Posted by kniz
It is called a "stress test". They take X-rays of your heart while you are rested then they put you on a jogging machine and get your heart rate up to a determined level, then more X-rays. If that comes out bad then you go in for the test where they go in around your crotch and look inside your arteries leading to the heart. If that doesn't go well, you end up on the table where Bill was.

In my case I kept having these bad feelings and finally went to the hospital. That night I had a heart attack, but they were there and gave me the latest medicine, which prevented heart damage. A week later they gave me the roto-router procedure which seems to have worked.
I would bet (and give you great odds) that Bill Clinton had regular stress tests. Presumably they gave false negative results.

No test is perfect. False negatives and false positive tests will always occur, with the former causing real disease to be missed and the latter causing disease appear to be present when, in fact, it is not.

In addition, and as mentioned, atherosclerosis can sometimes undergo accelerated progression and/or acute change in the nature of the blockage. Given the diffuse nature of Clinton's blockages, I doubt things happened suddenly, though.

The most definitive test is the angiogram. It won't miss serious blockages and conversely can prove that there are no or minimal blockages present (at least at the time of the test). Still, angiograms carry significant risk (stroke, heart attack, death, kidney failure, loss of leg, ...). They, of course, also deliver a fair dose of radiation. Bottom line is that they're not usually done unless the suspicion of serious blockages is high or there is no other way to establish the diagnosis.

One emerging technique, not dependent on angiograms, involves measuring the amount of calcium in the coronary arteries (usually using a type of CT scan). At present, the precise utility of such tests is unclear. For a not terribly accessible, sleep-inducing review look here.

Qad is an expert on this type of thing and I hope he'll weigh in.
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  #6  
Old 09-07-2004, 11:20 PM
Demo Demo is offline
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Quote:
Originally Posted by kniz
It is called a "stress test". They take X-rays of your heart while you are rested then they put you on a jogging machine and get your heart rate up to a determined level, then more X-rays. If that comes out bad then you go in for the test where they go in around your crotch and look inside your arteries leading to the heart. If that doesn't go well, you end up on the table where Bill was.
Just some elaboration on this from a registered nuclear medicine technologist.

In the test described above, we actually inject the patient with a radioactive tracer. The radioactive part is Technetium 99m and the tracer part is a potassium analog. Since the heart takes up potassium from the blood stream, this is a good way to determine which parts of the heart are recieving blood. As mentioned above, the patient is injected with the tracer in a resting state and then imaged (Nitpick: Not with x-rays, as the radioactive material emits gamma rays as it decays. The "gamma camera" detectors are passive and basically just record a pixel whenever they are hit with a gamma ray.) This first scan lets us know if there is any previous damage to the heart. An area of the heart that has been harmed by a heart attack i.e. infarcted tissue, will not take up the tracer. The patient is then stressed on a treadmill (usually pushing the patient on a standard treadmill protocol which increases in speed and elevation every three minutes until (at least) the patient's target heart rate is achieved (85% x 220-age). At the peak of stress the patient is injected with a higher dose of the tracer and then exercised for a minute or two more. Finally a second set of pictures are taken. These images are compared with the original images to see if there are any new defects. If there are, it is assumed that it is due to blockage of a coronary artery. For patients who can't walk on a treadmill we can still "stress" them using a pharmacologic agent like Adnosine or Persantine, among others. These basically just dilate the vessels, increasing blood flow except for in the arteries with plaque, which in turn shows us the same thing we'd see if the patient were exercising. Also remember that with this test we are imaging the heart muscle, as opposed to the actual arteries. So it is an indirect method of determining blockages. We still have very high specificity and sensitivity, but it's something to keep in mind. Also, in any newer facility, they will have the ability to "gate" the study, which means they can take moving pictures of your heart, allowing us to view your heart wall motion, which can be helpful in diagnosing other disorders of the heart.

In our office I think we charge somewhere around $2600 for the test. If you know anything about medical billing, we only actually collect this much on about 50% of the cases. It's almost always covered by insurance, but you can check with your hospital/cardiology office before having it to make sure it will be covered. If you have any risk factors(abnormal EKG, family history, chest pain/tightness, shortness of breath, high blood pressure, high cholesterol, diabetes, etc) you're generally covered.

As for your other questions, this test is very safe. I've never had a patient die or go into arrest on me while doing it over the last five years(knocks on wood). Something to check is to see if you will be monitored by a cardiologist during the test, as not all sites do this. The worst part about the test is the length. In my office it takes about two and a half hours. Some people have mild reactions to the pharmacologic stress agents, but they are generally quite mild and don't last too long. You should feel fine by the time you leave the office/hospital.

The "gold standard" in coronary artery diagnosis is the angiogram. In this test a line is placed in a large artery in the groin, then iodine is inected while rapid sequential x-rays are taken, showing the path of the iodine as it passes through the heart.

Also mentioned about is the heartscan, also known as EBT (electron beam tomography) which is basically a high speed CAT scan. It shows elevated calcium levels in the heart vessels. Personally, I don't place a lot of trust in this test as an end diagnostic tool, but if it brings people at risk into my office, then I figure it can't be bad. I posted a while ago about this, I'll see if I can find it.

Finally, the up and coming test that might prove to put the rest of us out of business is cardiac MRI, which has amazing resolution, but is not too popular yet. Because there are few centers doing it (and few physicians with experience reading the scan) this won't be a feasible alternative for a while.

Hope that helps.
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  #7  
Old 09-07-2004, 11:24 PM
Demo Demo is offline
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Here's the previous thread about EBT. I hope I haven't contradicted myself.
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  #8  
Old 09-08-2004, 06:04 PM
bughunter bughunter is offline
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I had a cardiac stress test performed two years ago at a well-respected local Hospital. They used an EKG and Doppler Ultrasound.

It took nearly a year for the two patches of chest hair they shaved off to grow back.
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  #9  
Old 09-08-2004, 06:34 PM
rocking chair rocking chair is offline
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sometimes you don't have any warnings. remember sergei grinkov? about the only thing that would have shown his blockage would be an angiogram. but who would think to do that test on an ice skater in his 20's?

david letterman asked for the test because of his family history and good thing he did.

it seems the best way to find out if you have a blockage is to check your family history, listen to your body, and keep pushing if you know something seems wrong and the tests come back okay.

my mum had a quad bypass, the only test that showed the blockage was the angiogram. she aced the stress tests, she walked 7 miles a day, had been on a low fat diet for years. the only things she had pointing to it was a chol. level over 200 and shortness of breath. i kept telling her to push for tests, she should not be winded after walking up a flight of stairs if she can walk 7 miles a day. after 3 months of tests they finally did the angio.
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  #10  
Old 09-08-2004, 08:10 PM
Una Persson Una Persson is offline
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Perhaps I've missed something, but if the angiogram only involves injecting iodine into the blood whilst taking X-Rays, why is there such a risk?

Also, I wonder why some doctors seem to think that the heart scan is worthwhile? One of mine is pushing me towards it, even though my enzymes, cholesterol, triglycerides, and BP have always been extremely good.

Question 3 is, when I had a heart and aortic ultrasound recently, the technician said she was "looking for plaque buildup" in my aorta, and didn't find any sign of it. But it seems to me that as rough a test as that really wouldn't show very much at all unless it was near closed, is that true?
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Old 09-08-2004, 08:24 PM
Polycarp Polycarp is offline
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Quote:
Originally Posted by Una Persson
Perhaps I've missed something, but if the angiogram only involves injecting iodine into the blood whilst taking X-Rays, why is there such a risk?

Also, I wonder why some doctors seem to think that the heart scan is worthwhile? One of mine is pushing me towards it, even though my enzymes, cholesterol, triglycerides, and BP have always been extremely good.

Question 3 is, when I had a heart and aortic ultrasound recently, the technician said she was "looking for plaque buildup" in my aorta, and didn't find any sign of it. But it seems to me that as rough a test as that really wouldn't show very much at all unless it was near closed, is that true?
There's a non-invasive test that does what you describe, but it's not always accurate. As somebody pointed out, the "gold standard" is to run a fiber-optic sensor up to your cardiac arteries using your femoral artery as an entry point; this is what I would understand an angiogram to mean.

And since that sensor is passing through arteries with a possible buildup of plaque partially blocking them, and an infarction is usually caused by a dislodged piece of clot or plaque causing a blockage, it does run the (slight but real) risk of causing what it's seeking to prevent.
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Old 09-08-2004, 08:27 PM
MLS MLS is offline
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IANAD, as previously stated, I have second-hand info due to having cardiac patients in the family. It's my understanding that the risks involved with an angiogram are not major, but it's not risk-free. Those I've heard of are:
An existing plaque could be dislodged or otherwise induced to become more of a problem than it was before.
The test involves puncturing a blood vessel in the groin, and there's the risk of unexpected bleeding.
The doctor could, theoretically, screw up and puncture something he didn't intend to.
You could have a reaction to the stuff that's being injected.
The input site could become infected.

These are not likelihoods, in fact, I'd guess they'd be quite rare. However, no doctor worth a dime is going to tell you the procedure is completely without risk.

And I see on preview that Polycarp has given a much more cogent explanation, but what the heck, I've got this already written anyway.
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Old 09-08-2004, 08:31 PM
Demo Demo is offline
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Quote:
Originally Posted by Una Persson
Perhaps I've missed something, but if the angiogram only involves injecting iodine into the blood whilst taking X-Rays, why is there such a risk?
There are a few risks. The biggest risk is allergic reaction to the large volume of iodine injected. Most people feel a mild warming sensation all over, but I've heard reports from patients who said it felt like their whole body was on fire, or like they were being electrocuted. Another risk is the puncture site. Since they are putting a catheter in such a large vessel, the site can bleed quite badly. Other, less common risks are breaking off plaque from the arterial wall and causing additional stenoses, rhythm abnormalities cause by irritation of the vessel/heart and air emboli(rare).

Quote:
Also, I wonder why some doctors seem to think that the heart scan is worthwhile? One of mine is pushing me towards it, even though my enzymes, cholesterol, triglycerides, and BP have always been extremely good.
If you're talking about a nuclear heart scan, they're incredibly worthwile. Do you have any other risk factors for coronary artery disease? Family history, chest pain, shortness of breath, diabetes, etc? Have you asked your physician why they want you to have the test? Did you have an abnormal EKG? Here's a Medline abstract that asserts a significant decrease in mortality in women from CAD because of noninvasive (NOT angiogram) diagnostic tests, including nuclear stress testing, echocardiography and stress EKG testing.

Quote:
Question 3 is, when I had a heart and aortic ultrasound recently, the technician said she was "looking for plaque buildup" in my aorta, and didn't find any sign of it. But it seems to me that as rough a test as that really wouldn't show very much at all unless it was near closed, is that true?
I don't know too much about echocardiography, but here's another Medline abstract that states:

Of 114 patients who had significant coronary stenoses at angiography, 96 had an abnormal exercise echocardiogram (overall sensitivity 84%). False negative results correlated with the performance of submaximal exercise, single-vessel disease and moderate (50% to 70% diameter) stenoses.
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Old 09-08-2004, 09:01 PM
Una Persson Una Persson is offline
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Quote:
Originally Posted by Demo
There are a few risks. The biggest risk is allergic reaction to the large volume of iodine injected. Most people feel a mild warming sensation all over, but I've heard reports from patients who said it felt like their whole body was on fire, or like they were being electrocuted. Another risk is the puncture site. Since they are putting a catheter in such a large vessel, the site can bleed quite badly. Other, less common risks are breaking off plaque from the arterial wall and causing additional stenoses, rhythm abnormalities cause by irritation of the vessel/heart and air emboli(rare).
That's somewhat reassuring. I'm thinking of having one early on to see how I'm doing.

Quote:
If you're talking about a nuclear heart scan, they're incredibly worthwile. Do you have any other risk factors for coronary artery disease? Family history, chest pain, shortness of breath, diabetes, etc? Have you asked your physician why they want you to have the test? Did you have an abnormal EKG? Here's a Medline abstract that asserts a significant decrease in mortality in women from CAD because of noninvasive (NOT angiogram) diagnostic tests, including nuclear stress testing, echocardiography and stress EKG testing.
I believe they kept referring to it as a "heart scan", and the main thing they were looking for was calcium. I'll need to get more info from them and find out exactly what.

I do have diabetes for 20+ years, and a family history. Thankfully, my total cholesterol is very low (120-140) and my HDL is high (about 60-70). In fact, the doctor said he'd never seen an LDL/HDL ratio of less than 1.0 before. My physician, however, feels the long-term diabetes and history outweighs any positives and is thinking of getting me in for the "heart scan".

Thank you for the link on the echocardiography. What I should be doing is asking my doctor more about it but I've been a little put off by several bad medical things happening to me and just haven't even wanted to ask anyone anything.
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  #15  
Old 09-08-2004, 09:27 PM
Demo Demo is offline
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Quote:
Originally Posted by Una Persson
I believe they kept referring to it as a "heart scan", and the main thing they were looking for was calcium. I'll need to get more info from them and find out exactly what.
If they're looking for calcium it's almost certainly an EBT scan. See above for a link to a thread discussing that.

If you've had diabetes(especially if you are insulin dependant) for a while and have family history of heart disease you should definitely pursue some course of action that will keep an eye on your coronary health.
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  #16  
Old 09-08-2004, 09:33 PM
Una Persson Una Persson is offline
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Ah, that older thread helped. You really are quite knowledgeable on this subject.
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