Hi everybody-
Has anyone had a stress thallium test done? Are you confident that it would indicate blockages if they were present?

It is a very good test to find out if there is reduced blood flow to any section of the heart.To pinpoint it you will have to have a cath done.

Hi everybody-
Has anyone had a stress thallium test done? Are you confident that it would indicate blockages if they were present?

As gooba stated, it is a good test to determine reduced blood flow in the heart. It is not a great test for determining a blocked artery with high degrees of certainty. A similar, but much more costly test that does a much better job is a PET scan using either ammonia or ribidium as the tracer agent. These agents must be made within a short time of the actual test and having the equipment to do it is costly. You have to really search to find a place that offers the PET scan. For more research on the comparison of a PET scan compred to the traditional SPECT thalium scan, see the following government site:

PET scan research and statistics (http://www.fda.gov/cder/regulatory/pet/ammonfinal.htm)

Well, it sounds like the thallium will do the job in finding a reduced blood flow, if any is present. I am 27 years old but have had a cholestorol of 358 since I was born. I have been experiencing some left arm numbness so the doc decided to run one on me. My Grandpa died at 28 of a heart attack so they want to be on the safe side. I can't take statins right now because I'm trying to have at least 1 more child. I just want to make sure nothing is getting blocked as of right now.

EKG and chest x-rays are fine. Thanks for your information and if you have any real life stories on this thallium, as determining reduced bloodflow, please share.

Thanks!

Well, it sounds like the thallium will do the job in finding a reduced blood flow, if any is present. I am 27 years old but have had a cholestorol of 358 since I was born. I have been experiencing some left arm numbness so the doc decided to run one on me. My Grandpa died at 28 of a heart attack so they want to be on the safe side. I can't take statins right now because I'm trying to have at least 1 more child. I just want to make sure nothing is getting blocked as of right now.

EKG and chest x-rays are fine. Thanks for your information and if you have any real life stories on this thallium, as determining reduced bloodflow, please share.

Thanks!
You need to be clear on your objectives and what you hope to rule out by the test. It would take a significant blockage (stenosis) for a SPECT scan (traditional thalium stress test) to pick this up. I am not at all discouraging the test. They serve a usefull purpose. You must, however, be clear as to what you expect to find out from the test. If they find any abnormality, they would likely consider an angio cath, which would tell you conclusively what the status of your arteries are.

I offer the following only as information that may or may not be relevant to you or others. I am friends with a 50 year old female that had a thalium stress test in March of 2003. She was admitted to the ER last saturday and ultimately found to have a 95% block requiring two stents. Since stenosis does take some time to develop, it is likely there was some level of stenosis existant when she had the thalium stress test. Whether it was detected or not I don't know but if it was, they did not inform her of it at that time.

A thalium stress is a reasonable first test. Of ocurse your Dr should be able to best inform you of the reasonable expectations related to the results.

You need to be clear on your objectives and what you hope to rule out by the test. It would take a significant blockage (stenosis) for a SPECT scan (traditional thalium stress test) to pick this up. I am not at all discouraging the test. They serve a usefull purpose. You must, however, be clear as to what you expect to find out from the test. If they find any abnormality, they would likely consider an angio cath, which would tell you conclusively what the status of your arteries are.

I offer the following only as information that may or may not be relevant to you or others. I am friends with a 50 year old female that had a thalium stress test in March of 2003. She was admitted to the ER last saturday and ultimately found to have a 95% block requiring two stents. Since stenosis does take some time to develop, it is likely there was some level of stenosis existant when she had the thalium stress test. Whether it was detected or not I don't know but if it was, they did not inform her of it at that time.

A thalium stress is a reasonable first test. Of ocurse your Dr should be able to best inform you of the reasonable expectations related to the results.

It is common that women will have a problem at times with this test.Their breast can distort the image and give a flase positive or make the test inconclusive.It does not take a significant blockage for this test to pick this up.Here is the purpose of the test.If a person has angina they are smart to run this test to see what is going on in the heart.They run it and find some areas of the heart are not getting enough blood flow.They then recommend a cath.They go in and look.Guess what,they find not significant blockages in the main arteries.Remember the best resolution they can get to is 0.5mm.Anything smaller and they cannot see it.Now they know that there is no blockage in the main arteries where they can intervene with angio or a stent,but they know that further downstream there has to be a blockage because that part of the heart is getting a reduced blood flow.
On the flip side.a person has angina and they run the test and the heart shows a slight reduction in blood flow.They do a cath and find a blockage in one of the main arteries.A significant blockage.They know from the thallium test that the heart is getting fairly decent blood flow even with the 95% blockage.They know that he has grown collaterals and they have a better idea for future reference on how his heart is.They do the angio and or stent and send him on his way.
That is why you have that test done.

I'll quote my cardiologist:
"We could do any of the stress tests with markers but we WILL wind up doing a catheterization for confirmation, so let's just do the catheter."
It seemed reasonable to me (but I was presenting with long term CLASSIC angina symptoms.)
He was right: a HUGE blockage that needed vascular catheterization. I was done in 5 days after my intial visit...less muss, less fuss!
(Who know's; a stress test might have killed me???:eek:)

The standard thallium stress test is a SPECT type scan. The "other" stress test that involves a scan is a PET test. If I were going to go for a SPECT scan, I would insist on geting referred for a PET scan (that is, if it was covered under my insurance and I was not too far away from a facility that performs them). A PET scan is much more costly, but also, significantly more accurate.

The purpose of the present study is to prospectively compare myocardial perfusion imaging with rubidium-82 (82Rb) by positron emission tomography (PET) with thallium-201 (201Tl) imaging by single-photon emission tomography (SPECT) by recording both studies with a single dipyridamole handgrip stress, and reading both sets of images with the same display technique. In a series of 202 patients with previous coronary arteriography, the sensitivity, specificity, and accuracy of 82Rb PET were 93%, 78%, and 90% and for 201Tl SPECT 76%, 80%, and 77%, respectively. When 70 patients with previous therapeutic interventions were excluded, the remaining 132 patients showed a sensitivity, specificity, and accuracy of 95%, 82% and 92% for 82Rb PET and 79%, 76%, and 78% for 201Tl SPECT. The improved contrast resolution of PET resulted in markedly superior images and a more confident identification of defects.

These differences are not insignificant. Just one more piece of information to consider.

pcovers,

Based on what you quoted, yes, the Rubidium PET does seem to be better than the traditional Thallium scan. My only question is that normally, doesn't the complete test also involve a follow up injection of Tc (Sestamibi) after exercise, which does show areas of ischemia upon exercise/exertion?

I know that in my case, the Tl scan did not show either blockage (50% LAD, 99% RCA determined by angiogram the day after), whereas the Tc scan after exertion showed that my heart muscle did have two areas of ischemia. Is comparing the Rb PET to the scan with Sestamibi comparing apples and oranges now? Quite possible...

As I said though, I did have unstable angina, and the Tl scan did not catch it.

pcovers,

Based on what you quoted, yes, the Rubidium PET does seem to be better than the traditional Thallium scan. My only question is that normally, doesn't the complete test also involve a follow up injection of Tc (Sestamibi) after exercise, which does show areas of ischemia upon exercise/exertion?

I know that in my case, the Tl scan did not show either blockage (50% LAD, 99% RCA determined by angiogram the day after), whereas the Tc scan after exertion showed that my heart muscle did have two areas of ischemia. Is comparing the Rb PET to the scan with Sestamibi comparing apples and oranges now? Quite possible...

As I said though, I did have unstable angina, and the Tl scan did not catch it.

I'm not sure if it is apples to oranges. I know that a comparison can be made. Some comparative data for Spect (sistamibi) and PET (rubidium or ammonia are as follows)

Improved Image Contrast
Sestamibi: 1.5 Million Counts per Image
82 Rubidium or 13 N Ammonia: 30 - 45 Million

The following URLs compare the specificity and sensitivity of SPECT (mibi) with PET (rubidium/ammonia):

SPECT with mibi (traditional thallium scan) (http://www.cadreversal.com/images/pettech001.gif)

PET (rubidium/ammonia) (http://www.cadreversal.com/images/pettech002.gif)

Interesting information.

I want to say thanks to all of you who have replied. I am very nervous about my health and you helped me find out valuable information.

Thank you :wave: