Re: cardiac PET scan

John Wendel said:

Dr.Andrew B.Chung If resting sestamibi images demonstrate a mild
reduction in tracer accumulation,however FDG PET images demonstrate a
disproportionately increased amount of FDG tracer accumulation in the
same region in comparison to the degree of sestamibi Would the above
findings in any way be a dead muscle tissues (old heart attacks)? I know
that above findings can be related to diaphragmatc atteunation
artifact,physiologic variant and mild ischemia,but can the above
findings be in any way dead muscle tissues (old heart attacks)?
Dr.Andrew B.Chung I do know that you are board certified cardiologist
and an expert in your field and one day,because of your expertise in
cardiology you are asked (an expert opinion) the above question by an
attorney in front of the judge and the jury.How would you answear the
above question?Thanks

I would answer that there is no such thing as a "perfect" test. When there
is conflicting data, someone has to think it through to figure out what is
going on.

--
Dr. Andrew B. Chung, MD/PhD
Board-Certified Cardiologist
http://www.heartmdphd.com/

Dr.Chung I asked you whether the above finding is in any way (shape and
form) an old heart attack and I think I did not ask you whether the
above test was perfect. I do know that there is a high probability that
it is not,but I would like an expert cardiologist opinion? Would you
please list diagnoses,in order of importance, of the above findings if
it is a highly unlikely an old heart attack?If on PET myocardial
viability study report says nothing about any heart attacks would one
have to assume that there is no evidence of old heart attacks? If there
is any evidnce of any heart attacks would it always be written on the
PET myocardial viability study report?If no why not?Thanks

[email hidden] (John Wendel) wrote in message news:<[email hidden]>...

Quoted message said:

Dr.Chung I asked you whether the above finding is in any way (shape and
form) an old heart attack and I think I did not ask you whether the
above test was perfect. I do know that there is a high probability that
it is not,but I would like an expert cardiologist opinion? Would you
please list diagnoses,in order of importance, of the above findings if
it is a highly unlikely an old heart attack? If on PET myocardial
viability study report says nothing about any heart attacks would one
have to assume that there is no evidence of old heart attacks? If there
is any evidnce of any heart attacks would it always be written on the
PET myocardial viability study report?If no why not?Thanks

This has been answered ad nausium. A typical interpretation of the
findings you described in the PET scan given the clinical question of
a possible inferior wall myocardial infarction and a normal F-18 FDG
studywould read:

"The F-18 FDG PET study shows no evidence of a recent or old
myocardial infarction in the inferior wall of the left ventricle."

no matter what the SPECT study showed.

Briefer form would be:

Normal exam.

If evidence of an MI is not mentioned, then there is no evidence of an
MI, the reader interpreted as something else like an artifact or the
reading physician missed it. That opens another whole ball of wax for
you regarding the intra vs. inter observer variability of
interpretation of an exam.

BTW, would you accept the opinion of someone who teaches cardiologist
fellows and reads 50 PET scans and up to 200 myocardial perfusion
SPECT scans a month?

Dr.Chung By using words "perfect" "someone" in your last answer you did
not answer my question?Do you agree with Patrick Ford last answer? Would
you accept the opinion of Patrick Ford "Normal exam" and if evidence
of an MI is not mentioned on PET myocardial viability study report,than
there is no evidence of an recent or old myocardial infractions (heart
attacks)?By the way, if there is no evidence of any heart attacks why it
is not written on the report "There is no evidence of any heart attacks
or myocardial infactions" and the sentence is not long?Thanks

John Wendel said:

Dr.Chung I asked you whether the above finding is in any way (shape and
form) an old heart attack and I think I did not ask you whether the
above test was perfect. I do know that there is a high probability that
it is not,but I would like an expert cardiologist opinion? Would you
please list diagnoses,in order of importance, of the above findings if
it is a highly unlikely an old heart attack?If on PET myocardial
viability study report says nothing about any heart attacks would one
have to assume that there is no evidence of old heart attacks? If there
is any evidnce of any heart attacks would it always be written on the
PET myocardial viability study report?If no why not?Thanks

Would be happy to see you in person and after examining you and reviewing
your history, tell you exactly what I think is going on.

--
Dr. Andrew B. Chung, MD/PhD
Board-Certified Cardiologist
http://www.heartmdphd.com/

Dr. Chung Would you accept the opinion of Patrick Ford in his posting?
If an 47 yrs old male wants to avoid BOTH HEART ATTACKS AND HEMORRHAGE
STROKES in the future,would it be better for 47 yrs old 180 pounds 6
feet male to have blood pressure 100/70 (no symptoms of low blood
pressure) t.cholestrol 180,tc/hdl 4.5 or with weight loss and diet BP
90/60 tc 120-135 and tc/hdl 3.5.Thanks

John:

I think you should take up Dr. Chung offer; or at least see a
cardiologist you trust. You ask specific questions then veer off into
other areas. Your PET question has been answer in that a normal F-18
FDG uptake in heart muscle essentially excludes dead heart muscle.

It does not exclude coronary artery disease or other vascular disease.
It does not exclude a previous "heart attack", where there has been a
blockage in blood flow that may have "injured" but did not kill the
tissue and the muscle has either recovered completely, hibernating or
somewhere in-between. It does not exclude a lot of other problems. It
adds little additional information regarding the risk of a future
cardiac events. Its use is targeted to excluding dead heart muscle,
usually as a precursor to revascularization. If the muscle is not
functioning properly but is not dead, then revascularization may
result in a return of function. If the heart muscle is dead, then why
have someone go through major surgery?

While F-18 FGD PET may be the gold standard for excluding dead heart
muscle, in cases where (1) revascularization is not the clinical
question being ask (2) an angiography has not been done (3) an
non-invasive procedure is preferred and (3) given the test that you
have mentioned have already been done, I would agree with Dr. Chung
recommendation on the echocardiogram. The echo provides a great deal
of additional information that is not available in the PET study.
Seeing how this thread had gone, I would bet that you ask for the best
non-invasive test to exclude an old infarct, not, what is the
appropriate next test, if any. Don't take this to mean one is the
right test to do and the other is the wrong test, because I am not
saying that.

Re: Risk factors. There are a lot of these risk factor assessment
sites that will pop out a number for you. There is a lot more
information that is pertinent that you have not supplied. This forum
lends itself to yes and no questions. Dr. Chung's answers tend to be
direct and to the point. It is not really possible to do a complete
history on this forum and impossible to do physical exam to answer all
of your concerns. Think you moving toward establishing as
patient-physician relationship, and that cannot be done appropriately
in a public forum.

In article <[email hidden]>,

John Wendel said:

Patrick Ford If the PET study "does not exclude a previous "heart
attack" where there has been a blockage in blood flow that may have
"injured" but did not kill the tissue and the musle has either recovered
completely,hibernating or somewhere in-between" would non invasive and
invasive tests exclude this type of "heart attack"? I do know that
cardiac MRI with injection (do not know if without) can exclude
hibernating muscle,but what about the muscle that is somewhere
in-between and the muscle that has recovered completely?Do these types
of "heart attacks" show up most of the time on EKG and Echo and in what
forms?Thanks

First, this type of "heart attack" is uncommon. As stated earlier
"heart attack" is non-specific term. If the muscle is not dead, there
will be no scar. If the heart muscle has recovered and the "occlusion"
was not due to atherosclerosis, like spasm due to ephedra, then the
other test would not detect it, unless there happen to be spasm while
the test was being done. If there was spasm plus significant
atherosclerosis coronary artery disease then the other stress test
would be used to detect it. If there is resting ischemia, severe
disease that may look like scar on the other test because the
myocardium is not functioning properly, This is were the F-18 FDG PET,
MRI scar imaging and some pharmacological stress test such as a
dobutamine echo would be used.

With a dobutamine echo, if there is improvement in wall motion from an
segment that is not moving normally, then that would be read as
hibernating or stunned. I am not a cardiologist nor do I read echoes,
therefore I would defer to cardiologist on these points. If the F-18
FDG PET was normal, then that would have already shown no scar present.

Dr.Chung and Patrick Ford Are you saying PET study with resting
sestamibi images demonstrating a mild reduction in tracer accumulation
however,FDG PET images demonstrate a disproportionately increased amount
of FDG tracer accumulation in the same region in comparison to the
degree of sestamibi can not exclude all old
(atherosclerotic,spasm,stunned)heart attacks and stress sestamibi
examination is needed to further evaluate for any possibility of old
heart attacks and even than stress sestamibi can not exclude spasm heart
attacks unless they happen while the test was being done? 2. I thought
that resting sestamibi and FDG PET images are enough to exclude all old
heart attacks and sttress sestamibi examination is used only to evaluate
for any possibility of ischemia (blockages) not old heart attacks.3. Do
you think resting sestamibi images demonstrating a mid reduction in
tracer accumulation is in any way shape and form an spasm heart attack
or any other that should be evaluated further with stress sestamibi
examination?Thanks

[email hidden] (John Wendel) wrote in message news:<[email hidden]>...

Quoted message said:

Dr.Chung and Patrick Ford Are you saying PET study with resting
sestamibi images demonstrating a mild reduction in tracer accumulation
however,FDG PET images demonstrate a disproportionately increased amount
of FDG tracer accumulation in the same region in comparison to the
degree of sestamibi can not exclude all old
(atherosclerotic,spasm,stunned)heart attacks and stress sestamibi
examination is needed to further evaluate for any possibility of old
heart attacks and even than stress sestamibi can not exclude spasm heart
attacks unless they happen while the test was being done? 2. I thought
that resting sestamibi and FDG PET images are enough to exclude all old
heart attacks and sttress sestamibi examination is used only to evaluate
for any possibility of ischemia (blockages) not old heart attacks.3. Do
you think resting sestamibi images demonstrating a mild reduction in
tracer accumulation is in any way shape and form an spasm heart attack
or any other that should be evaluated further with stress sestamibi
examination? Thanks

You are being very binary, or black or white, about a process that has
a wide spectrum. All of these tests have a level of confidence that
range from good to excellent, but all test have false positives and
false negatives.

If you bruised your leg today, you could injure the skin, muscle,
bones and other tissues and structures and for the next few weeks you
leg would be sore. There are test that would show an injury during
this time frame. Unless there was concern for a significant fracture,
it is highly unlikely that any of these not so cheap tests would be
done because the history and physical exam explains the findings. Five
years from now, and I am using an extreme time frame, none of these
tests would show any leg damage or evidence that you bruised your leg.
Doing additional test to try and show you injured your leg at this
point would not help separate you from a group that had not bruised
their legs or who are at a higher risk of bruising their legs. Yes you
had a leg injury but it is now normal. Do you see the difference
between having your leg mangled and permanently injured and a bruise
that will have complete recovery? You ask about old injury, not old
injury that resulted in permanent damage. If the heart is normal now,
then these tests will not show an injury that is no longer present.

Without the proper evaluation of other risk factors and history and
physical exam these test only show small pieces of the puzzle. That is
why you should see someone who deals with these issues on a daily
basis and likely had a decade or more of medical training before
taking their cardiology boards.

A stress/rest MIBI SPECT with a non-reversible inferior wall defect
and a normal F-18 FDG PET is most likely due to diaphragmatic
attenuation of the inferior wall, or less likely resting ischemia.
Usually the clinical questions is not resting ischemia vs
diaphragmatic attenuation artifact but resting ischemia vs scar
because there is known dysfunction of the heart in that area. Normal
wall motion at rest and stress would virtually exclude resting
ischemia. Gated SPECT or echo could do that.

Assuming normal wall motion and left ventricular ejection fraction,
then that person would be at a low risk and statistically could not be
separated off from someone with a normal SPECT study.

Spasm may be episodic and would likely show up on many diagnostic
tests if it was occurring during the test and the test may be normal
if the spasm was not happening. A good history would be the starting
point. There are test and therapies for coronary artery spasm, but
that is out side of my area.

Dr.Chung and Patrick Ford On resting sestamibi images this area
demonstrates preservation of systoic thickening on ECG gated images and
also radiologist mentioned that it could merely be a physiologic
variant.Gated images demonstrate a normal ejection fraction.This person
also had before the above test a normal stress echo with normal Baseline
and Exercise Basal, Midvent,and Apiical findings and a Wall Motion Score
of 1.00.In your honest opinion do you think this person should have
another Echo and even another stress sestamibi examination to further
evaluate for any possibilities of old heart attacks and (mild) ischemia
if the above findings are your findings? I would accept your opinion of
this person having a second opinion,because of another doctor's
findings,but would you recommend this person another Echo and even
stress sestamibi examination,if the above findings are your findings?If
yes why?Which of the two expected findings would be correct
diagnosis:diaphragmatic atteunation artifact or mild ischemia?During
cardiac PET viability study is chest also imaged and would any
significant chest abnormality on PET viability study be detected and
written on PET myocardial viability study report?BTW What would be a
gated resting images normal limits of left ventricular ejection
fraction?Thanks