False Positive in Thallium Stress Test

Posted By David Weinstein on January 12, 1999 at 06:03:49:







I suffered from a severe blockage in the RCA and moderate in the LAD. After
Thallium stress test showed ischemia in areas covered only by the RCA, angioplasty
was performed on the RCA (this site and ccf were great help in the decision
making process).   3 weeks later I had another Thallium stress test, which
shows similar results in ischeia (EKG showed depression again as well)as
prior to the angioplasty. However, the effort related angina symptoms are
gone and  the second Thallium test was "brutal" in effort, compared to
the first one.  I still suffer from reflux, for which I am treated,
so there is heartburn and slight pain in the throat on and off.
I was told that we may have a case of false positiveness becasue of the
proximity to the time of the angioplasty, since the heart muscle may have
been in "hybernation" in that area, and need more time for the cells to
take on the Thallium. I was told to come back in 3 months.
How credible is this "hybernation" hypothesis? I can understand that the
Thallium, brought to the cell by the blood, may not reach.  However, why
should the EKG show a deression, why should it disappear after more time?
Is it really necessary to wait that long?