How to convince a doctor that you need a specific test/referal?

I have had 2 holter tests, echocardiogram and stress test, all came back fine.
However, I still experience palipitations, arrythmias, tachardyias. When i had the holter monitors done, i took it easy and did not do anything physically demanding, this was a mistake, I should have exerted myself because i usually have the arrythmias after doing something physical. I spoke to my uncle who is a cardiologist in Michigan and he told me to get a Thallium stress test done as this is one of the best tests to do. Now the problem is, when i ask my doctors to let me get this test done, they say no.

Im really worried about my health and well-being, i really need and want this test done- even if it comes back fine it would be for piece of mind.

How do I convince my doctor to let me get this thallium test done??

[Momto3]

Your doctors must feel confident in their decision not to send you for a thallium stress test.  Have your even talked with your doctor about an event monitor?  You could wear it for a month and that would give you a better opportunity to record your heart's activity when you feel symptomatic.

Hope you're feeling better today.