thallium stress test and beta blockers?

[cangel65]

Hi, I am a 41 yr old male and have been experiencing some chest pain and shortness of breath. The ER Doctor said I checked out fine but did hear some kind of "clicking" so as a precaution my doctor has scheduled me for a Thallium stress test. I will admit that I am not too terribly familiar with the test but I do understand it to be some type of stress /imaging test that shows how well blood flows to the heart.

I am told that I am not to take Toprol (beta blockers) 48 hours prior to the test and I'm more than a little worried about this. I'm concerned about suddenly stopping any medication that I've been on for any long term period of time and know from past experience it can in my case trigger nasty migraines at the very least.

Here is my question: Is this really necessary? Will the beta blocker really interfere with the test or is it just some unnecessary medical testing precaution to cover all of the bases? I guess I am also asking how exactly could a beta blocker interfere with the test?

Thanks, Carrie

[Flycaster305]

The reason the beta blockers need to be withdrawn is because they need your heart rate to be elevated to get an accurate mapping of your heart.  I assure you, if you take the beta blocker within the 48 hour window, the stress test will be extremely uncomfortable for you.  When taking a beta blocker it's difficult to elevate your heart rate above 100 bpm, and they need your heart rate, given your age, to get to about 145 bpm.  The short answer is that you absolutely need to stop taking it to have an accurate test.  That being said, I hope you relay to your doctor your difficulties when you stop Toprol before you take the stress test.  Let us know about your test.

[ed34]

when you stop your beta blockers you will find that you probably can't do as much before
feeling discomfort. Just take it easy. Also, you may find that your breathing feels different. Some people get on the verge of a panic, but you need to just remember that
you will be fine. When you leave the centre after the tests, you can take your beta blocker, I took one with me. It took about 20 mins before I felt the nice relaxing effects
from it.

[cangel65]

Now I understand. Thanks so much you guys! It makes perfect sense now.