If your echo was normal the test is very likely just to be totally sure but a clean echo is a very good sign so try to keep it in perspective. Most doctors just are overly cautious. Take care.
Thanks both of you, I guess I'm just super nervous about it coming back positive that something is wrong. I appreciate your kind words.
Think positive. The thyroid issue is probably the underlying cause so taking the synthroid (or generic) should take care of it. I am on 75 mcg and it has worked great. I once accidentally doubled up and that may have caused a PVC run. The only inconvenience with that is you can't eat for an hour after taking it in the morning. Otherwise, side effects are rare.
Find a way to cope with the anxiety and get through it. The alternative is to walk away from the test which is not desirable.