sesta-MIBI

I am a 50 y/o. wht. female.  I am obese at 220 pounds; controlled HTN (120/70's); hyperlipidemia (240; ratio of 5.0); I do not smoke, drink alcohol, use recreational drugs or caffeine; I exercise aerobically as well as with weights.  I have panic disorder that is disabling. Since 1989 I have suffered from heart palpitations. I have had a normal echo, 2 Holter monitors that showed benign supraventricular contractions (majority were single beats; an occasional couplet and a very rare run); 3 treadmill tests all normal.  The last stress EKG was done a week ago.  I achieved 6 minutes at a speed of 3.3 mph and a 14% incline. My heart rate was 177. I experienced no chest pain, dizziness, shortness of breath, lightheadedness etc.  I have also had a head to toe physical that showed everything WNL (except for my lipids).  During EXTREME moments of stress, I experience what I can only call a "stitch". I get this on the left side where the shoulder joint meets the breast and it extends, somewhat into the armpit. There is no pressure, squeezing or radiation of this sensation. I also experience heart palpitations during these episodes. This could not be duplicated on the treadmill test. My internist feels it is possibly a nerve branch or muscle spasm. I currently take the following medications:
clonidine 0.1 mg, tid
clonidine 0.2 mg, qhs
lozol, 2.5 mg, qd
verapamil 120 mg, qhs
premarin, 0.625 mg, qd
xanax, 0.25 mg, qid, prn (I take this rarely)
Vitamin E, 800 mg,qd
Vitamin C 2000 mg, qd
ASA 81 mg, qd
Garlic supplements
multivitamin
Just this week I was started on
lipitor, 10 mg, qd

I experience no chest pain, shortness of breath or any other cardiac symptoms except the palpitations I have had for 10 years and the rare "stitch".  My internist feels I am "fine". I tend to agree. My question is, do you feel a sesta-MIBI would be warranted for me, at this time?  This was not suggested by my doctor. It was suggested by a friend. I don't want to ignore something important, but, at the same time, I really don't want, nor can I afford, unnecessary testing. Apologies for the length of this and thanks for your input.

[Cleveland Clinic, MD]

It's probably not necessary and as you say is very expensive.