Symptom question

[Moony37]

I have had left-sided chest pain (pain scale 1-3) that comes and goes and sometimes radiates up to my shoulder and down my arm, nearly every day for the last two months.  I've had a few runs of a day or two in that time period with no pain but that's about it.  I'm on Toprol XL 100 mg to control SVT and palpitations, and it's done very well controlling those but it has done nothing for the chest pain.  Last Monday morning I had some nausea, followed by an hour's worth of on-and-off stabbing chest pain, then my usual chest pain with lightheadedness and dizziness and shortness of breath.  I was sent to the ER by my family doctor, where cardiac bloods, EKG, and chest x-ray were normal.  My cardio scheduled a Cardiolite stress test and another echo for the next day.  The Cardiolite showed "borderline moderate ischemia" but am having a stress echo next Wednesday to rule out artifact.  Wednesday evening my chest pain was at about a 4-5 at one point but went away completely after having a beer, returning about an hour later at its usual level.  Later that night I had a pretty bad episode of SVT but I passed it off as being due to having been out late and drinking that night.  Yesterday I had to come home from work two hours early due to shortness of breath, chest pain, and dizziness/lightheadedness.

Today was awful.  I had chest pain when I woke up, which was unusual because it usually doesn't start until I've been up and around for a few minutes and it usually goes away when I lay down on my left side.  At work I felt some tachy, then some odd beats (Holter showed I have PACs and late beats), then got really lightheaded and dizzy and that lasted for well over two hours.  My chest pain was floating around, too, going from left of my sternum up into my shoulder as usual, but I could also feel it on the right side and in different points in my left upper back than usual.  I also became extremely tired, to the point that I could barely keep my eyes open at times.  Then all of it started coming and going, to where I'd feel no pain or dizziness (still extremely tired) and I'd think it was done and it would suddenly all start again, and I was short of breath when I was dizzy (but I was dizzy before I was short of breath).  I came home from work early and slept for four hours and was still exhausted when I woke up.  Right now I still have chest pain, same as usual, and still a bit dizzy when I sit/stand up, plus completely exhausted.  I got six hours of sleep last night and I felt more or less rested when I woke up this morning, so I'm not tired because of that.

Any thoughts as to what's going on?  I thought about going to the ER today but I'm tired of being told "there's nothing we can do until we have a firm diagnosis".  The ischemia diagnosis is still up in the air, of course, but could ischemia be causing all of this?