I keep getting thsi wierd pain on the left side of my chest in the center of my breast pretty much. It's sharp, kind of like stabbing, but not like a knife going in and out..Jsut deeper and deeper in. When I hold it, it feels better. I've ahd this going on a while and it's the least of my problems. So I always forget to mention it to the doc. But it happened last night, and it took a while to go away...Like a half hour, and I got very weak. I was sitting and if i'd of tried to stand, I would of fallen. I have mitral valve prolapse & tachycardia. But other than that no real heart problems. I was passing outa few months ago b/c the medicine to lower my heart rate was lowering my bp too much and I was passing out.
Sometimes my bp goes up or down and my symptoms coordiate, like lightheaded/dizziness and/or feeling out of breath/really bad headache.
But it's usually just for a few mins.

Any suggestions on what this pain could be??

Thanks in advance