Throbbing in chest

[Rob2008]

I have this squeezing throbbing down deep on my chest that is likened to someone having their hand in there squeezing something.   Only way I can describe it it's like a narrowed area of a pipe and where the pipe narrows pressure builds up at the entry end.   This is amplified with sluggish intense throbbing for example when I first stand up.    I feel dull pressure in my chest most of the time, at rest or not, and I have horrid fatigue, lightheadedness, especially during exercise, and early heartbeats that I've never had before.      My echo, EKG chest Xray and blood tests were all normal.   This illness , whatever it is, is bringing me to my knees, please help me.

[Cleveland Clinic]

Not really sure what this could be, but you may need a stress test since it occurs after exercise. Apart from that a Holter monitor may show an arrhythmic cause of these symptoms.

[Rob2008]

And random, brief blood pressure drops, especially while standing and after exercise.

[Rob2008]

Doc, a quick follow up question if I may??
sorry I forgot to mention I had a nuclear test on the same day as my echo and it was OK.    Do I maybe need a chest scan to look at my aorta, or something like that?   Or does an echo rule out that?    Or a MRI of the heart?               You say that it occurs after exercise, this is not really the case.   It is pretty much a looming awareness of pulsing in my chest 75% of the time and it's made worse when I first stand up.     I have weakness and feel lightheaded with it the time even with normal arm pressure.