You seem to be in excellent shape, however your markedly elevated heart rates with the "glitter or stars" symptoms may be a sign that your heart is not able to meet the demands of your body (the increased heart rate is a compensatory response to pump more blood; however the stars/stinging may be a sign that there is still not enough oxygen reaching your brain and toes). Though it seems that you have had this symptom for years and have done fine.
I agree with you that this new symptom of left sided chest tightness is very concerning, as it may represent that your heart itself is not receiving enough oxygen (whether due to decreased oxygen supply from a coronary blockage; or increased oxygen demand from your exercise routine). While the normal EKG and ultrasound are reassuring, I'm assuming that they were both performed in a resting state? If not done already, you should discuss undergoing a stress test with your physician. By monitoring an EKG and ultrasound during peak stress (while you are running on a treadmill), you can get a better idea of whether your heart is hurting from the stress of marked activity. If the stress test is able to elicit your chest tightness, without any change in your EKG or ultrasound at that time, it may be a reassuring sign. If there are abnormalities noted, your physician may recommend a heart catheterization as a definitive way to look for a heart blockage.
Yes, I do agree with you that your chest tightness does sound concerning and that it does warrant a more extensive work-up before being felt to be nothing of importance.
I wouldn't purchase a Holter monitor for a couple reasons:
1) Holters are more suited towards looking for arrhythmias, and would not be a good diagnostic tool for potential heart blockages (ie it looks at the wiring, rather than the plumbing). In your specific case, it may be more valuable to obtain a stress ultrasound to see exactly how your heart responds under stress.
2) I was not aware of Holter monitors being sold over the counter, and cannot comment on their accuracy. Just as importantly, they should be interpreted by licensed professionals (ie cardiologists, nurses trained in Holter, etc).
I would recommend re-emphasizing the severity of your symptoms to your physician. If s/he is not concerned, consider getting a second opinion. Good luck.
Thank you so much for your response. Yes the tests I had were at rest. I did ask about a stress test but the doctor told me I was fine and joked and said "I don't expect to see you for another 30 years for an appointment if I am still around". So I just let it go. But I do know my body and feel something isn't right. Maybe something is off or maybe I'm fine but I want to be confident that I wont do damage or worse if I push through chest pain becuase of something that was missed. In a race I will push and go the extra gear with pain or whatever to have a good race outcome (I have almost blacked out more than once at the finish). In the end my family and my health is most important. So I assume I need to see another doctor possibly. I just felt my current doctor was not wanting to do anything further.
I thought about purchasing a Holter monitor since the my co pay is similair to the cost of one to purchase on ebay. I could wear it during an intense training session and see what happens. Would that be good idea? Thanks again for your wonderful help. It is very much appreciated.