Exertional chest pain and air hunger

23, AFAB, BMI of 22. Non smoker.

Pre-existing Ulcerative colitis in remission.

I get bloodwork done every couple of months, and am in the clear for iron deficiency + anemia.

I have a regular resting heart rate. (70-80bpm)

This has been a lifelong problem, that does not get better even when I did competitive swimming, training 2-3 times per week.

Only ever had 1 EKG done around the age of 12 which was fine.

All of these heart rate measurements are done with my smart watch (I have used both garmin and Apple Watches) and I occasionally checked manually, so I’m decently sure they’re accurate.

My main symptoms:

-Generally elevated heart rate when not seated. Here some examples: Leisurely walking 120bpm on good days, 140+bpm on worse days. Biking on flat ground 140bpm on good days 160+ on bad days. This heart rate rises slowly as I continuously exercise. Usually no problems from it.

-Things that make it worse are heat, humidity and carrying something (even if it is an almost empty backpack)

-Intolerance to running. I can make it maybe 2 minutes. My heart rate climbs continuously until I reach ~190bpm. Below 180bpm I feel pretty alright, breathing is normal. Approaching and surpassing 180bpm I slowly get central chest pain. If I keep going I get relatively sudden air hunger, I have to force myself to breathe evenly and not gasp for air. Breathing itself doesn’t feel obstructed. If I stop running this settles and disappears within a few minutes. If I keep going I get lightheaded.

-The above mentioned chest pain and air hunger also happen generally when my heart rate gets that high, but running gets it to happen very reliably.

-I get occasional periods where I have chest pain whenever my heart rate surpasses 140bpm. This pain is on the left of my chest, radiating to the back and neck. It is a mixture of pressure and pulling pain. The pain disappears when my heart rate lowers. These periods last a day or two and are accompanied by higher exertional heart rate. Maybe once every few months.

-I have in suspicion of it being postural measured laying and standing heart rate but the difference isn’t too large (Laying=70-80bpm, Sitting=80-90bpm, Standing=100-110bpm)

The chest pain is mainly what concerns me. I have a referral to a cardiologist for further testing. The wait times are quite long, so while I’m on the waitlist I was curious if there were any theories on what this may be caused by? Is this something that could just be normal?