Your son should see a cardiologist and have some further testings done such as a stress test as well as an echo. There are a lot of things that can result in passing out, many are not related to the heart at all, but you can't be certain of that until he has had further testing. See a cardiologist.
His BP is responding the way it should given his heart rate. As his BP was up too, this is good. This is two of the components looked for on a stress test, how BP correlates with HR and your sons is doing what it should.
When I was his age I got the same issues in the doc's office. My HR would go tachy on me and my BP would go up to those levels (white coat syndrome). At home they would settle down. Now that I'm 42 they no longer do this, I don't know why. Youth, hormones, I also just lost close to 40 pounds. Is your son overweight? that could be a factor.
His fatigue might be due to a viral infection, this may also have something to due with him passing out and short of breath. Some viruses can be symptomatic for months, with fatigue and soreness. The viral component can even affect the heart and pericardium, resulting is pericarditus. Quite often it resolves on its own. These "light" versions of pericarditus are difficult to detect.
Also, maybe have a heart to heart talk with him to see if he's been taking any supplements to help with his endurance, I can imagine this would be weighing on his mind to make the team, so to speak.