Struggling to Get a Diagnosis for Tachycardia and Palpitations

I'm 22 with Tachy too, still unsure of the cause but they increased my propanolol and my heart rate dropped to under 90 for the first time in probably 3 years (yay!) My primary care doctor was able to order a halter monitor for me, which you can get in the mail and get picked up when you're finished. A good first option to look into?

I saw a cardiologist and an EP specialist. They did a bunch of tests and put in an implanted loop recorder which finally gave us answers. Best of luck, i hope you find out what's going on soon