I feel for you and totally relate, especially to the frustration of being told it's not life-threatening. You said it exactly right. It is significantly life-altering. I'm a bit older (69 F) and have had episodes of SVT for the past 6 years. Initially 1-2 episodes/year and recently escalating. I also have significant mitral valve prolapse with regurgitation and am scheduled for surgery next week. I've been warned by my cardiologist and electrophysiologist that this will probably not fix the SVT, which they think is the less serious condition. It doesn't feel less serious to me since it has put me in the hospital 3 times in the past year. I keep asking, "how long should I put up with a heart rate greater than 200" before going to the hospital but no doctor has given me an answer. Once at the hospital (or in ambulance) I convert quickly with 1-2 shots of adenosine. If they are able to fix my heart valves, then the EP is recommending ablation, but I have a fear that they won't be able to trigger the SVT since it is very intermittent.

I am going to list the interventions I've tried and hope others will let me know if they have suggestions.
1) Metoprolol 50 mg
2) No caffeine at all for past 5 years
3) Regular exercise up until recently when valve issue became urgent (walk 4 mi, weights 2x/wk, Pilates 3x/wk)
4) Yoga/Meditation when heart rate elevates
5) Vagal maneuvers to try to reduce HR (never had success)
6) Cold shower to try to reduce HR (never had success)
7) Propafenone during SVT episode (seemed to work after about 30 min on one occasion)
8) My Apple watch records the SVT episodes and the cardiologist does look at the EKG's but it only confirms what she already knows.

Any thoughts on how long to try to deal with an episode before seeking help or other things to try to get rhythm to convert back to normal? I see from this group chat that many people have worse episodes than I do and I truly don't know how you have managed. I feel bad for each of you.

Thanks for listening.