79 year old male. Diagnosed with SVT 20 years

Good that you're keeping tabs on it. Some just learn to ignore it, some don't care, some are so annoyingly symptomatic that it reduces the quality of their lives severely.

As long as you self-convert to NSR all the time, or as long as you are always in NSR and not in fibrillation, even if it's after 4-8 hours, that's good. However, if you're going longer, especially past the 24 hour mark, you need expert care, and you should avail yourself of it soon. In fact, any time you're measured HR is over 100 for more than 24 hours, you should consult a physician or go to the local ER. Even our hearts tire from exertion after a while.

If there is even a whiff of the occasional AF, you should be on a DOAC (Direct Oral Anti-Coagulant) such as apixaban or rivaroxaban, or perhaps warfarin is better if you have other issues being controlled by drugs.

@jackjburdick, does it only happen when golfing? Have you considered giving up golfing? Does it happen only in the sun? Maybe you could golf on a gray or cooler day?

I am really big on avoiding triggers!

It does happen when golfing. Recently in cool weather. Go to Y and play pickle ball and no problem

If yuo give up golf, do you think it will stop happening?

Not sure. Wednesday It came on while playing golf. Did some maneuvers and walked to car after 5 holes. Rate in 90s at car, and normal when I got home at about 2pm. Later in evening I got up to let dogs out and rate went from about 65 to 139. Never could get back to normal until I took my daily 360mg Cardizem about 8pm. Normally take at 11 when I go to bed. The drug worked, and everything was good until golf Friday. I track rate on Apple Watch.