Hi when he wore the monitor did they catch anything? Maybe he should ask about wearing an events recorder. He can wear that until he has a episode.
Your boyfriend should definitely go get checked out. It is likely what he has is not life threatening but it is important to get that established and then he can go from there how he wants to treat his rapid heart beat. Ask him to go see his GP who will likely then have him either go for heart tests first or straight to a cardiologist. It might be helpful for him to get a heart monitor of some sort. I bought a watch. When he feels himself having an episode he can write down when it started, what he was doing, how fast his heart was beating and how long it lasted. This will at least give the doctor something to work with to begin with. Best of luck. Eventhough most svts are not life threatening it is still not something to ignore. As we age the condtion will persist and continue to get worse if left untreated. And on top of that in the long haul I personally don't think it is good to let your heart constantly have the episodes. Now good luck to you talking him into it.