Do you notice when your heart starts racing? If you do then you should try some of those vagal maneuvers. Did they show you how to do them? They really do help if you catch it early. You might have to stop and get off the bike to do them effectively. I taught myself how to stop the arrhythmias before I even knew what I was doing or what was wrong. Sometimes just changing positions helped too.

I've had PSVT symptoms for 30 years. It was only diagnosed 5 years ago because they couldn't catch my heart misbehaving to see what it was doing. The episodes got more frequent with age. I had an ablation done 4 years ago, (successful, yay!) After I started riding my bike again 5 years ago, the arrhythmias got to be more of a nuisance. It was harder to stop them doing vagal maneuvers when I had been exercising and I ended up having to lie down by the side of the bike path to try to stop them a few times. I guess I could've called the paramedics to come and give me a shot of adenosine and maybe I would've if it had gotten scary. My cardiologist had assured me that I wasn't in danger from them and I didn't need to go off to the hospital when I had an episode but that I should ask the paramedics for the trace of it and bring it to him later. You, of course, should do what your doctors advise. Also, always carry your cell phone when you ride.