Afib patients all have different experiences with this heart problem. My symptom is raised and irregular heartbeat rate that may last a long time or do not convert back to normal. My resting heartbeat is around 50 beat per minute (bpm). During my afib episode it can go as high as 200 bpm. Another symptom I had that may not be common is that when the irregular heartbeat returns to normal on its own, my heart may stop beating for several seconds. The longest recorded pause is 7.5 second. In this case, my brain may not get enough blood and I would pass out. I fell on the ground this way three times. One time was when I was riding and I broke my left wrist. This convinced me to have an ablation, a procedure using a thin tube (catheter) inserted through a blood vessel to reach the atrial to burn tissues that erroneously pass heart electric signals to create irregular heartbeats. The first one was so successful that I started to ride as usual with my full energy to sprint. Six months later, my afib returned. I had a second ablation, and after that I have been much more careful with my bike riding.
My observations have indicated that as long as my heartbeat rate does not exceed a certain threshold (130 bpm) for long and as long as I have a good rest between my bicycle rides, I can avoid bad (long) afib episodes. So I changed my riding style from fast sprints to moderate long distance. I no longer ride with groups because I must slow down or stop to control my heartbeat rate, which is at least annoying and can be dangerous in a group ride. Solo rides allow me to build my muscls for endurance rides at my own pace. I keep my heartbeat under 120 bpm most of the time. These days I still have afib episodes once a while. Typically, it would start when I experience some sort of sudden change. Quickly drinking ice cold liquid when I am hot and sweaty would trigger my afib. A quick start after a rest on a ride would also.
I discovered a breathing method that helps prevent the onset of my afib and return quickly my heartbeat to normal from an afib episode. It is simple: Slowly exhale all air in your lung until nothing left. Let your lung take care of inhaling naturally. And repeat. I do this when I have an afib episode and when I climb steep hills, e.g., a short steep hill (15 – 20%) with my heartbeat above 140 bpm.
With this breathing method and my trained muscls, my heartbeat rate was below 100 bpm most of the time. I made sure I always rode without struggling, even on uphills, however slowly I had to go. I forced myself to stop and take a break every 20 miles or so, regardless of whether I felt I needed to. At the end of each day, I might be tired but not exhausted. The rotation of long and short daily rides gave me chances to rest a half day. If that was not enough, I would stop and take a full day rest. I had three afib episodes during the trip, all caused by my careless drinking of cold liquid in a hot day when I stopped at gas stations to rest. I was able to control them and return my heartbeat to normal using my breathing method.
Chidong Zhang's WA2MA Bike Trip 