Oh No. Not Again!

Are you curious what atypical atrial fibrillation (afib) looks like when it starts in the midst of a bike ride? Good news (OK, not really) — I can satisfy your curiosity after last night’s training ride. The graphs above and below are from that ride. The one below is just trimmed to show the exciting bits.

The blue lines of the trimmed image are the workout’s power goals and the purple lines are my actual power output. This image shows the 2nd and 3rd sets of the planned workout (5 minutes hard / 5 minutes easy 5 times)

Red line is my heart rate. Normally pushing watts like this I would be 130’ish (plus/minus 10 depending on the day). The left blue block was the second set of 5 minutes and you can see my heart rate was fine, right around 130 — until we went into the recovery period and about a minute in I was suddenly registering around 150 (right around minute 31).

Foreshadowing: I was in afib at that point (but didn’t recognize it yet.)

I was breathing hard and thinking that old age had finally caught up to me… but I dove into the 3rd set of the workout because I love attacking a good hard bike workout. And, under load, measured heart rate actually dropped a wee bit. But when the 5 minute were up the heart rate didn’t drop. And I was huffing and puffing. And light headed. And I knew…

I was in afib. It was back. Shit.

I slid off the bike and checked my pulse. There’s no mistaking that feeling. Walked into the kitchen, had a glass of water and small pity party but then five or ten minutes later I felt my pulse convert and go back to beating normally. phew. That saves a doctor visit.

In the first paragraph, I said this was atypical atrial fibrillation. So what’s atypical about it? Apparently, for most people in afib their heart rate is not only uneven/sporadic but also starts beating very fast. Mine is uneven and sporadic (feels like a drunken conga line that skips random beats in my chest) but does not really speed up. As I (barely) understand, the heart speeds up to compensate for the arrhythmic beating to keep oxygen flowing. Since mine doesn’t, I tend to get very light headed and out of breath very fast. This has caused “amusing” incidents in the past.

The risks? Well, if your heart isn’t beating properly then the blood isn’t circulating through it properly and you run a real risk of generating a clot in the heart. Where do clots in the heart go? Straight to the brain. We want to avoid that.

After fighting this crap for most of my 40’s, I had a cardiac ablation almost 3 years ago and, shortly after, resumed a normal life. Unfortunately, over the next 3 years I also resumed some bad habits which were my original afib triggers: caffeine, alcohol, and endurance athletics don’t mix.

Guess who’s writing this article while sipping a cup of decaff coffee today? Day 1 of the lifestyle reboot (again) begins.