Wednesday, July 8, 2009

Racing with Hardware


A happy "ICD in competition story". The press tells us that this particular footballer had a "heart attack" but those of us with arrhythmias know this was probably just a virile run of V-tach. Thanks to Todd German for pointing out this link


Competing in a bike race with an implanted defibrillator was much less anxiety provoking than I imagined. But I was pretty nervous at the start line all the same. In races before my cardiac adventures I had become pretty blaisé about racing, I was immune to typical pre -race stomach butterflies. Twenty-odd years of racing will do that to you. Well, the butterflies are back. Starting a race was nerve wracking, and exciting. Not exciting enough to trigger any reggae heart rhythms though. My pulse was steady in the 70s as we were given the whistle.

The race was pretty much all out from the gun. The pack went nearly single file in the first mile and stayed that way for most of the first half of the race, averaging 28mph over the first 4 of 8 laps on the rolling six-mile Central Park circuit. Once I was warmed up this was perfect for me. My training has all been low threshold endurance and some controlled sub-max speed. Prior to the race I did zero training for sharp accelerations and zero efforts where I maintained a heart rate of more than 90% of threshold for more than 3 minutes at a time. The constant speed of the race eliminated the need to respond to sharp accelerations, but I sat above 90% for a long, long time, 22 minutes out of a 1hr45 minute race.

Which was precisely what I was looking for. Being forced to push myself at a steady race pace was eye-opening. Apart from the expected suffering my heart felt fine. By the second half of the race I was feeling pretty good. I was in no position to actually be a factor in the race, no attacking, or sticking my nose in the wind, but I was able to surf along just fine.

And that was pretty much how the race went: staying in the wheels, far enough towards the front to keep out of trouble. The pace calmed down for a few minutes here and there, but I never let my self get into a position where I needed to jump after an attack, I just let the pack swell around me and took my own sweet time circulating back to the front.

While cruising at 130bpm during one lull in the action I suddenly felt the tell-tale thumping of errant heart beats. My heart rate monitor went from 130 to 80 in about 5 seconds, then slowly regained speed to 130 again - over a 30 second span. I had never seen that before, usually my HRM spikes, rather than dips. I immediately put up my hand (the universal bike racer signal for a mechanical problem - usually flat tire) and drifted backwards coasting. But the thumping was over as suddenly as it came. I rode caboose for a minute or so and once I was sure that the anomaly was gone I accelerated back into the field.

After the weekend I "Carelinked" my ICD data to my doctor and was told that I had a five beat run of VT followed by several "salvos" of PVCs over the course of one minute at precisely that time of day. I was told not to worry, this was not a serious problem. Discussing the event we came to the conclusion that it might be a situation where my heart was responding to the new level of effort with some misbehavior that might die down once it gets habituated. I'm willing to buy that explanation, I've had similar experiences with previous up-ticks in training, but they were always confined to PVCs, not VT, however short.

Anyway, apart from that momentary scare, the rest of the race went smoothly. We came into the last lap and I wasn't sure what my strategy would be for dealing with the inevitable field sprint, the most dangerous part of most races. It is often better to stay in the top 20 in the lead up to a sprint, in order to avoid crashes as fatigued riders jockey for position. Either that or stay as far back as possible without risking getting dropped. I opted for the former, which can mean a constant fight to hold position in a frenetically circulating pack. But on this day everything was smooth, I sat in 10-20th position for the last 3 miles and when the final push to the line came I found the right wheels and ended up finishing 10th with no real sprint effort. In the sprint my heart rate did hit 171, the second high water mark of the race, but I never really pulled on the bars and gave it my all.

Apart from the minor mid-race heart weirdness it was a successful venture. The next day I was suitably exhausted but managed a 55 mile jaunt at a recovery pace. As the week progressed and I recovered, I felt a definite surge in PVCs. Riding seemed to be the thing that calmed them, and by midweek they were pretty much gone.

Next...to do or not to do?...race number two...