N=1
There is a war going on inside my body, between the forces of good and evil. When the good guys are winning, my newly remodeled heart does what it is supposed to: it beats faster when I exercise, with a solid correlation between the rate of beating and the intensity of the exercise, and it slows down when I’m done. With the bad guys, there’s no telling what might happen. My heart breaks all of the rules.
There are at least three things that my heart does when it misbehaves. One is to beat slightly out of rhythm. It’s going along at a strong and steady sixty beats per minute, for example, and there is a longer than normal pause between beats, or two beats come close together. This doesn’t seem to be a big deal most of the time, and I think my heart did some of this before my surgery. Some days though, it seems to happen all day long. The second thing that happens is a sudden and apparently random increase in my heart rate. If I happen to be doing something active, my heart rate sometimes keeps going up even after I’ve slowed down or stopped altogether. This, I’m pretty sure, is atrial fibrillation, or it’s cousin, atrial flutter. The third thing I’ve only noticed once or twice. It is the opposite of the second thing. Right in the middle of a workout, my heart slows down, dipping below my normal resting heart rate, then after a few seconds it kicks back into a normal and appropriate rhythm. People often ask me if can feel these things happening. To some degree I can. The first one feels like something flopping in my chest, not unlike the feeling I get as the roller coaster goes up that first steep hill, or before giving a speech to a large audience. The second one is more subtle. If I’m sitting, or even walking at an easy pace, I probably don’t notice it at all. If I’m climbing stairs, or jogging, or doing anything that is putting demands on my circulatory system, I become suddenly hungry for air. It doesn’t hurt, but it is very unpleasant. The third thing, even though it is the opposite, feels a lot like the second.
Lately I have been exploring the relationship between exercise and atrial fibrillation (AF). To that end, when I work out I wear a Garmin watch on my wrist and a heart monitor strapped to my chest. The Garmin app gives me a picture of my workout that includes a graph of my pace, and a graph of my heart rate. Here is one example:
The blue graph shows my pace. At the beginning, I’m jogging at an easy warm up pace for a few minutes. I stop and walk a little. Then I run 400 meters at a slightly faster pace, followed by some walking again. I repeat this cycle seven more times. The red graph shows my heart rate. Notice how nicely to two graphs line up. When I am running faster (blue), my heart beats faster (red). When I walk, my heart rate slows down. On this day, the forces of good were victorious.
This is a picture of the exact same workout on another day:
It starts with some easy jogging, then I begin the 400 meter repeats. My goal for this workout is to control the running pace so that my heart rate never goes above 140 beats per minute. After each 400 meter segment, I walk until my heart rate returns to 100 or below before starting the next run. On this day, all goes well for the first three repeats, but in the middle of the 4th one things fall apart. My heart rate shoots up to around 180 beats per minute. I discontinue my run, but my heart rate continues to increase. It stays at a ridiculously high rate for a few minutes, while I’m walking home, then eventually and inexplicably returns to normal.
I discussed all of this with my cardiologist, and sent him these pictures. He agreed that the high heart rate was suspicious, but couldn’t say for sure if it was AF. To shed more light on that, he suggested that I consider buying something called a “kardia.” This astounding piece of technology, not much bigger than a stick of gum, works with an app on my phone to provide an actual EKG, anytime, anywhere. I turn on the phone app, hold the device near my phone, touch it with the tips of two fingers on each hand, and hold still for 30 seconds. It gives me the EKG in pdf format, which I can print, email to myself, or send to my doctor. It even gives me a preliminary analysis, identifying possible abnormalities. Here is a sample:
Pretty cool, right? A finger on my pulse, a heart monitor strapped to my chest, an EKG machine in my pocket, and a smartphone: these are my tools. Over the next few weeks, until my scheduled cardiac ablation, I’m going to use them to learn everything I can about my own heart. In future posts, I will write about things I’ve already learned about the relationship between AF and exercise. Sometimes is seems to be triggered by slow warm-ups, but goes away when I run faster. Sometime it is just the opposite. What is up with that? Is it affected by coffee, tea or alcohol, or anything else that makes life worth living? Do magnesium or fish oil supplements help? Is paying all of this attention to it making it worse? Is going to the track with a bag full of electronic equipment in the hopes of catching my heart in the throes of a quivering dysrhythmic paroxysm, possibly increasing my odds of having a stroke, really any better than just staying home, sitting on the couch and binge-watching episodes of Kantaro: The Sweet Tooth Salaryman? These are questions I hope to answer. And one more: why, of all of the EKGs I've taken over the last few weeks, is the one I took just five minutes ago and put in this blog post, the one just above this paragraph, why is that one the most beautifully symmetrical EKG I've seen yet?