Claw and I had to get a new doctor since we live in Canada now. We haven’t registered into the Canadian system yet, and still have health insurance in the USA. So last week, we crossed the border into northern Minnesota to get our first annual physical with a new primary care physician.
At the appointment, the nurse did the standard things. Blood pressure, heart rate, questionnaire. She had trouble with my heart rate, measuring it twice. Apparently it was low. When the doctor came in, she wanted to check my heart rate too. She confirmed it was low. She asked if I’ve ever had an EKG.
There’s never really been a time in my life where I’ve paid attention to my heart rate. Not to say I don’t find it interesting. On the contrary, a couple of my favourite scientific articles are about how well the total number of heart beats in a lifetime predict life expectancy across mammals of all sorts of size better than chronological age (Levine 1997).
Isn’t that a cool result? All these different mammals have very different heart rates (15 bpm for whale, 600 bpm for mouse) and life expectancies (40 years for whale, 2 years for mouse), yet all have roughly the same amount of total heartbeats throughout their lifetime. If you are a mammal, you get about 10 billion heart beats and that’s it. It’s a better predictor of how much life you get than chronological time. Human is a little bit of an outlier, likely due to modern medicine squeezing out another half-log of heartbeats, but it’s a real finding. Your life is measured in heartbeats, not time. When it comes to life expectancy, the heart is the undisputed MVP organ.
To use an expression I hate, this knowledge lives rent-free in my head. I’ve carried a small but persistent sense of dread that the things I have done throughout my career and as a student have shortened my life. The copious amounts of coffee, red bull and other stimulants I’ve leaned on to power up and manically charge through all obstacles and competition have spent way too many precious heart beats. Additionally, I’ve always had a hunch my heart was naturally too quick. That even without the stimulants, my heart would give out unnaturally early.
So what’s a normal resting rate for a human? For a healthy Brazilian male, (which I am not), it’s 64 beats per minute. (According to the Brazilian Longitudinal Study of Adult Health (Dantas, Milll et al. 2017)
So how low was my resting heart rate at the clinic?
43-48 bpm. I just looked down at the Apple watch I’m borrowing from Claw, 47 bpm as I write. That’s low. So low, the EKG function on the watch doesn’t even work.
I found another source stating that mean resting heart rates are 61.4 with a standard deviation of 3.7. If that’s true it looks like I’m something like 4 standard deviations away from the mean. That’s so much of an outlier, it’s hard to believe.
After talking with the doctor, some things in the past started to click. At an urgent care facility about 10 years ago, they gave me an EKG when I just had a muscle spasm. I thought they were just ruling out a heart attack, even though I was in my thirties at the time and decently healthy.
A few years ago, I had a kidney stone that was broken up with lithotripsy. Afterwards, because the pain was unbelievable, we went to an ER to verify everything was ok (it was, I was just in agony). Claw recently told me that after they hooked me up to the heart monitor, a crowd of nurses and medical personnel gathered around it just to observe and watch my slow heart rate (I was out of it, not paying attention and had no idea).
Since the appointment last week, I have been wearing Claw’s Apple watch because it has heart monitoring functions. The doctor suggested it to gather data. Just checked again. 44 bpm. Fuck me, I have an elephant heart.
So I have a very slow heart. the medical term for it is Bradycardia. In my case it doesn’t seem to be a problem.
There weren’t any clues. I truly had no idea. I’m still having a hard time accepting that it’s unusual. I eat like shit, sugar and junk food binges. I’m kind of athletic, but not really. I try to exercise my way out of a crap diet, living by the terrible motto, “If the fire burns hot enough, you can eat anything”. Even so, I’m definitely not a super athlete or anything. I don’t do any cardio, although I do workout 5 out of 7 days. Nothing nuts, just 30 minutes of not particularly strenuous weightlifting. When I weightlift, my heart has no problem powering up to over 160 bpm.
Anyways, I’m fascinated and weirdly proud of this. I have a lower bpm than an athlete half my age. In the dark part of my mind, I thought I had an abused rabbit heart that was fast wearing out. Instead I’m a sea turtle, very slowly creeping towards the finish line. So much of our life is the product of random uncontrollable circumstances. I’m thankful that of all things to be an extreme outlier on, this is it.
The Ancient Undergrad 