We are taught early in life that heart muscle repairs itself very slowly. You probably worried that it will wear out one day. So you determine to look after your primary pump by eating carefully and taking suitable exercise. You do what you can to keep the pipes clean and flexible so that your heart can pump some 8000 litres of blood around your body each and every day for whatever term you consider to be your life expectancy. That life expectancy in Ireland was 79.6 years for men and 83.4 for women according to the CSO in 2017.
I noted in another Irish report last year that men aged 70 years in 2017 had a remaining life expectancy of 15 years. It’s 17 years for women.
I also remember a Guardian article in 2008 that suggested that people who managed themselves carefully from their 70s could have a big impact on their remaining life expectancy. That was in part why I started vigorous long distance walking in my 50s. Then I watched my father’s mental decline over a decade as congestive heart failure resulted in ever less oxygen reaching his brain. I’m more active than he ever was so I wonder if my genetic inheritance will limit my longevity.
I also wonder why we care about life expectancy without considering quality indices? Assuming you have choice, what’s the point of a final decade if you’re not mentate?
Some say the human heart is rated for about three billion beats? Other estimates range from 2 to 2.3 billion. I prefer the higher estimate though I have no peer reviewed evidence for my preference. If I use the lower, say 2.15 billion beats and the average human resting heart rate of 70, I would have a life expectancy of 58.4 years. Since I’m 12% beyond that already (and living in Ireland), I’ll continue to model my future with the greater service from my first heart of 3 billion beats. Since I have no idea what my resting heart rate has been in the prior 64 years, I will assume it was higher than ideal at 70. And so the three billion beats gives me an expectation of 81.5 years of good service with a resting heart rate of 70 bpm over those 81.5 years. This is close enough to the CSO actuarial estimates for me use as my baseline. If I’m mentate, I’ll consider any beats beyond the baseline as a bonus.
My Fitbit indicates that my resting heart rate has risen from a weekly average of 62 to 68 bpm during the lockdown and I know this will accelerate my demise. Under normal circumstances, I manage my nutrition and activity levels relatively well. I’ve been do it better over the last decade or so than I ever did before. Unfortunately, my activity levels have fallen during our self-imposed and extended lockdown and that will probably shave a few days off my life.
Plug your own heart beat numbers here, if you dare. (Caveats: this is a fun curiosity not a reliable health predictor and there are other sources that cause me to suggest 3 billion is more a reasonable expectation than the 2 to 2.3 billion lifetime beats on the web calculator.)
Please note that life expectancy has different interpretations, challenges and relevancies in different countries at different times. For example, life expectancy in the United States has decreased several years in a row. Deaths per 100,000 has risen by 6% but most steeply within the age group 25-64. Could this be social support failing in the ‘first world’ between 2010 and 2017? And this is mortality. What about general health? Is this getting worse too? Is this an indicator of a systemic weight problem?
Caveat emptor: these journals are my daily musings and may not be correct.