Why doesn’t my heart get tired of beating?
The average human heart beats an astonishing 100 000 times each and every day. Can you imagine any of your other muscles putting in a performance like that? Try running around the clock and even the best ultramarathoners will feel their leg muscles scream in agony. And don’t even think about attempting a 24/7 round of push-ups if you ever want to move your arm muscles again. What is it about the heart that allows it to do so many reps day in and day out without ever breaking a sweat? Unlike our body’s other muscles, the heart has a trick up its sleeve and it’s called cardiomyocytes – a special type of cell that is very resistant to fatigue.
The heartbreak of getting old
But even with its fatigue-resistant superpowers, the heart is still subject to that bane of athletes and amateurs everywhere: age. “Just as we start to slow down as we grow older, so too does the heart,” says Renate Schnabel, a cardiologist at the University Heart & Vascular Center Hamburg. “Its vessels might feel a bit stiff, and it needs to work a little harder at things that were once easier to do – all of which causes you to feel more tired more easily.” With age also comes the risk of developing age-related diseases, some of which involve the heart and its ability to keep on ticking. In fact, age is the main risk factor for many of the most common diseases, including atrial fibrillation (Afib). “Afib is a cardiovascular disease characterised by an irregular, often rapid heartbeat – sometimes beating far more than 100 times per minute,” explains Schnabel. “This rhythm causes blood clots to form in the heart that could lead to a stroke.” According to Schnabel, up to a third of all older men and women will develop Afib, with the risk increasing exponentially the older one gets. “This is a very dangerous condition that not only increases the risk of having a stroke, but can also cause dementia and heart failure,” she adds. What makes Afib so confounding is that it may be difficult to diagnose. “Because many people don’t recognise the symptoms, or don’t have any symptoms, screening for unrecognised Afib is one of our best bets for early detection,” remarks Schnabel. “We have efficient ways to treat the disease, but we can’t start treating it if we don’t first diagnose it.”
Be proactive about healthy living
Beyond early detection and screening or figuring out how to build a time machine to go back to your early 20s, Schnabel recommends being proactive about healthy ageing. “Diet, exercise, addressing cardiac risk factors, seeing your doctor regularly, not smoking, losing weight – these are all things you can do to help keep your heart – and thus yourself – healthy,” she concludes. Schnabel is at the forefront of a global effort to improve healthcare’s ability to detect and diagnose Afib. Her work on the EU-funded MMAF and AFFECT-EU projects includes using software and artificial intelligence to predict a patient’s risk of having the disease.
Keywords
MMAF, atrial fibrillation, heart disease, cardiologist, heart, cardiomyocytes, Afib, cardiovascular disease, stroke