December 6, 2021

I, Science

The science magazine of Imperial College

Long thought to be the seat of the soul, the heart remains an emotive symbol of passion and there’s apparently still no better way to proclaim an infatuation than with a big pink heart stamped on glossy cardboard. The heart “nourishes, cherishes, quickens the whole body, and is indeed the foundation of life, the source of all action”, William Harvey wrote in On the Motion of the Heart and Blood in Animals, his 1628 treatise on the circulatory system – and in a sense, we’d probably agree with him today.

Harvey was the first to realise that the heart circulates the blood and detailed its one-way valves and pumping – rather than sucking – action. For 1,500 years before Harvey – and indeed for some time after – the accepted explanation of how the blood moved around the body was due to Galen (AD 129-217), who believed that on each beat newly produced blood – created either in the heart or in the liver – was sent out to the body’s organs which consumed it.

Harvey reached his more accurate explanation partly by observing hearts that were still beating, even though the rapidity of a heart’s movement made it difficult to pin down the exact points of systole and diastole (contraction and relaxation), and partly by establishing mathematically that blood was not being consumed, since the volume pumped far exceeded the amount the body could produce.

Harvey’s pioneering work has led, five centuries later, to an understanding of the heart and circulatory system that not only allows us to transplant hearts but build and implant artificial ones. A dying man’s heart was replaced by an artificial one last year by surgeons at the Texas Heart Institute, but perhaps the most unnatural feature of this “turbine-like device” is that it does not beat. Instead, it provides a continuous flow, like a tap, meaning that though this man’s blood circulates, he has no pulse. Let’s hope he’s not too deep a sleeper.

Ideas about the heart’s role in our emotional make-up are apparently hard to give up too. Some of the comments at the end of this article about the implanted device question whether the man can still feel. “[H]ow about valentines day where everything is hearts and glitter?” one commenter asks.

Yet before we throw romance out of the window, let’s not forget that it may still be possible to die of a broken heart. Takotsubo cardiomyopathy – or broken heart syndrome – is a sudden weakening of the myocardium – the heart muscle – that can be brought on by emotional stress. According to the press release accompanying a recent study published in Circulation: Journal of the American Heart Association, “medical professionals should be aware that the bereaved are at much higher risk for heart attacks than usual.” Though, admittedly, in some cases this could be due to people neglecting to take regular medication for a heart condition that already exists.

Anyway, now we’re all in the mood, maybe it’s time to pluck up the courage to send that Valentine’s message. Indeed, feel free to use the comments below. But if you’re typing, make sure you choose your words – and emoticons – carefully, as this touching exchange found on makes clear.

<raindog> I’ll ring you when I head out…
<morgamic> <3
<raindog> lol
<morgamic> want me to pick you up?
<raindog> nice testicles
<morgamic> it’s a heart you jackass.
<raindog> oh

Thanks to Victoria Charlton for telling me about broken heart syndrome.