Heart. Johannes Hinrich von Borstel

data into the computer, and assisting in the treatment of minor to moderate wounds — this was my day-to-day experience as an intern. Additionally, the senior consultant would give me a short lesson at the end of each day, when he would explain in some detail the patient care and treatment strategies during the shift. He had a talent for explaining even the most complicated things in such a way that I could understand them, even without a medical degree.

      Soon, I was learning to sew wounds. Well, okay, I started on bananas. But, importantly, I learned that wounds are not always necessarily bloody. And perhaps most importantly of all, I came to understand the close connection between sensitive patient care and effective medical treatment. The senior consultant had the ability to recognise when patients were unhappy and to bring a smile back to their faces. He mentored me, far beyond the realm of medical issues.

      With great patience, he explained the structure of the human body, from the skin down to the internal organs. And that’s when I once again encountered my great (medical) love: the heart. Full of awe, I listened to him explain the muscles of the heart and its four-chambered structure. I heard tales of his time on call as an emergency doctor, of heart attacks, and of how to treat diseases of the heart. And the more I learned, the more my admiration grew for this fist-sized bundle of energy nestling in our chest. From that point on, I knew there could be no other — the heart had stolen my heart.

      This book will take you on a journey to the heart. I begin by looking at the development and growth of the heart, and find out what that has to do with the theatre, loops, and bunny ears. I will also show you that our vascular system behaves like a network of highways — sharing all their features, from damaged roads to traffic congestion. You will see the sophisticated design of our heart, and how the processes of our atria and ventricles can run out of control. You will also learn what happens to our ticker when we smoke like a chimney, pay regular visits to McDonald’s, and enjoy more than the occasional drop of the hard stuff. And I explain why emergency medicine has nothing to do with the esoteric arts but it’s still necessary to be able to read coffee grounds.

      Moving on, I will describe what diseases weaken our heart and pass on a few tips about healthy eating for the heart. I will then investigate whether the Easter Bunny would have a healthier heart if it were a vegan, why medieval physicians liked to quaff their patients’ urine, and why Bucks Fizz isn’t the only deadly quartet.

      Next, we’ll go on holiday together, but it will be a white-knuckle ride. The scene of the crime: the ventricles of the heart — since, as I will reveal, many a young holidaymaker’s heart is less rested after their holiday than before. I’ll clarify what exactly determines a healthy heart rhythm, what factors can influence it, and what we can do when that rhythm goes wrong. And I will take a look at the most drastic measure to get a heart beating again: resuscitation.

      That’s only required when one’s heart stops beating — and to make sure this doesn’t happen to you, I will prescribe a little something to prevent it: sex, which strengthens and supports the body and its defensive army, the immune system. I will zoom in on the tiny little warriors that make up our defence forces, and explain why Churchill’s recipe for a long life (‘No sports!’) might not be the best advice. In passing, I will take you on a tour through our blood and its components, and have a look at blood pressure.

      Finally, I will show that even our state of mind and butterflies in the stomach can influence our heart. Is it possible to die of a broken heart? Whether it is or not, we should never underestimate the powers of self-healing. But modern medicine also has quite an inventory of tools to help repair a damaged heart, from replacing worn parts to installing a completely new engine.

      These are the stations on our journey to the heart — each more fascinating than the last. And now it’s time for that journey to begin!

       The Loop in the Heart

How our heart develops, how it is structured, and how its transport routes work

       The Longest Theatre Play in the World

      Ba-boom, ba-boom, ba-boom, ba-boom, ba-boom. The sound of a beating heart, powerfully performing its life-preserving service day after day. It beats without a break, no matter whether we’re asleep or awake. It’s already beating on the first day of our lives and continues until we draw our last breath. But what happens to our faithful ticker in the time in between, that is, during our lifetime? The answer is actually not very complicated.

      I’m a passionate theatre-goer, and it occurs to me that the experience of a heart over its average 80-year existence is like a classical drama with five acts. The first act is the introduction. From the beginning of the second act, the action begins to rise. It reaches its climax in the middle of the drama, in act three. From that point on, all begins to go tragically downhill. After the fourth act, when everything moves from bad to worse, the fifth act ends with the inevitable tragedy, the curtain comes down, and the play is over.

      But enough of this talk: the scene is now set for a real drama of the heart.

       Act One: the unborn heart

      In the theatre, plays usually begin by presenting the characters in the first act. So, allow me to introduce you. Very soon after an egg cell is fertilised, which is the point that marks the start of the rather complicated process of embryo development, the foundations are laid for the construction of a functioning heart. A rather unprepossessing collection of cells assembles, called the cardiogenic plate.^* It forms two strands, which then develop into tubes.

      At the same time, the pericardium, or heart sac, forms, and the heart continues its development inside this. The pericardium will later continue to envelop the adult heart. Inside the pericardium, the two parallel tubes now merge to create a larger one, called the tubular heart. It begins to move and eventually to curve in shape. Although it bears little resemblance to a rollercoaster or a display of aerobatic prowess, this process is called cardiac looping.

      This isn’t the end of the heart’s development by far. Next, our heart grows ears — although not ones it can hear with. Like those fluffy bunny ears that are so popular at hen’s nights, they only look similar to the real thing. Scientists are still unsure about the precise function of these heart-ears, which are in fact nothing more than appendages to the heart’s atria. What doctors do know, though, is that they are responsible for the release of a hormone that will later stimulate urinary excretion. Our heart not only pumps blood around our bodies, it also helps us to pee.

      By this stage, almost a month has gone by since the egg cell was fertilised, and the embryonic heart can now be divided into recognisable sections that will become the chambers known as the atria (where blood enters the heart) and the ventricles (where blood is expelled). Precursors to the cardiac valves form, as do the early stages of the septum, or dividing wall between the right and left side of the heart. However, that wall does not form a complete partition in the embryonic heart, and will not fully close until a few days after birth.

      In fact, there is an oval hole between the right and left atria, called the foramen ovale. Blood flows through this aperture from the right atrium into the left, and then on around the embryo’s body. Why is that? The reason is simple: embryos are not yet able to breathe independently, so it would make little sense to invest in the laborious process of pumping blood through the embryo’s lungs. This short-cut is all it takes to avoid that.

      What eventually results from all this development is muscly on the outside and hollow on the inside (and thus could be said to bear a resemblance to a certain former governor of California).

       Act Two: the newborn heart

      The heart of a newborn baby is quite different from that of an adult. About the size of a walnut, it works much more quickly. It beats up to 150 times a minute — even at rest: baby doesn’t have to have been doing any sport. That’s about twice as fast as the normal adult heart rate. The reason for this is simply that a newborn’s heart is still very small