This week is national Heart Week. Between 4 May and 10 May the Heart Foundation hopes to increase awareness around heart health and encourages us to take positive steps towards reducing heart disease risk. But it could be Heart Week anytime. Nevertheless, in keeping with the theme, let’s talk about the heart.
The first thing to say about the heart is that you’ve only got one. In all seriousness, this is important to accept. The body is actually a very forgiving vessel. In many cases it’s got redundancy – two kidneys, two lungs etc. We’ve been engineered with some good back up plans! For the heart though, that doesn’t exist.
The simplest way to look at the heart is to consider it to be a pump. Blood returns to your heart from the body via two main collecting veins, the venae cavae. Blood is then pumped to your lungs to get oxygen, and then back to your heart where it is then pumped back out into your arteries via the aorta.
What makes your heart tick?
Your heart is quite an amazing organ in so much that it displays what is known as “spontaneous pacemaker activity”. This basically means that it has the ability to just keep pumping. That’s to say, it’s not your brain that fundamentally tells your heart to pump – it just pumps away and your brain and body only tell it to speed up or slow down. I still remember when I was a kid at my grandmother’s small farm in India, she was about to cook a tortoise curry (yes in India tortoises are on the menu), and she cut out the heart of the tortoise and put it down the board. I watched it beating completely separated from its body. I was absolutely stunned. Our hearts can do this also.
Any part of the heart can spontaneously generate electrical activity, however one particular area of the heart (the sinoatrial, or SA, node) initiates electrical impulses at the fastest rate and is therefore the heart’s natural pacemaker. When impulses are generated here, the subsequent electrical pathway usually results in a coordinated contraction of the atria then ventricle such that blood is pumped out. When impulses are generated from the SA node, we call this “sinus rhythm”. Your brain sends chemicals such as adrenaline in your blood that stimulate the SA node to speed up or slow down.
What can go wrong?
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Not enough blood getting to the heart. Although your heart is filled with blood, the muscle of the heart itself, because it’s always squeezing, can get deprived of oxygen. It relies on arteries to get enough oxygen to it to work effectively. And as we know, they can become blocked over time or suddenly. The symptoms of heart artery blockages are shortness of breath, chest pain, or sometimes heart rhythm issues causing palpitations.
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Valve issues. There are four chambers in the heart. The two smaller atria (left and right) sit on top of the two larger ventricles (left and right). The valves sit between the atria and ventricle on each side, or between the ventricle and artery that is connected to it on each side. Altogether there are 4 valves. They essentially control the direction and timing of the movement of blood and in general can have one of two problems: they either don’t open up fully to let the blood flow (usually called “stenosis”) or they don’t close fully when they’re meant to, allowing blood to leak backwards (called “regurgitation”)
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Rhythm issues. Sometimes your heartbeat doesn’t start in the SA node as it’s supposed to or the conduction pathway doesn’t work normally. These are called “cardiac arrythmias”. There are different reasons this can happen including what we said earlier – not enough oxygen getting to the heart. Or it can be a problem with the wiring of the heart itself. For some people, there are small impulses occurring all over the upper part of the atria, resulting in uncoordinated contraction of the atria, akin to generalised trembling. This is called “atrial fibrillation”, which you may have heard of before. It’s a common problem, especially in older Australian.
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The heart muscle gets weak. Alcohol and certain viruses can cause the heart muscle to get inflamed and unable to contract well. This is called “myocarditis”. The case of viruses is interesting. I recently had a fairly young patient in his 20s who had chest pain, and they ended up having myocarditis. The cause of this was eventually put down to a virus. Damn that dreaded lurgy! The heart muscle can also become weak from inadequate blood supply, either gradually over time or from a heart attack.
- The sack around the heart. The heart is enveloped by a lining called the pericardium. It’s like a flexible sack. That sac itself can get inflamed (called pericarditis). This is usually caused by a virus. It can also accumulate too much fluid (a pericardial effusion). I personally once had chest pain which turned out to be from pericarditis. Damn that lurgy again!
Now that’s my Cook’s tour (that’s a bad pun, thanks to granny!) around the heart.
In all seriousness, we all know that the heart is a vital organ. The good news is, whilst it used to be almost inevitable that people would get heart issues as they aged, and indeed, it is a common occurrence still, there is so much we can do to protect the heart. Unlike other organs, it’s uncommon to get any cancer, so really, the rest is our job to look after it.
How do you look after your heart?
Once again, it’s a case of move it or lose it. If you stay active, you keep your heart employed and it keeps it pumping well. Apart from that, there are factors that negatively influence the state of your heart, mainly by leading to blockages of the heart arteries. These main “cardiac risk factors” are:
- High blood pressure
- High cholesterol
- Diabetes
- Smoking
There are other factors like being a man (dammit!), having a positive family history of heart disease (dammit again!) and having hairy ears (no seriously there is a correlation, and triple dammit!).
In the past, it was really hard to know if your heart was ok, despite trying your best to minimise your risk factors. However, these days, technology allows us to check fairly simply for any blockages with low dose CT scans. This is called a CT Coronary Angiogram. I reckon I’ve mentioned this before, but being Heart Week, it’s worthwhile mentioning again.
So as bugs used to say, “That’s all folks”. The heart is an amazing organ. You’ve only got one, so stay active and look after it. And these days, there are so many fairly simple ways to know if you have got any issues, and ways to fix those issues. So, you can keep pumping!
In Heart Week – Know thy heart. Know thyself!
If you’d like to know anything about your heart including what can be done to look after it, or if you’ve got any symptoms, then check in with your GP. We’re here to help.
Author: Dr Floyd Gomes