The human heart……the subject of countless love stories, songs and poems……the seat of the soul…..the most potent and yet fragile set of emotions……the human heart may be all of these things, and more, but let’s take a look at some rather more practical and biological and factual aspects of our hearts…
The heart is essentially a pump. It pumps blood around the body. The main purpose of circulation (blood circulation) is to deliver oxygen (oxygenated blood) to the cells of the body and to remove carbon dioxide. The heart does this in partnership with the lungs – it is our lungs that remove the CO2 and add the O2 – and this is why the heart pumps blood through the lungs as well as around the rest of the body. This pumping action is achieved by muscles; the heart is essentially a large muscle that is adapted to beat continuously (to pump) for a lifetime.
The heart beats at around 70-80 beats per minute (BPM, also known as “pulse”) – faster in older and less fit folks, slower in younger and fitter types (professional athletes may have resting heart rates in the 40s). The maximum heart rate for most people is calculated as 220 minus [age of person] so a 40 year old’s maximum heart rate is about 220 – 40 = 180. Most aerobic training programmes suggest training at around 60 to 80% of maximum heart rate, so 120-140 for our notional 40-year-old.
There are two types of blood vessel in the human body: arteries take oxygenated blood from the heart and lungs to the body while veins return deoxygenated blood back to the heart. Most forms of cardiovascular disease (including heart attacks, strokes, and peripheral vascular disease) are caused by narrowing and obstruction to blood flow in arteries (these obstructions are caused by atherosclerosis, cholesterol, age, lifestyle and other factors). When veins are obstructed we see conditions such as deep vein thrombosis (DVT) and swelling of the legs.
The human heart is roughly-round or an approximate sphere, usually about the size of a fist or a grapefruit. The heart, being a muscle itself, requires its own blood supply and this is delivered through the coronary arteries. Ischaemic heart disease (IHD; angina and heart attack) occurs when these coronary arteries are blocked. Angina describes a temporary obstruction that does not cause lasting damage whereas a heart attack occurs when the obstruction is longer lasting and results in death of a piece of heart muscle. The warning signs of a possible heart attack include chest pain (usually central, may be left-sided) that is “crushing” and tight in nature (a belt around the chest), shortness of breath, anxiety & fearfulness. Associated symptoms may include pain that radiates to the jaw and arm (usually left side), cold sweats, a sensation that the heart is racing too fast, as well as nausea & vomiting. A heart attack is often, but not always, precipitated by physical exertion and or extreme stress. A heart attack is a true medical emergency: speedy and advanced care (specialist ICU) can save lives and improve outcomes tremendously these days so any suspected heart attack should be dealt with real urgency.
The doctors involved in heart health include general practitioners (lifestyle advice, screening or early signs of disease, early emergency care), physicians (specialists in internal medicine including cardiac care), cardiologists (super specialist in cardiovascular disease), and cardiac surgeons (operate on heart conditions).
There is no evidence that the human heart has anything to do with emotions, feelings, relationships, romance, or any such. These beliefs tend to persist, at least in popular culture, and for the most part, do no actual harm.
The human heart may not be the seat of the soul but it most certainly is the thing that keeps us alive by beating over 100 000 times a day, every day, for as long as we live. When it stops, so do we. There is much we can do to look after our hearts, and so we should.
Written by Dr Colin Burns
