An introduction to your heart

Atanomy of the heart

Before we explore the different areas of cardiac healthcare or ‘specialties’, let’s take a brief look at how the heart works, which will help us understand how things can sometimes go wrong.

Your heart is the central point of your circulatory system. It is a vital organ which keeps you alive.

The heart is a muscle made of four chambers which pumps blood and oxygen constantly, supplying your whole body, responding to extra demand placed on it, such as vigorous exercise, when needed. The rhythm of your heartbeat is regulated by electrical signals from the heart’s ‘natural pacemaker’, the sinus node in the right atrium, which make the heart muscle contract and relax at a steady pace to pump the blood.

If either of these systems fails to work properly health problems will occur.

If the arteries which channel blood to your heart muscle become blocked either partially or fully you can experience a heart attack*. The treatment for this includes drug therapy, percutaneous coronary intervention (PCI) (a procedure using a balloon and stent(s) to open up an artery) or cardiac surgery. Or, if the electrical system is not working properly the rhythm of the heart might be irregular, too fast, too slow or the heart can even suddenly stop beating altogether, which is a cardiac arrest. Both of these cardiac events are a medical emergency and the person must receive treatment fast to maximise the chances of survival.

Other long term health problems can include:

  • Heart failure is the term doctors use for when the heart is no longer able to pump the blood around the body as well as it should.
  • Cardiac arrhythmia is where there is an abnormal heart rhythm. A relatively common form of arrhythmia is atrial fibrillation. This can lead to abnormal flow in the heart chambers, and sometimes results in a clot forming in a heart chamber.
  • Finally, babies can be born with structural problems of the heart. These abnormalities are called congenital heart disease, and urgent surgery may be required on the baby’s heart before the first birthday, and often within the first couple of weeks after birth.


* Most heart attacks are due to blockages. However, it is now recognised that a small number (up to 10 %) occur due to a temporary constriction of the coronary arteries, small blood vessels or a spontaneous tear in the inner lining of the blood vessels. See 4th Universal definition of an MI figure 4 in section 7.2