EDP column by Professor Ketan Dhatariya
“My doctor has told me that I have a heart murmur, but that this is nothing to be concerned about. What is this?”
The heart is made up of four chambers that act together to pump the heart around the body. The upper two chambers are known as the atria and the lower two are the ventricles. The heart is also divided into right and left sides, with the right side responsible for pumping blood to the lungs and the left side for pumping blood to the rest of the blood. Each side of the heart usually pumps about 5 litres of blood per minute.
The upper two chambers, the atria, contract whilst the ventricles are relaxed and this helps to fill the ventricles with blood. The blood is allowed to flow into the ventricles through valves between the atria and ventricles. These valves (the tricuspid and mitral valves) ensure that blood flows only in one direction. When the ventricles contract, the tricuspid and mitral valves close and so the blood is only able to leave through two other (aortic and pulmonary) valves.
Blood flow through the heart is usually very smooth. This means that there is very little resistance to flow. However, as one ages, or with certain heart conditions, the flow through the heart – and in particular across the valves – can become turbulent, especially if the valves are too stiff and do not open fully. This turbulence can be heard using a stethoscope as a murmur. This situation can be likened to putting your finger over the end of a hosepipe. With your finger off the end, flow through the pipe is smooth, but if you close the end a little with your finger, then the flow becomes very turbulent.
Your doctor can often tell which valve may be affected by examining you and listening to your heart whilst getting you to breathe in and out. However, if there is some difficulty in deciding what is causing the murmur then your doctor may ask you to have a special ultrasound scan of the heart. This is called an echocardiogram and is used to examine its structure and function.
Treatment, if any, depends on what is found. Many people need only to be seen every now and again by their GP to ensure all stays well. Others may need to be seen by the heart specialists.
As always, if your doctor says something to you that you do not understand, ask them to explain in language that makes sense to you.
For more information about Heart Murmurs click these links:
http://www.nhs.uk/conditions/congenital-heart-disease/pages/introduction.aspx