A heart murmur is not a disease, but rather a sound that a doctor can hear through a stethoscope placed on a patient’s heart.
The typical sound produced by your heartbeat has two components: “lub-dup”.
This is caused by your heart valves closing.
Other sounds can also be present, such as a murmur.
This heart murmur can be described as a swishing or whooshing sound.
Some can be harmless, but others can be a sign of heart disease.
Some heart murmurs can even be present at birth; these are known as congenital heart murmurs.
Others develop later in life.
Heart murmurs are caused by blood flowing abnormally across your heart valves.
Your heart’s function is to pump blood throughout your body.
Your heart is divided into four chambers: two atria and two ventricles.
There are “doors” connecting these chambers, which are called heart valves.
Heart valves are made of leaflets or cusps.
They open and close to let blood flow from one chamber of your heart to another.
Most importantly, they have to make sure that your blood moves at the exact right time and in the right direction, in order to get it oxygenated and then distributed throughout your body, which is the very essence of why you are alive.
The four valves of your heart are the:
- Aortic valve
- Mitral valve
- Pulmonary valve
- Tricuspid valve.
When the heart ventricles contract, it is called systole.
Blood is pumped out of the heart and into your body during systole.
When the ventricles relax, it is called diastole.
During this relaxation, your heart’s chambers fill with blood to get ready for the next contraction cycle.
Systole happens somewhere between the first and second heart sounds (i.e. between the “lub” and the “dup”).
It is so quick that you will hardly have time to register it.
Heart murmurs are classified based on when they happen in a heartbeat cycle.
A systolic murmur happens when your heart muscle contracts.
A diastolic murmur happens when your heart muscle relaxes.
A doctor would be able to hear when those murmurs happen – whether it is between the first heart sound and the second, or whether it is between the second heart sound and the next first heart sound.
There is also such a thing called a continuous heart murmur.
This happens both during systole and diastole.
Some systolic murmurs are “innocent”, i.e. nothing to be concerned about, especially in a child.
But diastolic and continuous murmurs are likely to be related to some sort of heart disease.
Nevertheless, all murmurs should be evaluated by a cardiologist.
When your blood is flowing more rapidly than normal through your heart chambers, it can cause an innocent heart murmur.
This is also called a normal or physiologic heart murmur.
This innocent murmur is common during exercise, especially strenuous workouts; childhood; and growth spurts, like in puberty.
It can also be present during pregnancy due to the extra load of the fetus for your heart to supply.
You can hear it during the first few days of a baby’s life.
However, some may continue throughout the person’s life.
You don’t have to worry about a physiologic murmur once it has been evaluated by a cardiologist.
There are actually plenty of causes of dangerous heart murmurs other than heart disease.
Those that are due to a problem with your heart include:
> Heart valve disease
This is when one or more of your heart valves are not working as they should.
When a valve allows blood to leak back the other way, it is known as valve regurgitation.
When a valve is thickened or stiff, it is known as valve stenosis.
These issues may be accompanied by other symptoms, such as that of heart failure (e.g. swelling in your ankles, palpitations, breathlessness, etc).
> Congenital heart defects
These are present from birth as your heart did not form properly while in the womb.
Examples include “hole in the heart” and tetralogy of Fallot.
> Infection of the heart
This is known medically as endocarditis.
It is usually caused by bacteria from a throat infection.
> Cardiomyopathy
This is when the heart muscle is larger, thicker and stiffer.
It can be inherited or caused by high blood pressure.
Then there are the causes outside the heart, such as anaemia and hyperthyroidism, which cause your heart to pump much faster.
No matter the murmur, it is best to get it seen to by a cardiologist, as a GP may not have the diagnostic machines to see what is wrong with you.
Dr YLM graduated as a medical doctor, and has been writing for many years on various subjects such as medicine, health, computers and entertainment. For further information, email starhealth@thestar.com.my. The information provided is for educational and communication purposes only, and it should not be construed as personal medical advice. Neither The Star nor the author gives any warranty on accuracy, completeness, functionality, usefulness or other assurances as to such information. The Star and the author disclaim all responsibility for any losses, damage to property or personal injury suffered directly or indirectly from reliance on such information.
Already a subscriber? Log in
Get 20% OFF The Star Digital Access
Cancel anytime. Ad-free. Unlimited access with perks.
