“The heart murmur is a whistling sound of blood going through an orifice creating turbulence.”

When patients go to their general practitioner for an annual check-up and are told they have a heart murmur, patients often feel an element of panic. Without knowing what a heart murmur is or what can cause a heart murmur, people may assume it is a sign of an imminent heart attack. The truth is, a heart murmur only points to a change in the valves and the good news is, it doesn’t always mean there is a problem. When a heart murmur is considered non-threatening, we call this an innocent heart murmur.

Finding Heart Murmurs

A doctor finds a heart murmur by listening to your chest with a stethoscope. A heart murmur is the abnormal whooshing sound made when blood moves through your heart’s valves. This indicates that there is something causing turbulence within the valve’s blood flow. This sound could be caused by a number of different things, only a few of which are cause for alarm. For instance, in pregnancy, a woman gains 10 to 15 pounds of blood volume. With the extra amount of blood trying to move efficiently through the body, the valves will make more noise than they normally might. Having a fever may also cause an innocent heart murmur. Younger children can get heart murmurs when they are going through a growth spurt. Even exercise can increase the speed of the blood flow creating a temporary heart murmur.

“Innocent murmurs are slow murmurs having to do with good but increased flow.”

Having hyperthyroidism may also cause a heart murmur. In this instance, the doors in your heart are functioning properly, but because of your overactive thyroid; blood is being pushed through the doors at a faster rate causing the doctor to hear a murmur. While this is not a danger to your heart, it is something you should have checked out by a general practitioner.

“You detect murmurs with a stethoscope, and you confirm them with an ultrasound because you don’t want to put everyone through an echo.”

Heart murmurs that are cause for concern include those caused by congenital heart valve defects and acquired heart valve disease.

The Nature of Your Heart Murmur

Once the doctor has heard your heart murmur with a stethoscope, they may be able to tell you it is no cause for concern and send you on your way. If they have any doubt, however, about the nature of the murmur they will want to confirm it using a Doppler ultrasound. When you are at a train station, you will always be able to hear the train coming into the station. You can tell by the sound when it is coming towards you and slowing down. As the train gets closer, the intensity of the sound waves increases. Christian Doppler used the same principals of sound waves to quantify valve disease in the 1840s. Doppler was an Austrian scientist who discovered what came to be known as the Doppler Effect. Through his studies, he realized that the frequency of the sound wave was dependent on its speed. Using these principles, we can characterize a murmur based on the sound of blood going through the orifice (i.e., the open valve). Depending on the intensity of the murmur that the doctor hears through the ultrasound or echocardiogram, we can quantify how troubling the state of the valve has become.

“We characterize a murmur by the sound going through that orifice, and, depending on the intensity that I can measure with the sonogram, I can quantify the degree of stenosis of the valve.”

Once your cardiologist has determined the extent and severity of the damage, they will begin exploring the specifics of the problem in more detail.