What is a heart murmur?

A heart murmur is an extra sound that doctors or nurses hear when they listen to the heart with a stethoscope. It usually sounds like an extra “whoosh” or “swish”.

Simply speaking, the heart muscle is a pump that:

1. receives oxygen-deprived, carbon dioxide-rich blood from the veins

2. pumps it to the lungs where it loads up on the former and gets rid of the latter

3. redistributes it back to the body and brain.

For the heart muscle to efficiently perform this role with the smartest amount of energy expenditure and the shortest time possible, there is a four-valve system set in place: two on the right side of the heart called tricuspid and pulmonic valves, and two on the left side called mitral and aortic valves. Working in concert, the four valves are responsible for a one-way flow of circulation inside the cardiac cavities (or chambers).

A heart murmur happens when the sound of blood flowing through the heart valves is loud enough to be heard. This can happen when:

a) the heart valves are normal but the flow of blood is high as it is in early life or pregnancy or some conditions like anaemia or overactive thyroid.

b) when there is an abnormal change in the way that the heart valves work. In that case, the valves could leak too much and let blood splash backward, called regurgitant valves, or they can get tight and not open well — stenotic valves.

Less frequently, murmurs could be related to the presence of holes, or defects, between the right and left sides of the heart, or between the heart and the surrounding vessels.

Most common holes are in the septum separating the upper heart chambers called atria — hence the name atrial septal defect — or between the lower cardiac cavities named ventricles, and the communication in that case is called ventricular septal defect.

How do I know if I have a heart murmur?

Most people learn that they have a heart murmur during a routine physical exam. If your doctor or nurse hears a murmur, he/she might have you hold your breath or change your position while they listen to your heart.

This will tell the healthcare professional more about the specifics of the murmur and its timing in the cardiac cycle. If it happens during heart contraction or systole, the murmur is called systolic murmur. If it occurs during the heart filling phase or diastole, it is called diastolic murmur.

Does it mean I have a heart problem?

Not always. As mentioned above, people with normal hearts and blood vessels can have heart murmurs. Doctors call these “innocent” murmurs. People of any age can have an innocent heart murmur, though they are especially easy to hear in people who are young, thin, or pregnant.

Will I need tests?

Maybe. When your doctor or nurse first hears a heart murmur, he or she will want to know if it is innocent or abnormal. He or she will ask you questions and do an exam. If your heart murmur is innocent, you will not need any tests. If your doctor or nurse thinks your heart murmur might be abnormal or they are not sure, they might order a test to find out what’s causing the murmur.

The test most commonly used is an echocardiogram, also called an echo. This test uses ultrasound waves to create a picture of your heart as it beats. It shows the size of the heart chambers, how well the heart is pumping, how good the heart valves are working, and if there are any holes or defects.

How is an abnormal heart murmur treated?

The treatment depends on the heart condition that is causing the abnormal murmur. It also depends on how serious the condition is.

If your heart condition is not serious, you might not need any treatment. But your doctor will follow your condition to see if it changes or gets worse over time. If your heart condition is serious or gets to be so, you might need a treatment. Treatment might involve a surgery.

Do I need antibiotics before I go to the dentist?

Probably not. In the past, doctors recommended that many people with a heart murmur take antibiotics before going to the dentist or having certain medical or dental procedures.

But now, only people with certain heart conditions need antibiotics before going to the dentist or having such procedures. This applies mainly to patients with advanced heart anomalies that they were born with, called advanced congenital heart disease, or who had at some point, some procedures done to their hearts like prostheses or devices

•This column is the first of three articles on diseases of the heart valves. Joe Yammine is a cardiologist at Bermuda Hospitals Board. He trained at the State University of New York, Brown University and Brigham and Women’s Hospital. He holds five American Board certifications. He was in academic practice between 2007 and 2014, when he joined BHB. During his career in the US, he was awarded multiple teaching and patients’ care recognition awards. The information herein is not intended as medical advice nor as a substitute for professional medical opinion. Always seek the advice of your physician. You should never delay seeking medical advice, disregard medical advice or discontinue treatment because of any information in this article.