A heart murmur is a sound that occurs when blood flows abnormally through the heart or heart valves. This condition is common and usually not a cause for concern.
When the heart beats, it makes two rhythmic sounds in a row with a noise that is described as “lub-dub.” If a heart murmur is present, the sound is different and often is described as a “swish” or “whoosh.” These “swish” and “whoosh” sounds can be heard with a stethoscope; heart murmurs are not audible to the human ear.
Most heart murmurs are not harmful and do not need treatment. These are called “innocent” murmurs, and they are common in babies and children. Sometimes, however, a murmur is a sign of a heart abnormality. If your doctor detects a murmur, they may recommend additional testing of your heart and valves.
Murmurs vary in terms of how loud they are, when they occur and how long they last. Health care providers assign a rating to heart murmurs, on a scale of 1 to 6. Murmurs with a rating of 1 are very quiet while those with a rating of 6 are loud.
Heart murmurs are divided into categories, depending on when they occur during the heartbeat cycle:
A murmur heard when the heart muscle contracts and pushes blood out of the heart is called a systolic murmur. If the noise is heard when the blood flows through a faulty valve or vessel, it is an ejection murmur. If the noise is heard when the blood flows backwards through the valves or vessels, it is a regurgitant murmur.
A murmur heard when the heart muscle relaxes between beats is called a diastolic murmur.
A continuous murmur can be heard when the heart muscle contracts and also when it relaxes. Continuous murmurs occur throughout the entire heartbeat cycle.
Systolic murmurs are often innocent murmurs. Diastolic or continuous murmurs are more likely to indicate a cardiac problem.
Innocent murmurs are not caused by heart abnormalities. Instead, they result from changes in blood flow due to temporary situations, including infections or having a fever, iron deficiency, overactive thyroid, growth spurts in children, increased physical activity or pregnancy. These murmurs may come and go at different times without causing other health problems.
Murmurs related to other cardiac conditions that may need treatment can be caused by:
Innocent murmurs generally do not cause symptoms and are often discovered during a routine exam by a health care provider.
Murmurs related to other cardiac conditions may cause symptoms. The symptoms vary, depending on the cause, and may include:
Babies born to mothers with uncontrolled diabetes or to mothers who use alcohol or drugs during pregnancy have an increased risk of heart murmurs.
In adults, certain cardiac conditions can increase the risk of developing heart murmurs. Heart infections, heart disease, high blood pressure, blood disorders or autoimmune disease may increase the risk for heart murmurs.
Heart murmurs cannot be prevented, but maintaining a heart-healthy lifestyle can reduce the risk of cardiac conditions related to murmurs. Children with heart murmurs often “outgrow” the condition as they get older.
Many murmurs are diagnosed while a health care provider is listening to the heart with a stethoscope. If a murmur is detected, your provider may recommend testing to determine whether the murmur is innocent, or if it indicates a heart problem. Testing can include:
This test uses sound waves to see the blood flow through the heart and heart valves to detect heartbeat abnormalities.
Also called an EKG or ECG, this test measures the heart’s electrical activity.
X-ray technology takes a picture of the heart to identify enlargement or other structural defects.
Innocent murmurs generally do not require any treatment. Sometimes they go away on their own, or they may persist but do not typically cause problems.
Murmurs caused by conditions like anemia (low iron levels) or hyperthyroidism (overactive thyroid) may disappear if the underlying condition is resolved.
If a murmur is caused by another heart problem, medication or surgical intervention may be necessary.
Treating underlying conditions that cause murmurs with medication can be beneficial. These medications can include blood thinners to prevent blood clots, ACE inhibitors, beta blockers or diuretics to lower blood pressure.
Murmurs that are caused by structural heart problems can be resolved by surgical intervention to correct the underlying problem. Depending on the specific condition, procedures can include minimally invasive or open heart surgery to repair damaged heart valves or to patch holes in the heart.
The experienced heart and vascular specialists affiliated with Memorial Hermann are dedicated to diagnosing, treating and managing a wide range of cardiac conditions with a patient-centered approach.
If your heart murmur is caused by an underlying cardiac condition, it is important to identify and control or correct the problem. From minimally invasive cardiac therapies to complex open heart surgical interventions, Memorial Hermann is at the forefront of innovative technology and the latest research to keep you heart-healthy.
If you’d like a referral to a heart and vascular specialist or want more information about our services, please fill out the form below or call us at (713) 219-3519. For other inquiries, such as obtaining medical records, imaging reports or test results, please call (713) 222-CARE (2273).