Benign functional heart murmur

Heart murmurs represent abnormal sounds heard during the heartbeat. In general, most of these sounds are completely harmless, so they are also called normal, benign, physiologic, flow, Still’s or innocent heart murmurs. However, sometimes, these sounds may also indicate certain heart problems and doctors are trained to determine the abnormality by listening to heart murmurs.

Children may have heart murmurs from the day they were born but adults may acquire them due to some medical problem or disease. The sounds could vary from very faint to extremely loud or cause the swishing noise and if associated with some other symptoms or signs, doctors may look for heart problems that have caused it.

About Heart Murmurs

As mentioned earlier, heart murmurs can be harmless (innocent) or abnormal. Children with innocent murmurs are healthy and they have no heart problems. On the other hand, abnormal murmurs are usually accompanied by some other signs and symptoms indicating certain heart problems such as congenital heart disease (if the murmur is present since birth), but also some other diseases, infection or in elderly just by the aging process.

These extra or unusual sounds may be heard like whooshing or swishing noise in some of the patients. Doctors use stethoscope to listen to the heart and determine the nature of these heart murmurs. The things doctors pay attention to when listening to these sounds are location, loudness of the murmur and also their timing. After this, they are able to say which type of murmurs the patient is suffering from.

If there are some other symptoms of the heart disease and the murmurs are diagnosed as abnormal, patients might be experiencing some heart problem. Abnormal heart murmurs are commonly caused by some heart defects present at birth (known as congenital defects of the heart). In the adult patients, abnormal heart murmurs may be provoked by infection, aging or some other medical condition happening in the body.

Heart murmur is the most common reason for a referral to a pediatric cardiologist. Virtually all children have a heart murmur during their childhood. Less than 1% of murmurs are pathological in children. Innocent/functional heart murmur is the most common type of heart murmur. There are multiple theories proposed to identify etiology of innocent heart murmur with varying consensus, but everybody agrees that innocent heart murmur does not carry any morbidity or mortality risk.

Murmur is a sound produced by vibrations caused by the flow of blood through the heart. Several different mechanisms are proposed regarding the development of any murmur such as turbulence from the blood flow, cardiac vibrations, Bernoulli effect, eddy current, etc.
Innocent heart murmurs in children can be categorized under four distinct groups: Still’s vibratory murmur, pulmonary flow murmur, supraclavicular systemic flow murmur, and venous hums. Many high output states like anemia, fever, arteriovenous malformation, etc. can also result in heart murmur.
Diagnosis of heart murmur, even if innocent, is associated with significant healthcare resource utilization and parental/caregiver anxiety. Appropriate use criteria for initial transthoracic echocardiography were released by the American Academy of Pediatrics, American Heart Association, American Society of Echocardiography, Heart Rhythm Society, etc. in the year 2014 which clearly notes transthoracic echocardiogram for presumed innocent heart murmur as “rarely appropriate” indication.
There are a few commercially available softwares in the market designed to aid with determining pathological nature of a heart murmur. These softwares have improved significantly over time but they still lag high specificity and sensitivity for making an accurate diagnosis consistently.

✓ Fact confirmed: Innocent Heart Murmur Arpan R Doshi; 2018 Dec 5.

How to Treat Heart Murmurs?

Innocent heart murmurs in healthy children do not require any therapy. The heart of these kids is completely healthy and does not have to be treated but just regularly checked. Pregnant women may also have some innocent heart murmurs because of the increased volume of the blood during this period of their life. However, this problem also does not need to be treated in any way.

Some patients can have heart murmurs due to other medical conditions such as anemia, fever or hyperthyroidism (overactive thyroid gland). Once the primary condition is properly managed, heart murmurs usually resolve too.

Abnormal heart murmurs are treated according to the cause of the problem. Drugs and surgery are options for congenital heart defects or some other heart problems.