Heart murmurs are sounds produced by the rapid flow of blood in the heart. These sounds can be heard with a stethoscope. Under normal conditions (proper opening and closing of the valves ), this blood flow is silent and therefore not audible during auscultation. However, for various reasons, turbulent flow can occur through these valves, which is heard as a whistling sound; this is what we call a murmur.
When a heart murmur is heard during auscultation, all we know is that there is turbulence in the blood as it passes through the heart valves . As such, it is not a diagnosis of a disease, since it can occur for many reasons, from physiological causes to those indicating an underlying problem that requires attention.
Some heart murmurs are harmless, also known as " functional " or "innocent," and are common in newborns and children. Functional murmurs can occur with fever or anemia, in cases of hyperthyroidism, or during pregnancy without indicating a heart problem. These are harmless and not a sign of heart disease because the heart is structurally normal. Innocent murmurs require no treatment or lifestyle changes and tend to disappear over time.
Just as there are innocent or physiological heart murmurs that should cause no concern, there are other murmurs caused by a problem with one of the heart valves, such as an abnormality in its opening or closing, or by a defect in the heart's septum. These are pathological murmurs that can be a sign of serious heart disease.
To distinguish between them, an echocardiogram may be necessary . An echocardiogram is a non-invasive test that uses ultrasound to assess the heart's chambers, structures, and blood flow. It allows us to see if the valves and other structures are functioning correctly to rule out heart disease and, if any is found, to determine its severity.
In children , murmurs that cause concern are usually due to a problem with the structure of the heart that is present from birth, due to the involvement of a valve or due to an abnormal communication between two chambers.
In adults , heart murmurs that cause concern are usually due to heart valve problems that develop over a lifetime. Diseases that can damage heart valves include the age-related buildup of calcium deposits that affect the opening (stenosis) and closing (insufficiency) of the valves, known as degenerative valve disease ; infection of the inner lining of the heart and valves, known as endocarditis ; and valve damage from rheumatic fever.
Treatment will depend on the type of pathology and severity, and may be monitored with lifestyle recommendations until correction of the defect is proposed through surgery or hemodynamic techniques when it is serious and/or symptoms appear.
By Dr. Alejandra Carbonell , Head of the Valvular Heart Disease Unit at UICAR