Murmurs

A heart murmur is a sign, the audible turbulence of blood flow through the heart or the major vessels; symptoms associated with heart murmurs vary by the underlying cause, as well as the nature and severity of any cardiac lesion producing the murmur. While the majority of heart murmurs are normal or innocent, they must be distinguished from the pathologic murmurs of congenital or acquired cardiac disease. Whereas <1% of the population has significant structural congenital cardiac disease, as much as 85% of the population may have a heart murmur during childhood; causes vary by the age of the patient at presentation. The causes of congenital heart disease are varied and include genetic disorders, metabolic disorders, teratogens, and syndrome complexes. The causes of acquired heart diseases in children include rheumatic fever, endocarditis, and cardiac injury caused by systemic illnesses. Whereas the echocardiogram defines the significance of pathologic heart abnormalities, the only way to definitively diagnose an innocent murmur is with a stethoscope.