Heart murmur

Heart murmurs are unique heart sounds produced when blood flows across a heart valve or blood vessel. This occurs when turbulent blood flow creates a sound loud enough to hear with a stethoscope. The sound differs from normal heart sounds by their characteristics. For example, heart murmurs may have a distinct pitch, duration and timing. The major way health care providers examine the heart on physical exam is heart auscultation; another clinical technique is palpation, which can detect by touch when such turbulence causes the vibrations called cardiac thrill. A murmur is a sign found during the cardiac exam. Murmurs are of various types and are important in the detection of cardiac and valvular pathologies (i.e. can be a sign of heart diseases or defects). There are two types of murmur. A functional murmur is a benign heart murmur that is primarily due to physiologic conditions outside the heart. The other type of heart murmur is due to a structural defect in the heart itself. Murmurs may be diagnosed as innocent or pathologic, with innocent murmurs all being physiologic, and pathologic murmurs, by contrast, having a wide variety of characteristics and having some sort of pathologic significance. Defects may be due to narrowing of one or more valves (stenosis), backflow of blood, through a leaky valve (regurgitation), or the presence of abnormal passages through which blood flows in or near the heart. It is estimated that 66% of children have heart murmurs at some point during childhood, with up to 60% of these being diagnosed as innocent by a pediatric cardiologist. The most common innocent murmurs include the Still’s murmur, a low-pitched murmur caused by blood flow in the ventricular outflow tract, as well as pulmonary and systolic murmurs. Most murmurs are normal variants that can present at various ages...