It is not a disease, but a kind of audible noise in auscultation. The heart, in his cycles, produces noises, the most spectaculars, and therefore, easier to listen / auscultate, which are generated by the valves in its movements. The blood in its movement generates sound but this sound is getting depressed in intensity from the heart on having to cross many layers to be heard from the exterior: cardiac muscle itself and its coverings, visceral fat, lungs interposition, bony structures (breastbone, ribs), muscles, breast tissue, fat, skin. Although all these slices, when we ear by auscultating the heart the blood movement, we named it “murmur” because it really resembles a blast. Luckily, in children, it is the regular specific sound in most cases since, logically, they have less thickness in layers, described above, filtrating the standard sound. Certain circumstances, also the normal ones (fever, exercise, stress…), are going to produce a more vigorous beat easing its perception; in fact, most of the children sent to a cardiologist due to a murmur, is because this one has been perceived in these circumstances. Heart murmurs are graded depending how loud the murmur sounds, and not on seriousness. There are perceived six grades: the less intense are grade I, and the more intense are grade VI. Murmurs in normal people are known by several names, indifferent: Functional murmurs, innocents…, they are of minimum intensity and are not accompanied by other signs nor symptoms.
The great majority of cardiac diseases are congenital injuries, and most of the acquired ones generate murmurs, which features are different to the functional murmurs. Injuries are not only diagnosed by the murmur, but also for further details of auscultation, medical examination and patients’ symptoms.
Although the auscultation and the medical examination by experimented doctors often accurately register murmurs, it is normal to perform some complementary examination (electrocardiogram, radiography, echocardiograms).