Heart murmurs are abnormal, repeated sound waves produced by turbulent blood flow in the heart chambers and in the sections of the great vessels just beyond the valves. Normally, there is silence between heartbeats. Any sound heard during this silence is a murmur.
Causes:
Blood flowing through a narrowed area (e.g. narrowing of the aorta),
Blood flowing into a widened area (e.g. aortic aneurysm),
Roughness of the inner lining (intima) of the vessels (clot, atherosclerotic plaque, scar),
Increased speed of blood flow through normal structures (thyrotoxicosis, nervous excitement),
Changes in the flow properties of the blood – reduced viscosity (e.g. anemia),
In congenital defects of the heart chambers or the septum between them, when blood moves from a high-pressure chamber to a low-pressure one (e.g. ventricular or atrial septal defect).
A "heart murmur", which is found mainly in newborns and worries parents, can sometimes be harmless and sometimes be caused by a heart disease.
If the murmur is caused by a hole in the heart, it disappears once the hole is closed surgically or percutaneously. If the murmur is caused by a narrowed vessel, it decreases after the vessel is opened with balloon treatment, even if it does not disappear completely.
Information on this site is general and does not replace an examination by a doctor.