Heart murmurs are caused by turbulent of blood flow through valves or ventricular outflow tracts.
It must be appreciated that the phenomena which cause murmurs may have effects throughout the body. Indeed a thorough examination may be sufficient for diagnosis and auscultation is required only as supportive evidence. In practise there is a limited combination of physical signs and murmurs.
Likewise, it will become apparent that the terms used to describe findings are a code which implies a specific diagnosis e.g. a continuous machinery-like murmur in a neonate indicates a patent ductus arteriosus.
Note low and medium frequency sounds (eg mid-diastolic murmurs) are more easily heard with the bell applied lightly to the skin. High frequency sounds (eg some regurgitant murmurs, ejection murmurs) are more easily heard with a diaphragm.
Note also that as far as a cardiologist is concerned, a heart murmur is not a sound - it is a murmur.
- Kirby B (1993).Clinical examination of the heart. Medicine International, 21(8), 294-99.
Last reviewed 11/2021