Functional murmur


A functional murmur is a heart murmur that is primarily due to physiologic conditions outside the heart, as opposed to structural defects in the heart itself. Serious conditions can arise even in the absence of a primary heart defect, and it is possible for peripheral conditions to generate abnormalities in the heart. Therefore, caution should be applied to use of the terms "innocent" or "benign" in this context.Use of the term dates to the mid 19th century.

Benign pediatric heart murmur

Functional murmurs are an important consideration in the precordial examination of an infant or child.

Presentation

  • Soft, less than 3/6 in intensity
  • Often position-dependent. Murmurs heard while supine and may disappear when upright or sitting.
  • Otherwise healthy individual, no concerns about growth, no symptoms of heart failure such as dyspnea on exertion.
  • Occurs during systole or continuously during both systole and diastole.
  • Physiologic splitting of S2
  • No palpable thrill

    Diagnosis

Types, and DDx

In the adult, hyperdynamic circulation of the blood may also produce a functional murmur, such as in anemia or thyrotoxicosis.

Prognosis

Innocent murmurs are inconsequential and usually disappear as the child grows. ECG and Chest XRAY are normal.