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EeroJokinen

Cardiac Murmur in a Child

Essentials

  • Approximately one child in a hundred has a congenital structural anomaly of the heart.
  • A vibratory sound is heard in at least every fifth child, and occasionally in more than half of the children (for example during fever).
  • Blood pressures from the right upper and lower extremities should be measured in each child with a systolic murmur to detect possible aortic coarctation.

Signs of congenital heart disease

  • Fatigue while sucking, poor weight gain, abnormal paleness, easy sweating and rapid breathing (> 40/min) may be signs of a heart defect in an infant.
  • Often the clinical condition of the child is quite normal in spite of a congenital heart malformation that requires surgery.
  • Cyanosis only around the mouth is usually an innocent finding caused by abundant vascularity in that area and slow peripheral circulation.
  • Cyanosis associated with congenital heart disease is always seen also in the face, trunk and tongue. The tongue reflects central blood circulation fairly well.

Systolic murmurs

Murmurs heard both in systole and diastole

  • A diastolic murmur is rarely innocent. Venous hum (audio samples Venous Hum Venous Hum) is the only benign diastolic murmur. The punctum maximum of this soft continuous murmur is at the root of the neck, above the clavicles, most clearly on the right side. The murmur disappears when the jugular veins are compressed, the head is turned or when the child lies down.
  • All other diastolic murmurs in children and adolescents require further examination by a specialist.
  • Patent ductus arteriosus (PDA) (audio samples Patent Ductus Arteriosus Coarctation of the Aorta) causes a murmur that is heard in systole and also continues to be heard after the second heart sound (continuous or "machinery" murmur). The punctum maximum is under the left clavicle. A small PDA may be associated with a systolic murmur audible in the pulmonary area.

Actions after detecting a murmur

  • See picture 1.
  • All cardiac murmurs heard, perhaps excluding very soft murmurs of I/VI grade, should be reported to the parents. A murmur heard during fever is usually a physiological ejection murmur, which may not be audible when the child has no fever. This is why a murmur heard during infection is not something to be alarmed about; it is enough to agree with the parents over when and where the child's heart will be auscultated next time. An exception to this rule are 1-2 month-old babies in whom a murmur should always be taken seriously.
  • When you give information about the murmur, it is best to mention that innocent murmurs are very common and that aortic coarctation has been ruled out in a child with normal blood pressures.
  • If a heart defect is suspected the child should be referred for further investigations.
    • Terms like 'a hole in the heart' should not be used. Neither should comments about cardiac surgery be made.
    • Normal physical activities should not be prohibited unless it is definitely and certainly necessary.
  • If the significance of the finding is uncertain and the child is in good health, the matter may be further investigated during the next child health clinic visit. However, the majority of significant structural heart defects is found during the first months of life, so murmurs heard in infancy should be well investigated.

Prophylaxis for endocarditis

  • See also recommendations on endocarditis prophylaxis Prevention of Bacterial Endocarditis and locally available guidance.
  • Prophylaxis for endocarditis denotes administration of a single dose of antimicrobials to provide protection against endocarditis in conjunction with tooth extraction or another procedure that causes laceration of the mucous membranes resulting in iatrogenic transient bacteraemia. It does not mean that antimicrobial medication should be more readily prescribed in common infections!
  • Endocarditis prophylaxis is only given to patients with a heart valve prosthesis, untreated cyanotic heart defect or turbulence adjacent to the prosthetic material, or who have a history of previous endocarditis. Endocarditis prophylaxis is not needed in other heart defects. Careful dental care is highly important in children and adolescents with a heart defect.