Editors

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

The tone of an innocent murmur (audio samples Physiological Ventricular Vibration Murmur Physiological Ejection Murmur in the Pulmonary Area Physiological Sound of Ejection) is mostly vibratory and of the ejection type (crescendo-diminuendo pattern). It is usually heard best in the third intercostal space on the left side of the sternum. The murmur is clearly less audible in the standing position.
In ventricular septal defect (VSD; (audio samples Muscular Vsd (Ventricular Septal Defect) Perimembranic Vsd (Ventricular Septal Defect) beneath the Tricuspid Valve Perimembranic Subaortal Vsd (Ventricular Septal Defect)) the murmur is usually plateau-shaped. It begins immediately with the first heart sound and ends with the second. The punctum maximum of the murmur is located in the 3rd-4th intercostal space.
In atrial septal defect (ASD; (audio samples Asd (Atrial Septal Defect) Secundum Asd in an 11-Year-Old Child) the punctum maximum is usually in the second to third i.c. space on the left side. The second heart sound is permanently split, also during expiration. Sometimes an additional weak systolic murmur is heard over the pulmonic area. ECG usually shows partial right bundle branch block.
A cardiac murmur with its punctum maximum high on the right side of the sternum is suggestive of a bicuspid aortic valve (audio sample Bicuspid Aortic Valve) or aortic stenosis (audio sample Valvular Aortic Stenosis). The latter radiates up to the neck. Echocardiography is indicated.
The tone of a murmur caused by pulmonary stenosis (audio samples Valvular Pulmonic Stenosis Pulmonary Stenosis)is harsher than that associated with an ASD or that of a physiological ejection sound of the pulmonary valve. The murmur may also be audible in the back.
No systolic murmur should be regarded as physiological before the possibility of aortic coarctation is ruled out. In addition to palpation of femoral pulses, blood pressures must be measured in right upper and lower extremities. Normally the systolic BP is at least as high in the lower as in the upper extremity. A murmur caused by aortic coarctation (audio samples Tight Aortic Coarctation Coarctation of the Aorta) can usually be heard better from the back side than the front. The punctum maximum is between the scapula and spine on the left side. In a young infant with left heart failure, there may be no murmur audible.
A physiological ejection murmur is a diagnosis by exclusion.

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.

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Information

Editors

Cardiac Murmur in a Child

Essentials

Signs of congenital heart disease

Systolic murmurs

Murmurs heard both in systole and diastole

Actions after detecting a murmur

Prophylaxis for endocarditis