17.6 Heart Murmur Flashcards
A 5-year-old child presenting for day case dental surgery under general anaesthesia is found to have a
heart murmur that has not been documented previously.
a) What features of the history (5 marks) and examination (5 marks) might suggest that the child has a significant congenital heart disease (CHD)?
> > History suggestive of cardiac failure:
failure to thrive, difficulty feeding as a
neonate, recurrent chest infections,
cough, poor exercise tolerance.
> > Squatting, parental report of cyanosis.
> > Family history of congenital cardiac disease.
> > Syndrome known to be associated
with congenital cardiac disease:
Down’s, VATER, Turner’s.
What features of the examination (5 marks) might suggest that the child has a significant congenital heart disease (CHD)?
Examination:
> > Irregular pulse.
> > Features of the murmur:
innocent murmurs are either a continuous
venous hum or early systolic.
All others are likely to be pathological:
harsh, variable sound, presence of a precordial thrill.
> > Signs suggestive of cardiac failure:
tachypnoea, accessory muscle
use, crackles on auscultation,
cool peripheries, sweating, tachycardia,
hepatomegaly.
> > Cyanosis.
> > Features suggestive of a
syndrome associated with
congenital cardiac defects.
c) Which imaging modalities might be used in the assessment of the ASD (2 marks) and
what specific additional information may be obtained? (2 marks)
Echo (transthoracic or transoesophageal):
» To determine whether secundum
or primum defect:
assessment of involvement of tricuspid
and mitral valves and
shunt between ventricles.
> > Assess the direction of the shunt.
> > Assess for the presence of
pulmonary hypertension.
Cardiac MRI:
» 3D structure of heart lesion, valvular involvement, shunt volume.
Cardiac CT:
» 3D structure of heart lesion, chamber size.
Chest x-ray:
» Assess for presence of pulmonary oedema.
d) List the current national guidelines regarding prophylaxis against infective endocarditis in children
with CHD undergoing dental procedures. (4 marks)
> > Be aware of the increased risk
of infective endocarditis in these children.
> > Explain to patients and/or their
parents that risk of prophylaxis outweighs
benefits.
> > Do not give antibiotic prophylaxis.
> > Do not give chlorhexidine mouthwash.
> > Prompt treatment if infection does occur.
b) If the murmur is caused by an atrial septal defect (ASD), what ECG findings would you expect?
(2 marks)
- > > Prolonged PR interval.
- > > Right bundle branch block.
- > > Left axis deviation if primum defect,
right axis deviation if secundum defect
