Congenital Heart Disease in the Emergency Department

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Ventricular Septal Defect (VSD)

VSDs are common, accounting for 30% of all cases of congenital heart disease. There is a defect anywhere in the ventricular septum (Fig 2), perimembranous (adjacent to the tricuspid valve) or muscular (completely surrounded by muscle).

They can be classified according to the size and location of the VSD.

Small and large

Peri-membranous, outlet, inlet or muscular

Small VSDs are smaller than the aortic valve in diameter, perhaps up to 3 mm. Large VSDs and complete AVSDs are the same size or bigger than the aortic valve.

Fig 2: VSD

Aorta

(i) Small VSD

Clinical presentation

Symptoms
  • Asymptomatic
Physical Signs
  • Loud pansystolic murmur at lower left sternal edge (loud murmur implies that it is not a large defect)
  • Quiet pulmonary second sound (P2)

Investigations

Chest radiograph
  • Normal
ECG
  • Normal
Echocardiography
  • Demonstrates the precise anatomy of the defect. It is possible to assess its haemodynamic effects using Doppler echocardiography. There is no pulmonary hypertension.

Management

These lesions will close spontaneously. This is ascertained by the disappearance of the murmur with a normal ECG on follow-up by a paediatrician or paediatric cardiologist and by a normal echocardiogram. Whilst the VSD is present, prevention of bacterial endocarditis is attempted by maintaining good dental hygiene.

(ii) Large VSD

Clinical presentation

Symptoms
  • Heart failure with breathlessness and faltering growth after 1 week old
  • Recurrent chest infections
Physical Signs
  • Tachypnoea, tachycardia and enlarged liver from heart failure
  • Active precordium
  • Soft pansystolic murmur or no murmur (implying large defect)
  • Apical mid-diastolic murmur (from increased flow across the mitral valve after the blood has circulated through the lungs)
  • Loud pulmonary second sound (P2) from raised pulmonary arterial pressure

Investigations

Chest radiograph
  • Cardiomegaly
  • Enlarged pulmonary arteries
  • Increased pulmonary vascular markings
  • Pulmonary oedema
ECG
  • Biventricular hypertrophy by 2 months of age
  • Superior axis in AVSD
Echocardiography
  • Demonstrates the anatomy of the defect, haemodynamic effects and pulmonary hypertension (due to high flow).

Management

The indications for surgical repair depend on the size of the VSD, degree of shunting, and associated lesions. Young infants with large VSDs, refractory heart failure, and large shunts should undergo surgical closure of the defects in infancy.