Ventricular Septal Defect

BASICS

DESCRIPTION

  • Congenital (usually) or acquired defect in the interventricular septum that allows communication of blood between the left and the right ventricles
  • Second most common congenital heart malformation reported in infants and children. It can also occur as a late complication of acute myocardial infarction (MI).
  • Severity of the defect is correlated with its size, with large defects being the most severe.
  • Blood flow across the defect typically is left to right, depending on defect size and pulmonary vascular resistance (PVR).
  • Prolonged left-to-right shunting of blood can lead to pulmonary hypertension (HTN). This may eventually lead to a reversal of flow across the defect and cyanosis (Eisenmenger complex)

Geriatric Considerations
Almost entirely associated with late complication of MIPediatric Considerations
Congenital defect

ALERT
  • Pregnancy may exacerbate symptoms and signs of a ventricular septal defect (VSD).
  • Can be tolerated during pregnancy if VSD is small
  • May be associated with an increased risk of preeclampsia in women with an unrepaired VSD

EPIDEMIOLOGY

Incidence

  • Congenital defect: no gender predilection, occurs in ~2/1,000 live births and accounts for 30% of all congenital cardiac malformations
  • Post-MI: Some studies suggest that gender may play a role.

Prevalence

In the United States:

  • Occurs in ~50% of all children with congenital heart disease
  • Low prevalence in adults (~0.3 per 1,000) due to spontaneous closure
  • Post-MI complication in ~0.2–3% of cases

ETIOLOGY AND PATHOPHYSIOLOGY

  • Congenital
  • In adults, late complication of MI
  • Some reports of iatrogenic causes

Genetics

Multifactorial etiology; autosomal dominant and recessive transmissions have been reported.

RISK FACTORS

  • Congenital VSD:
    • Risk of sibling being affected: 4.2%
    • Risk of offspring being affected: 4%
    • Prematurity
  • Post-MI VSD:
    • Advanced age
    • Arterial HTN
    • First MI
    • Most frequent within 1st week after MI
    • Most commonly after anterior wall acute MI

GENERAL PREVENTION

Avoid prenatal exposure to known risk factors (ibuprofen cyclooxygenase [COX] inhibitors, marijuana, organic solvents, febrile illness). For adults, avoid risk factors for MI and obtain evaluation before pregnancy.

COMMONLY ASSOCIATED CONDITIONS

  • Congenital:
    • Tetralogy of Fallot
    • Aortic valvular deformities, especially aortic insufficiency and bicuspid aortic valve
    • Down syndrome (trisomy 21), endocardial cushion defect
    • Transposition of great arteries
    • Coarctation of aorta
    • Tricuspid atresia
    • Truncus arteriosus
    • Patent ductus arteriosus
    • Atrial septal defect
    • Pulmonic stenosis
    • Subaortic stenosis
  • Adult: coronary artery disease

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