Ventricular Septal Defect (VSD), Congenital

• • A congenital heart lesion that increases pulmonary arterial blood flow

  • Results in left-to-right shunt, results in lung infection, pulmonary vascular congestion, pulmonary artery (PA) hypertension, right heart failure, pulmonary vasoconstriction, pulmonary vascular obstructive disease

  • Eisenmenger syndrome: Increased pulmonary hypertension such that left-to-right shunt ceases and shunt becomes right-to-left, requiring heart-lung transplant

  • Inhaled nitric oxide, oxygen, or IV tolazoline reverses PA vasoconstriction

  • PA band is palliative and can reduce PA flow to alleviate RV failure and progression of pulmonary hypertension

  • Defects occur in 4 anatomic positions

  • -Perimembranous septum (85%), anterior to crista supraventricularis, beneath leaflet of tricuspid valve, or muscular septum

  • Often associated with more complex defects: Truncus arteriosus, AV canal defect, tetralogy of Fallot, transposition of great arteries

  • Isolated perimembranous defects may have associated patent ductus arteriosus (PDA), aortic coarctation

  • Supracristal defects may have aortic regurgitation

Epidemiology

• • VSD accounts for 25% of congenital cardiac anomalies

  • In infants, 33% of defects are small, many close spontaneously by age 8

Symptoms and Signs

• • If defect small, asymptomatic

  • If large, heart failure with dyspnea, frequent respiratory infections, poor growth

  • Pansystolic murmur at left lower sternal border

  • Loud S2 with apical diastolic flow murmur and biventricular enlargement

  • Dyspnea on exertion, poor weight gain, easy fatigability

  • Chronic respiratory difficulties, poor feeding

  • Pulmonary vascular disease may develop

Imaging Findings

• • Chest film: Enlarged heart, congested lung fields

  • Echocardiography: Diagnostic

  • Catheterization: If older defect or young child: Assess pulmonary artery pressure and vascular resistance

• • May be a part of a more complex defect (truncus arteriosus, AV canal defect, tetralogy of Fallot)

  • Isolated perimembranous defects may also have PDA or aortic coarctation

  • Supracristal defects occasionally have aortic valve regurgitation

• • Physical exam

  • Echocardiography

  • Cardiac catheterization selectively

• • 33% have small defects, often close spontaneously by age 8

  • 33% have large defects (symptomatic) require aggressive treatment

  • Synthetic patch closure, sutures away from conduction system

  • May require deep hypothermic circulatory arrest

  • Percutaneous device closure recently used

Surgery

Indications

• • Medically refractory symptoms in infant

  • Elevated PA pressure

  • Canal-type defect or malaligned conoventricular defect

  • Aortic insufficiency (supracristal defect)

Complications

• • Risk of damage to conduction system

Prognosis

• • Operative mortality rare

  • Severe preoperative failure: Mortality, 3-5%

  • Symptomatic improvement dramatic

  • Pulmonary resistance: No change

References