Ventricular Septal Defect (Congenital)

Incidence: About 2–6:1000 live births.

May be isolated or part of several complex malformations such as TOF.

Mortality higher in older children; elevated PVR (>7 Wood units); surgery may be complicated by complete heart block.

Worsening of L-to-R shunt with hyperventilation and increased FIO ₂

Paradoxical embolization

Hypothermia

Post–CPB pulm Htn and RV failure

Small defects asymptomatic, present with murmur, and usually close spontaneously.

Larger unobstructed defects result in CHF symptoms, poor weight gain, and URIs beginning at 3–12 wk of age, as decreases in PVR cause increase in L-to-R shunting.

Untreated large L-to-R shunting may result in fixed pulm Htn (Eisenmenger syndrome) in some pts.