PATHO

• MC cyanotic CHD

1. Stenotic pulmonary artery ➔ right ventricle outflow obstruction

2. Stenosis ➔ RVH ➔ boot shaped CXR

3. VSD (stenotic pulmonary artery ➔ ↑ RV pressure ➔ R ➔ L shunt ➔ cyanosis)

4. Aorta overrides septal defect (can be really close to defect)

   • Degree of stenosis ➔ severity of cyanosis

SSX

• Mild obstruction ➔ mild cyanosis; severe obstruction ➔ severe cyanosis

• Tet spell: hypercyanosis with stressor (feeding, pooping, crying, activity)

  • Squatting ➔ ↑ afterload ➔ temporary shunt reversal ➔ sx relief

• Harsh systolic murmur of VSD

DX

• ECHO (fetal echo ➔ dx before birth)

• CXR shows boot shaped heart (RVH moves LV over)

TX

• Newborn gets prostaglandin to maintain PDA til surgery (can cause apnea, secure airway first)

• If missed prenatally and presents with severe RV outflow obstruction (activity/stressor ➔ tet spell)

  • O2 (duh?), knees to chest, sedate (morphine), ± β-blockers

• HF sx get ionotropes and loops (ACEi contraindicated)

PATHO

• Dextro: Reversal of aorta and pulmonary artery

  • RV ➔ aorta ➔ body ➔ RA (circuit of deoxy blood)

  • LV ➔ pulmonary artery ➔ lungs ➔ LA (circuit of oxygenated blood)

  • Survival depends on connection between circuits via VSD, PDA, ASD

• Levo: Vessels in appropriate place but ventricles swapped

  • No obvious sx at birth but the tricuspid valve isn't designed for high pressure ➔ ↑ risk of HF

SSX

• Dextro: Low O2 sat despite supplemental O2

DX

• ECHO

• CXR shows egg on string - (enlarged heart ➔ egg, atrophy of thymus ➔ string)

TX

• Maintain mixing of two circuits: Prostaglandin infusion to maintain PDA, ± balloon septostomy to enlarge or create ASD until

  • until arterial switch operation