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  • • A congenital heart lesion that decreases pulmonary arterial blood flow resulting in a right-to-left shunt

    • Cyanosis and decreased oxygen delivery causes compensatory polycythemia (Hct > 70%) and spontaneous thrombosis

    • Exercise, acidosis, pain worsens cyanosis, can cause hypoxic spells

    • Squatting increases systemic resistance, causing increased pulmonary flow and oxygen saturation

    • β-Blockers (decreases spasm), fluid intake, HCO3 administration, norepinephrine (increases systemic resistance) may help decrease hypoxia

    • Clubbing due to proliferation of capillaries and AV fistulas in extremities

    • Bronchial and mediastinal arteries enlarge

    • Ductus arteriosus maintains flow to lungs during fetal development

    • Alprostadil early can allow time for optimization before definitive treatment

    • 4 anomalies:

    • 1. Ventricular septal defect (VSD)

      2. Pulmonary stenosis or atresia

      3. Overriding aorta

      4. RV hypertrophy

    • Pulmonary stenosis may involve infundibulum, valve, or main pulmonary artery (PA)

    • Extent of pulmonary atresia/stenosis has wide spectrum of severity

    • Pulmonary flow depends on aortopulmonary collaterals, can be extensive enough to cause congestive heart failure

    • Spasm of infundibular muscle may cause unconciousness and death

Symptoms and Signs

  • • Symptoms related to amount of pulmonary blood flow

    • With close of ductus, cyanosis and acidosis may be severe

    • Hypoxic spells and cyanosis may lead to cerebral hypoxia and death

    • Squatting and clubbing

    • Prominent RV impulse, single S2

    • Ejection murmur, left third intercostal space

    • Murmur softens during cyanotic spell

Laboratory Findings

  • ECG: RV hypertrophy

Imaging Findings

  • Chest film: Small heart size + cyanosis + decreased pulmonary flow

    Echocardiography: Confirms diagnosis

    Catheterization: Necessary to define size of pulmonary arteries and identify aortopulmonary arteries

  • • Consider other congenital anomalies

    • Diminutive PA can lead to right heart failure with operative repair

    McGoon ratio: Diameter of PAs normalized to diameter of aorta > 2.0

  • • Chest x-ray

    • ECG

    • Echocardiography, cardiac catheterization

  • • Most symptomatic at diagnosis

    • Alprostadil, HCO3, oxygen

    One stage correction: Patch repair of VSD, patch to infundibulum to widen outflow tract, pulmonary insufficiency tolerated in child, may not be long-term

    Two stage: Initial systemic-PA shunt, later stage definitive correction

    Tetralogy of Fallot with pulmonary atresia: Connect large aortopulmonary shunts to RV outflow or to shunt; induces growth of vasculature


  • • Operative options to increase pulmonary flow:

    • -Blalock-Taussig shunt: Subclavian artery to ipsilateral PA end to side fashion

      -Modified Blalock-Taussig shunt:

      Subclavian to PA using PTFE

      -Glenn: Superior vena cava (SVC) to PA shunt

      -Fontan: SVC and inferior vena cava (IVC) rerouted to PA

      -Excision of obstructive muscle, patch enlargement of infundibulum, and valve replacement


  • • Once diagnosed, repair


  • • RV dysfunction common

    • Mortality < 5% in stenosis; 30-45% in atresia

    • ...

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