Tetralogy of fallot

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  • Most common cyanotic CHD manifesting in post-infancy period. Tet spells are acute episodes of hypoxia and cyanosis caused by right-to-left shunting across the VSD. Patients will present with irritability, agitation, grunting, crying, and central cyanosis.


  1. VSD
  2. RV outflow obstruction (pulmonic stenosis)
  3. Overriding aorta
  4. RV hypertrophy

Clinical Presentation

  • Systolic ejection murmur along the left sternal border[1]
  • Cyanosis worse during feeding and crying[1]
  • May squat to relieve symptoms: increases afterload and decreases shunt[1]
  • Acute respiratory distress (Tet Spells) due to increased right outflow tract obstruction[1]


  • Echo
  • CXR: shows the classic “boot-shaped” heart

Differential Diagnosis

Congenital Heart Disease Types


  • Definitive Treatment: Surgery
  • Acute Presentation (Tet spell):
  1. Valsalva
  2. Place in knee-chest position
    1. Increases SVR > more blood into pulm ciruclation
  3. Morphine 0.1-0.2Mg/kg IV or IM
    1. Mechanism of action unclear
    2. Consider Intranasal Fentanyl
  4. Fluids IV
    1. Improves RV filling
  5. Beta blockers IV
    1. Relaxation of RVOT
  6. Phenylephrine
    1. Similar to knee-chest position
  7. Prostaglandin E1 0.1 mg/kg bolus followed by infusion 0.05 to 0.1 mg/kg/min
    1. Maintains the ductus
    2. Side Effects: Hypotension, Bradycardia, Seizures and Apnea

See Also


  1. 1.0 1.1 1.2 1.3 Horeczko T, Inaba AS: Cardiac Disorders; in Marx JA, Hockberger RS, Walls RM, et al (eds): Rosen’s Emergency Medicine: Concepts and Clinical Practice, ed 8. St. Louis, Mosby, Inc., 2014, (Ch) 171: p 2139-2169.
  2. Knipe K et al. Cyanotic congenital heart diseases. Radiopaedia. http://radiopaedia.org/articles/cyanotic-congenital-heart-disease