Tetralogy of Fallot
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- Tetralogy of Fallot is a ventricular septal defect associated with right ventricular (RV) outflow obstruction (infundibular and/or valvular pulmonic stenosis), concentric RV hypertrophy, and overriding aorta (1).
- Pathophysiology depends primarily on severity of RV outflow tract obstruction.
- RV and left ventricular (LV) pressures generally are equal owing to the defect.
- RV pressures can be elevated with ventricular septal defect proximal to the level of RV obstruction.
- Right-to-left shunting predominates, resulting in varying degrees of arterial oxygen desaturation.
- System(s) affected: cardiovascular, pulmonary
Pregnancy is usually well tolerated following successful surgical repair.
- 5–10% of all congenital heart disease (1)
- Most common cardiac anomaly within the 1st year of life requiring intervention
- Predominant age: newborn; case reports of adult presentation
- Predominant sex: male = female
In the United States: 3.9/10,000 live births
Etiology and Pathophysiology
- Minority of cases are familial, autosomal dominant mode of inheritance.
- 20% association with velocardiofacial syndrome (22q11 deletion) by FISH analysis
- Predominately sporadic
- Increased incidence with advanced maternal age
Commonly Associated Conditions
- Stenotic pulmonary artery
- Patent ductus arteriosus
- Atrial septal defect
- Right-sided aortic arch: 25%
- Atrial septal defect: 15%
- Anomalous coronary arteries: 9%
- 20–25% associated with a syndrome, including Down, Alagille, DiGeorge, and velocardiofacial