Tricuspid atresia

Background

• A cyanotic congenital heart defect
• Absence of tricuspid valve resulting in absence of communication between the right atrium and right ventricle
• Due to absence of communication with the right ventricle, RV becomes either under-developed or entirely absent
• Third most common cyanotic congenital heart disease

Associated cardiac lesions

• ASD (100%)
• Right ventricular hypoplasia (100%)
• VSD (95%)
• Pulmonary outflow obstruction (75%)
• Transposition of the great arteries (28%)

Physiology

• Blood from the RA must exit through the ASD (no tricuspid valve)
• Right to left atrial shunting allows deoxygenated systemic venous blood to enter the LA, then LV
• Cyanosis is present due to mixing of systemic and pulmonary venous blood in the LA

Clinical Features

• 50% present on the first day of life, additional 30% present by 1 month of age
• Central cyanosis is the most notable feature on physical exam and can be progressive
• May also present with poor feeding
• Holosystolic murmur at left lower sternal border if VSD is present
• Continuous murmur if there is a [[PDA
• Jugular venous distention and prominent “a” wave and hepatomegaly if there is a restrictive atrial level communication
• Tachypnea may be present in patients with unrestrictive pulmonary blood flow
• EKG may show left axis deviation and LVH
• Heart size is normal typically

Differential Diagnosis

Congenital Heart Disease Types

• Cyanotic
  • Tetralogy of fallot
  • Total anomalous pulmonary venous return
  • Transposition of the great arteries
  • Tricuspid atresia
  • Truncus arteriosus
  • Ebstein anomaly
  • Hypoplastic left heart syndrome
• Acyanotic
  • AV canal defect
  • Atrial septal defect (ASD)
  • Ventricular septal defect (VSD)
  • Cor triatriatum
  • Patent ductus arteriosus (PDA)
  • Pulmonary/aortic stenosis
  • Coarctation of the aorta
• Differentiation by pulmonary vascularity on CXR
  • Increased pulmonary vascularity
    • Large ASD
    • Large VSD
    • Total anomalous pulmonary venous return
    • Transposition of the great arteries
    • Truncus arteriosus
  • Decreased pulmonary vascularity
    • Tetralogy of fallot
    • Rare heart diseases with pulmonic stenosis

Evaluation

• Echocardiography
• Chest x-ray
  • May have a paucity of pulmonary markings and normal heart size in patients with normal pulmonary blood flow (no VSD)
  • May have cardiomegaly and prominence of pulmonary vascularity in patients with increased pulmonary blood flow (large VSD)
• ECG
  • May demonstrate tall P waves, left axis deviation, LVH, and diminished RV forces

Management

• Stabilize cardiopulmonary function prior to surgery
• Supplemental oxygen
• Mechanical ventilation
• Inotropic agents (eg, dopamine and dobutamine) improve myocardial contractility
• Prostaglandin E1
  • Maintain adequate ductal dependent pulmonary flow
  • Start infusion at 0.05 mcg/kg/min IV and titrate up to 0.1 mcg/kg/min, monitoring for hypotension and apnea
  • Side Effects: Hypotension, Bradycardia, Seizures and Apnea
• Staged surgical repair

Disposition

• Admit

See Also

• Congenital heart disease