Case of the Week: November 21-November 28, 2002

One year old Male with Cyanosis and Clubbing

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Case Details

Answer

Diagnosis: DIAGNOSIS: Tetralogy of Fallot (TOF) - Coeur en Sabot Sign

Definition and Incidence

The most common type of cyanotic congenital heart disease in children, accounting for 8% of congenital heart disease.

The four classic components:

  1. Large, subaortic ventricular septal defect 

  2. Obstructed right ventricular outflow tract

    • invariable infundibular

    • +/- pulmonary annulus

    • main pulmonary valve artery

    • right or left pulmonary artery

    • absent pulmonary value 

  3. Right ventricular hypertrophy

  4. Overriding aorta

 SEE IMAGE BELOW

Anatomic Associations:

  • Right aortic arch - 25%

  • Coronary arteries anomalies - 5%

Clinical Features

  • Age at which symptoms begin depends on the degree of right ventricular outflow tract obstruction, which determines the amount of right-to-left shunting. Because infundibular stenosis is usually progressive, eventual right-to-left shunting and cyanosis may not appear until 3-4 months or later. 

  • Symptoms include episodic loss of consciousness and squatting when fatigued (to increase pulmonary flow and thus 02 saturations).

  • ECG reveals right ventricular hypertrophy.

Radiolographic Features

Plain Film

  • Normal to slightly enlarged cardiac silhouette

  • "Boot-shaped" heart or Coeur-en-sabot appearance

    • (due to 1) RVH --> uplifting of cardiac apex and 

    • 2) small pulmonary arteries --> concave main pulmonary artery segment)

  • Large aorta

    • (because almost all blood flow from both ventricles is delivered to the aorta)

  • Right aortic arch - 25% of patients

  • Decreased pulmonary vasculature

  • Pulmonary vasculature may be asymmetric

    • (secondary to left pulmonary artery stenosis)

MRI

  • Used to delineate main, right, and left pulmonary arteries, and assess extent of aortopulmonary collateral flow to help both palliative treatment and definitive surgical correction. 

Treatment

  • Palliative shunts (symptomatic but poor surgical candidates)

  • Blalock-Taussig: any surgical connection between the subclavian artery and the pulmonary artery.

  • Total corrective repair: VSD closure, removing infundibular muscle causing obstruction, and inserting either a transannular patch or external conduit to relieve obstruction between right ventricle and main pulmonary artery.

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VCU Department of Pediatric Radiology Virginia Commonwealth University VCU Medical Center