Learning Radiology xray montage
 
 
 
 
 

Persistent Left Superior Vena Cava



  • Incidence-uncommon

    • 0.3% of general population;
    • 4.3-11% of patients with CHD

  • Two types

    • Persistent left SVC connecting to right atrium via coronary sinus is only common anomaly of SVC (90% of this anomaly)
    • In other 10%, persistent SVC connects to left atrium
      • Most with connection to left atrium have associated ASD or heterotaxy syndromes
      • This produces a right-to-left shunt of a rather small magnitude

  • Etiology

    • Failure of regression of left anterior and common cardinal veins and left sinus horn

  • Course of persistent left SVC

    • Draining into right atrium
      • Starts at junction of left subclavian vein and left internal jugular
      • Passes lateral to aortic arch
      • Receives left superior intercostal vein
      • Anterior to left hilum
      • Joined by hemiazygos system
      • Crosses posterior wall of left atrium
      • Receives great cardiac vein to become coronary sinus (common)

Yellow arrows point to left-sided persistent SVC
passing lateral to aortic arch and anterior to left hilum

  • Draining into left atrium
    • Starts at junction of left subclavian vein and left internal jugular
    • Passes lateral to aortic arch
    • Receives left superior intercostal vein
    • Anterior to left hilum
    • Joined by hemiazygos system
    • Passes between the left atrial appendage (anteriorly) and the left superior pulmonary vein posteriorly
  • Absent / small left brachiocephalic vein (65%)
  • Really this abnormality produces bilateral SVCs
  • In small percentage, right SVC is absent (10-18%)

The leads of the AICD enter the left subclavian vein and subsequently drain into a persistent left superior vena cava (red arrows) and from there into right atrium and right ventricle.

Freedom, Culham and Moes, Angiography of Congenital Heart Disease, 1984