Ventricular Septal Defect (VSD)
  • A defect in the ventricular septum resulting in a communication between the right and left ventricle.
  • Common congenital abnormality which occasionally requires surgical intervention.
  • Can occur after a myocardial infarction usually to patients presenting late to hospital.
  • Classically the smaller the VSD the louder the heart murmur usually best heart at the left lower sternal border and is pansystolic.

Types of VSD

  1. Subarterial: Least common and associated with aortic insufficiency due to close proximity to the aortic valve.
  2. Membranous: Most common type of VSD involving the membranous septum and accounting for usually 80% of cases.
  3. AV canal type.
  4. Muscular: Second most common type and most likely to close spontaneously. 


Often characterized as Restrictive vs non-restrictive and based on the size small, medium and large.

  • In Restrictive VSD’s the LV pressure is higher than the RV.
  • In non-restrictive RV and LV have similar pressures.

Example 1 Muscular VSD

Parasternal views demonstrating flow accross the ventricular septum.

Apical 4 chamber view demonstrating a clear defect in the septum and colour doppler confirms left to right blood shunting.

Continuous wave doppler across the VSD demonstrating the peak gradient.

Example 2 Membranous VSD

  • Parasternal long axis view showing evidence of a membranous VSD. Note the colour flow just below the aortic valve, this is the common location for membranous VSD.
  • There is also trace aortic regurgitation.
  • Short axis view at the level of the aortic valve demonstrating colour flow into the right ventricle.
  • Zoomed apical 5 chamber demonstrating colour flow across the ventricular septum consistent with a membranous VSD.