Ventricular septal defect classification
Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1]
Overview
Based on the size of the defect, VSD can be classified into small, medium, and large ventricular septal defects.
Classification
VSDs can be classified into small, medium, and large based on the size of the defect[1]
Small VSDs
There is a small left-to-right shunt (Qp/Qs < 1.5) and a normal ratio of PA to systemic pressures.
Medium-Sized VSDs
There is a moderate shunt left-to-right present (Qp/Qs = 1.5-2.0) that still has some resistance to flow across the defect.
Large VSDs
There is a large defect on the ventricular septum, > 1 cm2/m2 of BSA, with a large shunt left-to-right (Qp/Qs is > 2), causing volume overload of the LV, which may result in its failure. The defect may approximate the size of the aortic orifice.

References
- ↑ Soto B, Becker AE, Moulaert AJ, Lie JT, Anderson RH (1980). “Classification of ventricular septal defects”. Br Heart J. 43 (3): 332–43. doi:10.1136/hrt.43.3.332. PMC 482284. PMID 7437181.
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