Name three other ways in which Doppler echocardiography is useful in the assessment of a VSD.

1. One can demonstrate Eisenmenger's physiology.
2. The size of the shunt (Qp/ Qs) can be determined.
3. The RVP can be derived, giving an accurate estimate of the pulmonary systolic pressure (assuming there is no pulmonary stenosis).

The modified Bernoulli equation is used to calculate ΔP. The LVP can be obtained by measuring the systolic cuff pressure (assuming there is no outflow tract gradient).
Because ΔP = LVP -RVP, RVP = LVP -ΔP. (Alternatively, the tricuspid regurgitant jet can be used to calculate the pulmonary systolic pressure.)