When a ventricQlar septa1 defect (VSD) is present, with no aortic stenosis, the peak velocitgr  across the defect reflects the difference in pressure between the right ventricle and left ventricle. The higher the VSD velociq, the lower the RV pressure. RV  pressure = arm BP-VSD  gradient

Example:

Arm BP = 120 WAD  velocity = 3 dsec
ΔP  = 4 (3)²
=  36 mmHg
RV  pressure  120 mrnHg-36  mmHg
* 84 mmHg
In  the absence df pulmonic stenosis, right ventricular systolic pressure should be equivblent to pulmonary artery systolic pressure.