VSD gradient CW Doppler

Echocardiographic still frame demonstrating the Doppler determination of pressure gradient across a membranous ventricular septal defect (VSD). The dotted cursor line denotes the angle of the continuous wave Doppler beam used to obtain the velocity across the VSD. The velocity (v) is 3.6 m/second and based upon the modified Bernoulli equation (pressure = 4 [v]²), and the gradient between the left and right ventricles is 53 mmHg. Note that this envelope is m-shaped, and the use of a mean or end systolic gradient may be more appropriate in this patient.