fig4
![Echocardiography: an overview - Part III](https://image.oaes.cc/a251030f-17ae-4989-8cbc-3b1df7232f71/4834.fig.4.jpg)
Figure 4. Increased Doppler flow velocity (3.9 m/s) across the right ventricular outflow tract demonstrating severe obstruction; the calculated gradient by modified Bernoulli equation is 60.7 mmHg (insert). Reproduced from Ref.[5]. PG: Peak gradient; PW: pulse width; V: Doppler flow velocity.