Bernoulli equation for Doppler pressure gradient

Bernoulli equation for calculation of pressure gradient by Doppler echocardiography is:

A: P=2V²

B: P=3V²

C: P=4V²

D: P=4V³

Correct answer: C: P=4V²

Original Bernoulli equation is a complex equation. This is a simplified equation routinely used in Doppler echocardiography for pressure gradient across valves while quantifying severity of stenosis. In the simplified equation, only the distal velocity is taken into consideration. Velocity proximal to the stenosis being much smaller, is ignored. Similarly, factors for flow acceleration and viscous friction are also not taken into consideration, being smaller values. In the simplified Bernoulli equation, P is the pressure gradient and V is the distal velocity measured by Doppler echocardiography. In modern machines, we do not need to calculate by the equation, the computer program calculates it automatically.