Adult Echocardiography Practice Exam

If the peak velocity across the mitral valve is 3 m/sec, how is the peak pressure gradient calculated?

1. Using the formula 4(v^2)

2. Using the continuity equation

3. Using Bernoulli's principle

4. Using the mean pressure difference

The correct answer is: Using the formula 4(v^2)

The peak pressure gradient across the mitral valve can be calculated using the formula derived from Bernoulli's principle, which states that the pressure gradient is proportional to the square of the velocity of blood flow. Specifically, the formula used is: \[ \text{Pressure Gradient} = 4(v^2) \] In this case, when the peak velocity across the mitral valve is 3 m/sec, you would substitute this value into the formula: \[ \text{Pressure Gradient} = 4(3^2) = 4 \times 9 = 36 \text{ mmHg} \] This calculation is based on the understanding that the pressure drop due to velocity across a valve can be quantified, and the factor of 4 comes from the conversion of the velocity squared into a pressure gradient measured in mmHg, which is standard in echocardiography practices. Other methods of calculating pressure gradients, such as the continuity equation, apply to different contexts within cardiac assessment, typically involving the aortic valve where cross-sectional areas and flow relationships are important. The mean pressure difference is also relevant in certain scenarios, but it does not directly provide a peak gradient in the way the Bernoulli equation does. Hence, in the