Aortic Valve Pressure Half Time Calculator

Formula

To calculate the Pressure Half Time (PHT):

\[ PHT = \frac{\ln(2)}{\ln \left( \frac{Pi}{Pf} \right)} \]

Where:

\(PHT\) is the Pressure Half Time in seconds
\(Pi\) is the Initial Pressure in mmHg
\(Pf\) is the Final Pressure in mmHg

What is Aortic Valve Pressure Half Time?

Aortic valve pressure half time (PHT) is a measure used in echocardiography to assess the severity of aortic regurgitation. It is the time it takes for the peak pressure gradient across the aortic valve to decrease by half during diastole. A shorter PHT indicates more severe regurgitation, while a longer PHT suggests less severe regurgitation. This measurement helps in the evaluation and management of patients with aortic valve disease.

Example Calculation

Let's assume the following values:

Initial Pressure (\(Pi\)) = 120 mmHg
Final Pressure (\(Pf\)) = 60 mmHg

Using the formula:

\[ PHT = \frac{\ln(2)}{\ln \left( \frac{120}{60} \right)} = \frac{0.693147}{\ln(2)} = \frac{0.693147}{0.693147} = 1 \text{ seconds} \]

The Pressure Half Time is 1 second.