1. What is Mean PA Pressure?

The mean pulmonary artery pressure (mPAP) represents the average pressure in the pulmonary artery during one cardiac cycle. It's particularly important for assessing pulmonary hypertension and cardiovascular function in water-related contexts.

2. How Does the Calculator Work?

The calculator uses the standard equation for mean PA pressure:

Where:

• \( dPAP \) — Diastolic pulmonary artery pressure (mmHg)
• \( sPAP \) — Systolic pulmonary artery pressure (mmHg)

Explanation: The equation approximates the mean pressure by accounting for the pressure waveform, where the mean is closer to diastolic pressure than systolic pressure.

3. Importance of mPAP Calculation

Details: Accurate mPAP estimation is crucial for diagnosing pulmonary hypertension, assessing right heart function, and guiding treatment decisions in water-related physiological studies.

4. Using the Calculator

Tips: Enter diastolic and systolic PA pressures in mmHg. Both values must be positive, and systolic pressure should be greater than or equal to diastolic pressure.

5. Frequently Asked Questions (FAQ)

Q1: Why is the formula weighted toward diastolic pressure?
A: The 1/3 factor accounts for the typical pressure waveform where the heart spends more time in diastole than systole.

Q2: What are normal mPAP values?
A: Normal mPAP is generally 8-20 mmHg at rest. Values ≥25 mmHg at rest indicate pulmonary hypertension.

Q3: When should PA pressures be measured?
A: PA pressures are typically measured via right heart catheterization for accurate assessment of pulmonary hemodynamics.

Q4: Are there limitations to this calculation?
A: The formula assumes a typical pressure waveform and may be less accurate in certain pathological conditions with abnormal waveforms.

Q5: How does water immersion affect PA pressures?
A: Water immersion increases central blood volume and typically raises PA pressures due to hydrostatic effects.