1. What is Pulmonary Vascular Resistance?

Pulmonary Vascular Resistance (PVR) is a measure of the resistance to blood flow through the pulmonary circulation. It is an important hemodynamic parameter used in the assessment of pulmonary hypertension and other cardiopulmonary conditions.

2. How Does the Calculator Work?

The calculator uses the PVR equation:

Where:

• \( mPAP \) — Mean Pulmonary Artery Pressure (mmHg)
• \( PCWP \) — Pulmonary Capillary Wedge Pressure (mmHg)
• \( CO \) — Cardiac Output (L/min)

Explanation: The equation calculates pulmonary vascular resistance in dyn·s/cm⁵, which can be converted to Wood units (1 Wood unit = 80 dyn·s/cm⁵).

3. Importance of PVR Calculation

Details: PVR measurement is crucial for diagnosing pulmonary hypertension, determining disease severity, guiding treatment decisions, and monitoring response to therapy in patients with cardiopulmonary disorders.

4. Using the Calculator

Tips: Enter mPAP and PCWP in mmHg, and CO in L/min. All values must be valid (mPAP > 0, PCWP ≥ 0, CO > 0). The result is presented in dyn·s/cm⁵.

5. Frequently Asked Questions (FAQ)

Q1: What is the normal range for PVR?
A: Normal PVR is typically between 20-130 dyn·s/cm⁵ (0.25-1.6 Wood units). Values above this range may indicate pulmonary hypertension.

Q2: How is PVR different from SVR?
A: PVR measures resistance in the pulmonary circulation, while Systemic Vascular Resistance (SVR) measures resistance in the systemic circulation.

Q3: When should PVR be measured?
A: PVR is typically measured during right heart catheterization in patients with suspected or known pulmonary hypertension.

Q4: What factors can affect PVR?
A: PVR can be affected by various factors including hypoxia, acid-base status, medications, and underlying cardiopulmonary diseases.

Q5: How is PVR used in clinical practice?
A: PVR is used to diagnose pulmonary hypertension, classify its severity, guide vasodilator therapy, and assess prognosis in various cardiopulmonary conditions.