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 calculated as the difference between mean pulmonary arterial pressure and pulmonary capillary wedge pressure divided by cardiac output.

2. How Does the Calculator Work?

The calculator uses the PVR equation:

Where:

• \( mPAP \) — Mean pulmonary arterial pressure (mmHg)
• \( PCWP \) — Pulmonary capillary wedge pressure (mmHg)
• \( CO \) — Cardiac output (L/min)

Explanation: The equation calculates the resistance in the pulmonary vasculature by determining the pressure gradient across the pulmonary circulation divided by the flow rate.

3. Importance of PVR Calculation

Details: PVR measurement is crucial for diagnosing pulmonary hypertension, assessing 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 cardiac output in L/min. All values must be valid (positive numbers with appropriate physiological ranges).

5. Frequently Asked Questions (FAQ)

Q1: What are normal PVR values?
A: Normal PVR is typically 0.25-1.6 Wood units. Values above 3 Wood units indicate pulmonary hypertension.

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

Q3: When is PVR measurement indicated?
A: PVR is typically measured during right heart catheterization in patients with suspected pulmonary hypertension, heart failure, or other cardiopulmonary conditions.

Q4: What factors can affect PVR?
A: PVR can be affected by hypoxia, acidosis, vasoconstrictor medications, pulmonary embolism, and various pulmonary diseases.

Q5: How is PVR used in clinical practice?
A: PVR is used to diagnose pulmonary hypertension, assess disease severity, guide vasodilator therapy, and evaluate patients for heart or lung transplantation.