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 (mPAP) and left atrial pressure (LAP) divided by cardiac output (CO).

2. How Does the Calculator Work?

The calculator uses the PVR equation:

Where:

• \( mPAP \) — Mean pulmonary arterial pressure (mmHg)
• \( LAP \) — Left atrial 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 is crucial for diagnosing and managing pulmonary hypertension, assessing right ventricular function, and guiding treatment decisions in cardiopulmonary diseases.

4. Using the Calculator

Tips: Enter mPAP and LAP in mmHg, CO in L/min. All values must be valid (mPAP > 0, LAP ≥ 0, CO > 0).

5. Frequently Asked Questions (FAQ)

Q1: What is a normal PVR value?
A: Normal PVR is typically between 0.25 and 1.6 mmHg·min/L (or 20-130 dyn·s·cm⁻⁵ when converted).

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

Q3: When is PVR measurement indicated?
A: PVR is commonly measured in patients with suspected pulmonary hypertension, heart failure, or congenital heart disease.

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

Q5: How is PVR used in clinical practice?
A: PVR helps diagnose pulmonary hypertension, assess disease severity, monitor treatment response, and evaluate patients for heart transplantation.