PVR measures how hard the right heart must work to push blood through the lungs. A PVR above 2 Wood units with a mean pulmonary pressure above 20 mmHg defines pre-capillary pulmonary hypertension (2022 ESC/ERS guideline).
How to use the Pulmonary Vascular Resistance Calculator
- Mean pulmonary artery pressure
- Pulmonary capillary wedge pressure
- Cardiac output
- Mean arterial pressure
- Central venous pressure
Results update as you type, and every field accepts the units shown in its menu.
How it works
Enter the values from a right heart catheterisation.
Inputs explained
| Field | What to enter |
|---|---|
| Mean pulmonary artery pressure | In mmHg |
| Pulmonary capillary wedge pressure | In mmHg |
| Cardiac output | In L/min |
| Mean arterial pressure | In mmHg |
| Central venous pressure | In mmHg |
What each result means
- PVR = ([Mean pulmonary artery pressure] – [Pulmonary capillary wedge pressure])÷[Cardiac output]
- PVR in dyn·s·cm⁻⁵ = [PVR]×80
- Transpulmonary gradient = [Mean pulmonary artery pressure] – [Pulmonary capillary wedge pressure]
- Systemic vascular resistance = ([Mean arterial pressure] – [Central venous pressure])÷[Cardiac output]×80
Example values
How the main result changes when Mean pulmonary artery pressure changes and everything else stays at the example values above:
| Mean pulmonary artery pressure (mmHg) | PVR (Wood units) |
|---|---|
| 12.5 | 0.1 |
| 18.75 | 1.35 |
| 25 | 2.6 |
| 31.25 | 3.85 |
| 37.5 | 5.1 |
| 50 | 7.6 |
Health note: this calculator is for education and screening only and is not a diagnosis or treatment advice. Discuss your results with a qualified clinician.
Formula
PVR (Wood units) = (mPAP − PCWP) ÷ CO
PVR (dyn·s·cm⁻⁵) = Wood units × 80
SVR = (MAP − CVP) ÷ CO × 80
Worked example
Inputs — Mean pulmonary artery pressure: 25 mmHg; Pulmonary capillary wedge pressure: 12 mmHg; Cardiac output: 5 L/min; Mean arterial pressure: 90 mmHg; Central venous pressure: 6 mmHg.
Results — PVR = 2.6 Wood units; PVR in dyn·s·cm⁻⁵ = 208; Transpulmonary gradient = 13 mmHg; Systemic vascular resistance = 1,344 dyn·s·cm⁻⁵.
Key terms
- PVR
- Pulmonary vascular resistance.
- PCWP
- Pulmonary capillary wedge pressure.
- Wood unit
- mmHg·min/L.
Frequently asked questions
What is a normal PVR?
Up to 2 Wood units (160 dyn·s·cm⁻⁵).
What is pulmonary hypertension?
A mean pulmonary artery pressure above 20 mmHg at rest.
What is a normal SVR?
About 800–1,200 dyn·s·cm⁻⁵.