PVR Calculator – Pulmonary Vascular Resistance
Calculate pulmonary vascular resistance (PVR) in Wood units and dyn·s·cm⁻⁵ from mPAP, PCWP, and cardiac output for hemodynamic assessment.
Enter mean pulmonary artery pressure, pulmonary capillary wedge pressure, and cardiac output to instantly compute PVR and assess pulmonary circulation.
PVR Calculator – Pulmonary Vascular Resistance
Calculate pulmonary vascular resistance (PVR) in Wood units and dyn·s·cm⁻⁵ from mPAP, PCWP, and cardiac output for hemodynamic assessment.
mmHg
mmHg
L/min
PVR calculation examples
Click any example button to load values into the calculator.
| Inputs (mPAP / PCWP / CO) | PVR Result | Clinical context |
|---|---|---|
| mPAP 15 mmHg, PCWP 8 mmHg, CO 5.0 L/min | 1.40 WU / 112 dyn·s·cm⁻⁵ | Normal pulmonary circulation. PVR < 2 WU indicates healthy pulmonary vascular tone. |
| mPAP 30 mmHg, PCWP 10 mmHg, CO 4.5 L/min | 4.44 WU / 356 dyn·s·cm⁻⁵ | Mildly-to-moderately elevated PVR. Suggests early pulmonary vascular disease requiring further evaluation. |
| mPAP 45 mmHg, PCWP 12 mmHg, CO 3.8 L/min | 8.68 WU / 695 dyn·s·cm⁻⁵ | Severely elevated PVR. Indicates significant pulmonary vascular disease and right ventricular strain. |
| mPAP 60 mmHg, PCWP 15 mmHg, CO 2.5 L/min | 18.00 WU / 1440 dyn·s·cm⁻⁵ | Very severe PVR elevation. Immediate specialist management and consideration of advanced PAH therapy required. |
About the PVR Calculator
Pulmonary vascular resistance (PVR) is a key hemodynamic parameter that quantifies the resistance to blood flow through the pulmonary circulation. It reflects the afterload experienced by the right ventricle and is essential for diagnosing, monitoring, and managing pulmonary hypertension, right heart failure, and other cardiovascular conditions.
PVR is calculated using the transpulmonary pressure gradient divided by the cardiac output. The transpulmonary gradient is the difference between the mean pulmonary artery pressure (mPAP) and the pulmonary capillary wedge pressure (PCWP), which serves as a surrogate for left atrial pressure. Dividing this gradient by the cardiac output (CO) gives PVR in Wood units (WU). Multiplying by 80 converts the result to the CGS unit dyn·s·cm⁻⁵, which is commonly used in research and some clinical settings.
In a healthy adult at rest, PVR typically falls between 0.5 and 1.5 Wood units (roughly 40–120 dyn·s·cm⁻⁵). Values below 2 WU are generally considered normal. A PVR between 2 and 4 WU suggests mild pulmonary vascular disease; between 4 and 8 WU indicates moderate disease with significant right ventricular strain; and above 8 WU represents severe pulmonary hypertension with a high risk of right ventricular failure.
Right heart catheterization remains the gold standard for directly measuring mPAP, PCWP, and CO. Once these values are obtained, this PVR calculator instantly computes resistance in both standard units, allowing clinicians to classify severity and guide therapeutic decisions. Vasodilator testing during catheterization uses serial PVR measurements to assess whether a patient is a candidate for calcium channel blockers or advanced pulmonary arterial hypertension therapies.
PVR is also used to distinguish between pre-capillary and post-capillary pulmonary hypertension. In pre-capillary forms (such as pulmonary arterial hypertension), elevated mPAP is accompanied by a normal PCWP and an elevated PVR. In post-capillary forms (such as left heart disease), both mPAP and PCWP are elevated, but PVR may be normal or only mildly raised. This distinction critically changes management: therapies targeting pulmonary vasodilation are appropriate for pre-capillary disease but not for isolated post-capillary disease.
This calculator is intended for educational and clinical decision-support purposes only. PVR values should always be interpreted in the context of a patient's full hemodynamic profile, symptoms, and clinical history. Treatment decisions must be made by qualified healthcare professionals.
How to use the PVR calculator
- Obtain the mean pulmonary artery pressure (mPAP) in mmHg, typically from right heart catheterization.
- Enter the pulmonary capillary wedge pressure (PCWP) in mmHg — mPAP must be greater than PCWP.
- Input the cardiac output (CO) in L/min as measured by thermodilution or Fick method.
- Click Calculate PVR to see PVR in both Wood units and dyn·s·cm⁻⁵ along with the severity classification.
- Use Reset to clear all fields, or click an example button to explore different clinical scenarios.
PVR calculator FAQ
What is pulmonary vascular resistance?
Pulmonary vascular resistance (PVR) is the resistance that the pulmonary vasculature presents to blood flow from the right ventricle. It is calculated as the transpulmonary gradient (mPAP minus PCWP) divided by the cardiac output. Elevated PVR indicates increased resistance to flow through the lungs and is a hallmark of pulmonary hypertension.
What is the normal range for PVR?
In healthy adults, PVR typically ranges from 0.5 to 1.5 Wood units (40–120 dyn·s·cm⁻⁵). Values below 2 WU (160 dyn·s·cm⁻⁵) are considered normal. PVR above 2 WU suggests pulmonary vascular disease, with the degree of elevation guiding severity classification and treatment.
What is the difference between Wood units and dyn·s·cm⁻⁵?
Both units measure the same quantity — pulmonary vascular resistance. Wood units (WU) are preferred in clinical cardiology because the numbers are more manageable (normal is about 1 WU). Dyn·s·cm⁻⁵ are used in research and some international centers; 1 WU equals 80 dyn·s·cm⁻⁵.
How does PVR differ from systemic vascular resistance (SVR)?
SVR reflects the resistance in the systemic circulation encountered by the left ventricle, while PVR reflects resistance in the pulmonary circulation encountered by the right ventricle. Normal SVR (8–20 WU) is about 10 times higher than normal PVR, which is why the right ventricle is a much thinner-walled pump than the left.
When is PVR measured clinically?
PVR is routinely measured during right heart catheterization for the evaluation of pulmonary hypertension, assessment of candidates for heart or lung transplantation, and pre-operative risk stratification. It is also measured during vasodilator challenge testing to determine whether pulmonary arterial hypertension is vasoreactive.
Is this calculator a substitute for right heart catheterization?
No. This calculator uses values already obtained from right heart catheterization or other hemodynamic measurements. It cannot replace the procedure itself. Accurate PVR calculation requires precisely measured mPAP, PCWP, and CO, which can only be reliably obtained through invasive catheterization in most clinical scenarios.