Pulmonary Vascular Resistance (PVR): A measure of the resistance that the right ventricle must overcome to pump blood through the pulmonary circulation. Normal PVR is typically < 250 dynes·sec/cm⁵ or < 3 Wood Units.
Hemodynamic Parameters
Guidelines & Evidence
Clinical Details
Section 1
When to Use
When to Use
Diagnosis and classification of Pulmonary Hypertension (PH).
Differentiating Pre-capillary PH (High PVR) from Post-capillary PH (Normal/Low PVR).
Evaluation of right ventricular afterload.
Assessing reactivity during vasopressor challenge.
Section 2
Formula & Logic
Formula
PVR = (mPAP − PCWP) / CO
Where mPAP = mean Pulmonary Arterial Pressure, PCWP = Pulmonary Capillary Wedge Pressure, CO = Cardiac Output.
Units
PVR is typically expressed in Wood Units (WU). To convert to dyn·s/cm⁵, multiply by 80.
Section 3
Pearls/Pitfalls
Defining PH
Per the latest guidelines, Pulmonary Hypertension is defined by an mPAP > 20 mmHg. Pre-capillary PH is further defined by a PCWP ≤ 15 mmHg AND a PVR ≥ 2 Wood Units.
Section 4
Next Steps
Complementary Calculators
Fick Cardiac Output
SVR Calculator
Cardiac Output Index
MAP Calculator
Stroke Volume Index
Wood Units Calculator
Section 5
Evidence Appraisal
Guideline Standard
2022 ESC/ERS Guidelines for the diagnosis and treatment of pulmonary hypertension.
Humbert M et al. • Eur Heart J.. 2022;Revised the PVR threshold from 3 Wood Units to ≥ 2 Wood Units for defining pre-capillary PH.
