How to Use Pulmonary Vascular Resistance Calculator
The Pulmonary Vascular Resistance Calculator is a hemodynamic calculator for turning catheterization or echo-estimated pressures into pulmonary vascular resistance. The form follows the hemodynamic structure of PVR: a pressure gradient divided by flow. It keeps the wedge or left atrial pressure visible because that subtraction drives the result.
Provide mean pulmonary artery pressure, left atrial pressure or pulmonary capillary wedge pressure, and cardiac output in L/min. Use pressures in mmHg and cardiac output in L/min. If the source report gives cardiac index instead of cardiac output, convert it before using this calculator.
The primary result is Wood units. The detail cards show the pressure gradient and the dyn·s·cm⁻⁵ conversion by multiplying Wood units by 80. Mean pulmonary artery pressure must be greater than wedge or left atrial pressure. A non-positive gradient usually indicates a copied value, unit, or timing problem.
Formula & Theory - Pulmonary Vascular Resistance Calculator
The Pulmonary Vascular Resistance Calculator uses this formula or scoring rule:
PVR (Wood units) = (Mean pulmonary artery pressure - Left atrial pressure) / Cardiac outputPVR isolates the pressure drop across the pulmonary circulation relative to flow. A positive pressure gradient is required; if wedge or left atrial pressure is equal to or higher than mPAP, the input set should be checked before interpretation.
Wood units are convenient at the bedside, while dyn·s·cm⁻⁵ is common in older hemodynamic reporting. The calculator shows both so the same case can be compared across report styles.
Use Cases for Pulmonary Vascular Resistance Calculator
The Pulmonary Vascular Resistance Calculator is especially useful for:
- right-heart catheterization teaching
- checking PVR unit conversion for a report
- screening hemodynamic examples in pulmonary hypertension education
- comparing changes in resistance after therapy or exercise testing
The tool is helpful for formula review, but PVR should be interpreted with oxygenation, volume status, left-sided filling pressures, and the reason the hemodynamic data were obtained.