Pulmonary Vascular Resistance
A hemodynamic measurement quantifying the resistance to blood flow through the pulmonary circulation, crucial for surgical decision-making in congenital heart disease.
Full Definition
Pulmonary vascular resistance (PVR) is a calculated hemodynamic parameter that measures the resistance to blood flow through the pulmonary vascular bed. It is calculated as the pressure gradient across the pulmonary circulation divided by the cardiac output (PVR = [mean PA pressure - LA pressure]/cardiac output) and expressed in Wood units or dynes·sec·cm⁻⁵. In congenital cardiology, PVR assessment is critical for determining operability in patients with left-to-right shunts, as elevated PVR may contraindicate surgical repair due to increased risk of postoperative pulmonary hypertension. Serial PVR measurements help guide timing of interventions and assess response to pulmonary vasodilator therapy.
Usage
Usage note: Include units (Wood units or dynes·sec·cm⁻⁵) when reporting numerical values.
In Context
- "Cardiac catheterization revealed elevated pulmonary vascular resistance of 8 Wood units, precluding surgical closure of the ventricular septal defect." — Catheterization report
- "The patient demonstrated significant improvement in pulmonary vascular resistance following targeted therapy with bosentan." — Pulmonary hypertension clinic note