Pulmonary vascular resistance (PVR) is a critical parameter in the assessment and treatment of patients with pulmonary hypertension, regardless of origin. Noninvasive estimation of PVR could be helpful.Methods
Consecutive patients with known or suggested pulmonary hypertension referred for cardiac catheterization were evaluated prospectively and the PVR was calculated invasively. Subsequently, the tricuspid regurgitation velocity (TRV), the velocity-time integral (mean of 3 measurements) of the right ventricular outflow tract (VTIm), and the right ventricular outflow tract diameter were recorded noninvasively.Results
The TRV/VTIm ratio and the TRV/VTIm corrected for the indexed RVOT diameter correlated well with the PVR at catheterization withR2= 0.711 andR2= 0.731, respectively, including patients with very high values of PVR. A TRV/VTIRVOT value of 38 provided a specificity of 100% for a PVR of 8 Woods units.Conclusion
Noninvasive estimation is feasible over a broad range of PVR values and could be a useful tool to estimate and longitudinally tracked changes in PVR.