[Estimation of pulmonary vascular resistance by Doppler echocardiography with simultaneous catheterization]

To establish a noninvasive prediction of pulmonary vascular resistance (PVR), we combined continuous wave Doppler pressure gradient with pulsed Doppler volumetric flow methods for measuring mean pulmonary arterial pressure (mPAP) and pulmonary flow (QP) respectively and calculated PVR by the Poiseullie equation. Simultaneous invasive and noninvasive measurements were made beat to beat in 28 patients: 18 patients with patent ductus arteriosus (PDA), 10 with other heart diseases complicated with pulmonary regurgitation (PR). In the PR group, the peak of Doppler determined pressure gradient during diastole correlated well with mPAP measured via catheter, r = 0.99. In the PDA group, the Doppler determined mPAP (subtracts mean pressure gradient across PDA measured by the continuous wave Doppler from brachial artery blood pressure) correlated well with catheter, r = 0.98, Doppler determined QP and PVR also correlated well with catheter, r = 0.98 and 0.99. There were high linear correlations between the mPAP, QP, PVR in all patients by Doppler and catheter, r = 0.99, 0.98, 0.98, respectively. The results indicate that combined continuous wave and pulsed Doppler can predict mPAP, QP, and PVR dynamic indices for PDA and other heart diseases complicated with PR quite accurately.