Noninvasive estimation of pulmonary vascular resistance by Doppler echocardiography in patients with pulmonary arterial hypertension.
Am J Cardiol. 2009 Mar 15;103(6):872-6
Authors: Kouzu H, Nakatani S, Kyotani S, Kanzaki H, Nakanishi N, Kitakaze M
Pulmonary vascular resistance (PVR) is an important hemodynamic variable in the management of patients with pulmonary hypertension. To establish a method of estimating PVR in patients with pulmonary arterial hypertension (PAH), Doppler echocardiography was performed within 24 hours of right heart catheterization in 43 patients with PAH (idiopathic PAH, n = 20; chronic thromboembolic pulmonary hypertension, n = 9; congenital heart disease, n = 9; and others). Correlations between invasive PVR and Doppler variables of pulmonary artery flow and tricuspid regurgitation were examined. Mean invasive PVR was 1,294 +/- 680 dyne s cm(-5). Linear regression analysis revealed significant correlations with invasive PVR for the time-velocity integral (TVI; r = -0.63, p = 0.009) of right ventricular outflow and peak tricuspid regurgitant pressure gradient (TRPG; r = 0.77, p <0.001). The TRPG/TVI ratio, which approximated the ratio of pulmonary artery pressure to pulmonary blood flow, showed an improved correlation coefficient of 0.82 (PVR = 187 + TRPG/TVI x 118, p <0.001). After excluding 5 patients with an intracardiac shunt, 26 of the remaining 38 patients (68%) met the hemodynamic criteria in international guidelines for the selection of lung transplantation candidates and were defined as the poor-prognosis group. A TRPG/TVI >7.6 showed 85% sensitivity and 92% specificity for identifying patients in the poor-prognosis group. In conclusion, TRPG/TVI provides a reliable estimation of PVR over a wide range in patients with PAH with various underlying causes.
PMID: 19268748 [PubMed - in process]