title: Noninvasive estimation of pulmonary vascular resistance by Doppler echocardiography in patients with pulmonary arterial hypertension.
abstract: 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.
authors.affiliation: Division of Cardiology, Department of Internal Medicine, National Cardiovascular Center, Osaka, Japan.
authors.forename: Hidemichi
authors.initials: H
authors.lastname: Kouzu
authors.forename: Satoshi
authors.initials: S
authors.lastname: Nakatani
authors.forename: Shingo
authors.initials: S
authors.lastname: Kyotani
authors.forename: Hideaki
authors.initials: H
authors.lastname: Kanzaki
authors.forename: Norifumi
authors.initials: N
authors.lastname: Nakanishi
authors.forename: Masafumi
authors.initials: M
authors.lastname: Kitakaze
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D006328:Cardiac Catheterization; D015150:Echocardiography, Doppler; D005260:Female; D006801:Humans; D006976:Hypertension, Pulmonary / Q000000981:diagnostic imaging* / Q000503:physiopathology; D008297:Male; D008875:Middle Aged; D012680:Sensitivity and Specificity; D014655:Vascular Resistance