Quantitative Assessment of Pulmonary Vascular Resistance and Reactivity in Children with Pulmonary Hypertension Due to Congenital Heart Disease Using a Noninvasive Method: New Doppler-Derived Indexes

Abstract

We assessed the usefulness of transthoracic Doppler-derived indexes obtained in the proximal pulmonary artery (PA) branch for estimating pulmonary vascular resistance (PVR) in 45 children with congenital heart disease (CHD) and 23 normal control subjects. The acceleration time, inflection time (InT), deceleration index, and peak velocity, which were measured from the systolic PA flow velocity curve obtained at the sites of the main PA, and right and left PA, were compared with the PVR in patients with CHD. In addition, changes in either Doppler-derived indexes or PVR during 100% oxygen administration were compared in 22 patients showing a baseline PVR >or=4.6 U/m(2) (high PVR). The heart-rate-corrected InT (InTc) values obtained in the left PA in the high PVR group were significantly lower than those in the main PA (4.7 +/- 1.5 vs. 7.5 +/- 3.0; p < 0.001). The InTc obtained from the left PA separated patients with high and low PVR (4.7 +/- 1.4 vs. 9.9 +/- 2.4; p < 0.001) and no significant differences in InTc were found between the low PVR and the control groups. An increase in InTc to >6 during 100% oxygen administration for the high PVR group indicated good PA reactivity with a sensitivity of 93%, specificity of 100%, and agreement of 95% (kappa = 0.83). Moreover, this InTc index correlated inversely with PVR (r = -0.80). In conclusion, our method can noninvasively separate high and low PVR and assess the PA reactivity for high PVR in children with CHD.

Normal Reference Values and z Scores of the Pulmonary Artery Acceleration Time in Children and Its Importance for the Assessment of Pulmonary Hypertension

“…Ambiguous results have been reported on the relevance of correction for HR of PAAT in the pediatric age group with groups showing no relevance on HR correlations to pulmonary hemodynamics, 6,28 although others found an influence of HR correction in children on the estimation of PVR and PAP. 29,30 For example, for a 10-year-old healthy boy, we would expect an HR of 80 bpm and, therefore, a PAAT of 128 ms. If this boy has a high HR of 120 bpm, we would expect a reduced PAAT of 104 ms.…”

Noninvasive assessment of pulmonary vascular resistance and pressure in patients with congenital heart disease: a new method using M-mode echocardiography

“…We previously reported the noninvasive assessment of PVR by recording of the pulmonary artery flow velocity using novel Doppler indexes. This method requires a good Doppler flow signal in the periphery pulmonary artery [8] and is difficult to perform in some patients with complex CHD [8]. The M-mode examination was predictive for all patients, including those with complex CHD.…”

“…The majority of studies have focused on the evaluation of pulmonary arterial pressure using the LV shape or tricuspid regurgitation Doppler flow velocity [5][6][7][8][9][10][11][12][13][14][15]. However, these methods could not accurately evaluate the PVR in patients with CHD.…”

Saudi Guidelines on the Diagnosis and Treatment of Pulmonary Hypertension: Pulmonary arterial hypertension associated with congenital heart disease

“…A variety of echocardiographic indices derived from right ventricular/pulmonary arterial systolic flow velocity curve have been used for this purpose. [2] Estimates of pulmonary-to-systemic blood flow ratio and vascular resistance ratio (Q p /Q s and pulmonary vascular resistance [PVR]/systemic vascular resistance [SVR]) can be obtained as well. However, many of these indices are more physiologically related to the right ventricular function than they are to the PVR itself.…”