Echocardiographic study of pulmonary venous flow in congenital heart disease  with increased pulmonary flow: a comparative study before and after oxygen at 100%. 

Author: Ivan Romero Rivera

Institution
Escola Paulista de Medicina - Universidade Federal São Paulo (UNIFESP)

Orientation
Antonio Carlos de Camargo Carvalho

Date
31 de Outubro de 2001

Address to contact
Av. Eng. Mário de Gusmão 1281. Apto 404. Edf Castelgandolfo.
CEP: 57035 – 000
Maceió. AL
irivera@cardiol.com.br

Summary

RIVERA, I.R. Echocardiographic study of pulmonary venous flow in congenital heart disease  with increased pulmonary flow: a comparative study before and after oxygen at 100%. São Paulo, 2001. Tese (Doutorado) - Escola Paulista de Medicina, Universidade Federal do Estado de São Paulo.

There is no echocardiographic method to estimate pulmonary vascular resistance (PVR) that could be useful in patients with congenital heart disease (CHD) and high pulmonary blood flow, to differentiate persistent vascular disease from dynamic and flow related pulmonary hypertension. The inhalation of 100% oxygen during cardiac catheterization has been the procedure of choice to test the pulmonary circulation in this situation
.
The aim of this study was to analyze the relationship between the variation of pulmonary blood flow velocity integral by Doppler echocardiography and the PVR by cardiac catheterization before and after inhalation of oxygen, in patients with CHD and left to right shunt.

Eighteen patients, 10 female, with age ranging from 4 months to 22 years, with CHD and left to right shunt were included in the study. All patients underwent complete cardiac catheterization including measurements of PVR and the Qp/Qs ratio, before and after 100% oxygen inhalation. Simultaneous estimation of left inferior pulmonary venous blood flow velocity integral and the Qp/Qs ratio were obtained by Doppler echocardiography.

There were no significant changes on clinical variables analyzed. On cardiac catheterization the PVR was significantly lower after oxygen (p=0.0001) with significant increase in the Qp/Qs ratio (p=0.0008). By Doppler echocardiography, the left inferior pulmonary vein blood flow velocity integral significantly increased after oxygen inhalation (p=0.0002), while the Qp/Qs ratio increased not significantly (p=0.16). The left inferior pulmonary vein blood flow velocity integral by Doppler echocardiography correlated with the PVR and Qp/Qs ratio by cardiac catheterization (r=-0.74 and 0.74 respectively). There were 83.3% concordance between the fall of PVR by cardiac catheterization and the increase of the left inferior pulmonary vein blood flow velocity integral by Doppler echocardiography after oxygen inhalation, with sensitivity of 85.7%, specificity of 75%, positive predictive value of 92.3%, and negative predictive value of 60%.

In conclusion, the variation of the left inferior pulmonary vein blood flow velocity integral by Doppler echocardiography was related to the fall of PVR in these group of children and adolescents with CHD and left to right shunt. A measurement of left inferior pulmonary vein blood flow velocity integral before and after oxygen inhalation may be a useful noninvasive test in children with this type of congenital defect and elevated pulmonary artery pressure.