Pattern of pulmonary venous blood flow in the hypoplastic left heart syndrome in the fetus

Abstract

Objective-To determine whether restriction at the atrial septum in the newborn with hypoplastic left heart syndrome can be predicted accurately by examining the pattern of pulmonary venous flow in the fetus. A restrictive atrial septum can contribute to haemodynamic instability before surgery for this lesion and has been associated with an increased mortality. Design-Pulmonary venous pulsed Doppler tracings were compared between fetuses with hypoplastic left heart syndrome and controls. The size of the atrial septal defect on the postnatal echocardiogram was graded according to the degree of restriction. Pulsed Doppler tracings of pulmonary venous blood flow were obtained in 18 fetuses with left atrial outflow atresia and compared with 77 controls, adjusted for gestational age. Postnatal echocardiograms were available for analysis in 13 of 18 neonates. Setting-A tertiary referral centre for fetal cardiology and paediatric cardiac surgery. Results-Fetuses with hypoplastic left heart syndrome were diVerent from controls in all pulmonary vein indices measured. As assessed from the postnatal echocardiogram, there were seven fetuses with a restrictive atrial septum. In these fetuses, the systolic flow velocity (p < 0.01), S/D ratio (p < 0.01), and peak reversal wave (p < 0.001) in the pulmonary vein tracing showed a good correlation with the degree of restriction. Conclusions-The Doppler pattern of pulmonary venous flow in the fetus with hypoplastic left heart syndrome appears to be a reliable predictor of restriction of the atrial septum in the neonate. This may help in the immediate post-delivery management of these infants before surgery. (Heart 1999;81:646-649)

Predictive Value of Fetal Pulmonary Venous Flow Patterns in Identifying the Need for Atrial Septoplasty in the Newborn With Hypoplastic Left Ventricle

“…11 Given these concerns, it is essential that reliable, clinically accurate means of identifying the fetus with HLHS and RAS are developed. Direct evaluation of the size of the foramen ovale (and the left-to-right shunt) can be performed but is often technically difficult 10,13 ; for these reasons, evaluation of the fossa ovalis was not routinely performed in our study subjects. Pulmonary venous flow alterations in HLHS in association with RAS have been described previously, 10,[13][14][15][16] are technically more easily obtained, and are thought to correlate clinically with the degree of left atrial hypertension produced by the restrictive foramen ovale.…”

“…Doppler recordings were obtained with the angle of insonation as parallel to the direction of flow as possible, with the sample volume placed in the pulmonary vein immediately proximal to its entry into the left atrium, as previously described. 13,15,18 Low-pass filters were adjusted to ensure recording of lower-velocity signals.…”

“…Changes in fetal pulmonary venous Doppler (PVD) flow patterns in the setting of left heart obstruction, reflective of left atrial hypertension, 12,13 are now routinely demonstrable by pulsed Doppler evaluation on fetal echocardiography. [13][14][15][16] Moreover, it has been demonstrated that in the fetus with left heart obstruction and RAS, there are changes in pulmonary venous flow patterns 13 associated with the need for emergent atrial septoplasty (EAS) in the newborn period.…”

“…[13][14][15][16] Moreover, it has been demonstrated that in the fetus with left heart obstruction and RAS, there are changes in pulmonary venous flow patterns 13 associated with the need for emergent atrial septoplasty (EAS) in the newborn period. 10 In our experience, however, there is significant variability in the pulmonary venous flow patterns even among fetuses with RAS ultimately requiring EAS in the newborn period ( Figure 1).…”

Fetal echo cardiography: the state of the art of the state of the heart

“…It was shown that in the normal human fetus the percentage of cardiac output perfusing the lung reaches 20% and is thus much higher than the rate of 5-7% known from animal experiments 89 . Pulmonary Doppler was then performed in fetuses at high risk for lung hypoplasia 90,91 , under hypoxia 48 and hyperoxygenation 92 as well as in heart defects 93 . We think that this new field of investigation has great potential and should be developed in the future, especially because lung diseases are the leading cause of death in the neonatal period.…”