Branch pulmonary artery Doppler in the assessment of atrial restriction
after the hybrid procedure for hypoplastic left heart syndrome
Abstract
Introduction: The hybrid procedure (HP) - bilateral pulmonary artery
bands+ductal stent - is an alternative palliation for high-risk
hypoplastic left heart syndrome (HLHS) patients. Assessment and
management of atrial restriction here is debated and we sought to
identify useful echocardiographic parameters. Methods: Patients
undergoing HP for HLHS were identified. Echocardiograms at birth,
immediately after HP and pre-and post-atrial intervention were reviewed
as well as time-matched echocardiograms in HP patients not requiring
atrial intervention. Atrial septal parameters and systolic (Svel),
diastolic (Dvel) and mean velocities were recorded on both bands and
systolic to diastolic velocity ratio (Svel:Dvel), pulsatility index (PI)
and velocity time integral (VTI) calculated. Results: Fifteen HP were
compared to 5 controls. Age effect was not significant. There was a
significant rise in peak Svel and changes in Dvel, Svel:Dvel and PI over
time (<0.05). Although the pattern of change similar, the fall
in Dvel and rise in Svel:Dvel and PI was more significant on the left.
Compared to controls, transatrial gradient and VTI were significantly
increased initially post-hybrid (median 0.4m/s vs 0.7m/s p=0.04; 29.1cm
vs 64.6cm p=0.018) but not significantly different prior to septostomy
when the only significant differences were seen with all left band
parameters. Conclusions: After HP the transatrial gradient alone cannot
be used. Significant changes in band Doppler parameters were not
apparent in the control group but were principally seen in the left band
with reduction in Dvel and increase in Svel:Dvel and PI in those
undergoing an atrial intervention.