Introduction
The hybrid procedure (HP, bilateral pulmonary artery bands and stenting
of the arterial duct) for hypoplastic left heart syndrome (HLHS) and its
variants was proposed in the early 1990s(1) as an alternative palliation
to the Norwood procedure, particularly to avoid cardiopulmonary bypass
in high-risk infants. Atrial septectomy forms part of the standard
Norwood procedure, whereas during the hybrid procedure any atrial
intervention will usually be performed off bypass. There is varying
opinion on the optimal timing of atrial intervention in patients with
HLHS undergoing HP from at the time of the procedure to performing later
if signs of atrial restriction(2-4). Decisions about whether or not to
intervene on the atrial septum are generally based on echocardiographic
assessment including mean gradient across the atrial septum, left atrial
size and pulmonary vein Doppler interrogation (5). These parameters may
be abnormal in HLHS (6) and are impacted by high pulmonary blood flow
after initial palliation. Such assessment is clinically important to
optimise free flow of oxygenated blood from the left atrium to the
systemic arterial circulation and to avoid severe left atrial
hypertension with potentially deleterious effects on development of the
pulmonary vasculature.
Fenstermaker at el(5) described changes in the pulmonary artery band
Doppler over time following HP. That study described alterations in the
shape of the Doppler trace in a small subset of patients who required
atrial septal intervention. In this retrospective study, we review the
characteristic of the branch pulmonary artery band Doppler values in
patients with HLHS after the hybrid procedure, who have required atrial
septal intervention prior to their second palliation. We hypothesized
that the previously seen changes in pulmonary artery band Dopplers would
aid in identifying patients who require atrial septal intervention.
Patients were divided into two groups (critical aortic stenosis and
classical HLHS) to further investigate the potential impact of residual
forward flow through the left heart.