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The Norwood procedure is performed as a neonatal palliative procedure for children born with hypoplastic left heart syndrome (HLHS) and other single-ventricle anomalies.1-4 Morbidity and mortality after the Norwood procedure has improved in the recent era of surgery, yet remains among the highest of all congenital heart defects.5-7
One of the most important causes of morbidity and mortality is recoarctation of the aorta (RCoA), which occurs in up to 37% of patients.2,5,8-12 In the setting of RCoA, patients with HLHS are at risk for ventricular dysfunction, atrioventricular valve regurgitation, and decreased systemic perfusion.8,9,13 RCoA is challenging to diagnose by transthoracic echocardiography (TTE), and current methods lack sensitivity and specificity.13-15 The current gold standard to diagnose RCoA is cardiac catheterization, which has potential risks in this patient population and often is not performed until there is a clinical suspicion of RCoA.
We sought to identify TTE measures that accurately discriminate RCoA and to create a clinical diagnostic rule with high sensitivity and specificity. Furthermore, we sought to determine if the diagnostic rule's performance varied based on shunt type.
Methods
The study protocol received institutional review board approval. Subjects who underwent a Norwood procedure from December 2005 to December 2009 at our institution were identified through a query of our surgical database. We excluded patients from analysis if they did not undergo a TTE at our institution within 1 month of an outcome-defining event. Outcome-defining event included RCoA diagnosed at cardiac catheterization, autopsy, or direct surgical inspection. Demographic data and preoperative factors that might be associated with RCoA were recorded from echocardiographic and clinical databases, including gender, age at surgery, gestational age, presence of a chromosomal anomaly, size of the ascending aorta, and subtype of HLHS. Perioperative data recorded from surgical databases included the type of shunt used during the Norwood procedure (Blalock-Taussig shunt [BTS] or right ventricle-to-pulmonary artery shunt). For subjects with multiple cardiac catheterizations, the first procedure was used for analysis. In addition to the TTE performed within 1 month of the outcome study, previous TTE studies were used to assess for change in ventricular performance and atrioventricular valve regurgitation over time.
TTE studies performed within 1 month of an outcome-defining event were analyzed. Data were recorded from previously obtained...