Aberrant Subclavian Artery in Interrupted Aortic Arch with Severe Aortic Outlet Obstruction: Cerebral Blood Flow as a Possible Determinant of Embryonic Cardiovascular Development?

Aberrant subclavian artery (ASCA) is frequently observed in interrupted aortic arch (IAA) with aortic/subaortic obstruction. Developmental significance of ASCA in IAA in utero remains elusive. Newborns with prenatally diagnosed isolated IAA under continuous prostaglandin E1 infusion were studied. Cross-sectional areas of aortic valve opening (AVOCSA) and patent ductus arteriosus (PDACSA) were represented by echocardiographic measurement of (diameter)2 indexed by body surface area (m2). Types of IAA and presence of ASCA were examined in relation to sizes of AVOCSA and PDACSA. Twenty-four newborns with IAA (six type A and 18 type B) were reviewed. Male dominance was seen in type B (male 72%). Twenty-three patients had left aortic arch. No type A patients had ASCA, but 50% of type B had ASCA; AVOCSA was significantly smaller in type B than in type A (p = 0.003). In type B, PDACSA was significantly larger in those with ASCA than without (p = 0.003), but AVOCSA exhibited no significant size difference between these two subgroups. Chromosome 22q11 deletion was only seen in type B (56%) and showed no significant correlation with the presence of ASCA. In type B IAA, the presence of ASCA was associated with larger PDACSA, suggesting an adaptive enlargement of the ductus arteriosus and ASCA in response to reduced antegrade flow across small AVOCSA, which may be augmenting cerebral blood flow. Preservation of cerebral blood flow may be another important determinant affecting embryonic cardiovascular development.

Transesophageal pacing studies reduce readmission but prolong initial admission in infants with supraventricular tachycardia: A cost-comparison analysis.

Background: Supraventricular tachycardia (SVT) is a common arrhythmia. Infants with SVT are often admitted to initiate antiarrhythmics. Transesophageal pacing (TEP) studies can be used to guide therapy prior to discharge. Objective: The objective of this study was to investigate the impact of TEP studies on length of stay (LOS), readmission, and cost in infants with SVT. Methods: This was a 2-site retrospective review of infants with SVT. One site (Center TEPS) utilized TEP studies in all patients. The other (Center NOTEP) did not. Patients with structural heart disease, patients with gestational age <34 weeks, and patients diagnosed after 6 months were excluded. At Center TEPS, repeat TEP studies were performed after titration of medication until SVT was not inducible. Primary endpoints were LOS and readmission for breakthrough SVT within 31 days of discharge. Hospital reimbursement data were utilized for cost-effectiveness analysis. Results: The cohort included 131 patients, 59 in Center TEPS and 72 in Center NOTEP. One patient was readmitted in Center TEPS vs 17 in Center NOTEP (1.6% vs 23.6%; P ≤ .001). Median LOS was longer for Center TEPS at 118.0 (interquartile range [IQR] 74.0-189.5) hours vs Center NOTEP at 66.9 (IQR 45.5-118.3) hours (P = .001). Twenty-one patients had multiple TEP studies. Median length of readmission for Center NOTEP was 65 (IQR 41-101) hours. Including readmission costs, utilization of TEP studies resulted in a probability-weighted cost of $45,531 per patient compared with $31,087 per patient without TEP studies. Conclusion: Utilization of TEP studies was associated with decreased readmission rates but longer LOS and greater cost compared with SVT management without TEP studies.