Echocardiographic Definition and Surgical Decision-Making in Unbalanced Atrioventricular Septal Defect

Abstract

Background-Although identification of unbalanced atrioventricular septal defect (AVSD) is obvious when extreme, exact criteria to define the limits of unbalanced are not available. We sought to validate an atrioventricular valve index (AVVI) (left atrioventricular valve area/total atrioventricular valve area, centimeters squared) as a discriminator of balanced and unbalanced forms of complete AVSD and to characterize the association of AVVI with surgical strategies and outcomes. Methods and Results-Diagnostic

Echocardiographic Features Defining Right Dominant Unbalanced Atrioventricular Septal Defect

“…2,6 From a diagnostic standpoint, unbalanced AVSD has been previously diagnosed primarily by ventricular size; however, unbalance can be present even if the contralateral ventricle is not particularly small. 3,4,7 Thus, recent studies of unbalanced AVSD have focused on the derangement in the distribution of blood flow into the affected ventricle.…”

“…4 The purpose of the current analysis (cluster analysis and discriminative function models) was to use all of the echocardiographic variables (both 2-dimensional size of structures and physiological parameters such as direction of flow at the ventricular septal defect and patent ductus arteriosus [Appendix]) and including AVVI, to see whether we could identify groups of patients with morphological similarities that may propose additional features that would discriminate patients with unbalanced AVSD. This study was performed in anticipation of a CHSS prospective observational cohort study to further define the concept of unbalance and thereby improve surgical decision-making.…”

“…3,4 AVVI measures the portion of the AVV allocated to each ventricle in a subxiphoid sagittal or left anterior oblique view. However, AVVI by itself cannot discriminate between those who require single ventricle or biventricular repair Background-Definition and management of right dominant unbalanced atrioventricular septal defect (AVSD) remains challenging because unbalance entails a spectrum of left heart hypoplasia.…”

“…We used previously published criteria to arbitrarily define right dominant unbalanced AVSD patients (AVVI≤0.4) for the purposes of sampling. 4 We then included all patients in the echocardiographic analysis who were classified as unbalanced using this method. A larger pool of patients from the CHSS database defined as balanced (AVVI>0.4 and <0.6) was available, from which patients were randomly selected for inclusion.…”

“…4 Of the 112 included pooled patients, the median age at the time of diagnosis was 20 days (minimum birth, maximum 2.9 years); 51% (57/111, missing=1) were male, and 57% (56/98, missing=14) had Down syndrome. For surgical strategy, 22/112 (20%) patients underwent single ventricle palliation, 82/112 (73%) underwent biventricular repair, 1 (1%) underwent pulmonary artery banding, and 7 (7/112=6%) patients had no surgical procedure performed.…”