Abstract 2088: Echocardiographic Definition of “Unbalanced” in Complete Atrioventricular Septal Defect: A Multi-institutional Study
Purpose: Although identification of unbalanced atrioventricular septal defect (AVSD) is obvious when extreme, exact criteria to define unbalanced AVSD are not available. We sought to validate an atrioventricular valve index (AVVI) (left AV valve area/total AV valve area, cm2) as a discriminator of balanced (bAVSD) and unbalanced (uAVSD) forms of complete AVSD.
Methods: Diagnostic echocardiograms and hospital records of 270 infants with AVSD at 4 CHSS institutions (2000 –2006) were reviewed and AVVI measured (n=251). Patients with an AVVI <0.4 (right dominant, n=43) or >0.6 (left dominant, n=8), had extensive echo analysis. Competing risks analysis examined 4 end states: biventricular repair (BVR), univentricular (UVR) repair, pulmonary artery banding (PAB), and death prior to surgery.
Results: Predicted end states at 12 months after diagnosis are: BVR repair, 87%; UVR repair, 8%; PAB, 1%; death without surgery, 1%. The majority of patients had bAVSD (AVVI30.4 – 0.6) and underwent BVR repairs (Figure 1⇓). Heterogeneous repair strategies were found when 0.19<AVVI<0.39 (UVR and BVR repairs), with a large proportion of deaths in this range. AVVI in right dominant patients correlated strongly with echocardiographic measures of left sided hypoplasia (e.g. small aortic valve annulus, left ventricular length or width). AVVI>0.6 (left dominant) was less common and dominated by BVR repairs.
Conclusions: AVVI effectively characterizes the transition between bAVSD and uAVSD with important correlation with chosen surgical strategy and survival. A larger multi-center trial will allow clarification of the relationship between patient factors, surgical strategy, and outcomes.