Abstract 12610: Larger Papillary Muscles and Thicker Chords Were Associated With Post-Operative Left Atrioventricular Valve Regurgitation in Partial AVSD, a Quantitative Three-Dimensional Echocardiography Study

Abstract

Background: Up to 15% of patients with partial Atrioventricular Septal Defects ( p AVSD) require re-repair of the Left AtrioVentricular Valve (LAVV), with 30% having significant regurgitation. Previous qualitative studies suggest abnormalities in papillary muscles, shortened chordae and thick chords as features associated with LAVVR. We aim to quantitatively assess the sub valvar apparatus in pAVSD using three-Dimensional Echocardiography (3DE) for its association with LAVVR. Hypothesis: We hypothesize that larger papillary muscle and chordal thickness in patients with p AVSD is associated with post-operative LAVVR. Methods: This is a prospective study between 2006 and 2018, of pAVSD aged 0-18 years. All underwent 3DE under sedation using X7-2 probe on a Philips iE33 ultrasound system. Utilizing offline QLAB multi-planar reconstruction (v.10.8.5) we measured anterolateral (APM) and posteromedial papillary (PPM) muscle length; cross sectional area and circumference; chordal length and thickness in mid systole. We measured post-operative vena contracta and LAVV diameter in Apical 4 chamber using 2D color Doppler. Cohort was divided into patients with significant post-operative LAVVR vs. controls based on LAVV vena contracta/LAVV annulus ratio cut off >0.25 (greatest one-third of cohort), LAVVR (n=22) and Controls (n=44). All variables are indexed to Body Surface Area, expressed as median [interquartile range] or mean (standard deviation). Results: LAVVR group were younger at initial surgery, had larger papillary muscles and thicker chords. Table 1 summarizes the variables for Control and LAVVR. Eighteen patients had LAVV re-repair, 14 (63%) were in LAVVR group and 4 (9%) in Controls. Median follow up was 1.5 years. Median time to re-repair was 1.3 years. Conclusion: p AVSD patients with a greater risk of post-operative LAVVR and subsequently re-repair were younger at first repair and had larger papillary muscles length, circumference and thicker chords.