Abstract 12854: Early and Late Features of Intracardiac Flow in Repaired Tetralogy of Fallot (rTOF) Patients Using Doppler Velocity Reconstruction (DoVeR)

Abstract

Background: Intracardiac flow analysis has implicated flow energy loss (FEL), kinetic energy (KE) and vortex strength (VS) as markers of ventricular dysfunction in repaired Tetralogy of Fallot (TOF); no studies have investigated early vs. late intracardiac flow conditions after repair. We utilized novel echocardiography (echo) based Doppler Velocity Reconstruction (DoVeR) to determine FEL, KE and VS in pre-operative TOF vs early post-repair (<1 month) and late post-repair (>10 years). Methods: This was a single-center retrospective cross-sectional study on TOF patients with pre- and post-operative surveillance transthoracic echo. Apical 4 chamber color Doppler views were collected. The streamfunction-vorticity formulation was used to reconstruct left ventricular (LV) blood velocity fields by DoVeR. Velocity flow fields were evaluated for peak FEL, KE and VS. The FEL was also normalized against KE to account for physiologic variations. Data were compared via one-way ANOVA. Results: Echo studies from 14 pre-operative (1.7±0.5 months), 14 early-post repair (3.6±2.3 months) and 15 late-post repair (16.5±6.6 years) TOF patients were included. There was significant variation in FEL, KE, VS, and normalized FEL across timepoints (all p<0.05) (Figure B). In general, when compared to pre-operative TOF, the early post-repair cohort had lower FEL/KE/VS corresponding to reduction in ventricular volume load; however late post-repair cohort had higher FEL/KE/VS, suggestive of effects from long-term interventricular interactions. Conclusion: The LV intracardiac flow in TOF changes early after initial repair and late after repair. DoVeR could potentially be used to serially evaluate TOF patients.