Abstract 17350: A Three-Dimensional Insight into the Complexity of Flow Convergence in Mitral Regurgitation: Adjunctive Benefit of Anatomic Regurgitant Orifice Area Measurements
Background: Mitral effective regurgitant orifice area (EROA) derived from flow convergence (FC) Methods is used to quantify severity of mitral regurgitation (MR). However, it is challenging and prone to inter-observer variability in complex valvular pathology. We hypothesized that anatomic regurgitant orifice area (AROA) measured by RT3DE can could provide an alternative to determining the severity of MR irrespective of valvular geometry.
Objectives: (1) To use 3D computational flow dynamics and finite element analysis (FEA) to determine the regurgitant orifice morphology and optimal distance for proximal isovelocity surface area (PISA) measurement. (2) To measure AROA from RT3D-TEE and compare it with 2D FC measurements of EROA in MR.
Methods: We studied 61 patients, undergoing clinically indicated TEE, with well-visualized FC. 3D computational flow dynamics and FEA were performed on MV orifice derived from 3D-TEE images. Then EROA was calculated from 2D TEE images using 2D FC technique, and AROA was obtained from zoomed RT3DE-TEE acquisitions using prototype software (MVQ, Philips).
Results: 3D FEA analysis revealed that a planar, central, point regurgitant orifice is reliable for clinical FC measurements provided that the radius is measured at an optimal distance from the orifice. In contrast, non-planar, complex MV orifices yielded distorted isovelocity contours where the assumptions underlying PISA become less applicable. EROA and AROA measurements correlated well (r=0.81) with a non-significant positive bias. However, in patients with eccentric MR, the bias was larger than in patients with central MR. Inter-measurement variability of the 2D FC technique was higher than RT3DE-based measurements.
Conclusions: 3D computational flow dynamics and FEA demonstrated the complexity of EROA measurements. Due to its superior reproducibility, 3D volumetric analysis of the AROA is a useful alternative to quantify MR when 2D FC measurements are challenging.
- © 2010 by American Heart Association, Inc.