Abstract 2256: Elliptical Assumption for Vena Contracta in Patients with Functional Mitral Regurgitation with Dynamic Changes is Accurate Through Whole Systole: Validation by Real-time 3D Transesophageal Echocardiography
Background: It is known that vena contracta (VC) is elliptical in patients with functional mitral regurgitation (MR), which shows dynamic changes during systole. It is not yet investigated whether this elliptical shape of VC also dynamic changes during whole systole or not. Real-time 3D color Doppler transesophageal echocardiography (3DTEE) allows depicting VC in an en face view. The aim of this study was to determine the dynamic changes of the size and shape of VC using 3DTEE in patients with functional MR during whole systole.
Methods: Full-volume color Doppler 3D datasets encompassing MR were acquired in 19 patients with functional MR using 3DTEE. VC area, and antero-posterior (AP) and commissure-commissure (CC) dimensions were measured in a cross-sectional plane of the 3DTEE. To adjust intersubject differences in heart rate and frame rate, time sequence was normalized by 6 systolic phases (0, 25, 50, 75, 100% of systole, and isovolumetric relaxation period).
Results: All the sizes of VC area, AP dimension and CC dimension were largest in early systole, becoming smallest in mid-systole, and again increasing at late systole. VC shape (ratio of AP to CC dimension) was constant during whole systole (early, mid and late systole: 0.31±0.08, 0.35±0.18, 0.43±0.23, n.s). Biplane elliptical VC area by both AP and CC dimension showed best correlation with actual VC area by 3DTEE throughout early, mid and late systole.
Conclusions: Direct visualization of dynamic VC area in patients with functional MR was feasible by 3DTEE. However, VC shape by 3DTEE was constant during whole systole, allowing practical evaluation of dynamic VC area by its AP and CC dimensions with elliptical assumption.