Dynamics of the right atrio-ventricular junction in human: a spatial high-resolution study with multiphase computed tomography. (25th November 2020)

• Record Type: Journal Article
• Authors: Jouan, J; Masari, I; Bliah, V; Soulat, G; Craiem, D; Mousseaux, E
• Is Part Of: European heart journal. Volume 41:(2020)Supplement 2
• Publication Date: 2020-11-25
• Subjects: Computed Tomography: Valve Disease; Cardiology -- Periodicals; Heart -- Diseases -- Periodicals; 616.12005
• DOI: 10.1093/ehjci/ehaa946.0169
• Languages: English
• ISSNs: 0195-668X

Abstract

Abstract: Introduction: In order to improve knowledge of the tricuspid valve (TV) function and its coupling with the right atrio-ventricular junction (RAVJ) and right ventricle (RV), new four-dimensional high-definition imagery methods are mandatory (3D+t). Purpose: Using an innovative reconstruction method based on multiphase cardiac computed tomography imaging (4D-MCCTI), we finely analyzed the morphological & dynamical features of tricuspid annulus (TA) and RAVJ components in order to assess new functional parameters of TV and RV functions. Methods: Volume imaging data sets through time were obtained from 4D-MCCTI of 30 subjects (sex ratio 1, mean age 57±11y.) with no rhythm, valvular or ventricular abnormalities on echocardiography and implemented in a custom software for 3D semi-automated delineation of 18 points around TA perimeter. Coordinates of these points in each of the 10 time-phases within an RR interval were used to calculate specific geometrical features of TA such as 3D/2D areas, perimeters, 360°-diameters and vertical deformation. Subsequently, RV and Right Atrium (RA) inner contours were also delineated (Figure). Results: TA shape was elliptical in horizontal projection with a mean eccentricity index (EcI) of 0.58±0.12; and saddle-shapped in vertical projection with a horn nearby the antero-septal commissure. This feature remained throughout the cardiac cycle but TA was more planar (minimal TA-height: 4.47±1.04 mm) and circular (minimal EcI=0.44±0.14) in mid-diastole when TA-3Darea and TA-3Dperimeter reached a maximum of 6.98±1.21 cm 2 /m 2 and 7.41±0.91 cm, respectively. Correlation between TA-3Darea, TA-2Darea and latero-septal diameter (LSD) were R 2 =0.99 and R 2 =0.73, respectively. LSD was minimal in early-systole (18.83±3.04 mm/m 2 ) and maximal in mid-diastole (20.04±3.05 mm/m 2 ). Correlation of TA-3Darea with RV and RA cross-sectional areas were R 2 =0.82 and R 2 =0.71, respectively. Conversely, there was no significant correlation between TA, RV and RA concentric contractions. Conclusions: Our method for 4D-MTCCI analysis has allowed confirming the shape and dynamics function of RAVJ throughout the cardiac cycle in healthy subjects, and giving new reference parameters for TV and RV evaluation. Funding Acknowledgement: Type of funding source: None