Transthocaric Three-dimensional Echocardiographic Imaging In The Assessment Of Primary Tricuspid Regurgitation

Objective: Primary tricuspid regurgitation(PTR)refers to retrograde flow caused by lesions in the tricuspid valve(TV)leaflet apparatus itself.Due to the structural complexity and the non-planar stereoscopic characteristics of TV,all the leaflets of TV could not be displayed simultaneously in a single view of transthoracic two-dimensional echocardiography(2DTTE).Thus,in order to diagnose the etiology and pathological features of PTR more accurately and improve the treatment and prognosis of patients,it is essential to diagnose TV lesions precisely before surgery.Three-dimensional transthoracic echocardiography(3DTTE)could provide a comprehensive view of TV.The aim of this study was to use 3DTTE to diagnose and evaluate PTR,to show three-dimensional views of PTR in different 3DTTE imaging modes,to summarize the methods and techniques of three-dimensional crop and rotation,in order to assist the diagnosis of involved leaflet.Methods: 34 patients with PTR who were used to diagnose in the First Affiliated Hospital of China Medical University were enrolled,and Echocardiography showed no abnormal cardiac structure and blood flow in 10 normal patients.3DTTE was performed on all subjucts and 3D full-volume,3D ZOOM and 3D-color images of TV were collected.Workstation was used for multi-plane and arbitrary two-point crop of the images,so as to evaluate the structure and pathological characteristics of TV.And the results and experience were described in detail.Result:1.Ten normal subjects showed a cross-sectional,coronal,and sagittal view of the TV structure.2.In the total thirty-four patients with PTR.2.1 Seven cases of Ebstein's anomaly,including one case with atrial septal defect and one case with endocardial cushion defect;one case of mild TR,four cases of moderate TR,two cases of severe TR;two cases underwent surgical treatment.2DTTE could only show the moving down of TV leaflet attachment point,while 3DTTTE could display the spirally trend and the path of the moving.2.2 Five cases of tricuspid valve dysplasia,including three cases with atrial septal defect,one case with bicuspid aortic valve;one case of mild TR,three cases of moderate TR,one case of severe TR;two cases underwent surgical treatment.2DTTE could only display two dimension and linear shape of the leaflets,and the redundant leaflets were showed removing to the right atrial.While 3DTTE could show different views of the leaflets,such as the area of the ineffective part of the redundant leaflets could be measured in the right atrial side view,and the subvalvular structure could be seen in the right ventricle side view,2.3 Eight cases of infective endocarditis,including four cases with ventricular septal defect;four cases of mild TR,three cases of moderate TR,one case of severe TR;four cases underwent surgical treatment.2DTTE could only display the two-dimensional view of vegetations,and could not accurately measure the size of vegetations and notice the damage of the leaflets.While 3DTTE could display the three-dimensional shape of vegetations,evaluate the size and spatial distribution of vegetations more accurately,and reveal the damage and perforation of TV more visually.2.4 Eleven cases of mucous degenerative diseases,including four cases of mild TR,four cases of moderate TR,three cases of severe TR;one case underwent surgical treatment.2DTTE could only show the redundant leaflet or ruptured chordae tendineae turning into the right atrium.While 3DTTE could display the right atrial view of the prolapsed leaflet which was consistent with the surgical field view and convenient for locating the lesion area,and the right ventricular view of the subvalvular structure,which was helpful for the diagnosis of the extension or rupture of the chordae tendineae.2.5 Three cases of chest trauma and iatrogenic valve injury(after pacemaker operation),the degree of regurgitation was severe,and two cases underwent surgical treatment.2DTTE could only show rupture of the chordae tendineae and/or papillary muscles,flail movement of the leaflet into the right atrium,or the wire interference with the leaflets motion.While 3DTTE could show the morphology of the lesion valve,the specific location of the involved chordae tendineae and/or papillary muscles and the position and relationship of the wire and TV,whether the wire penetrating the leaflet,and how the wire affecting the movement of the leaflet.Conclusion:In the diagnosis and identification of PTR,3DTTE can be better displayed the overall holistic view of the TV three leaflets and the change of the local structure of the diseased leaflets,and clearly located the lesion location and stereoscopic morphology,which was an effective supplement to 2DTTE.Different imaging modes and view planes of 3DTTE were chosen for PTR paients with different eiology.During the collection and analysis of the figures,the full-volume imaging of parasternal short axis view of aorta was the clearest.