Reference ranges of tricuspid annulus geometry in healthy adults using a dedicated three-dimensional echocardiography software package

Abstract

BackgroundTricuspid annulus (TA) sizing is essential for planning percutaneous or surgical tricuspid procedures. According to current guidelines, TA linear dimension should be assessed using two-dimensional echocardiography (2DE). However, TA is a complex three-dimensional (3D) structure.AimIdentify the reference values for TA geometry and dynamics and its physiological determinants using a commercially available three-dimensional echocardiography (3DE) software package dedicated to the tricuspid valve (4D AutoTVQ, GE).MethodsA total of 254 healthy volunteers (113 men, 47 ± 11 years) were evaluated using 2DE and 3DE. TA 3D area, perimeter, diameters, and sphericity index were assessed at mid-systole, early- and end-diastole. Right atrial (RA) and ventricular (RV) end-diastolic and end-systolic volumes were also measured by 3DE.ResultsThe feasibility of the 3DE analysis of TA was 90%. TA 3D area, perimeter, and diameters were largest at end-diastole and smallest at mid-systole. Reference values of TA at end-diastole were 9.6 ± 2.1 cm2 for the area, 11.2 ± 1.2 cm for perimeter, and 38 ± 4 mm, 31 ± 4 mm, 33 ± 4 mm, and 34 ± 5 mm for major, minor, 4-chamber and 2-chamber diameters, respectively. TA end-diastolic sphericity index was 81 ± 11%. All TA parameters were correlated with body surface area (BSA) (r from 0.42 to 0.58, p < 0.001). TA 3D area and 4-chamber diameter were significantly larger in men than in women, independent of BSA (p < 0.0001). There was no significant relationship between TA metrics with age, except for the TA minor diameter (r = −0.17, p < 0.05). When measured by 2DE in 4-chamber (29 ± 5 mm) and RV-focused (30 ± 5 mm) views, both TA diameters resulted significantly smaller than the 4-chamber (33 ± 4 mm; p < 0.0001), and the major TA diameters (38 ± 4 mm; p < 0.0001) measured by 3DE. At multivariable linear regression analysis, RA maximal volume was independently associated with both TA 3D area at mid-systole (R2 = 0.511, p < 0.0001) and end-diastole (R2 = 0.506, p < 0.0001), whereas BSA (R2 = 0.526, p < 0.0001) was associated only to mid-systolic TA 3D area.ConclusionsReference values for TA metrics should be sex-specific and indexed to BSA. 2DE underestimates actual 3DE TA dimensions. RA maximum volume was the only independent echocardiographic parameter associated with TA 3D area in healthy subjects.

Three-dimensional echocardiography of the tricuspid valve

“…Unlike the mitral valve, each TV leaflet is attached to one set of papillary muscles, increasing the risk of wide noncoaptation with annular and RV dilation ( 9 ). The TV is oval and nonplanar (with the most ovoid shape occurring at end-diastole) ( 11 ) and is 20% larger than the MV ( 9 ).…”

“…In addition to the limitations associated with 2DTTE, 3DTTE allows for evaluation of entire leaflets, including the subvalvular structures, other surrounding structures, and right heart chambers ( 5 , 22 ). 3D imaging of the TVA has also been compared to cardiac computed tomography (CCT) imaging and shown to underestimate TVA parameters, but these differences were clinically negligible ( 11 , 12 ), without having to undergo the extensive imaging protocols of CCT as well as reducing the risk of radiation and contrast exposure. Although technical skills are required to obtain a 3D image, many modern 2D transducers are able to acquire 3D images by using 2D planes.…”

“…Unlike the mitral valve, each TV leaflet is attached to one set of papillary muscles, increasing the risk of wide noncoaptation with annular and RV dilation (9). The TV is oval and nonplanar (with the most ovoid shape occurring at enddiastole) (11) and is 20% larger than the MV (9). In addition to understanding the anatomy and physiology of the TV in diseased conditions, 3D echocardiography has greatly contributed to our knowledge of normal TV annulus (A) geometry (11,12).…”

“…The TV is oval and nonplanar (with the most ovoid shape occurring at enddiastole) (11) and is 20% larger than the MV (9). In addition to understanding the anatomy and physiology of the TV in diseased conditions, 3D echocardiography has greatly contributed to our knowledge of normal TV annulus (A) geometry (11,12). TVA measurements obtained via 2D echocardiography have been shown to be consistently underestimated in all views compared to 3D echocardiography (13), owing to the complex geometry of the TVA that 2D imaging is unable to accurately assess.…”

Echocardiography Imaging of the Right Ventricle: Focus on Three-Dimensional Echocardiography

“…According to 3D echocardiography-derived RV volumes, patients with PH can be classified into three morphological subsets of RV adaptation and remodeling associated with distinct prognoses, such as RV-adapted, RV adapted-remodeled, and RV adverse-remodeled groups [106]. Routinely used conventional echocardiography parameters, such as PAP, Measurement of tricuspid annulus diameter by 2D echocardiography from apical four-chamber view represents only the mediolateral size, which does not usually reflect the tricuspid annulus size with its complex geometry accurately [42,93]. In most cases, a change in the anteroposterior diameter can be observed; therefore, the mediolateral diameter does not reflect the extent of tricuspid annular dilatation [93].…”