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European Journal of Echocardiography (2009) 10, 477–484
doi:10.1093/ejechocard/jep044
REVIEW PAPER
Evaluation of the tricuspid valve morphology and
function by transthoracic real-time three-dimensional
echocardiography
Luigi P. Badano1*, Eustachio Agricola2, Leopoldo Perez de Isla3, Pasquale Gianfagna1,
and Jose Louis Zamorano3
1
Echo-Lab, Department of Cardiopulmonary Sciences, University Hospital ‘S Maria della Misericordia’, P.le S Maria della
Misericordia 15, 33100 Udine, Italy; 2Division of Noninvasive Cardiology, San Raffaele Hospital, Milan, Italy; and 3Unidad de
Imagen Cardiovascular, Instituto Cardiovascular—Hospital Clı́nico San Carlos, Madrid, Spain
Received 27 December 2008; accepted after revision 5 April 2009
KEYWORDS
Echocardiography;
Three-dimensional;
Real-time;
Tricuspid valve;
Tricuspid insufficiency;
Tricuspid stenosis;
Tricuspid regurgitation;
Surgery
Assessment of tricuspid valve (TV) function plays an important role in a number of clinical disease
states, including left-sided valve disease and heart failure. However, the TV is a complex structure
that, unlike the aortic and mitral valve, it is not possible to visualize in one cross-sectional view
using either transthoracic or transoesophageal two-dimensional echocardiography (i.e. imaging all
three TV leaflets and their attachment in the annulus simultaneously). Conversely, three-dimensional
echocardiography allows users to visualize the whole TV apparatus from any perspective. This may significantly improve our understanding of the pathophysiological mechanisms underlying the various TV
diseases and functional tricuspid regurgitation, and potentially suggest ways to improve surgical treatment. This review details the current status of real-time three-dimensional echocardiography evaluation of TV morphology and function with its clinical applications and limitations.
Introduction
Function of the tricuspid valve (TV) plays an important role in
several heart diseases, including left-sided valve disease and
heart failure, and the development of functional tricuspid
regurgitation is directly associated with increased morbidity
and mortality.1–5 These data have increased motivation to
repair functional tricuspid regurgitation, especially at the
time of concomitant surgery for left-sided disease.3
However, the unsatisfactory results of current approaches
suggest an incomplete understanding of the underlying mechanisms.3,6 As in the case of mitral regurgitation, a better
understanding of the pathophysiological mechanisms underlying functional tricuspid regurgitation could potentially
suggest ways to improve surgical treatment.
The assessment of the TV is mostly done by twodimensional echocardiography (2DE) despite unique configuration of tricuspid leaflets and annulus, and anatomic
complexity of the right ventricle. As a result, simultaneous
visualization of the three TV leaflets has not been achieved
routinely from standard 2DE imaging views. Usually, only
* Corresponding author. Tel: þ39 0432 552444; fax: þ39 0432 482353.
two leaflets can be imaged in one 2DE view and determination of individual leaflet involvement (especially the posterior leaflet) is challenging when a disease process is
present.7 This limitation can be partially overcome with an
anterior to posterior sweep to see both the anterior and
the posterior leaflets using the apical 4-chamber or subcostal view. Afterwards, the echocardiographer starts a difficult
mental process to reconstruct a stereoscopic image of the
TV based on the interpretation of the multiple tomographic
images obtained with the sweep. Sometimes, the mental
exercise of reconstruction may be inadequate to obtain a
precise diagnosis even for an experienced observer, particularly when dealing with complex valvular abnormalities.
The advent of real-time three-dimensional echocardiography (RT-3DE) may obviate for this exercise by allowing a
more objective and quantitative evaluation of TV anatomy
and function that would reduce the subjectivity in the
interpretation of images. However, compared with the
mitral and aortic valves, the TV has been less widely
studied with 3D echocardiography.8,9
This review details the current status of RT-3DE evaluation
of TV morphology and function with its clinical applications
and limitations.
E-mail address: [email protected]; [email protected]
Published on behalf of the European Society of Cardiology. All rights reserved. & The Author 2009.
For permissions please email: [email protected]
478
L.P. Badano et al.
Figure 1 Visualization of the tricuspid valve leaflets by two-dimensional echocardiography. The lines on the anatomical drawing show the
range of the two-dimensional tomographic planes for each corresponding view. Below the two-dimensional images has been reported the percentage of leaflet identification in each standard two-dimensional view. Modified by Anwar et al.7
Anatomy
The TV is a complex anatomic structure composed of leaflet
tissue, chordae tendineae, papillary muscles, and the supporting annular ring, right atrium, and ventricular myocardium and it is the most apically placed valve with the
largest orifice.
The TV leaflets (anterior, posterior, and septal) are
attached to a fibrous annulus and are of unequal size: the
anterior leaflet is usually the largest and extends from the
infundibula region anteriorly to the inferolateral wall posteriorly; the septal leaflet extends from the interventricuar
septum from the infundibulum to the posterior ventricular
border; the posterior leaflet attaches along the posterior
margin of the annulus from the septum to the inferolateral
wall. The insertion of the septal leaflet of the TV is characteristically apical relative to the septal insertion of the
anterior mitral leaflet.
The tricuspid annulus shows a non-planar structure with
an elliptical saddle-shaped pattern having two high points
(oriented superiorly towards the right atrium) and two low
points oriented inferiorly toward the right ventricle that is
best seen in mid-systole.10
Three papillary muscle groups usually support the TV leaflets and lie beneath each of the three commissures.
Approaches to three-dimensional imaging
of the tricuspid valve
Unlike the aortic and mitral valve it is not possible to visualize all TV leaflets simultaneously in one cross-sectional view
by standard 2DE either transthoracic or transoesophageal
due to the position of the TV in the far field (Figure 1).
RT-3DE supplements 2DE and transoesophageal echocardiography with detailed images of the morphology of the
valve including leaflets size and thickness, annulus shape
and size, myocardial walls, and their anatomic relationships.
RT-3DE with its unique capability of obtaining a short-axis
plane of the TV allows simultaneous visualization of the
three leaflets moving during the cardiac cycle and their
attachment in the tricuspid annulus (Figure 2). RT-3DE
allows the echocardiographer to visualize leaflet coaptation
and separation of the commissures. A detailed anatomical
structure of the TV including unique description and
measurement of tricuspid annulus shape and size, TV leaflets shape and mobility, and TV commissural width has
been reported by Anwar et al.7
Like 2DE, there are three main approaches to be used with
RT-3DE: parasternal, apical, and subcostal. However, when
trying to imagine a cardiac structure with RT-3DE we
should take into account the point spread function of the
system that describes the response of any imaging system
to a point object. The degree of spreading (blurring) of
any point object varies according to the dimension
employed. In current RT-3DE systems it will be around
0.5 mm in the axial or azymuthal (y) dimension, around
2.5 mm in the lateral (x) dimension, and around 3 mm in
the elevation (z) dimension. As a result we will obtain the
best images (less degree of spreading, i.e. distortion)
when using the axial dimension and the worst (greatest
degree of spreading) when we use the elevation dimension.
These concepts have an immediate practical application in
the choice of the best approach to obtain an en-face view
of the TV from the right atrium (the so called ‘surgical
view’). According to the point spread function of RT-3DE,
the best results are expected to be obtained by using the
parasternal short-axis approach because structures are
imaged by the axial and lateral dimensions. Conversely,
the worst result is expected to be obtained by the apical
approach which uses the lateral and elevation dimensions.
An intermediate result will be obtained by using the
3D-echocardiography to image TV
479
Figure 2 Normal tricuspid valve leaflets visualized by real-time three-dimensional echocardiography from atrial (left panel) and ventricular
side (right panel). ATL, anterior tricuspid leaflet; Ao, aorta; MV, mitral valve, PTL, posterior tricuspid leaflet; STL, septal tricuspid leaflet.
parasternal right ventricular inflow in which the axial and
elevation dimensions are used.
An additional feature of matrix array 3DE transducer is
that they can acquire both in actual real-time (particularly
in real-time zoom mode), and in full-volume (wide angled)
acquisition (i.e. four consecutive cardiac cycles merged
together). Both of these acquisition modalities are useful
for imaging the TV. The real-time zoom mode has several
advantages over the full-volume acquisition: (1) image resolution is much higher than that of full-volume mode; (2)
since we do not need neither suspended respiration nor
acquisition of multiple cardiac cycles, it is feasible also in
dyspnoic patients and in patients with atrial fibrillation;
(3) the possibility to electronically steer the 3D beam by
rotating the ‘track ball’, with no need of moving the transducer, may be a major advantage for the purpose of imaging
the TV from the parasternal approach, because this
approach often requires a very acute angle between the
transducer and the skin combined with the need to fit a
large transducer footprint between a rib interspace. (4) by
steering the 3D beam in order to place the long axis of the
TV along the y-axis can facilitate visualization of the three
leaflets and the full shape of the valve orifice from both
atrial or ventricular side. Using full-volume acquisition
allows a wider coverage of the region of interest. Therefore,
most relevant structures and their spatial relationships (e.g.
lefleats, chordae, and papillary muscles) can be more realistically delineated, and anatomic continuity can be assessed.
But this approach has at least two major limitations: (1) a
reduced spatial resolution of the structures with respect
to the real-time zoom mode, and (2) the possible presence
of artifacts due to rhythm disturbances and respiratory
movements.
From the practical point of view, in order to acquire an
RT-3DE data set of the TV, it is recommended to place the
transducer in a modified parasternal long-axis position to
visualize right ventricular inflow, set the overall gain
control higher than normal, centre the TV in the 3D
volume, steer the 3D beam, or manually adjust the transducer, to optimize the image to simultaneously view all three
leaflets and acquire. From the apex, the TV can be imaged
in a similar way as it is used for 2D imaging. Acquisition of
a full-volume data set or real-time zoom mode from the
apical approach optimized for right heart structures will
yield the widest field of visualization for the TV complex
(e.g. leaflets, annulus, chordae, papillary muscles, and
right ventricle) allowing assessment of their spatial relationships and anatomic continuity. After acquisition, cropping
from the apex towards the base, or from the atrial roof
towards the apex will display the en face view of the TV
from the ventricular and from atrial (‘surgical view’) side,
respectively. Frequently, it is possible to visualize TV and
mitral valve side-by-side by full volume modality. The subcostal approach can be used in some patients to obtain adequate views of the TV. Beam steering is very useful when
using this approach because an acute angle between the
abdomen surface and the transducer is frequently required
to place the transducer close to the liver and below the
costochondral junction.
In patients with good 2DE images, assessment of TV
anatomy and function with RT-3DE is feasible in around
90% of normal subjects.7
Tricuspid regurgitation
The most common cause of tricuspid regurgitation is not a
primary TV disease but rather an impaired valve coaptation
caused by a dilation of the right ventricle and/or of the tricuspid annulus.11 A variety of primary disease processes can
affect the TV complex directly and lead to valve incompetence: infective endocarditis, congenital disease like
Ebstein anomaly or atrioventricular canal, rheumatic fever,
carcinoid syndrome, endomyocardial fibrosis, myxomatous
degeneration of the TV leading to prolapse, penetrating
and non-penetrating trauma, and iatrogenic damages
during cardiac surgery, biopsies, catheter placement in
right heart chambers (Figure 3).12–18
As in the case of mitral regurgitation, a complete understanding of leaflet morphology and of the pathophysiological
mechanisms underlying tricuspid regurgitation could potentially lead to improved techniques for valve repair and to
design physiologically suitable annular rings.
Even though primary valve diseases are uncommon
causes of TV regurgitation, RT-3DE can be useful for a
better characterization of valve lesions in different aetiologies (Figure 3). Rheumatic involvement of the TV is less
common than that of left-sided valves. Regurgitation is a
consequence of deformity, shortening and retraction of
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L.P. Badano et al.
Figure 3 Three-dimensional assessment of the mechanism of regurgitation in various tricuspid valve disease: anterior tricuspid leaflet prolapse with ruptured chordae (A, right atrial ‘surgical’ view); pacemaker lead interference causing immobilization of the septal leaflet (B,
right atrial view); carcinoid tricuspid valvulopathy with adhesion of the valve leaflets to right ventricular walls that prevent the valve to
close during systole (C, right ventricular view. Courtesy by Andreas Hagendorff, Leipzig, Germany); nearly complete detachment of the posterior tricuspid leaflet during biopsy in a heart transplant patient (D, right ventricular view); functional tricuspid regurgitation, dilated
annulus, and tenting of the three leaflets with loss of systolic coaptation (E, right ventricular view); rheumatic tricuspid valve
steno-insufficiency (F, right ventricular view).
one or more leaflets of the TV as well as shortening and
fusion of the chordae tendinee and papillary muscles.
2DE usually detects thickening and the distortion of the
leaflets but cannot provide a comprehensive assessment
of extension of valve apparatus involvement. The fullvolume data set from apical approach usually provides a
comprehensive assessment of the whole TV apparatus
which can be examined from different perspectives. The
‘en face’ view of the TV obtained by RT-3DE allows the
visualization of the commissural fusion which is helpful to
establish a correct diagnosis of rheumatic aetiology of TV
regurgitation (Figure 3F). TV leaflets’ involvement in
degenerative myxomatous disease is visualized by RT-3DE
as bulging or protrusion of one or more segments of a
single or multiple TV leaflets (Figure 3A). In addition, the
presence of chordal rupture and extension of the concomitant annular dilation can be assessed in the same view
(Figure 3A). In the carcinoid disease, the valve appears
thickened, fibrotic with markedly restricted motion
during cardiac cycle, RT-3DE can show the regions of ineffective leaflet coaptation and the lack of commissural
fusion (Figure 3C).
Tricuspid annular dilatation seems to be the underlying
mechanism of functional TV regurgitation. The extent of
TV annulus dilatation may be a more reliable indicator of
TV pathology than the degree of regurgitation itself.3
Using RT-3DE, two independent groups10,19 were able to
demonstrate that, similar to the mitral annulus, the
normal TV annulus is saddle shaped, with the highest
points located in an anterior–posterior orientation and the
lowest points in a medio-lateral orientation (Figure 4).
They also elucidated the mechanism of functional tricuspid
regurgitation by showing that with the development of functional TR, the tricuspid annulus becomes dilated, more
planar, and circular. In addition, they showed that as the
annulus becomes more circular with tricuspid regurgitation,
Figure 4 (A) Right atrial view of the tricuspid valve (TV) in a
normal subject with a clear delineation of the tricuspid annulus
and its spatial relationships with mitral valve (MV) and aorta (Ao).
(B) Reconstructed tricuspid annulus viewed from profile and
showing its saddle shape, with the highest points located in an
anterior–posterior orientation and the lowest points in a mediolateral orientation. (C ) Reconstructed tricuspid annulus viewed
from the right atrium.
the increase of the anterior–posterior distance was greater
than that of the medio-lateral distance. This may result
from dilation of the tricuspid annulus preferentially along
3D-echocardiography to image TV
481
Figure 5 Comparison of tricuspid annulus diameter measurements by two-dimensional (A) and three-dimensional echocardiography (B and
C ). When the measurement taken by two-dimensional echo is reported on the three-dimensional image of the tricuspid annulus (B) it can be
realized that it does not represent the minor nor the major diameter of the annulus and underestimates both (C).
Figure 6 Rheumatic tricuspid valve stenosis seen from the right ventricle. The deformed and thickened leaflets are clearly visualized as well
as fused commissures and the stenotic orifice of the valve (A). Stenotic tricuspid valve orifice can easily and accurately be planimetered to
obtain an objective measure of stenosis severity (B).
its free-wall distance. This latter finding has an important
clinical implication.
Matsunaga et al.20 demonstrated that pre-operative tricuspid annular dilation was associated with the development of late post-operative tricuspid regurgitation after
repair of ischaemic mitral regurgitation. Dreyfus et al.3
reported that when the decision to perform tricuspid annuloplasty was based on the extent of tricuspid annular
dilation rather than the degree of tricuspid regurgitation
at the time of surgery, the long-term outcome of patients
was improved. Reference measures for TV repair include tricuspid annulus size .2.1 cm/m2 and tricuspid annulus fractional shortening ,25%.21 However, both Matsunaga and
Dreyfus used 2DE for decision-making surgery and this may
have led to some inaccuracies in measuring the true
annular size.
Anwar et al.22 demonstrated that the tricuspid annulus
shape is not circular but oval, with a minor and a major
diameter, both in normal sized and in dilated annulus. In
addition, they showed that the currently used tricuspid
annulus diameters measured with 2DE (both measured in
apical 4-chamber view and in parasternal short-axis view)
systematically underestimated the actual tricuspid annulus
size (Figure 5). As a consequence, 65% of patients with
normal tricuspid annulus diameter at 2DE showed grade
1–2 tricuspid regurgitation compared with 30% of patients
with normal tricuspid annulsus size at RT-3DE.22 Conversely,
calculation of tricuspid annulus fractional shortening yielded
the same results using 2DE and RT-3DE.22 This is because the
extent of underestimation of tricuspid annulus diameter
made by 2DE is comparable in diastole and in systole.
In addition to tricuspid annulus shape, size, and function,
RT-3DE allows to assess TV leaflet geometry in functional tricuspid regurgitation. In patients with pulmonary hypertension (i.e. right ventricular to right atrium gradient
30 mmHg), Sukmawan et al.23 reported that patients
with tricuspid regurgitation showed a tethering of tricuspid
leaflets into the right ventricle. The measured TV tenting
volume was linearly correlated with right ventricular
volume and with TV regurgitant jet area.
At the moment there are no data supporting the use of
RT-3DE in selecting patients to be addressed to surgical
repair of functional tricuspid regurgitation. However as in
the case of mitral regurgitation, an improved assessment
of valve anatomy and understanding of the pathophysiological mechanisms underlying the TV regurgitation could
suggest new and more effective techniques for TV repair.
Finally, RT-3DE can help in estimating the severity of TV
regurgitation using colour flow. Velayudhan et al.24 demonstrated the feasibility of obtaining the area of the vena contracta of the tricuspid regurgitant jet by cropping the
RT-3DE colour Doppler data set with imaging planes
482
L.P. Badano et al.
exactly parallel to the TV orifice. They found a poor correlation between the area of the vena contracta obtained by
RT-3DE and its width measured by 2DE supporting the
concept that, similar to mitral regurgitation, the vena contracta of the regurgitant tricuspid jet has a complex geometry. However, they found reasonable relationships between
the area of the vena contracta measured with RT-3DE and
conventional estimates of tricuspid regurgitation severity
by 2DE colour Doppler (i.e. regurgitant jet area and its
ratio with right atrial area) and proposed new criteria for
estimating tricuspid regurgitation severity based on vena
contracta area: ,0.5 cm2 for mild; 0.5–0.75 cm2 for moderate; and .0.75 cm2 for severe.
Tricuspid stenosis
Tricuspid stenosis is uncommon in adult patients. In nearly
all cases it is due to rheumatic disease in association with
rheumatic mitral and/or aortic valve involvement. Carcinoid
heart disease can also lead to tricuspid stenosis.
2DE images show thickening and shortening of the TV leaflets. Doppler recordings of trans-tricuspid flow velocity
allow calculation of mean gradient and pressure half-time
valve area as described for the mitral valve.25 However,
unlike what it is routinely done for mitral stenosis, neither
transthoracic nor transesophageal 2DE can provide an en
face view the stenotic orifice and visualize commissural
fusion. Using RT-3DE, the orifice of TV stenosis can be
clearly visualized and planimetered (Figures 3F and 6).26
Infective endocarditis of the tricuspid valve
In patients with TV endocarditis, RT-3DE may show the
stereoscopic morphology and attachments of vegetations,
mobility of vegetations with blood flow, and possible complications such as leaflet prolapse or perforation (Figure 7).
The size of a vegetation is an important predictor for
embolic events and for response to treatment. Maximum
diameter measurements from 2DE are routinely used to
determine mass size. However, most vegetations are irregularly shaped, making it difficult to accurately image or
select the largest diameter. The selection of a diameter
that is not truly the largest may lead to underestimation
of the true size of the vegetation and a misrepresentation
of patients’ prognosis. RT-3DE images the entire volume of
a vegetation allowing for accurate measurements in multiple planes.27
Congenital
Ebstein’s anomaly is a congenital defect of the TV in which
the origins of the septal or posterior leaflets, or both, are
displaced downward into the right ventricle with a large
sail-like anterior leaflet that results in atrialization of the
right ventricular inflow. There is a wide spectrum of severity. Although 2DE can show the characteristic displacement
of the septal leaflet and the redundant and elongated
anterior leaflet, the complex anatomy of the disease and
the mechanisms of valve regurgitation are very difficult to
assess. In adult patients with Ebstein anomaly of the TV,
Patel et al.28 have reported that RT-3DE was particularly
useful in delineating the chordal attachment of the three
leaflets of the TV. This was accomplished by multiple systematic cropping and sectioning of the RT-3DE data sets,
Figure 7 Tricuspid valve endocarditis in a young intravenous drug
addict. Non-tomographic views allow to visualize the actual shape
and attachment point of the vegetation (arrow). ATL, anterior tricuspid leaflet; STL, septal tricuspid leaflet, RA, right atrium; RV,
right ventricle.
which shows the characteristic bubble-like appearance
resulting from bulging of the non-tethered areas of the TV
leaflets (Figure 8). In addition, an en face view of the
valve obtained with RT-3DE can be used to measure the
leaflet surface areas, and to visualize the regions of ineffective leaflet coaptation (Figure 8). Moreover, RT-3DE can be
useful in evaluating the size of the functional right ventricle, and to obtain an en face view of the vena contracta
of estimating severity of tricuspid regurgitation.
Present limitations and future perspectives
Despite all the data supporting the use of RT-3DE to assess
TV morphology and function, especially in patients who
are candidates to cardiac surgery for left-sided diseases,
this technique has not been integrated into the clinical
routine. There are several reasons to explain this: some pertaining the 3D technique per se, and they have been discussed elsewhere,8,9 and two others are related to the
application of the technique to the study of the TV.
The first reason is a clinical one. At the moment, there is
no evidence that 3D assessment of TV anatomy and function
may improve surgical results. However, clinical research is
active in this field and results are expected soon.
The second reason is the lack of standardized measures
and specific software to be used to quantitate tricuspid
annulus and leaflet size and shape, as it has been developed
for the mitral valve. The increasing interest for the TV by
both echocardiographers and surgeons will fuel development and implementation of such a tool.
3D-echocardiography to image TV
483
Figure 8 Ebstein’s anomaly seen from the right ventricle. The deformed leaflets are clearly visible as well as the characteristic bubble-like
aspect of septal (S, with arrows) and posterior (P, red arrows) leaflets as effect of tethering of the leaflet where the chordae are attached.
The anterior leaflet (A) surface area can be visualized and the regions of ineffective leaflet coaptation easily identified.
Conclusions
Imaging of the TV by 2DE is hampered by inability to visualize all three leaflets simultaneously. Conversely, RT-3DE provides a unique tool for a comprehensive assessment of
morphology and function of the TV complex pre-operatively.
Understanding the anatomy and the pathophysiological
mechanisms underlying the various TV diseases will
provide the basis for surgical planning in order to tailor
the intervention to patient’s individual case.
8.
9.
10.
11.
Conflict of interest: none declared.
References
1. Behm CZ, Nath J, Foster E. Clinical correlates and mortality of hemodinamically significant tricuspid regurgitation. J Heart Valve Dis 2004;3:
784–9.
2. Hung J, Koelling T, Semigran MJ, Dec GW, Levine RA, Di Salvo TG. Usefulness of echocardiographic determined tricuspid regurgitation in predicting event-free survival in severe heart failure secondary to
idiopathic-dilated cardiomyopathy or to ischemic cardiomyopathy. Am J
Cardiol 1998;82:1301-3, A10.
3. Dreyfus GD, Corbi PJ, Chan KM, Bahrami T. Secondary tricuspid regurgitation or dilatation: which should be the criteria for surgical repair? Ann
Thorac Surg 2005;79:127–32.
4. Nath J, Foster E, Heidenreich PA. Impact of tricuspid regurgitation on
long-term survival. J Am Coll Cardiol 2004;43:405–9.
5. Sagie A, Schwammenthal E, Newell JB et al. Significant tricuspid regurgitation is a marker for adverse outcome in patients undergoing percutaneous balloon mitral valvuloplasty. J Am Coll Cardiol 1994;24:696–702.
6. McCarthy PM, Bhudia SK, Rajeswaran J, Hoercher KJ, Lytle BW,
Cosgrove DM et al. Tricuspid valve repair: durability and risk factors for
failure. J Thorac Cardiovasc Surg 2004;127:674–85.
7. Anwar AM, Geleijnse ML, Soliman OI, McGhie JS, Frowijn R, Nemes A
et al. Assessment of normal tricuspid valve anatomy in adults by real-
12.
13.
14.
15.
16.
17.
18.
time three-dimensional echocardiography. Int J Cardiovasc Imaging
2007;23:717–24.
Lang RM, Mor-Avi V, Sugeng L, Nieman PS, Sahn DJ. Three-dimensional
echocardiography. The benefits of the additional dimension. J Am Coll
Cardiol 2006;48:2053–69.
Badano LP, Dall’Armellina E, Monaghan MJ, Pepi M, Baldassi M, Cinello M
et al. Real-time three-dimensional echocardiography: tehnological
gadget or clinical tool? J Cardiovasc Med 2007;8:144–62.
Ton-Nu TT, Levine RA, Handschumacher MD, Dorer DJ, Yosefy C, Fan D
et al. Geometric determinants of functional tricuspid regurgitation:
insights from 3-dimensional echocardiography. Circulation 2006;114:
143–9.
Sagie A, Schwammenthal E, Padial LR, Vazquez de Prada JA, Weyman AE,
Levine RA. Determinants of functional tricuspid regurgitation in incomplete tricuspid valve closure: Doppler color flow study of 109 patients.
J Am Coll Cardiol 1994;446–53.
Nucifora G, Badano LP, Allocca G, Gianfagna P, Proclemer A, Cinello M
et al. Severe tricuspid regurgitation due to entrapment of the anterior
leaflet of the valve by a permanent pacemaker lead: role of real time
three-dimensional echocardiography. Echocardiography 2007;24:649–52.
Schnabel R, Khaw AV, von Bardeleben RS, Strasser C, Kramm T, Meyer J
et al. Assessment of the tricuspid valve morphology by transthoracic
real-time-3D-echocardiography. Echocardiography 2005;22:15–23.
Ahlgrim AA, Nanda NC, Berther E, Gill EA. Three-dimensional echocardiography: an alternative imaging choice for evaluation of tricuspid valve
disorders. Cardiol Clin 2007;25:305–9.
Pothineni KR, Duncan K, Yelamanchili P, Nanda NC, Patel V, Fan P et al.
Live/real-time three-dimensional transthoracic echocardiographic
assessment of tricuspid valve pathology: incremental value over the twodimensional technique. Echocardiography 2007;24:541–52.
Parranon S, Abadir S, Acar P. New insight into the tricuspid valve in
Ebstein anomaly using three-dimensional echocardiography. Heart
2006;92:1627.
Anwar AM, Attia WM, Nosir YF, El-Amin AM. Unusual bileaflet tricuspid
valve by real time three-dimensional echocardiography. Echocardiography 2008;25:534–6.
Reddy VK, Nanda S, Bandarupalli N, Pothineni KR, Nanda NC. Traumatic
tricuspid papillary muscle and chordae rupture: emerging role of threedimensional echocardiography. Echocardiography 2008;25:653–7.
484
19. Fukuda S, Saracino G, Matsumura Y, Daimon M, Tran H, Greenberg NL
et al. Three-dimensional geometry of the tricuspid annulus in healthy
subjects and in patients with functional tricuspid regurgitation: a realtime, 3-dimensional echocardiographic study. Circulation 2006;114:
I492–I498.
20. Matsunaga A, Duran CM. Progression of TR after repaired functional
ischemic mitral regurgitation. Circulation 2005;112:I-453–I-457.
21. Colombo T, Russo C, Ciliberto GR, Lanfranconi M, Bruschi G, Agati S et al.
Tricuspid regurgitation secondary to mitral valve disease: tricuspid
annulus function as guide to tricuspid valve repair. Cardiovasc Surg
2001;9:369–77.
22. Anwar AM, Geleijnse ML, Ten Cate FJ, Meijboom FJ. Assessment of
tricuspid valve annulus size, shape and function using real-time threedimensional echocardiography. Interact Cardiovasc Thorac Surg 2006;5:
683–7.
23. Sukmawan R, Watanabe N, Ogasawara Y, Yamaura Y, Yamamoto K, Wada N
et al. Geometric changes of tricuspid valve tenting in tricuspid regurgitation secondary to pulmonary hypertension quantified by novel system
L.P. Badano et al.
24.
25.
26.
27.
28.
with transthoracic real-time 3-dimensional echocardiography. J Am Soc
Echocardiogr 2007;20:470–6.
Velayudhan DE, Brown TM, Nanda NC, Patel V, Miller AP, Mehmood F et al.
Quantification of tricuspid regurgitation by live three-dimensional transthoracic echocardiographic measurements of vena contracta area. Echocardiography 2006;23:793–800.
Pearlman AS. Role of echocardiography in the diagnosis and evaluation
of severity of mitral and tricuspid stenosis. Circulation 1991;84:
I 193–I 197.
Faletra F, La Marchesina U, Bragato R, De Chiara F. Three dimensional
transthoracic echocardiography images of tricuspid stenosis. Heart
2005;91:499.
Asch FP, Bieganski PM, Panza JA, Weissman NJ. Real-time 3-dimensional
echocardiography evaluation of intracardiac masses. Echocardiography
2006;23:218–24.
Patel V, Nanda NC, Rajdev S, Mehmood F, Velayudhan D, Vengala S et al.
Live/real time three-dimensional transthoracic echocardiographic
assessment of Ebstein’s anomaly. Echocardiography 2005;22:847–54.