|Year : 2015 | Volume
| Issue : 1 | Page : 19-25
Right ventricular dimensions and function: Why do we need a more accurate and quantitative imaging?
Paola Gripari, Manuela Muratori, Laura Fusini, Gloria Tamborini, Sarah Ghulam Ali, Denise Brusoni, Mauro Pepi
Centro Cardiologico Monzino IRCCS, Milan, Italy
|Date of Web Publication||9-Jun-2015|
Centro Cardiologico Monzino, Istituto Di Ricovero e Cura a Carattere Scientifico, Via Parea, 420138 Milan
Source of Support: None, Conflict of Interest: None
The right ventricle plays an important role in the morbidity and mortality of patients presenting with symptoms and signs of cardiopulmonary disease. This cardiac chamber has a unique crescent shape, which adds complexity to the quantification of its size and function. Until recently, little uniformity in echocardiographic imaging of the right heart existed because of a lack of familiarity with various techniques, and the enormous attention directed towards left heart quantification. Three-dimensional (3D) echocardiography, a major technological breakthrough in the field of cardiovascular imaging, provides several advantages over two-dimensional (2D) imaging in the quantitative evaluations of right ventricle because of its independence from any geometrical assumption. In this review, we focus on the contribution of this new modality to the evaluation of right ventricle.
Keywords: Right ventricle, systolic function, three-dimensional echography, cardiac magnetic resonance
|How to cite this article:|
Gripari P, Muratori M, Fusini L, Tamborini G, Ali SG, Brusoni D, Pepi M. Right ventricular dimensions and function: Why do we need a more accurate and quantitative imaging?. J Cardiovasc Echography 2015;25:19-25
|How to cite this URL:|
Gripari P, Muratori M, Fusini L, Tamborini G, Ali SG, Brusoni D, Pepi M. Right ventricular dimensions and function: Why do we need a more accurate and quantitative imaging?. J Cardiovasc Echography [serial online] 2015 [cited 2020 Nov 28];25:19-25. Available from: https://www.jcecho.org/text.asp?2015/25/1/19/158420
| Introduction|| |
Despite the right ventricle plays an important role in determining the morbidity and mortality of patients with cardiopulmonary disease, ,,, the systematic assessment of right heart function is not uniformly carried out.
Recent guidelines , recommend that in all clinical studies, a comprehensive examination of the right ventricle should be performed, taking into account the study indication and available clinical information.
This review covers the contribution of three-dimensional (3D) echocardiography in the evaluation of right ventricular (RV) volumes and function, its advantages in comparison to the standard echo-Doppler evaluation, and its accuracy versus cardiac magnetic resonance imaging (CMR).
| Standard echocardiographic examination of the rv|| |
The parameters to be performed and reported should include a measure of RV size, right atrial (RA) size, RV systolic function (at least one of the following: Fractional area change (FAC), tricuspid annular plane systolic excursion (TAPSE), peak systolic velocity (PSV); with or without RV index of myocardial performance (RIMP)), and systolic pulmonary artery (PA) pressure (SPAP) with estimate of RA pressure on the basis of inferior vena cava (IVC) size and collapse. In many conditions, additional measures such as PA diastolic pressure (PADP) and an assessment of RV diastolic function are indicated. ,
Starting with the standard methods to evaluate RV dimensions; apical four-chamber, RV-focused apical four-chamber and modified short-axis, left parasternal RV inflow, and subcostal views provide the images required for a comprehensive assessment of RV size.
Measurements by two-dimensional (2D) echocardiography are challenging because of the complex geometry of the RV and the lack of specific right-sided anatomic landmarks to be used as reference points. The conventional apical four-chamber view results in considerable variability in how the right heart is sectioned, and consequently, RV linear dimensions and areas may vary widely with relatively minor rotations in transducer position. Specifically recent guidelines(5,6) suggest that diameter >42 mm at the base and >35 mm at the midlevel indicates RV dilatation. Similarly, longitudinal dimension >86 mm indicates RV enlargement. Concerning RA dimensions, these are routinely estimated in the apical four-chamber view. RA area >18 cm 2 , RA length (defined as the major dimension) >53 mm, and RA diameter (also known as the minor dimension) >44 mm indicate at end-diastole RA enlargement.
As far as RV systolic function is concerned, TAPSE is easily obtainable and represents a measure of RV longitudinal function, as well as PSV of the tricuspid annulus at tissue Doppler imaging (TDI), while FAC (four-chamber view) is a simplified method considering both longitudinal and radial shortening. We previously evaluated the feasibility of a routine use of FAC, TAPSE, and PSV as measures of RV systolic function in 900 patients, including 750 pathological and 150 normal subjects matched for age, referred for transthoracic echocardiography in our laboratory.  The methods were easy, not time consuming, and inter- and intra observer variabilities were very low for TAPSE (0.24 ± 1.3 and 0.17 ± 1.4 mm, respectively) and PSV (0.15 ± 1.8 and 0.21 ± 1.5 cm/s) and higher for FAC (4.22 ± 7 and 1.1 ± 3.9%), due to a limited definition of the endocardial border in RV lateral free wall and in the apex. A cutoff of 17 mm for TAPSE, 12 cm/s for PSV, and 37% for FAC identified abnormal RV function with high specificity (even though with low sensitivity).
These previous data are in accordance with recent guidelines , recommending these values as indexes of RV dysfunction: TAPSE <16 mm; FAC <35% as index of RV systolic dysfunction, and PVS <10 cm/s.
RIMP provides an index of global RV function. RIMP >0.40 by pulsed Doppler and >0.55 by TDI indicates RV dysfunction. By measuring the isovolumic contraction time (IVCT), isovolumic relaxation time (IVRT), and ejection time (ET) indices from the pulsed TDI velocity of the lateral tricuspid annulus, one avoids errors related to heart rate variability. RIMP can be falsely low in conditions associated with elevated RA pressures, which will decrease the IVRT.
Strain and strain rate are useful parameters for estimating RV global and regional systolic function. Longitudinal strain is calculated as the percentage of systolic shortening of the RV free wall from base to apex, while longitudinal strain rate is the rate of this shortening. RV longitudinal strain is less confounded by overall heart motion, but depends on RV loading conditions as well as RV size and shape. RV longitudinal strain should be measured in the RV-focused four-chamber view. Compared with speckle tracking-derived strain, the angle dependency of TDI strain is a disadvantage. RV speckle-tracking echocardiographic strain is influenced by image quality, reverberation, and other artifacts, as well as attenuation. However, peak global longitudinal RV strain excluding the interventricular septum has been recently reported to have prognostic value in various diseases; such as heart failure, acute myocardial infarction, pulmonary hypertension, and amyloidosis; and to predict RV failure after left ventricular assist device implantation. Maffessanti et al., compared indices of RV function obtained using different echocardiographic modalities, before and after cardiac surgery in 42 patients. They demonstrated that TAPSE, PSV, and FAC significantly decreased after surgery, while 3D RV ejection fraction (EF) was preserved; speckle-tracking echocardiographic results were dependent on the considered direction with preserved radial, but decreased longitudinal strain values.  [Figure 1] shows examples of 2D methods for the RV evaluation.
|Figure 1: Examples of different methods for RV function evaluation. Top left: Fractional shortening area; top middle: TAPSE; top right: DTI of the tricuspid annulus. Bottom left, mid, and right: Images of RV strain evaluation. LV = Left ventricle, PSV = Peak systolic velocity, TAPSE = Tricuspid annulus peak systolic excursion, RV = Right ventricular, TAPSE = Tricuspid annular plane systolic excursion, DTI = Doppler tissue imaging|
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All dimensional and functional parameters of the right chambers should be associated to the estimation of the SPAP differentiating volume and pressure overload. Tricuspid regurgitation velocity reliably permits estimation of RV systolic pressure with the addition of RA pressure, assuming no significant RV outflow tract obstruction. It is recommended to use the RA pressure estimated from IVC and its collapsibility, rather than arbitrarily assigning a fixed RA pressure.
In 1994, we described a new formula for echo-Doppler estimation of RV systolic pressure based on tricuspid regurgitation and IVC collapsibility.  In 110 patients, the new method based on IVC collapsibility correlated better than the old ones with invasive RA, RV, and pulmonary pressures. In brief, we suggested that RA pressure may be better defined assigning 6, 9, and 16 mmHg, when IVC collapsibility was >45%, between 35-45% and <35%, respectively. Consequently, based on these IVC indexes, different RA pressure values may be added to the tricuspid gradient. Several papers confirmed the importance of IVC collapsibility and redefined the method considering IVC dimensions also. Guidelines , suggested that IVC diameter <2.1 cm that collapses >50% with a sniff suggests a normal RA pressure of 3 mmHg (range, 0-5 mmHg); whereas, an IVC diameter >2.1 cm that collapses <50% with a sniff suggests a high RA pressure of 15 mmHg (range, 10-20 mmHg). In indeterminate cases in which the IVC diameter and collapse do not fit this paradigm, an intermediate value of 8 mmHg (range, 5-10 mmHg) may be used, or, preferably, secondary indices of elevated RA pressure should be integrated. These include restrictive right-sided diastolic filling pattern, tricuspid E/E' ratio >6, and diastolic flow predominance in the hepatic veins (which can be quantified as a systolic filling fraction <55%). In indeterminate cases, if none of these secondary indices of elevated RA pressure are present, RA pressure may be downgraded to 3 mmHg. If there is minimal IVC collapse with a sniff (<35%) and secondary indices of elevated RA pressure are present, RA pressure may be upgraded to 15mmHg. If uncertainty remains, RA pressure may be left at the intermediate value of 8 mmHg. In patients who are unable to adequately perform a sniff, an IVC that collapses <20% with quiet inspiration suggests elevated RA pressure. This method of assigning an RA pressure is preferable to assuming a fixed RA pressure value for all patients.
| 3D EXAMINATION OF THE RV|| |
Because of the peculiar RV morphology and function, 2D echocardiography has several limitations in the evaluation of the right ventricle, which can be readily overcome by a 3D echo gated wide-angled acquisition, which enables complete assessment of its geometry, volumes, and EF. The right ventricle is composed of three anatomic and functional subunits, which extend from the tricuspid valve annulus to the proximal in fundibulum, the RV body to the apex, and the RV outflow tract to the pulmonary valve. This divides the RV cavity into three sections: Inlet, apical trabecular, and outlet, respectively.
Several methods and software packages have been used to evaluate the right ventricle.  3D data are generally acquired in a full-volume dataset from the four-chamber apical view adapted to include the entire right ventricle. 3D echocardio graphic data sets are typically digitally stored and then post-processed offline. After full-volume acquisition, current RV analysis software displays 2D cut planes of the RV sagittal, four-chamber, and coronal views; allowing calculation of RV volumes from end-diastolic and end-systolic endocardial border tracings of these three views. The RV volumes are calculated by summation of the volumes for each slice through the complete data set. Curves of global and regional RV function may be generated and analyzed [Figure 2].
|Figure 2: Examples of 3D right ventricular imaging. Top left: 3D imaging of a normal RV; top right: 3D imaging of a severe dilatation and hypertrophy of the RV. Bottom: Images of RV assessment by 3D reconstruction. The inflow, outflow, and apical segments of the RV are clearly delineated. Curves of global function and RV ejection fraction are also shown (bottom right panel). 3D = Three dimensional|
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Several studies utilized this method in normal and pathologic heart to evaluate feasibility and accuracy. In 2008, Tamborini et al.,  investigated the feasibility of transthoracic 3D RV analysis in 200 subjects (48 normal, 104 patients with valvular heart disease, 20 patients with idiopathic dilated cardiomyopathy, and 28 patients with pulmonary hypertension). This study compared and correlated 3D RV data with classic 2D and Doppler parameters, including TAPSE and PSV on TDI, RV FAC, RV stroke volume by the Doppler method, and SPAP. 3D-derived RV diastolic and systolic volumes were 103 ± 38 and 46 ± 28 mL, respectively. RV EF was correlated negatively with SPAP and positively with TAPSE, PSV, and FAC. 3D echocardiography showed that patients with pulmonary hypertension had the largest RV volumes and the lowest RV EF and those with idiopathic dilated cardiomyopathy were characterized by lower RV EF than those patients with valvular disease. At least one good 3D acquisition of the RV was achieved in all individuals in a mean time of 3 ± 1 min and the RV image quality was good in most individuals (85%). Thus, the investigators concluded that the new quantitative 3D method to assess RV volumes and function was feasible, relatively simple, and not time consuming.
More recently, another study provided normal reference values for RV volumes and function that may be useful for the identification of clinical abnormalities.  The mean RV end-diastolic and end-systolic volumes were 49 ± 10 and 16 ± 6 mL/m 2 , respectively, and the mean RV EF was 67 ± 7%. Significant correlations were observed between RV parameters and body surface area. Normalized RV volumes were significantly correlated with age and gender. RV EF was lower in men, but differences across age deciles were not evident. In a larger population and a multicenter study  RV volumes (end-diastolic volume and end-systolic volume), stroke volume, and EF were measured by 3D echocardiography. In 540 healthy adult volunteers, prospectively enrolled, and evenly distributed across age and sex the relation of age, sex, and body size parameters was investigated in detail using bivariate and multiple linear regression. Analysis was feasible in 507 (94%) subjects (260 women; age, 45 ± 16 years; and range, 18-90). Age, sex, height, and weight significantly influenced RV volumes and EF. Sex effect was significant (P < 0.01), with RV volumes larger and EF smaller in men than in women. Older age was associated with lower volumes (end-diastolic volume, −5 mL/decade; endsystolic volume, −3 mL/decade; and EF, −2 mL/decade) and higher EF (+1% per decade). Inclusion of body size parameters in the statistical models resulted in improved overall explained variance for volumes (end-diastolic volume, R2 = 0.43; end-systolic volume, R2 = 0.35; and stroke volume, R2 = 0.30), while EF was unaffected. Ratiometric and allometric indexing for age, sex, and body size resulted in no significant residual correlation between RV measures and height or weight.
These 3D references values confirmed 2D standard measurements showing that gender and body surface area are important determinants of RV dimensions and systolic function as measured on 2D echocardiography. 
| ADVANTAGES OF 3D VS 2D EXAMINATION IN SPECIFIC DISORDERS|| |
In 2009, Tamborini et al.,  evaluated RV function in 40 patients with mitral valve prolapse undergoing surgical valvular repair and to compare and correlate 3D RV EF with 2D derived TAPSE and PSV of tricuspid annulus before and after surgery. Transthoracic 2D and 3D echocardiography were performed presurgery and 3, 6, and 12 months postsurgery. TAPSE (15.5 ± 3, 16.5 ± 3, and 18.5 ± 4 mm at 3, 6, and 12 months, respectively) and PSV of the tricuspid annulus (11.9 ± 2, 12 ± 2, and 12.8 ± 3 cm/s at 3, 6, and 12 months, respectively) were significantly lower after surgery in comparison with presurgical values. On the contrary, preoperative RV EF (58.4 ± 4%) did not change after surgery (56.9 ± 5, 59.5 ± 5, and 58.5 ± 5% at each step). This explains why in the literature after cardiac surgery (independently on the type of surgery) TAPSE is always reduced, even though a damage and dysfunction in all cases is not reasonable. Therefore in a patient with previous cardiac surgery, TAPSE is not a surrogate of RV systolic function and 3D echocardiography may overcome this limit.
Moreover in several clinical conditions such as congenital heart disease, artificial heart, and LV device assistance; the value of 3D echocardiography has been proved. ,
| CMR FOR RV EVALUATION AND CORRELATIONS BETWEEN CMR AND 3D ECHOCARDIOGRAPHY|| |
CMR is the second-line imaging modality after echocardiography for comprehensive RV evaluation. This technique is well suited for the visualization of RV anatomy and the quantitative measurement of RV parameters (dimensions, mass and function) because of the variable configuration of this chamber that requires a 3D volume acquisition.
CMR-derived RV volumes show good correlation with in vivo standards, and this technique has shown optimal accuracy and reproducibility for RV measurements; ,, on the basis of these characteristics, CMR has become the clinical reference technique for accurate assessment of global RV function. Short-axis images and the summation disc method are used for calculation of RV volumes and EF without any geometrical assumption and RV normal clinical ranges for these parameters have been established from both a spoiled gradient echo sequence , and more recently, from the steady-state free precession technique , that yields significantly improved blood-myocardium contrast, acquisition speed, and the ability to greatly enhance the temporal resolution of the cines with improved image quality.
CMR also provides advanced imaging of the RV myocardium that includes tissue characterization. Different T1- and T2-weighted sequences combined with late-enhancement imaging after gadolinium administration can be used for the assessment and differentiation of cardiomyopathies including arrhythmogenic RV cardiomyopathy, metabolic storage diseases, and cardiac tumors. ,, Late enhancement imaging shows intramyocardial fibrosis, inflammation, and scars; and it has been demonstrated to be important in various clinical settings as pulmonary hypertension or ischemic RV disease. ,,
Given that CMR represents the reference technique for the RV comprehensive evaluation and has been used as the gold standard for quantitative RV assessment; however, its widespread use in clinical settings is limited because it is expensive, time-consuming, and sometimes contraindicated.
3D echocardiography is considered theoretically ideal for estimation of RV volumes and function, otherwise not feasible by standard 2D echocardiography. This new echocardiographic method has been reported to be in good agreement with validation studies in vitro and in vivo. ,,,, In clinical studies, however, it has often been reported that, mostly because of technical factors  and despite the excellent correlation, 3D echocardiography underestimates RV volumes compared with CMR. The accuracy of the 3D echo method has been analyzed in healthy individuals and in patients with different pathologies.
Gopal et al.,  investigated the accuracy of 2D and 3D echocardiography with both disc summation and apical rotation methods compared to CMR for the assessment of RV volume and function in 71 normal subjects. 3D echocardiography with the disc summation technique showed the least underestimation of, and thus the best agreement with CMR derived RV volumes. Also, in this study, normal reference ranges of RV indexed volumes, stroke volume, and EF were reported.
In 2006, Prakasa et al.,  evaluated 58 patients with RV dysplasia concluding that 3D echocardiographic measurements of RV volumes and EF closely correlate with CMR values and may be useful in the follow-up of patients with arrhythmogenic RV dysplasia. However, real-time 3D echocardiography underestimated CMR- derived RV volumes, especially end-systolic volumes, significantly.
Jenkins et al.,  investigated in 50 patients with left ventricular wall motion abnormalities whether 3D echocardiography was superior to 2D echocardiography for the follow-up of RV function. In this study, RV volumes and EF were studied with 2D echocardiography with three different methods (area-length, the modified 2D subtraction method, and the Simpson method of discs). CMR was again used as a reference standard. CMR-derived RV end-diastolic and end-systolic volumes were slightly underestimated by 3D echo with a greater mean difference for 2D echocardiography with the area length method and the Simpson method of discs, and were greatly overestimated by the 2D subtraction method.
In 2010, Grewal et al.,  demonstrated that 3D echocardiography compared with CMR was both accurate and reproducible for assessing RV volumes and EF in adult patients with Tetralogy of Fallot and severe pulmonary regurgitation.
In 2010, Sugeng et al.,  undertook volumetric analysis of the RV by real-time 3D echocardiography, CMR, and cardiac computed tomography (CCT) on images obtained in RV-shaped phantoms and in patients with a wide range of pathologies. The in vitro measurements showed that volumetric analysis of CMR images yielded the most accurate measurements; CCT measurements showed slight (4%) but consistent overestimation; and 3D measurements showed small underestimation, but considerably wider margins of error. In humans, both 3D echo and CCT measurements correlated highly with the CMR reference and showed the same trends of underestimation and overestimation noted in vitro.
These observations confirm the fact that evaluating the RV morphology is challenging, in part because of its particular crescent shape, leading us to wonder whether it is valuable to search for strict correlations between dimensions obtained with different imaging techniques.
| References|| |
Sun JP, James KB, Yang XS, Solankhi N, Shah MS, Arheart KL, et al
. Comparison of mortality rates and progression of left ventricular dysfunction in patients with idiopathic dilated cardiomyopathy and dilated versus non dilated right ventricular cavities. Am J Cardiol 1997;80:1583-37.
De Groote P, Millaire A, Foucher-Hossein C, Nugue O, Marchandise X, Ducloux G, et al
. Right ventricular ejection fraction is an independent predictor of survival in patients with moderate heart failure. J Am Coll Cardiol 1998;32:948-54.
Ghio S, Gavazzi A, Campana C, Inserra C, Klersy C, Sebastiani R, et al
. Independent and additive prognostic value of right ventricular systolic function and pulmonary artery pressure in patients with chronic heart failure. J Am Coll Cardiol 2001;37:183-8.
Spinarova L, Meluzin J, Toman J, Hude P, Krejci J, Vitovec J. Right ventricular dysfunction in chronic heart failure. Eur J Heart Failure 2005;7:485-9.
Rudski LG, Lai WW, Afilalo J, Hua L, Handschumacher MD, Chandrasekaran K, et al
. Guidelines for the echocardiographic assessment of the right heart in adults: A Report from the American Society of Echocardiography Endorsed by the European Association of Echocardiography, a registered branch of the European Society of Cardiology, and the Canadian Society of Echocardiography. J Am Soc Echocardiogr 2010;23:685-713.
Lang RM, Badano LP, Mor-Avi V, Afilalo J, Armstrong A, Ernande L, et al
. Recommendations for cardiac chamber quantification by echocardiography in adults: An update from the american society of echocardiography and the european association of cardiovascular imaging. J Am Soc Echocardiogr 2015;28:1-39.
Tamborini G, Pepi M, Galli CA, Maltagliati A, Celeste F, Muratori M, et al
. Feasibility and accuracy of a routine echocardiographic assessment of right ventricular function. Int J Cardiol 2007;115:86-9.
Maffessanti F, Gripari P, Tamborini G, Muratori M, Fusini L, Alamanni F, et al
. Evaluation of right ventricular systolic function after mitral valve repair: A two-dimensional Doppler, speckle-tracking, and three-dimensional echocardiographic study. J Am Soc Echocardiogr 2012;25:701-8.
Pepi M, Tamborini G, Galli C, Barbier P, Doria E, Berti M, et al
. A new formula for echo-Doppler estimation of right ventricular systolic pressure. J Am Soc Echocardiogr 1994;7:20-6.
Lang RM, Badano LP, Tsang W, Adams DH, Agricola E, Buck T, et al
. EAE/ASE Recomendations for image acquisition and display using three-dimensional echocardiography. J Am Soc Echocardiogr 2012;25:3-46.
Tamborini G, Brusoni D, Torres Molina JE, Galli CA, Maltagliati A, Muratori M, et al.
Feasibility of a New Generation 3-Dimensional Echocardiography for Right Ventricular Volumetric and Functional Measurements. Am J Cardiol 2008;102:499-505.
Tamborini G, Ajmone Marsan, N, Gripari P, Maffessanti F, Brusoni D, Muratori M, et al
. Reference values for right ventricular volumes and ejection fraction with real-time three-dimensional echocardiography: Evaluation in a large series of normal subjects. J Am Soc Echocardiogr 2010;23:109-15.
Maffessanti F, Muraru D, Esposito R, Gripari P, Ermacora D, Santoro C, et al
. Age-, body size-, and sex-specific reference values for right ventricular volumes and ejection fraction by three-dimensional echocardiography: A multicenter echocardiographic study in 507 healthy volunteers. Circ Cardiovasc Imaging 2013;6:700-10.
D'Oronzio U, Senn O, Biaggi P, Gruner C, Jenni R, Tanner FC, et al
. Right heart assessment by echocardiography: Gender and body size matters. J Am Soc Echocardiogr 2012;25:1251-8.
Tamborini G, Muratori M, Brusoni D, Celeste F, Maffessanti F, Caiani EG, et al
. Is right ventricular systolic function reduced after cardiac surgery? A 2- and 3-dimensional echocardiographic study. Eur J Echocard 2009;10:630-4.
Grewal J, Majdalany D, Syed I, Pellikka P, Warnes CA. Three-dimensional echocardiographic assessment of right ventricular volume and function in adult patients with congenital heart disease: Comparison with magnetic resonance imaging. J Am Soc Echocardiogr 2010;23:127-33.
Sechtem U, Pflugfelder PW, Gould RG, Cassidy MM, Higgins CB. Measurement of right and left ventricular volumes in healthy individuals with cine MR imaging. Radiology 1987;163:697-702.
Grothues F, Smith GC, Moon JC, Bellenger NG, Collins P. Comparison of interstudy reproducibility of cardiovascular magnetic resonance with two-dimensional echocardiography in normal subjects and in patients with heart failure or left ventricular hypertrophy. Am J Cardiol 2002;90:29-34.
Bellenger NG, Davies LC, Francis JM, Coats AJ, Pennell DJ. Reduction in sample size for studies of remodelling in heart failure by the use of cardiovascular magnetic resonance. J Cardiovasc Magn Reson 2000;2:271-8.
Tandri H, Daya SK, Nasir K, Bomma C, Lima JA, Calkins H, et al
. Normal reference values for the adult right ventricle by magnetic resonance imaging. Am J Cardiol 2006;15;98:1660-4.
Kawut SM, Lima JA, Barr RG, Chahal H, Jain A, Tandri H, et al
. Sex and race differences in right ventricular structure and function: The multi-ethnic study of atherosclerosis-right ventricle study. Circulation 2011;123:2542-51.
Buechel EV, Kaiser T, Jackson C, Schmitz A, Kellenberger CJ. Normal right- and left ventricular volumes and myocardial mass in children measured by steady state free precession cardiovascular magnetic resonance. J Cardiovasc Magn Reson 2009;11:9.
Maceira AM, Prasad SK, Khan M, Pennell DJ. Reference right ventricular systolic and diastolic function normalized to age, gender and body surface area from steady-state free precession cardiovascular magnetic resonance. Eur Heart J 2006;27:2879-88.
Tandri H, Castillo E, Ferrari VA, Nasir K, Dalal D, Bomma C, et al
. Magnetic resonance imaging of arrhythmogenic right ventricular dysplasia: Sensitivity, specificity, and observer variability of fat detection versus functional analysis of the right ventricle. J Am Coll Cardiol 2006;48:2277-84.
Tandri H, Macedo R, Calkins H, Marcus F, Cannom D, Scheinman M, et al
. Role of magnetic resonance imaging in arrhythmogenic right ventricular dysplasia: Insights from the North American arrhythmogenic right ventricular dysplasia (ARVD/C) study. Am Heart J 2008;155:147-53.
Carbone I, Francone M, Chimenti C, Galea N, Russo M, Frustaci A. Right ventricular late enhancement as a magnetic resonance marker of glycogen storage disease. Circulation 2010;122:189-90.
Shehata ML, Lossnitzer D, Skrok J, Boyce D, Lechtzin N, Mathai SC, et al
. Myocardial delayed enhancement in pulmonary hypertension: Pulmonary hemodynamics, right ventricular function, and remodeling. AJR Am J Roentgenol 2011;196:87-94.
Kumar A, Abdel-Aty H, Kriedemann I, Schulz-Menger J, Gross CM, Dietz R, et al
. Contrast-enhanced cardiovascular magnetic resonance imaging of right ventricular infarction. J Am Coll Cardiol 2006;48:1969-76.
Larose E, Ganz P, Reynolds HG, Dorbala S, Di Carli MF, Brown KA, et al
. Right ventricular dysfunction assessed by cardiovascular magnetic resonance imaging predicts poor prognosis late after myocardial infarction. J Am Coll Cardiol 2007;49:855-62.
Shiota T, Jones M, Chikada M, Fleishman CE, Castellucci JB, Cotter B, et al
. Real-time three-dimensional echocardiography for determining right ventricular stroke volume in an animal model of chronic right ventricular volume overload. Circulation 1998;97:1897-900.
Hubka M, Bolson EL, McDonald JA, Martin RW, Munt B, Sheehan FH. Three-dimensional echocardiographic measurement of left and right ventricular mass and volume: In vitro
validation. Int J Cardiovasc Imaging 2002;18:111-8.
Pini R, Giannazzo G, Di Bari M, Innocenti F, Rega L, Casolo G, et al
. Transthoracic three-dimensional echocardiographic reconstruction of left and right ventricles: In vitro
validation and comparison with magnetic resonance imaging. Am Heart J 1997;133:221-9.
Chen G, Sun K, Huang G. In vitro
validation of right ventricular volume and mass measurement by real-time three-dimensional echocardiography. Echocardiography 2006;23:395-9.
Jiang L, Siu SC, Handschumacher MD, Luis Guererro J, Vazquez de Prada JA, King ME, et al
. Three-dimensional echocardiography. In vivo
validation for right ventricular volume and function. Circulation 1994;89:2342-50.
Hoch M, Vasilyev NV, Soriano B, Gauvreau K, Marx GR. Variables influencing the accuracy of right ventricular volume assessment by real-time 3-dimensional echocardiography: An in vitro
validation study. J Am Soc Echocardiogr 2007;20:456-61.
Gopal AS, Chukwu EO, Iwuchukwu CJ, Katz AS, Toole RS, Schapiro W, et al
. Normal values of right ventricular size and function by real-time 3-dimensional echocardiography: Comparison with cardiac magnetic resonance imaging. J Am Soc Echocardiogr 2007;20:445-55.
Prakasa KR, Dalal D, Wang J, Bomma C, Tandri H, Dong J, et al
. Feasibility and variability of three dimensional echocardiography in arrhythmogenic right ventricular dysplasia/cardiomyopathy. Am J Cardiol 2006;97:703-9.
Jenkins C, Chan J, Bricknell K, Strudwick M, Marwick TH. Reproducibility of right ventricular volumes and ejection fraction using real-time three-dimensional echocardiography: Comparison with cardiac MRI. Chest 2007;131:1844-51.
Sugeng L, Mor-Avi V, Weinert L, Niel J, Ebner C, Steringer-Mascherbauer R, et al
. Multimodality comparison of quantitative volumetric analysis of the right ventricle. JACC Cardiovasc Imaging 2010;3:10-8.
[Figure 1], [Figure 2]