© 2014, Wiley Periodicals, Inc. DOI: 10.1111/echo.12486
Echocardiography
ECHO IN ADULT CONGENITAL HEART DISEASE
Echocardiographic Assessment of Ebstein’s Anomaly Oscar J. Booker, M.D., and Navin C. Nanda, M.D. Division of Cardiovascular Disease, University of Alabama at Birmingham, Birmingham, Alabama
Ebstein’s anomaly is a complex congenital lesion which primarily involves the tricuspid valve. The tricuspid leaflets are tethered to varying degrees to the right ventricular free wall and the ventricular septum often resulting in significant tricuspid regurgitation and a small functioning right ventricular chamber. Although the septal leaflet originates normally at the right atrioventricular junction, the proximal portion is often completely tethered to the ventricular septum resulting in a misconception and erroneous statements in many publications that its attachment is apically displaced. Although two-dimensional echocardiography represents the primary modality for the diagnosis of this anomaly, three-dimensional echocardiography provides incremental value in characterizing the extent and severity of tethering of individual tricuspid valve leaflets. This information is useful in surgical decision making whether to repair or replace the tricuspid valve. (Echocardiography 2015;32:69–80) Key words: Ebstein’s anomaly, echocardiography, three-dimensional echocardiography, congenital heart disease
Ebstein’s anomaly is a rare congenital disorder that was first recognized by Wilhelm Ebstein in 1864 following the death of a 19-year-old laborer. The tricuspid anatomy was identified at the necropsy and his description of the phenomenon was subsequently published. Various scholarly works followed until the 1950s when Soloff, Stauffer and Zatuchni made the first pathologically confirmed clinical diagnosis of the anomaly.1,2 We now know that Ebstein’s anomaly occurs in about 1 in 20 000 live births.3–5 This accounts for less than 1% of all cases of congenital heart disease, but about 40% of congenital heart disease involving the tricuspid valve.6 There is no predilection for gender, race, or ethnicity.7–9 Clinical Features: The clinical features of Ebstein’s anomaly vary depending upon the severity of the disease and the presence of associated abnormalities. The classical findings include right heart failure, arrhythmia, cyanosis, and sudden cardiac death. Adults have a more indolent presentation and will often initially present with atrial arrhythmias, progressive cyanosis, or increasing fatigability. The amount of cyanosis is related to the size of any right to left intra-cardiac shunts. The presence of significant right to left intra-cardiac Address for correspondence and reprint requests: Navin C. Nanda, M.D., University of Alabama at Birmingham, Echo Lab SW/S102, 619 19th Street South, Birmingham, AL 35249. Fax: 205-934-6747; E-mail: [email protected]
shunting predisposes to brain abscesses, paradoxical embolization and increases the risk of sudden death.10 On auscultation, a characteristic diastolic sound mimicking an opening snap may be heard in patients with Ebstein’s anomaly leading to an erroneous clinical diagnosis of mitral stenosis. This sound is produced by the opening movement of the enlarged sail-like anterior leaflet of the tricuspid valve. Tricuspid Anatomy: There is a maxim in cardiac anatomy that states the valve belongs to the ventricle. During fetal development, the tricuspid valve originates partially from the endocardial cushion and the myocardium.11 The leaflets and tensile apparatus delaminate from the muscular atrioventricular septum.12 The tricuspid valve has 3 leaflets that are suspended from the atrioventricular junction. The leaflets are named according to their relative position: anterior, posterior (inferior), and septal. There are 3 papillary muscles; each muscle services 2 leaflets via chordae tendineae. Multiple papillary muscles may be present in the right ventricle and occasionally the leaflets may have attachment to muscle bands and trabeculations which are numerous in the right ventricle. The major abnormality in Ebstein’s anomaly is tethering or plastering of the tricuspid leaflets to the right ventricular free wall and the ventricular septum to varying degrees producing a “bubblelike” appearance.13 Complete tethering of the 69
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proximal portion of the septal leaflet to proximal ventricular septum gives the appearance of apical displacement of the origin of the septal leaflet. Actually, in almost all cases, the septal leaflet originates normally from the usual position at the atrioventricular junction. Very rarely, the proximal portion of the leaflet is absent and in that case the remainder of the septal leaflet takes origin from the ventricular septum. The posterior or inferior leaflet is also commonly adherent to the posterior aspect of the right ventricular wall which is adjacent to the diaphragm. The anterior tricuspid leaflet which is enlarged and sail-like but also originates in the region of the atrioventricular junction like the other 2 leaflets may also show intermittent patchy tethering to the right ventricular free wall. However, this is usually not extensive and its motion is generally not significantly restricted. These abnormalities of the tricuspid valve result in a reduction in the size of the functioning right ventricle and depending on the severity of “atrialization” of the right ventricle, the functioning chamber could be very small leading to right ventricular failure. In some patients, the functional right ventricle may appear small on two-dimensional (2D) imaging but is generally larger by three-dimensional assessment.14 The tricuspid valve abnormalities lead to reduced or noncoaptation of the leaflets in systole leading to varying degrees of tricuspid regurgitation. Occasionally, the motion of the septal leaflet of the tricuspid valve may be further restricted by abnormal chordal attachments to the ventricular septum which further accentuates tricuspid regurgitation severity. Associated Cardiac Abnormalities: Atrial septal defects, mainly secundum type, are present in over 80% of patients with Ebstein’s abnormality.15,16 Muscular bands stretching from across the fibrous annulus can serve as accessory pathways. As many as 36% of patients with Ebstein’s anomaly will have at least one accessory pathway17,18 which may contribute to supraventricular tachycardias and contribute to sudden death. Other associated abnormalities include but not limited to ventricular septal defects, bicuspid or atretic aortic valves, pulmonary stenosis, pulmonary atresia, and mitral valve prolapse.19 As many as 18% will have left ventricular dysplasia suggestive of noncompaction.20 Echocardiographic Findings: M-Mode: On M-mode, there is a delayed closure of the tricuspid valve in relation to the mitral valve closure.21,22 Because of right atrial enlargement and
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an enlarged anterior tricuspid leaflet, it is easy in most cases to image the tricuspid valve and the anterior mitral leaflet together in the same beat facilitating assessment of delay in valve closure. A delay of greater than 65 msec is considered diagnostic of Ebstein’s anomaly23,24 (Fig. 1). The right ventricle tends to be dilated and systolic anterior movement of the inter-ventricular septum is common. In most patients, the maximum amplitude of the anterior tricuspid leaflet is greater than that of the anterior mitral leaflet.21 The septal tricuspid leaflet may be seen best when the insonation beam approaches the ventricular apex. Two-Dimensional Echocardiography: Two-dimensional transthoracic echocardiography (2DTTE) is one of the most important tests in the evaluation of Ebstein’s anomaly. With this modality, there will be the classic apparent apical displacement of the septal tricuspid valve leaflet seen in the apical four-chamber view. The finding of greater than 8 mm/m2 displacement as compared to mitral valve attachment is consistent with the diagnosis.25 Dysplasia and restricted tricuspid leaflet motion can often be visualized. The extent of apparent displacement of the septal and posterior (inferior) leaflets of the tricuspid valve and the size and function of the functioning right ventricle can be evaluated. The posterior
Figure 1. M-mode echocardiography. Complete recording of the tricuspid valve (TV) demonstrating functional events. A = peak produced by atrial systole; B = beginning of ventricular systole; C = point of mitral valve closure; D = beginning opening movement of mitral valve; E = fully opened position of valve; F = end of rapid ventricular filling phase. ECG = electrocardiogram; PCG = phonocardiogram. (Reproduced with permission from Nanda and Gramiak.24)
Echo in Ebstein’s Anomaly
leaflet, which may be more severely involved than the septal leaflet, is best and most convincingly visualized in the right ventricular two-chamber view. Other views such as the aortic short axis and the right ventricular inflow views with variations in transducer angulation have also been used to examine the posterior leaflet (Fig. 2). The exaggerated motion of the anterior leaflet noted above can also be seen on 2D imaging. Abnormal chordal attachments of the septal tricuspid leaflet to the ventricular septum restricting its motion can be visualized in the four-chamber view. The
size of the tricuspid valve annulus and the degree of any reduction in coaptation of the tricuspid leaflets in systole can be assessed. Right ventricular outflow tract aneurysmal dilatation can also be seen.26,27Lastly, many other associated cardiac abnormalities can be positively identified with 2DTTE.28–35 Ebstein’s anomaly is the most common cause of primary tricuspid regurgitation.26 As such, color Doppler is an essential component of the echocardiographic examination.36 Assessment of the severity of tricuspid regurgitation is critical as
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Figure 2. Ebstein’s anomaly. Two-dimensional transthoracic echocardiography. Apparent apical displacement of the attachment of septal leaflet (S) of the tricuspid valve (TV) as compared to the mitral valve (MV) is seen in apical four-chamber view (A). This displacement is related to tethering of the septal leaflet to the inter-ventricular septum resulting in a bubble-like appearance. The septal leaflet in this patient and in almost all other patients with Ebstein’s anomaly actually originates normally from the atrioventricular junction. B. Shows severe tricuspid regurgitation (TR). C. Posterior (P) leaflet of the TV can be seen in right ventricular two-chamber view. D. Left ventricular short-axis view at the level of mitral valve demonstrates all the three leaflets of the tricuspid valve. Movie clips S2A, S2B, S2C, and S2D. A = anterior tricuspid leaflet. (Reproduced with permission from Kapoor PM, Bhagatwala K, Karia N, Nanda NC: Echocardiographic Examination of the Tricuspid Valve. In: Nanda NC (Ed): Comprehensive Textbook of Echocardiography. New Delhi, India: Jaypee Brothers Medical Publishers (P) Ltd, 2013, pp. 989–1035.)
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the severity of the regurgitation will determine many of the sequelae of the disease. Presence of patent foramen ovale or secundum atrial septal defect, commonly seen in this anomaly, together with right to left shunting because of increased right atrial pressure can also be well characterized by the 2D echo modality. Twodimensional transesophageal echocardiography (2DTEE) is useful in characterizing the features of Ebstein’s anomaly in patients with poor acoustic windows and in the intra-operative setting (Figs. 3–6).
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Three-Dimensional Echocardiography: Diagnosis of Ebstein’s anomaly by 2DTTE is largely relegated to identification of the classic appearance of apparent apical displacement of the tricuspid leaflets. Visualization of the posterior leaflet by 2DTTE is difficult at best. A more complete morphologic evaluation of the tricuspid valve is sometimes required. 2DTTE cannot adequately delineate tethered from nontethered segments which can be of critical importance for surgical planning. Both three-dimensional (3D) TTE and 3D echocardiographic reconstruction
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Figure 3. Ebstein’s anomaly in a 24-year-old male. Two-dimensional transesophageal echocardiography. A, B. Transverse plane examination done at 0° shows the free (A) component of the anterior tricuspid leaflet as well as the part tethered (arrowheads) to the right ventricular free wall (A). In B, marked apparent ventricular displacement (arrows) of the septal (S) tricuspid leaflet is demonstrated. This is due to extensive tethering of the leaflet to the ventricular septum such that there is marked atrialization of the right ventricle (RV) and the functional RV is very small in this patient. Note that the septal leaflet originates normally from atrioventricular junction. C. Longitudinal plane examination done at 90° shows both the free (P) and tethered (arrowheads) components of the posterior (P) tricuspid leaflet. AV = aortic valve; LA = left atrium; LV = left ventricle; RA = right atrium; RV = right ventricle; VS = ventricular septum. (Reproduced with permission from Maxted et al.13)
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Figure 4. Ebstein’s anomaly in a 72-year-old female. Two-dimensional transesophageal echocardiography. A, B. The four-chamber views (done at multiplane angulations of 180° and 0°) show apparent ventricular deviation of a diminutive septal leaflet (S) of the tricuspid valve, because of tethering (arrowheads) to the ventricular septum(VS). The anterior tricuspid leaflet has 2 portions, one freely mobile (A) and the other tethered (arrow in B) to the anterior wall of the right ventricle (RV). C–E. Multiplane angulations of 111° (C), 93° (D), and 90° (E) show free (P, A) and tethered (arrow in C and arrowheads in D and E) components of both posterior (P) and anterior (A) tricuspid leaflets. F. Color Doppler examination done at a plane angulation of 180° show predominantly nonmosaic red flow signals filling a large portion of the huge right atrium (RA) in systole indicative of very severe tricuspid regurgitation (TR). Absence of mosaic signals reflects insignificant pressure gradient across the noncoapting and hence very severely incompetent tricuspid valve with the right ventricle and right atrium practically acting as one chamber. A = aorta; EU = eustachian valve; LA = left atrium; LV = left ventricle; MV = mitral valve; VS = ventricular septum. (Reproduced with permission from Maxted et al.13)
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Figure 5. Ebstein’s anomaly in a 32-year-old female. Two-dimensional transesophageal echocardiography. A–C. Transverse plane examination done at 0° demonstrates marked apparent ventricular deviation (arrowheads) of the septal (S) leaflet of the tricuspid valve because of tethering. The anterior (A) leaflet is elongated. Longitudinal plane B, C. examinations done at 90° show both free (P) and tethered (arrowheads) portions of the posterior (P) tricuspid leaflet. D in C denotes an associated secundum atrial septal defect. A0 = aorta; EU = Eustachian valve; LA = left atrium; LV = left ventricle; MV = mitral valve; RA = right atrium; RV = right ventricle. (Reproduced with permission from Maxted et al.13)
Figure 6. Ebstein’s anomaly in a 17-year-old male. Two-dimensional transesophageal echocardiography. A–C. The transverse plane four-chamber view at 0° shows the freely moving portion (A) of the anterior tricuspid leaflet as well as the component tethered (arrowheads) to the right ventricular anterior free wall. Two parts of the septal tricuspid leaflet (S) are also demonstrated. A small portion has a bubble-like appearance near the annulus and the other larger component shows marked apparent inferior displacement (arrows) into the right ventricle. The bubble-like appearance of the tethered portions of the anterior and septal leaflets is due to nonuniform tethering of the leaflets to the right ventricular wall. This is a typical finding in this anomaly. D. Longitudinal plane examination at 90° shows 2 portions of the posterior leaflet, one freely moving (P) and the other tethered to the right ventricular posterior (inferior) free wall (arrowheads). E, F. Transgastric examination also shows both the freely moving (P) and the tethered portions of the posterior tricuspid leaflet. G. Color Doppler examination in the four-chamber view demonstrates mosaic signals filling a large portion of the right atrium (RA) in systole indicative of severe tricuspid regurgitation (TR). Movie clip S6A–C. AV = aortic valve; CH = chordae; LA = left atrium; LV = left ventricle; MV = mitral valve; PA = main pulmonary artery; TV = tricuspid valve; VS = ventricular septum. (Reproduced with permission from Maxted et al.13)
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have shown the ability to accurately characterize the extent and severity of tethering of each of the tricuspid leaflets37–39 (Figs. 7–9). Live/real time 3D echocardiography is not only helpful in evaluating the structural characteristics of the tricuspid valve but also functional assessment. Quantification of tricuspid regurgitation is not usually required. However, there are
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certain conditions where a more rigorous assessment of tricuspid regurgitation is important as the surgical management may change depending upon its severity. One such example is Ebstein’s anomaly where there is exercise induced cyanosis. Color 3DTTE evaluation of the vena contra area provides incremental benefit in the evaluation of tricuspid regurgitation.38
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Figure 7. Live/real time three-dimensional transthoracic echocardiography in Ebstein’s anomaly associated with transposition of the great vessels. A. Four-chamber view shows apparent displacement of the attachment of the septal leaflet of the tricuspid valve (TV) towards the apex. B. Tethering of the septal leaflet of the TV results in a bubble-like appearance (yellow arrowhead) in the middle portion of the ventricular septum as the nontethered portion moves towards closure during systole. This transverse section was taken at a level denoted by #1 in A. C. Transverse section taken at a more inferior level (#2 in A) demonstrates bubble-like appearance of both septal (yellow arrowhead) and posterior (black arrowheads) TV leaflets produced by tethering. Movie clip S7C. a = anterior TV leaflet; LA = left atrium; LV = left ventricle; MV = mitral valve; RA = right atrium; RV = right ventricle. (Reproduced with permission from Patel et al.37)
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Figure 8. Live/real time three-dimensional transthoracic echocardiography in isolated Ebstein’s anomaly. A. Transverse section taken at the apex of TV shows a large area of noncoaptation (N) as well as tethering and bubble-like appearance of anterior (yellow arrows) and posterior (black arrowhead) TV leaflets. B–D. Transverse sections taken more basally demonstrate multiple “bubbles” in the septal (yellow arrowheads) and posterior (black arrowheads) TV leaflets. Inset in D shows all 3 leaflets of the tricuspid valve in the open position. E. Oblique section shows multiple “bubbles” (black arrowheads) in the posterior (P) TV leaflet produced by tethering to RV inferior wall. Inset in E shows a long snake-like posterior (P) TV leaflet. F. The oblique section shown in E has been rotated to more optimally view the attachment of posterior (p) TV leaflet to the RV inferior wall. AV = aortic valve; other abbreviations as in previous figure. G. The arrowhead in another patient with Ebstein’s anomaly shows a bubble-like appearance resulting from tethering of the septal leaflet (S) of the tricuspid valve to the ventricular septum. H, I. The arrowhead points to a large defect in the anterior leaflet of the tricuspid valve in a different patient with Ebstein’s anomaly. Note also small, discrete nodular areas of thickening on the anterior tricuspid leaflet. Asterisks represent loss of tricuspid valve tissue which is considerable in this patient. The septal leaflet of the tricuspid valve was tethered to the ventricular septum. AV = aortic valve; LV = left ventricle; RV = right ventricle; P = posterior tricuspid valve leaflet. Movie clips S8B, S8D, S8D (inset), S8E (inset) and F, S8G, 8H. (A–F reproduced with permission from Patel V, Nanda NC, Rajdev S, Mehmood F, Velayudhan D, Vengala S, Copeland RB, Madadi P.37 G–I Reproduced with permission from Pothineni K, et al: Live/real time three-dimensional transthoracic echocardiographic assessment of tricuspid valve pathology: Incremental value over the twodimensional technique. Echocardiography 2007;24:541–552).
The benefits of 3D in the setting of Ebstein’s anomaly are not limited to assessment of the tricuspid valve. A more complete assessment of the functional right ventricle, including volumes, is now a reality. Similarly, assessment of the
atrialized portion of the ventricle is important as these thinned portions of myocardium are poorly muscled and prone to aneurysmal changes. The improved anatomic detail can also help distinguish coexistent cardiac abnormalities. 3D’s 77
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Figure 9. Isolated Ebstein’s anomaly. A–C. Shows tethering of all 3 TV leaflets. The resulting “bubbles” are denoted by arrowheads for the septal (yellow) and posterior (black) TV leaflets and an arrow for the anterior (a) TV leaflet. LV = left ventricle; RV = right ventricle. (Reproduced with permission from Patel et al.37)
superior anatomic definition may also provide incremental benefit over 2D in surgical planning. Surgical Planning: In general tricuspid valve repair is preferred over replacement. Echocardiography plays a major role in the determination of the suitability for repair. Characteristics that are favorable for repair include a free leading edge and at least 50% delamination of the anterior tricuspid leaflet.39–45 78
The addition of 3D imaging provides superior anatomic visualization compared to 2D imaging alone.29 An enlarged and aneurysmal atrialized right ventricle might promote clot formation and likely has deleterious hemodynamic consequences. The right atrium and atrialized right ventricle are considered markedly enlarged when their end-diastolic combined measured area is greater than that of the functional right ventricle, left ventricle and left atrium in a four-chamber view.10
Echo in Ebstein’s Anomaly
Conclusion: Ebstein’s anomaly is a complex congenital heart condition that primarily affects the tricuspid valve. Therapeutic options are dependent upon the severity of tricuspid involvement and any other associated conditions. Echocardiography, in its many forms, stands as the primary diagnostic tool for the evaluation of the condition. References 1. Soloff LA, Stauffer HM, Zatuchni J: Ebstein’s disease: Report of the first caser diagnosed during life. Am J Med Sci 1951;222:554–561. 2. Soloff LA, Stauffer HM, Zatuchni J: Ebstein’s disease: Description of the heart of the first case diagnosed during life. Am J Med Sci 1957;233:23–27. 3. Van Son JA, Konstantinov IE, Zimermann V: Wilhelm Ebstein and Ebstein’s malformation. Eur J Cardiothorac Surg 2001; 20:1082–1085. 4. Nora JJ, Nora AH, Toews WH: Letter. Lithium, Ebstein’s anomaly, and other congenital heart defects. Lancet 1974;2:594–595. 5. Patane S, Marte F, Di Bella G, et al: Ebstein’s anomaly in adult. Int J Cardiol 2009;136:e6–e7. 6. Hauck AJ, Freeman DP, Ackermann DM, et al: Surgical pathology of the tricuspid valve: A study of 363 cases spanning 25 years. Mayo Clin Proc 1988;63:851–863. 7. Lupo PJ, Langlois PH, Mitchell LE: Epidemiology of Ebstein anomaly: Prevalence and patterns in Texas, 1999-2005. Am J Med Genet A 2011;155A:1007. ~ or A, Ferencz C, Neill CA, et al: Ebstein’s 8. Correa-Villasen malformation of the tricuspid valve: Genetic and environmental factors. The Baltimore-Washington Infant Study Group. Teratology 1994;50:137. 9. Pradat P, Francannet C, Harris JA, et al: The epidemiology of cardiovascular defects, part I: A study based on data from three large registries of congenital malformations. Pediatr Cardiol 2003;24:195. 10. Celermajer DS, Bull C, Till JA, et al: Ebstein’s anomaly: Presentation and outcome from fetus to adult. J Am Coll Cardiol 1994;23:170–176. 11. Lamers WH, Viragh S, Wessels A, et al: Formation of the tricuspid valve in the human heart. Circulation 1995;91:111–121. 12. Anderson KR, Zuberbuhler JR, Anderson RH, et al: Morphologic spectrum of Ebstein’s anomaly of the heart: A review. Mayo Clin Proc 1979;54:174–180. 13. Maxted W, Nanda NC, Kim K, et al: Transesophageal echocardiographic identification and validation of individual tricuspid valve leaflets. Echocardiography 1994;11:585–596. € ller D, et al: The functional right 14. Fratz S, Janello C, Mu ventricle and tricuspid regurgitation in Ebstein’s anomaly. Int J Cardiol 2013;167:258–261. 15. Danielson GK, Driscoll DJ, Mair DD, et al: Operative treatment of Ebstein’s anomaly. J Thorac Cardiovasc Surg 1992;104:1195–1202. 16. Brickner ME, Hillis LD, Lange RA: Congenital heart disease in adults: Second of two parts. N Engl J Med 2000; 342:334–342. 17. Watson H: Natural history of Ebstein’s anomaly of tricuspid valve in childhood and adolescence: An international co-operative study of 505 cases. Br Heart J 1974;36:417–427. 18. Smith WM, Gallagher JJ, Kerr CR, et al: The electrophysiologic basis and management of symptomatic recurrent tachycardia in patients with Ebstein’s anomaly of the tricuspid valve. Am J Cardiol 1982;49:1223–1234.
19. Attenhofer Jost CH, Connolly HM, Edwards WD, et al: Ebstein’s anomaly: Review of a multifaceted congenital cardiac condition. Swiss Med Wkly 2005;135:269–281. 20. Attenhofer Jost CH, Connolly HM, O’Leary PW, et al: Left heart lesions in patients with Ebstein anomaly. Mayo Clin Proc 2005;80:361–368. 21. Daniel W, Rathsack P, Walpurger G, et al: Value of M-mode echocardiography for non-invasive diagnosis of Ebstein’s. Br Heart J 1980;43:38–44. 22. Farooki ZQ, Henry JG, Green EW: Echocardiographic spectrum of Ebstein’s anomaly of the tricuspid valve. Circulation 1976;53:63–68. 23. Daniel W, Rathsack P, Walpurger G, et al: Value of M-mode echocardiography for non-invasive diagnosis of Ebstein’s anomaly. Br Heart J. 1980;43:38–44. 24. Nanda NC, Gramiak R: Clinical Echocardiography. Saint Louis: The C.V. Mosby Company, 1978, P.193. 25. Edwards WD: Embryology and pathologic features of Ebstein’s anomaly. Prog Pediatr Cardiol 1993;2:5–15. 26. Shiina A, Seward JB, Edwards WD, et al: Two-dimensional echocardiographic spectrum of Ebstein’s anomaly: Detailed anatomic assessment. J Am Coll Cardiol 1984;3(2 Pt 1):356–370. 27. Paranon S, Acar P: Ebstein’s anomaly of the tricuspid valve: From fetus to adult: Congenital heart disease. Heart 2008;94:237–243. 28. Seward JB: Ebstein’s Anomaly. Echocardiography 1993;10:641–664. 29. Cogswell TL, Sagar KB, Wann LS, et al: Doppler Echocardiography in Ebstein’s Anomaly: A Noninvasive “Zucker Catheter”. Echocardiography 1986;3:143–147. 30. Tak T, Nibley C, Gunawardane K, et al: Origin and Site of the Tricuspid Regurgitant Jet Determined by Color Flow Imaging in Ebstein’s Anomaly. Echocardiography 1990;7:675–678. 31. Vargas-Barron J, Rijlaarsdam M, Romero-Cardenas A, et al: Transesophageal Echocardiographic Study of Ebstein’s Anomaly. Echocardiography 1995;12:253–261. 32. Fram DB, Missri J, Therrien ML, et al: Assessment of Ebstein’s anomaly and its surgical repair using transesophageal two-dimensional echocardiography and Doppler color flow mapping. Echocardiography 1991;8:367–371. 33. Singh B, Subramanyan A, Jayaranganath M, et al: Ebstein’s anomaly with subpulmonary obstruction–a rare association. Echocardiography 2013;30:E209–E212. 34. Ilercil A, Barack J, Malone MA, et al: Association of Noncompaction of Left Ventricualr Myocardium with Ebstein’s Anomaly. Echocardiography 2006;23:432–433. 35. Jayaprasad N, Thomas V, Madhavan S, et al: A rare association of Ebstein’s anomaly of tricuspid valve with rheumatic mitral stenosis. Echocardiography 2007;24:176–178. 36. Chopra HK, Nanda NC, Fan PH, et al: Can two-dimensional echocardiography Doppler color flow mapping identify the need for tricuspid valve repair? J Am Coll Cardiol 1989;14:1266–1274. 37. Patel V, Nanda NC, Rajdev S, et al: Live/real time threedimensional transthoracic echocardiographic assessment of Ebstein’s anomaly. Echocardiography 2005;22:847–854. 38. Velayudhan DE, Brown TM, Nanda NC, et al: Quantification of tricuspid regurgitation by live three dimensional transthoracic echocardiographic measurements of vena contracta area. Echocardiography 2006;23:793–800. 39. Ahmed S, Nanda NC, Nekkanti R, et al: Transesophageal three-dimensional echocardiographic demonstration of Ebstein’s Anomaly. Echocardiography 2003;20:305–307. 40. Attenhofer Jost CH, Connolly HM, Dearani JA, et al: Ebstein’s anomaly. Circulation 2007;115:277–285. 41. Danielson GK, Maloney JD, Devloo RA: Surgical repair of Ebstein’s anomaly. Mayo Clin Proc 1979;54:185–192.
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42. Danielson GK, Fuster V: Surgical repair of Ebstein’s anomaly. Ann Surg 1982;196:499–504. 43. Carpentier A, Chauvaud S, Mace L, et al: A new reconstructive operation for Ebstein’s anomaly of the tricuspid valve. J Thorac Cardiovasc Surg 1988;96:92–101. 44. Quaegebeur JM, Sreeram N, Fraser AG, et al: Surgery for Ebstein’s anomaly: The clinical and echocardiographic evaluation of a new technique. J Am Coll Cardiol 1991;17: 722–728. 45. Chauvaud S, Berrebi A, d’Attellis N, et al: Ebstein’s anomaly: Repair based on functional analysis. Eur J Cardiothorac Surg 2003;23:525–531.
Supporting Information Additional Supporting Information may be found in the online version of this article:
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Movie clip S2A. Movie clip S2B. Movie clip S2C. Movie clip S2D. Movie clip S6A–C. Movie clip S7C. Movie clip S8B. Movie clip S8D (inset) Movie clip S8D. Movie clip S8E (inset), F. Movie clip S8G. Movie clip S8H.
Echocardiography
ECHO IN ADULT CONGENITAL HEART DISEASE
Echocardiographic Assessment of Ebstein’s Anomaly Oscar J. Booker, M.D., and Navin C. Nanda, M.D. Division of Cardiovascular Disease, University of Alabama at Birmingham, Birmingham, Alabama
Ebstein’s anomaly is a complex congenital lesion which primarily involves the tricuspid valve. The tricuspid leaflets are tethered to varying degrees to the right ventricular free wall and the ventricular septum often resulting in significant tricuspid regurgitation and a small functioning right ventricular chamber. Although the septal leaflet originates normally at the right atrioventricular junction, the proximal portion is often completely tethered to the ventricular septum resulting in a misconception and erroneous statements in many publications that its attachment is apically displaced. Although two-dimensional echocardiography represents the primary modality for the diagnosis of this anomaly, three-dimensional echocardiography provides incremental value in characterizing the extent and severity of tethering of individual tricuspid valve leaflets. This information is useful in surgical decision making whether to repair or replace the tricuspid valve. (Echocardiography 2015;32:69–80) Key words: Ebstein’s anomaly, echocardiography, three-dimensional echocardiography, congenital heart disease
Ebstein’s anomaly is a rare congenital disorder that was first recognized by Wilhelm Ebstein in 1864 following the death of a 19-year-old laborer. The tricuspid anatomy was identified at the necropsy and his description of the phenomenon was subsequently published. Various scholarly works followed until the 1950s when Soloff, Stauffer and Zatuchni made the first pathologically confirmed clinical diagnosis of the anomaly.1,2 We now know that Ebstein’s anomaly occurs in about 1 in 20 000 live births.3–5 This accounts for less than 1% of all cases of congenital heart disease, but about 40% of congenital heart disease involving the tricuspid valve.6 There is no predilection for gender, race, or ethnicity.7–9 Clinical Features: The clinical features of Ebstein’s anomaly vary depending upon the severity of the disease and the presence of associated abnormalities. The classical findings include right heart failure, arrhythmia, cyanosis, and sudden cardiac death. Adults have a more indolent presentation and will often initially present with atrial arrhythmias, progressive cyanosis, or increasing fatigability. The amount of cyanosis is related to the size of any right to left intra-cardiac shunts. The presence of significant right to left intra-cardiac Address for correspondence and reprint requests: Navin C. Nanda, M.D., University of Alabama at Birmingham, Echo Lab SW/S102, 619 19th Street South, Birmingham, AL 35249. Fax: 205-934-6747; E-mail: [email protected]
shunting predisposes to brain abscesses, paradoxical embolization and increases the risk of sudden death.10 On auscultation, a characteristic diastolic sound mimicking an opening snap may be heard in patients with Ebstein’s anomaly leading to an erroneous clinical diagnosis of mitral stenosis. This sound is produced by the opening movement of the enlarged sail-like anterior leaflet of the tricuspid valve. Tricuspid Anatomy: There is a maxim in cardiac anatomy that states the valve belongs to the ventricle. During fetal development, the tricuspid valve originates partially from the endocardial cushion and the myocardium.11 The leaflets and tensile apparatus delaminate from the muscular atrioventricular septum.12 The tricuspid valve has 3 leaflets that are suspended from the atrioventricular junction. The leaflets are named according to their relative position: anterior, posterior (inferior), and septal. There are 3 papillary muscles; each muscle services 2 leaflets via chordae tendineae. Multiple papillary muscles may be present in the right ventricle and occasionally the leaflets may have attachment to muscle bands and trabeculations which are numerous in the right ventricle. The major abnormality in Ebstein’s anomaly is tethering or plastering of the tricuspid leaflets to the right ventricular free wall and the ventricular septum to varying degrees producing a “bubblelike” appearance.13 Complete tethering of the 69
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proximal portion of the septal leaflet to proximal ventricular septum gives the appearance of apical displacement of the origin of the septal leaflet. Actually, in almost all cases, the septal leaflet originates normally from the usual position at the atrioventricular junction. Very rarely, the proximal portion of the leaflet is absent and in that case the remainder of the septal leaflet takes origin from the ventricular septum. The posterior or inferior leaflet is also commonly adherent to the posterior aspect of the right ventricular wall which is adjacent to the diaphragm. The anterior tricuspid leaflet which is enlarged and sail-like but also originates in the region of the atrioventricular junction like the other 2 leaflets may also show intermittent patchy tethering to the right ventricular free wall. However, this is usually not extensive and its motion is generally not significantly restricted. These abnormalities of the tricuspid valve result in a reduction in the size of the functioning right ventricle and depending on the severity of “atrialization” of the right ventricle, the functioning chamber could be very small leading to right ventricular failure. In some patients, the functional right ventricle may appear small on two-dimensional (2D) imaging but is generally larger by three-dimensional assessment.14 The tricuspid valve abnormalities lead to reduced or noncoaptation of the leaflets in systole leading to varying degrees of tricuspid regurgitation. Occasionally, the motion of the septal leaflet of the tricuspid valve may be further restricted by abnormal chordal attachments to the ventricular septum which further accentuates tricuspid regurgitation severity. Associated Cardiac Abnormalities: Atrial septal defects, mainly secundum type, are present in over 80% of patients with Ebstein’s abnormality.15,16 Muscular bands stretching from across the fibrous annulus can serve as accessory pathways. As many as 36% of patients with Ebstein’s anomaly will have at least one accessory pathway17,18 which may contribute to supraventricular tachycardias and contribute to sudden death. Other associated abnormalities include but not limited to ventricular septal defects, bicuspid or atretic aortic valves, pulmonary stenosis, pulmonary atresia, and mitral valve prolapse.19 As many as 18% will have left ventricular dysplasia suggestive of noncompaction.20 Echocardiographic Findings: M-Mode: On M-mode, there is a delayed closure of the tricuspid valve in relation to the mitral valve closure.21,22 Because of right atrial enlargement and
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an enlarged anterior tricuspid leaflet, it is easy in most cases to image the tricuspid valve and the anterior mitral leaflet together in the same beat facilitating assessment of delay in valve closure. A delay of greater than 65 msec is considered diagnostic of Ebstein’s anomaly23,24 (Fig. 1). The right ventricle tends to be dilated and systolic anterior movement of the inter-ventricular septum is common. In most patients, the maximum amplitude of the anterior tricuspid leaflet is greater than that of the anterior mitral leaflet.21 The septal tricuspid leaflet may be seen best when the insonation beam approaches the ventricular apex. Two-Dimensional Echocardiography: Two-dimensional transthoracic echocardiography (2DTTE) is one of the most important tests in the evaluation of Ebstein’s anomaly. With this modality, there will be the classic apparent apical displacement of the septal tricuspid valve leaflet seen in the apical four-chamber view. The finding of greater than 8 mm/m2 displacement as compared to mitral valve attachment is consistent with the diagnosis.25 Dysplasia and restricted tricuspid leaflet motion can often be visualized. The extent of apparent displacement of the septal and posterior (inferior) leaflets of the tricuspid valve and the size and function of the functioning right ventricle can be evaluated. The posterior
Figure 1. M-mode echocardiography. Complete recording of the tricuspid valve (TV) demonstrating functional events. A = peak produced by atrial systole; B = beginning of ventricular systole; C = point of mitral valve closure; D = beginning opening movement of mitral valve; E = fully opened position of valve; F = end of rapid ventricular filling phase. ECG = electrocardiogram; PCG = phonocardiogram. (Reproduced with permission from Nanda and Gramiak.24)
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leaflet, which may be more severely involved than the septal leaflet, is best and most convincingly visualized in the right ventricular two-chamber view. Other views such as the aortic short axis and the right ventricular inflow views with variations in transducer angulation have also been used to examine the posterior leaflet (Fig. 2). The exaggerated motion of the anterior leaflet noted above can also be seen on 2D imaging. Abnormal chordal attachments of the septal tricuspid leaflet to the ventricular septum restricting its motion can be visualized in the four-chamber view. The
size of the tricuspid valve annulus and the degree of any reduction in coaptation of the tricuspid leaflets in systole can be assessed. Right ventricular outflow tract aneurysmal dilatation can also be seen.26,27Lastly, many other associated cardiac abnormalities can be positively identified with 2DTTE.28–35 Ebstein’s anomaly is the most common cause of primary tricuspid regurgitation.26 As such, color Doppler is an essential component of the echocardiographic examination.36 Assessment of the severity of tricuspid regurgitation is critical as
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Figure 2. Ebstein’s anomaly. Two-dimensional transthoracic echocardiography. Apparent apical displacement of the attachment of septal leaflet (S) of the tricuspid valve (TV) as compared to the mitral valve (MV) is seen in apical four-chamber view (A). This displacement is related to tethering of the septal leaflet to the inter-ventricular septum resulting in a bubble-like appearance. The septal leaflet in this patient and in almost all other patients with Ebstein’s anomaly actually originates normally from the atrioventricular junction. B. Shows severe tricuspid regurgitation (TR). C. Posterior (P) leaflet of the TV can be seen in right ventricular two-chamber view. D. Left ventricular short-axis view at the level of mitral valve demonstrates all the three leaflets of the tricuspid valve. Movie clips S2A, S2B, S2C, and S2D. A = anterior tricuspid leaflet. (Reproduced with permission from Kapoor PM, Bhagatwala K, Karia N, Nanda NC: Echocardiographic Examination of the Tricuspid Valve. In: Nanda NC (Ed): Comprehensive Textbook of Echocardiography. New Delhi, India: Jaypee Brothers Medical Publishers (P) Ltd, 2013, pp. 989–1035.)
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the severity of the regurgitation will determine many of the sequelae of the disease. Presence of patent foramen ovale or secundum atrial septal defect, commonly seen in this anomaly, together with right to left shunting because of increased right atrial pressure can also be well characterized by the 2D echo modality. Twodimensional transesophageal echocardiography (2DTEE) is useful in characterizing the features of Ebstein’s anomaly in patients with poor acoustic windows and in the intra-operative setting (Figs. 3–6).
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Three-Dimensional Echocardiography: Diagnosis of Ebstein’s anomaly by 2DTTE is largely relegated to identification of the classic appearance of apparent apical displacement of the tricuspid leaflets. Visualization of the posterior leaflet by 2DTTE is difficult at best. A more complete morphologic evaluation of the tricuspid valve is sometimes required. 2DTTE cannot adequately delineate tethered from nontethered segments which can be of critical importance for surgical planning. Both three-dimensional (3D) TTE and 3D echocardiographic reconstruction
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Figure 3. Ebstein’s anomaly in a 24-year-old male. Two-dimensional transesophageal echocardiography. A, B. Transverse plane examination done at 0° shows the free (A) component of the anterior tricuspid leaflet as well as the part tethered (arrowheads) to the right ventricular free wall (A). In B, marked apparent ventricular displacement (arrows) of the septal (S) tricuspid leaflet is demonstrated. This is due to extensive tethering of the leaflet to the ventricular septum such that there is marked atrialization of the right ventricle (RV) and the functional RV is very small in this patient. Note that the septal leaflet originates normally from atrioventricular junction. C. Longitudinal plane examination done at 90° shows both the free (P) and tethered (arrowheads) components of the posterior (P) tricuspid leaflet. AV = aortic valve; LA = left atrium; LV = left ventricle; RA = right atrium; RV = right ventricle; VS = ventricular septum. (Reproduced with permission from Maxted et al.13)
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Figure 4. Ebstein’s anomaly in a 72-year-old female. Two-dimensional transesophageal echocardiography. A, B. The four-chamber views (done at multiplane angulations of 180° and 0°) show apparent ventricular deviation of a diminutive septal leaflet (S) of the tricuspid valve, because of tethering (arrowheads) to the ventricular septum(VS). The anterior tricuspid leaflet has 2 portions, one freely mobile (A) and the other tethered (arrow in B) to the anterior wall of the right ventricle (RV). C–E. Multiplane angulations of 111° (C), 93° (D), and 90° (E) show free (P, A) and tethered (arrow in C and arrowheads in D and E) components of both posterior (P) and anterior (A) tricuspid leaflets. F. Color Doppler examination done at a plane angulation of 180° show predominantly nonmosaic red flow signals filling a large portion of the huge right atrium (RA) in systole indicative of very severe tricuspid regurgitation (TR). Absence of mosaic signals reflects insignificant pressure gradient across the noncoapting and hence very severely incompetent tricuspid valve with the right ventricle and right atrium practically acting as one chamber. A = aorta; EU = eustachian valve; LA = left atrium; LV = left ventricle; MV = mitral valve; VS = ventricular septum. (Reproduced with permission from Maxted et al.13)
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Figure 5. Ebstein’s anomaly in a 32-year-old female. Two-dimensional transesophageal echocardiography. A–C. Transverse plane examination done at 0° demonstrates marked apparent ventricular deviation (arrowheads) of the septal (S) leaflet of the tricuspid valve because of tethering. The anterior (A) leaflet is elongated. Longitudinal plane B, C. examinations done at 90° show both free (P) and tethered (arrowheads) portions of the posterior (P) tricuspid leaflet. D in C denotes an associated secundum atrial septal defect. A0 = aorta; EU = Eustachian valve; LA = left atrium; LV = left ventricle; MV = mitral valve; RA = right atrium; RV = right ventricle. (Reproduced with permission from Maxted et al.13)
Figure 6. Ebstein’s anomaly in a 17-year-old male. Two-dimensional transesophageal echocardiography. A–C. The transverse plane four-chamber view at 0° shows the freely moving portion (A) of the anterior tricuspid leaflet as well as the component tethered (arrowheads) to the right ventricular anterior free wall. Two parts of the septal tricuspid leaflet (S) are also demonstrated. A small portion has a bubble-like appearance near the annulus and the other larger component shows marked apparent inferior displacement (arrows) into the right ventricle. The bubble-like appearance of the tethered portions of the anterior and septal leaflets is due to nonuniform tethering of the leaflets to the right ventricular wall. This is a typical finding in this anomaly. D. Longitudinal plane examination at 90° shows 2 portions of the posterior leaflet, one freely moving (P) and the other tethered to the right ventricular posterior (inferior) free wall (arrowheads). E, F. Transgastric examination also shows both the freely moving (P) and the tethered portions of the posterior tricuspid leaflet. G. Color Doppler examination in the four-chamber view demonstrates mosaic signals filling a large portion of the right atrium (RA) in systole indicative of severe tricuspid regurgitation (TR). Movie clip S6A–C. AV = aortic valve; CH = chordae; LA = left atrium; LV = left ventricle; MV = mitral valve; PA = main pulmonary artery; TV = tricuspid valve; VS = ventricular septum. (Reproduced with permission from Maxted et al.13)
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have shown the ability to accurately characterize the extent and severity of tethering of each of the tricuspid leaflets37–39 (Figs. 7–9). Live/real time 3D echocardiography is not only helpful in evaluating the structural characteristics of the tricuspid valve but also functional assessment. Quantification of tricuspid regurgitation is not usually required. However, there are
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certain conditions where a more rigorous assessment of tricuspid regurgitation is important as the surgical management may change depending upon its severity. One such example is Ebstein’s anomaly where there is exercise induced cyanosis. Color 3DTTE evaluation of the vena contra area provides incremental benefit in the evaluation of tricuspid regurgitation.38
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Figure 7. Live/real time three-dimensional transthoracic echocardiography in Ebstein’s anomaly associated with transposition of the great vessels. A. Four-chamber view shows apparent displacement of the attachment of the septal leaflet of the tricuspid valve (TV) towards the apex. B. Tethering of the septal leaflet of the TV results in a bubble-like appearance (yellow arrowhead) in the middle portion of the ventricular septum as the nontethered portion moves towards closure during systole. This transverse section was taken at a level denoted by #1 in A. C. Transverse section taken at a more inferior level (#2 in A) demonstrates bubble-like appearance of both septal (yellow arrowhead) and posterior (black arrowheads) TV leaflets produced by tethering. Movie clip S7C. a = anterior TV leaflet; LA = left atrium; LV = left ventricle; MV = mitral valve; RA = right atrium; RV = right ventricle. (Reproduced with permission from Patel et al.37)
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Figure 8. Live/real time three-dimensional transthoracic echocardiography in isolated Ebstein’s anomaly. A. Transverse section taken at the apex of TV shows a large area of noncoaptation (N) as well as tethering and bubble-like appearance of anterior (yellow arrows) and posterior (black arrowhead) TV leaflets. B–D. Transverse sections taken more basally demonstrate multiple “bubbles” in the septal (yellow arrowheads) and posterior (black arrowheads) TV leaflets. Inset in D shows all 3 leaflets of the tricuspid valve in the open position. E. Oblique section shows multiple “bubbles” (black arrowheads) in the posterior (P) TV leaflet produced by tethering to RV inferior wall. Inset in E shows a long snake-like posterior (P) TV leaflet. F. The oblique section shown in E has been rotated to more optimally view the attachment of posterior (p) TV leaflet to the RV inferior wall. AV = aortic valve; other abbreviations as in previous figure. G. The arrowhead in another patient with Ebstein’s anomaly shows a bubble-like appearance resulting from tethering of the septal leaflet (S) of the tricuspid valve to the ventricular septum. H, I. The arrowhead points to a large defect in the anterior leaflet of the tricuspid valve in a different patient with Ebstein’s anomaly. Note also small, discrete nodular areas of thickening on the anterior tricuspid leaflet. Asterisks represent loss of tricuspid valve tissue which is considerable in this patient. The septal leaflet of the tricuspid valve was tethered to the ventricular septum. AV = aortic valve; LV = left ventricle; RV = right ventricle; P = posterior tricuspid valve leaflet. Movie clips S8B, S8D, S8D (inset), S8E (inset) and F, S8G, 8H. (A–F reproduced with permission from Patel V, Nanda NC, Rajdev S, Mehmood F, Velayudhan D, Vengala S, Copeland RB, Madadi P.37 G–I Reproduced with permission from Pothineni K, et al: Live/real time three-dimensional transthoracic echocardiographic assessment of tricuspid valve pathology: Incremental value over the twodimensional technique. Echocardiography 2007;24:541–552).
The benefits of 3D in the setting of Ebstein’s anomaly are not limited to assessment of the tricuspid valve. A more complete assessment of the functional right ventricle, including volumes, is now a reality. Similarly, assessment of the
atrialized portion of the ventricle is important as these thinned portions of myocardium are poorly muscled and prone to aneurysmal changes. The improved anatomic detail can also help distinguish coexistent cardiac abnormalities. 3D’s 77
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Figure 9. Isolated Ebstein’s anomaly. A–C. Shows tethering of all 3 TV leaflets. The resulting “bubbles” are denoted by arrowheads for the septal (yellow) and posterior (black) TV leaflets and an arrow for the anterior (a) TV leaflet. LV = left ventricle; RV = right ventricle. (Reproduced with permission from Patel et al.37)
superior anatomic definition may also provide incremental benefit over 2D in surgical planning. Surgical Planning: In general tricuspid valve repair is preferred over replacement. Echocardiography plays a major role in the determination of the suitability for repair. Characteristics that are favorable for repair include a free leading edge and at least 50% delamination of the anterior tricuspid leaflet.39–45 78
The addition of 3D imaging provides superior anatomic visualization compared to 2D imaging alone.29 An enlarged and aneurysmal atrialized right ventricle might promote clot formation and likely has deleterious hemodynamic consequences. The right atrium and atrialized right ventricle are considered markedly enlarged when their end-diastolic combined measured area is greater than that of the functional right ventricle, left ventricle and left atrium in a four-chamber view.10
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Conclusion: Ebstein’s anomaly is a complex congenital heart condition that primarily affects the tricuspid valve. Therapeutic options are dependent upon the severity of tricuspid involvement and any other associated conditions. Echocardiography, in its many forms, stands as the primary diagnostic tool for the evaluation of the condition. References 1. Soloff LA, Stauffer HM, Zatuchni J: Ebstein’s disease: Report of the first caser diagnosed during life. Am J Med Sci 1951;222:554–561. 2. Soloff LA, Stauffer HM, Zatuchni J: Ebstein’s disease: Description of the heart of the first case diagnosed during life. Am J Med Sci 1957;233:23–27. 3. Van Son JA, Konstantinov IE, Zimermann V: Wilhelm Ebstein and Ebstein’s malformation. Eur J Cardiothorac Surg 2001; 20:1082–1085. 4. Nora JJ, Nora AH, Toews WH: Letter. Lithium, Ebstein’s anomaly, and other congenital heart defects. Lancet 1974;2:594–595. 5. Patane S, Marte F, Di Bella G, et al: Ebstein’s anomaly in adult. Int J Cardiol 2009;136:e6–e7. 6. Hauck AJ, Freeman DP, Ackermann DM, et al: Surgical pathology of the tricuspid valve: A study of 363 cases spanning 25 years. Mayo Clin Proc 1988;63:851–863. 7. Lupo PJ, Langlois PH, Mitchell LE: Epidemiology of Ebstein anomaly: Prevalence and patterns in Texas, 1999-2005. Am J Med Genet A 2011;155A:1007. ~ or A, Ferencz C, Neill CA, et al: Ebstein’s 8. Correa-Villasen malformation of the tricuspid valve: Genetic and environmental factors. The Baltimore-Washington Infant Study Group. Teratology 1994;50:137. 9. Pradat P, Francannet C, Harris JA, et al: The epidemiology of cardiovascular defects, part I: A study based on data from three large registries of congenital malformations. Pediatr Cardiol 2003;24:195. 10. Celermajer DS, Bull C, Till JA, et al: Ebstein’s anomaly: Presentation and outcome from fetus to adult. J Am Coll Cardiol 1994;23:170–176. 11. Lamers WH, Viragh S, Wessels A, et al: Formation of the tricuspid valve in the human heart. Circulation 1995;91:111–121. 12. Anderson KR, Zuberbuhler JR, Anderson RH, et al: Morphologic spectrum of Ebstein’s anomaly of the heart: A review. Mayo Clin Proc 1979;54:174–180. 13. Maxted W, Nanda NC, Kim K, et al: Transesophageal echocardiographic identification and validation of individual tricuspid valve leaflets. Echocardiography 1994;11:585–596. € ller D, et al: The functional right 14. Fratz S, Janello C, Mu ventricle and tricuspid regurgitation in Ebstein’s anomaly. Int J Cardiol 2013;167:258–261. 15. Danielson GK, Driscoll DJ, Mair DD, et al: Operative treatment of Ebstein’s anomaly. J Thorac Cardiovasc Surg 1992;104:1195–1202. 16. Brickner ME, Hillis LD, Lange RA: Congenital heart disease in adults: Second of two parts. N Engl J Med 2000; 342:334–342. 17. Watson H: Natural history of Ebstein’s anomaly of tricuspid valve in childhood and adolescence: An international co-operative study of 505 cases. Br Heart J 1974;36:417–427. 18. Smith WM, Gallagher JJ, Kerr CR, et al: The electrophysiologic basis and management of symptomatic recurrent tachycardia in patients with Ebstein’s anomaly of the tricuspid valve. Am J Cardiol 1982;49:1223–1234.
19. Attenhofer Jost CH, Connolly HM, Edwards WD, et al: Ebstein’s anomaly: Review of a multifaceted congenital cardiac condition. Swiss Med Wkly 2005;135:269–281. 20. Attenhofer Jost CH, Connolly HM, O’Leary PW, et al: Left heart lesions in patients with Ebstein anomaly. Mayo Clin Proc 2005;80:361–368. 21. Daniel W, Rathsack P, Walpurger G, et al: Value of M-mode echocardiography for non-invasive diagnosis of Ebstein’s. Br Heart J 1980;43:38–44. 22. Farooki ZQ, Henry JG, Green EW: Echocardiographic spectrum of Ebstein’s anomaly of the tricuspid valve. Circulation 1976;53:63–68. 23. Daniel W, Rathsack P, Walpurger G, et al: Value of M-mode echocardiography for non-invasive diagnosis of Ebstein’s anomaly. Br Heart J. 1980;43:38–44. 24. Nanda NC, Gramiak R: Clinical Echocardiography. Saint Louis: The C.V. Mosby Company, 1978, P.193. 25. Edwards WD: Embryology and pathologic features of Ebstein’s anomaly. Prog Pediatr Cardiol 1993;2:5–15. 26. Shiina A, Seward JB, Edwards WD, et al: Two-dimensional echocardiographic spectrum of Ebstein’s anomaly: Detailed anatomic assessment. J Am Coll Cardiol 1984;3(2 Pt 1):356–370. 27. Paranon S, Acar P: Ebstein’s anomaly of the tricuspid valve: From fetus to adult: Congenital heart disease. Heart 2008;94:237–243. 28. Seward JB: Ebstein’s Anomaly. Echocardiography 1993;10:641–664. 29. Cogswell TL, Sagar KB, Wann LS, et al: Doppler Echocardiography in Ebstein’s Anomaly: A Noninvasive “Zucker Catheter”. Echocardiography 1986;3:143–147. 30. Tak T, Nibley C, Gunawardane K, et al: Origin and Site of the Tricuspid Regurgitant Jet Determined by Color Flow Imaging in Ebstein’s Anomaly. Echocardiography 1990;7:675–678. 31. Vargas-Barron J, Rijlaarsdam M, Romero-Cardenas A, et al: Transesophageal Echocardiographic Study of Ebstein’s Anomaly. Echocardiography 1995;12:253–261. 32. Fram DB, Missri J, Therrien ML, et al: Assessment of Ebstein’s anomaly and its surgical repair using transesophageal two-dimensional echocardiography and Doppler color flow mapping. Echocardiography 1991;8:367–371. 33. Singh B, Subramanyan A, Jayaranganath M, et al: Ebstein’s anomaly with subpulmonary obstruction–a rare association. Echocardiography 2013;30:E209–E212. 34. Ilercil A, Barack J, Malone MA, et al: Association of Noncompaction of Left Ventricualr Myocardium with Ebstein’s Anomaly. Echocardiography 2006;23:432–433. 35. Jayaprasad N, Thomas V, Madhavan S, et al: A rare association of Ebstein’s anomaly of tricuspid valve with rheumatic mitral stenosis. Echocardiography 2007;24:176–178. 36. Chopra HK, Nanda NC, Fan PH, et al: Can two-dimensional echocardiography Doppler color flow mapping identify the need for tricuspid valve repair? J Am Coll Cardiol 1989;14:1266–1274. 37. Patel V, Nanda NC, Rajdev S, et al: Live/real time threedimensional transthoracic echocardiographic assessment of Ebstein’s anomaly. Echocardiography 2005;22:847–854. 38. Velayudhan DE, Brown TM, Nanda NC, et al: Quantification of tricuspid regurgitation by live three dimensional transthoracic echocardiographic measurements of vena contracta area. Echocardiography 2006;23:793–800. 39. Ahmed S, Nanda NC, Nekkanti R, et al: Transesophageal three-dimensional echocardiographic demonstration of Ebstein’s Anomaly. Echocardiography 2003;20:305–307. 40. Attenhofer Jost CH, Connolly HM, Dearani JA, et al: Ebstein’s anomaly. Circulation 2007;115:277–285. 41. Danielson GK, Maloney JD, Devloo RA: Surgical repair of Ebstein’s anomaly. Mayo Clin Proc 1979;54:185–192.
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42. Danielson GK, Fuster V: Surgical repair of Ebstein’s anomaly. Ann Surg 1982;196:499–504. 43. Carpentier A, Chauvaud S, Mace L, et al: A new reconstructive operation for Ebstein’s anomaly of the tricuspid valve. J Thorac Cardiovasc Surg 1988;96:92–101. 44. Quaegebeur JM, Sreeram N, Fraser AG, et al: Surgery for Ebstein’s anomaly: The clinical and echocardiographic evaluation of a new technique. J Am Coll Cardiol 1991;17: 722–728. 45. Chauvaud S, Berrebi A, d’Attellis N, et al: Ebstein’s anomaly: Repair based on functional analysis. Eur J Cardiothorac Surg 2003;23:525–531.
Supporting Information Additional Supporting Information may be found in the online version of this article:
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Movie clip S2A. Movie clip S2B. Movie clip S2C. Movie clip S2D. Movie clip S6A–C. Movie clip S7C. Movie clip S8B. Movie clip S8D (inset) Movie clip S8D. Movie clip S8E (inset), F. Movie clip S8G. Movie clip S8H.
