**10. Diagnosis**

#### **10.1. Electrocardiography**

The electrocardiogram (ECG) is usually abnormal and helps to confirm the clinical diagnosis. Sinus rhythm is usually present at the time of initial diagnosis. ECG may show tall and broad P waves as a result of right atrial enlargement, as well as complete or incomplete right bundlebranch block. Complete AV block is rare and first degree AV block is present in approximately half the patients. The QRS axis in the frontal plane occasionally shows right-axis deviation. Most patients have right bundle branch block and many have low-voltage QRS complexes in the right precordial leads. Right ventricular hypertrophy criterion are extremely uncommon [41, 45].

deviation in a patient with EA suggests the presence of the Mahaim variant of preexcitation, produced by atriofascicular tracts.The patients with arrhythmias or symptoms compatible with arrhythmia are significantly older than those without symptoms or arrhythmias [46–48]. Accessory conduction pathways [Wolff-Parkinson-White (WPW) syndrome] arrhythmias are seen approximately 15–20%. Atrial fibrillation or flutter can occur with increasing frequency

**Figure 1.** ECG of a patient with Ebstein's anomaly and the wolf Parkinson white syndrome showing the typical changes,

Ebstein's Anomaly

141

http://dx.doi.org/10.5772/intechopen.78067

Even prior to the widespread application of complex surgical antiarrhythmic procedures, surgical intervention appeared to decrease the frequency of arrhythmias, at least in early, short-term follow-up. Despite the overall reduction in arrhythmias, when arrhythmias were observed early during postoperative recovery, these patients had an increased risk of late

The cardiac silhouette may vary from nearly normal to extreme cardiomegaly. When the heart is severely dilated, it takes a globular shape similar to that observed with large pericardial effusions or severe dilated cardiomyopathy. The dilated right atrium is responsible for most of the enlarged cardiac silhouette. In the frontal view, the right atrium produces a significant convexity of the right heart border, and in the lateral view, the right atrium may fill the entire retrosternal space. The convex left border is primarily due to dilation of the right ventricular outflow tract. The convexities of both left and right heart borders produce the characteristic

with older age. ECG shows EA patients with WPW syndrome in **Figure 1**.

with reduced PR interval, and preexcitation (delta wave) configuration of the QRS complex.

sudden death [15, 49].

**10.2. Chest radiography**

The downward displacement of the septal leaflet of the TV is associated with discontinuity of the central fibrous body and septal atrioventricular ring with direct muscular connections, thus creating a potential substrate for accessory atrioventricular connections and preexcitation. Occasionally, the pattern is transient or intermittent. Paroxysmal tachyarrhythmias in EA are based on fast conducting atrioventricular accessory pathways with both antegrade and retrograde conduction properties in most patients. In addition, wide QRS tachycardia over a septal accessory atrioventricular pathway, ventricular tachycardia, or flutter, as well as ectopic atrial tachycardia, atrial flutter, and atrial fibrillation can occur. Concealed accessory pathways, without manifest delta waves, are also common. Absence of anterograde preexcitation, therefore, neither indicates that the accessory connection is no longer present nor that the patient is no longer susceptible to tachycardia. The patient may still have retrograde conduction, which allows for atrioventricular reciprocating tachycardia. The presence of left axis

**Figure 1.** ECG of a patient with Ebstein's anomaly and the wolf Parkinson white syndrome showing the typical changes, with reduced PR interval, and preexcitation (delta wave) configuration of the QRS complex.

deviation in a patient with EA suggests the presence of the Mahaim variant of preexcitation, produced by atriofascicular tracts.The patients with arrhythmias or symptoms compatible with arrhythmia are significantly older than those without symptoms or arrhythmias [46–48]. Accessory conduction pathways [Wolff-Parkinson-White (WPW) syndrome] arrhythmias are seen approximately 15–20%. Atrial fibrillation or flutter can occur with increasing frequency with older age. ECG shows EA patients with WPW syndrome in **Figure 1**.

Even prior to the widespread application of complex surgical antiarrhythmic procedures, surgical intervention appeared to decrease the frequency of arrhythmias, at least in early, short-term follow-up. Despite the overall reduction in arrhythmias, when arrhythmias were observed early during postoperative recovery, these patients had an increased risk of late sudden death [15, 49].

#### **10.2. Chest radiography**

usually normal, even in the presence of tricuspid insuficiency. The jugular venous pulsations may not have a large V wave because of poor transmission of the venous pulse wave in the presence of a dilated and compliant right atrium [41, 42]. Jugular venous and hepatic distention may be present in advanced cases. The praecordium is usually not overactive. After the neonatal period, it is auscultation that often alerts the physician to the diagnosis of EA. The systolic murmur of tricuspid regurgitation is variable and its intensity depends on the degree to which contractility of the fRV is preserved. Multiple first heart sounds are heard because the highly mobile anterosuperior valvar leaflets and anterior leaflet mimic ejection clicks. Occasionally, the heart sounds are soft, but usually they are of normal intensity. The first heart sound is widely split because of the increased excursion of the anterosuperior leaflet and the subsequent delayed closure of the abnormal TV. The second heart sound is often split owing to the late closure of the pulmonary valve as a result of the conduction delay associated with severe RV enlargement. A holosystolic murmur is found along the left sternal border in those with an organized jet of tricuspid regurgitation. Diastolic murmurs are rare, unless there is coexisting pulmonary regurgitation. Low-intensity diastolic murmurs can be auscultated in the same location as a result of antero-grade flow across the TV [42]. Importantly, murmurs may be very soft or absent if the coaptation gap is very large; the velocity of to-and-fro flow is low, and rapid equalization of pressure across the functional TV does not result in blood flow turbulence.

The electrocardiogram (ECG) is usually abnormal and helps to confirm the clinical diagnosis. Sinus rhythm is usually present at the time of initial diagnosis. ECG may show tall and broad P waves as a result of right atrial enlargement, as well as complete or incomplete right bundlebranch block. Complete AV block is rare and first degree AV block is present in approximately half the patients. The QRS axis in the frontal plane occasionally shows right-axis deviation. Most patients have right bundle branch block and many have low-voltage QRS complexes in the right precordial leads. Right ventricular hypertrophy criterion are extremely uncommon [41, 45].

The downward displacement of the septal leaflet of the TV is associated with discontinuity of the central fibrous body and septal atrioventricular ring with direct muscular connections, thus creating a potential substrate for accessory atrioventricular connections and preexcitation. Occasionally, the pattern is transient or intermittent. Paroxysmal tachyarrhythmias in EA are based on fast conducting atrioventricular accessory pathways with both antegrade and retrograde conduction properties in most patients. In addition, wide QRS tachycardia over a septal accessory atrioventricular pathway, ventricular tachycardia, or flutter, as well as ectopic atrial tachycardia, atrial flutter, and atrial fibrillation can occur. Concealed accessory pathways, without manifest delta waves, are also common. Absence of anterograde preexcitation, therefore, neither indicates that the accessory connection is no longer present nor that the patient is no longer susceptible to tachycardia. The patient may still have retrograde conduction, which allows for atrioventricular reciprocating tachycardia. The presence of left axis

**10. Diagnosis**

**10.1. Electrocardiography**

140 Structural Insufficiency Anomalies in Cardiac Valves

The cardiac silhouette may vary from nearly normal to extreme cardiomegaly. When the heart is severely dilated, it takes a globular shape similar to that observed with large pericardial effusions or severe dilated cardiomyopathy. The dilated right atrium is responsible for most of the enlarged cardiac silhouette. In the frontal view, the right atrium produces a significant convexity of the right heart border, and in the lateral view, the right atrium may fill the entire retrosternal space. The convex left border is primarily due to dilation of the right ventricular outflow tract. The convexities of both left and right heart borders produce the characteristic globular cardiac silhouette. In cyanotic patients with a right-to-left shunt, the pulmonary vascularity is decreased. A cardiothoracic ratio of 0.65 carries a poor prognosis [14].

#### **10.3. Echocardiography**

Two-dimensional echocardiography is the diagnostic test used also in the long-term assessment of patients with EA. More recently 3D echocardiography has been utilized as an adjunct for the assessment of additional details about TV anatomy-leaflets and subvalvar apparatus, the size and function of the cardiac chambers, and other associated cardiac defects. The single most sensitive and specific diagnostic feature is the displacement of the annular hinge of the septal leaflet. The distance between the valvar hinge points can easily be measured. Apical displacement of the septal leaflet of the TV from the insertion of the mitral anterior leaflet hinge point should be at least 8 mm/m<sup>2</sup> when evaluated in the apical four-chamber view [14]. An echocardiogram (four-chamber view) of a patient with severe Ebstein's anomaly showing a displaced septal leaflet, atrialized RV and small functional RV is shown in **Figure 2**.

Other echocardiographic features that help in diagnosis include: (1) elongation of the anterosuperior leaflet, (2) tethering of the leaflets to the underlying myocardium, (3) shortened cordal support, (4) attachment of the leading edge of the anterosuperior leaflet to the right ventricular myocardium, (5) displacement of the annular attachment of the anterosuperior leaflet, (6) absence of the septal or mural leaflets, (7) congenital fenestration of the leaflets, and (8) enlargement of the valvar annulus [24].

Echocardiography is also used to evaluate the suitability for valvar repair, associated cardiovascular abnormalities, and myocardial function. The most important determinant of a durable monoleaflet repair is a freely mobile anterosuperior leaflet, especially its leading edge. The mobile leaflet tissue should be visualized within the right ventricular inflow tract, and this assessment must be made in the apical four-chamber view. Extensive adherence of more than half of the anterosuperior leaflet to the ventricular myocardium makes a successful repair unlikely. A single central jet of regurgitation is more easily eliminated than multiple regurgitant orifices. Even when there is a significant amount of leaflet tissue, direct muscular insertions from the ventricular free wall into the body of the anterosuperior leaflet can make repair impossible. The functional impact of the malformation of the RV and TV should be determined. Anatomic and functional severities are usually similar, but they are not always the same. For example, a patient can have a severe anatomic displacement with EA but only mild functional impairment. This generally occurs if the interatrial communication is small, the displaced valve is relatively competent, and the myocardium is only mildly dysfunctional. Both aspects of severity play an important role in determining the functional state, prognosis, and reparability of the TV. The degree of RA and RV enlargement and functional state of the RV myocardium should also be defined. Other important features include the degree of dilation of RVOT, the presence and size of any ASD, and the degree of transvalvar regurgitation. The left ventricular myocardium has also been described as being abnormal in a significant number of patients with EA. Therefore, quantitative evaluation of LV performance should also be a routine component of the echocardiographic evaluation in EA patients. VSD and pulmonary stenosis may also be associated with EA. Doppler and color flow echocardiographic

assessment can help determine hemodynamic alterations such as valvar regurgitation and intracardiac shunting [13, 17, 24, 40]. An echocardiogram shows the displacement septal leaflet of TV and the anterosuperior leaflet which is the largest, redundant and contains fenestra-

**Figure 2.** (a) Echocardiographic view (four-chamber view, apex up) of a patient with Ebstein's anomaly showing a displaced septal leaflet (arrow). (b)The anterior leaflet is severely tethered and nearly immobile. The functional right ventricle (RV) is small. aRV indicates atrialized right ventricle; LA, left atrium; LV, left ventricle; and RA, right atrium.

Ebstein's Anomaly

143

http://dx.doi.org/10.5772/intechopen.78067

tions that led to tricupid regurgitations **Figure 3**.

globular cardiac silhouette. In cyanotic patients with a right-to-left shunt, the pulmonary vas-

Two-dimensional echocardiography is the diagnostic test used also in the long-term assessment of patients with EA. More recently 3D echocardiography has been utilized as an adjunct for the assessment of additional details about TV anatomy-leaflets and subvalvar apparatus, the size and function of the cardiac chambers, and other associated cardiac defects. The single most sensitive and specific diagnostic feature is the displacement of the annular hinge of the septal leaflet. The distance between the valvar hinge points can easily be measured. Apical displacement of the septal leaflet of the TV from the insertion of the mitral anterior leaflet

An echocardiogram (four-chamber view) of a patient with severe Ebstein's anomaly showing

Other echocardiographic features that help in diagnosis include: (1) elongation of the anterosuperior leaflet, (2) tethering of the leaflets to the underlying myocardium, (3) shortened cordal support, (4) attachment of the leading edge of the anterosuperior leaflet to the right ventricular myocardium, (5) displacement of the annular attachment of the anterosuperior leaflet, (6) absence of the septal or mural leaflets, (7) congenital fenestration of the leaflets, and

Echocardiography is also used to evaluate the suitability for valvar repair, associated cardiovascular abnormalities, and myocardial function. The most important determinant of a durable monoleaflet repair is a freely mobile anterosuperior leaflet, especially its leading edge. The mobile leaflet tissue should be visualized within the right ventricular inflow tract, and this assessment must be made in the apical four-chamber view. Extensive adherence of more than half of the anterosuperior leaflet to the ventricular myocardium makes a successful repair unlikely. A single central jet of regurgitation is more easily eliminated than multiple regurgitant orifices. Even when there is a significant amount of leaflet tissue, direct muscular insertions from the ventricular free wall into the body of the anterosuperior leaflet can make repair impossible. The functional impact of the malformation of the RV and TV should be determined. Anatomic and functional severities are usually similar, but they are not always the same. For example, a patient can have a severe anatomic displacement with EA but only mild functional impairment. This generally occurs if the interatrial communication is small, the displaced valve is relatively competent, and the myocardium is only mildly dysfunctional. Both aspects of severity play an important role in determining the functional state, prognosis, and reparability of the TV. The degree of RA and RV enlargement and functional state of the RV myocardium should also be defined. Other important features include the degree of dilation of RVOT, the presence and size of any ASD, and the degree of transvalvar regurgitation. The left ventricular myocardium has also been described as being abnormal in a significant number of patients with EA. Therefore, quantitative evaluation of LV performance should also be a routine component of the echocardiographic evaluation in EA patients. VSD and pulmonary stenosis may also be associated with EA. Doppler and color flow echocardiographic

a displaced septal leaflet, atrialized RV and small functional RV is shown in **Figure 2**.

when evaluated in the apical four-chamber view [14].

cularity is decreased. A cardiothoracic ratio of 0.65 carries a poor prognosis [14].

**10.3. Echocardiography**

142 Structural Insufficiency Anomalies in Cardiac Valves

hinge point should be at least 8 mm/m<sup>2</sup>

(8) enlargement of the valvar annulus [24].

**Figure 2.** (a) Echocardiographic view (four-chamber view, apex up) of a patient with Ebstein's anomaly showing a displaced septal leaflet (arrow). (b)The anterior leaflet is severely tethered and nearly immobile. The functional right ventricle (RV) is small. aRV indicates atrialized right ventricle; LA, left atrium; LV, left ventricle; and RA, right atrium.

assessment can help determine hemodynamic alterations such as valvar regurgitation and intracardiac shunting [13, 17, 24, 40]. An echocardiogram shows the displacement septal leaflet of TV and the anterosuperior leaflet which is the largest, redundant and contains fenestrations that led to tricupid regurgitations **Figure 3**.

to its contribution to the development of hydrops. If the ratio of the combined right atrial and atrialized ventricular area compared to the combined area of the functional right ventricle and left heart is greater than one, fetal or neonatal outcome is very poor. Other fetal or neonatal findings associated with increased risk of mortality were a larger ASD, functional or anatomic

Ebstein's Anomaly

145

http://dx.doi.org/10.5772/intechopen.78067

Diagnostic cardiac catheterization is rarely necessary in EA patients, except for preoperative coronary angiography or diagnosis of the associated cardiac anomalies. RV and pulmonary artery pressures are usually normal, even if the RV end-diastolic pressure is increased. RA pressure may be normal, despite severe TV regurgitation, especially if the right atrium is markedly dilated. Oximetry may show systemic arterial desaturation in the presence of an

Cardiac magnetic resonance imaging (CMRI) is used for the quantitative measurement of right atrial and ventricular size and systolic function in Ebstein's patient. Axial imaging is a more reliable analysis for defining the disease severity [41]. Cardiac magnetic resonance imaging of a patient with severe Ebstein's anomaly showing displacement of septal leaflet, atrialized right ventricle (ARV) and small functional right ventricle is shown in **Figure 4**, septal bowing in **Figure 5**.

**Figure 4.** Cardiac MRI of a patient with Ebstein's anomaly showing displacement of septal leaflet, atrialized right ventricle (ARV) and small functional right ventricle (fRV); LA, left atrium; LV, left ventricle; and RA, right atrium.

pulmonary atresia, or reduced LV function [40–42].

**10.4. Cardiac catheterization and hemodynamics**

**10.5. Cardiac magnetic resonance imaging**

interatrial communication and right-to-left shunting [13, 14].

**Figure 3.** An echocardiogram (four-chamber view, apex up)showing the displacement of septal leaflet(in the right hand panel), anterior leaflet fenestrations, and tricuspid regurgitations (in the left hand panel). The hinge point of the normal septal tricuspid leaflet is positioned slightly toward the cardiac apex relative to the septal hinge point of the anterior mitral leaflet. This displacement is exaggerated in hearts with Ebstein's malformation, as shown in the image (outlined by the arrow, in the right hand panel) This can be quantitated by the displacement index, dividing the distance between the valvar insertions divided by the body surface area. A value of greater than 8 mm/m<sup>2</sup> is diagnostic of Ebstein's malformation. It should be noted that the valvar leaflets are also abnormal in Ebstein's malformation. LA, left atrium; LV, left ventricle; RA, right atrium; RV, right ventricle.

Echocardiography also plays an important role in the intraoperative and postoperative assessment of adequacy of TV repair or replacement. The most important use of intraoperative echocardiography is the immediate evaluation of the repaired valve functions. The postoperative examination is used to assess prosthetic valvar function, the changes in right and left ventricular functions and to exclude significant residual atrial level shunting. Postoperative echocardiography is also important to evalute the adequacy of the surgical repair, presence of pericardial or pleural effusion, mediastinal hematoma, intracardiac thrombus, and the degree of residual tricuspid regurgitation or tricuspid stenosis. The flow can rarely be compromised in the RCA because of its proximity to the plicated portion of the aRV [13, 41].

#### *10.3.1. Prenatal detection of Ebstein's malformation*

Echocardiography can accurately define the EA features in the fetus. Characteristics related with the early neonatal mortality include marked enlargement of the right heart, severe tethering of the anterosuperior leaflet, left ventricular compression, and associated lesions as pulmonary atresia [42). Pulmonary hypoplasia develops as a result of severe cardiomegaly and hydrops with pleural and pericardial effusions. Detection of rhythm disturbances, such as supraventricular tachycardia, should be attempted at the time of fetal echocardiography due to its contribution to the development of hydrops. If the ratio of the combined right atrial and atrialized ventricular area compared to the combined area of the functional right ventricle and left heart is greater than one, fetal or neonatal outcome is very poor. Other fetal or neonatal findings associated with increased risk of mortality were a larger ASD, functional or anatomic pulmonary atresia, or reduced LV function [40–42].

#### **10.4. Cardiac catheterization and hemodynamics**

Diagnostic cardiac catheterization is rarely necessary in EA patients, except for preoperative coronary angiography or diagnosis of the associated cardiac anomalies. RV and pulmonary artery pressures are usually normal, even if the RV end-diastolic pressure is increased. RA pressure may be normal, despite severe TV regurgitation, especially if the right atrium is markedly dilated. Oximetry may show systemic arterial desaturation in the presence of an interatrial communication and right-to-left shunting [13, 14].

#### **10.5. Cardiac magnetic resonance imaging**

Echocardiography also plays an important role in the intraoperative and postoperative assessment of adequacy of TV repair or replacement. The most important use of intraoperative echocardiography is the immediate evaluation of the repaired valve functions. The postoperative examination is used to assess prosthetic valvar function, the changes in right and left ventricular functions and to exclude significant residual atrial level shunting. Postoperative echocardiography is also important to evalute the adequacy of the surgical repair, presence of pericardial or pleural effusion, mediastinal hematoma, intracardiac thrombus, and the degree of residual tricuspid regurgitation or tricuspid stenosis. The flow can rarely be compromised

malformation. It should be noted that the valvar leaflets are also abnormal in Ebstein's malformation. LA, left atrium;

**Figure 3.** An echocardiogram (four-chamber view, apex up)showing the displacement of septal leaflet(in the right hand panel), anterior leaflet fenestrations, and tricuspid regurgitations (in the left hand panel). The hinge point of the normal septal tricuspid leaflet is positioned slightly toward the cardiac apex relative to the septal hinge point of the anterior mitral leaflet. This displacement is exaggerated in hearts with Ebstein's malformation, as shown in the image (outlined by the arrow, in the right hand panel) This can be quantitated by the displacement index, dividing the distance between

is diagnostic of Ebstein's

Echocardiography can accurately define the EA features in the fetus. Characteristics related with the early neonatal mortality include marked enlargement of the right heart, severe tethering of the anterosuperior leaflet, left ventricular compression, and associated lesions as pulmonary atresia [42). Pulmonary hypoplasia develops as a result of severe cardiomegaly and hydrops with pleural and pericardial effusions. Detection of rhythm disturbances, such as supraventricular tachycardia, should be attempted at the time of fetal echocardiography due

in the RCA because of its proximity to the plicated portion of the aRV [13, 41].

the valvar insertions divided by the body surface area. A value of greater than 8 mm/m<sup>2</sup>

*10.3.1. Prenatal detection of Ebstein's malformation*

LV, left ventricle; RA, right atrium; RV, right ventricle.

144 Structural Insufficiency Anomalies in Cardiac Valves

Cardiac magnetic resonance imaging (CMRI) is used for the quantitative measurement of right atrial and ventricular size and systolic function in Ebstein's patient. Axial imaging is a more reliable analysis for defining the disease severity [41]. Cardiac magnetic resonance imaging of a patient with severe Ebstein's anomaly showing displacement of septal leaflet, atrialized right ventricle (ARV) and small functional right ventricle is shown in **Figure 4**, septal bowing in **Figure 5**.

**Figure 4.** Cardiac MRI of a patient with Ebstein's anomaly showing displacement of septal leaflet, atrialized right ventricle (ARV) and small functional right ventricle (fRV); LA, left atrium; LV, left ventricle; and RA, right atrium.

the tachycardia in almost 90% of cases, depending on its mechanism; however, recurrence is

Ebstein's Anomaly

147

http://dx.doi.org/10.5772/intechopen.78067

Children who have survived infancy generally remain asymptomatic for several years. The surgery can be postponed until symptoms appear, cyanosis becomes evident, or paradoxical emboli occur. Deliberations about an operation should begin if evidence of deterioration exists, such as progressive increase in right heart size, reduction in systolic function, or appearance of ventricular or atrial tachyarrhythmias. Indications for operation in the symptomatic neonates include severe cyanosis, GOSE of three or four with mild cyanosis, cardiothoracic ratio > 80% and severe TR. However, in older ages, operation is clearly indicated if the symptoms progress to New York Heart Association functional class III or IV and medical management has little to offer. A biventricular reconstruction is feasible if the LV is functionally normal, enough RV cavity is present and TV morphology is suitable. A 1.5 ventricle repair can be applied to the patients with the RV failure. Heart transplantation is reserved for the

Some patients with cyanosis on exercise, who have a shunt at the atrial level but only mild or moderate regurgitation of the TV, may benefit from device closure to alleviate cyanosis and to prevent paradoxical emboli. Some centers commonly perform such procedures either as a staged approach or for long-term palliation [50]. The degree of TV regurgitation must be

A variety of surgical methods were introduced in the treatment of Ebstein's anomaly. Those treatments included a TV repair or replacement for the principle element in the treatment of Ebstein's anomaly and additional concomitant procedures for the correction of comorbid anomalies such as ablation of accessory conduction pathways, resection or plication of the atrialized right ventricle, application of 1.5-ventricular repair (bidirectional cavo-pulmonary shunt), and single-ventricle repair for advanced right ventricular dysfunction. Heart transplantation is suggested for the patients with severe left ventricular dysfunction. Neonatal operation has high operative mortality, whereas operation performed beyond infancy and into adulthood has low operative mortality. Late survival and quality of life for hospital sur-

Ebstein's anomaly is a complex congenital anomaly with a wide anatomic and clinical spectrum. Management is complex and must be individual because of the different anatomic and hemodynamic variables, and associated malformations, in Ebstein's anomaly. These patients

assessed carefully because closure of an ASD alone may worsen RV dysfunction.

vivors are excellent for the majority of patients in all age brackets [51–54].

common. Long-term success is achieved in only one-third of the cases [15, 46–48].

**11.3. Surgical treatment**

*11.3.2. Surgical options*

**12. Conclusion**

*11.3.1. Indications for operation*

patients with severe biventricular dysfunction.

**Figure 5.** An example of a cardiac MRI showing septal bowing in short axis views. (Used with permission of the Sonomed Imaging Center).
