**3.9 Ebstein's anomaly**

128 Echocardiography – In Specific Diseases

Tetralogy of Fallot (TOF) consists of VSD, overriding aorta, RVOT obstruction, and RV hypertrophy. It can be associated with right aortic arch, additional VSDs, absence of the pulmonic valve, coronary artery anomalies, systemic venous anomalies, AP window, and LVOT obstruction. Surgery involves VSD closure and repair or reconstruction of RVOT

The pathophysiological changes in patients with TOF are related to the shunt flow across a large VSD and the degree of RVOT obstruction. RV pressure is increased due to large VSD flow and RVOT obstruction. When the RV pressure is greater than systemic pressure, a right-to-left shunt and arterial desaturation will ensue. There may be little or no right-to-left shunt if the RVOT obstruction is not severe. The common associated cardiac anomalies include right-sided aortic arch in 25%, ASD in 10%, and coronary anomalies in 10% of

Preoperative TEE exam can evaluate the degree of RV hypertrophy and aortic overriding, the site and severity of RVOT obstruction, size and location of VSD, direction and magnitude of shunt flow, ventricular and valvular function, morphology of pulmonary arteries, and associated cardiac lesions such as ASD. Overriding aorta and anterior malalignment of outlet septum can be best seen in mid-esophageal aortic valve long-axis view (Figure 14). RVOT obstruction and shunt across VSD can be evaluated in mid-esophageal RV inflow-outflow view (Figure 15). Valvular and supravalvular pulmonary stenosis can be demonstrated in upper-esophageal aortic short-axis view. Post-repair TEE evaluation should include the presence and degree of residual RVOT obstruction, residual intracardiac shunt, peripheral

pulmonary stenosis, aortic and pulmonary regurgitation, and ventricular function.

Fig. 14. Tetralogy of Fallot. The mid-esophageal aortic valve long-axis view demonstrates the overriding of aorta. LA, left atrium; LV, left ventricle; RV, right ventricle; Ao, aorta.

**3.8 Tetralogy of fallot** 

(Shinebourne et al., 2006).

patients with TOF.

Ebstein's anomaly is characterized by abnormal attachment of septal and posterior tricuspid leaflets in the RV, away from normal tricuspid annulus position. The anterior leaflet is normally attached at annulus, but morphologically enlarged, "sail-like", and tethered to RV wall. The anterior leaflet may functionally obstruct the RVOT. Because tricuspid valve orifice is displaced downward to RV cavity at the junction of the inlet and trabecular components, the proximal portion of the RV is functionally integrated into RA, termed atrialized RV. The severity of hemodynamic compromise is related to the downward displacement of the leaflets, the degree of outflow tract obstruction and valvular regurgitation, the severity of myocardial dysfunction, and other concomitant cardiac abnormalities. RV output is decreased by decreased RV volume and varying degrees of RVOT obstruction. The most commonly accompanied disease is secundum type ASD or PFO. Cyanosis will occur if there is a large right-to-left shunt. Clinical presentation varied extremely from normal tricuspid function found incidentally on autopsy to severe cyanosis, compromised cardiac function, and fetal death. Appropriate surgical intervention depends on the age at presentation and associated anomalies. Tricuspid valve is either repaired or replaced depending on the extent of atrialized ventricle and morphology of tricuspid valve. Single ventricle repair may be performed in patients with poor RV condition.

Considering the variety of the disease entity and different surgical approaches, intraoperative TEE has a significant role in preoperative evaluation and decision making. In mid-esophageal four-chamber view, we can calculate the displacement index, which is the apical displacement of tricuspid valve septal leaflet in millimeters indexed to body surface area. A displacement index more than 8mm/m2 is a sensitive predictor of Ebstein's anomaly

Intraoperative Transesophageal Echocardiography for Congenital Heart Disease 131

directed to RV, aorta, and systemic circulation. This changes the parallel, noncommunicating circulation to serial connection with oxygenation. The intraoperative study mainly involves an assessment of systemic and pulmonary venous pathways. We should look for obstruction of systemic and pulmonary venous return, baffle leak, and ventricular function. Though atrial switch operation corrects hemodynamic abnormalities, it does not correct anatomical imperfections. Later complications include systemic RV failure, baffle

Arterial switch operation, the Jatene procedure, has been performed for anatomical repair since 1980s (Skinner et al., 2008). The great arteries are transected above the sinus valsalva and anastomosed to their appropriate ventricular outflows. Coronary arteries are translocated to the systemic outflow. Perioperative TEE should evaluate the size and flow of two neo-arteries, and check for any valvular stenosis or regurgitation. Because coronary arteries are relocated, TEE becomes an important tool for segmental and global function

Fig. 17. Transposition of great arteries. The pulmonary artery (PA) arises from left ventricle

Levo-transposition of great arteries (l-TGA), also commonly referred to as congenitally corrected transposition of the great arteries (ccTGA), is an acyanotic congenital heart disease. In segmental analysis, this condition is described as AV discordance and VA discordance, with aorta anterior and to the left of the PA. RV serves as the systemic ventricle. Although the physiology of blood flow is correct, systemic RV may develop

(LV) and the aorta (Ao) arises from right ventricle (RV).

failure progressively.

evaluation, thus providing indirect evidence of coronary perfusion.

obstruction, and arrhythmia.

(Oechslin et al. 2000). The preoperative TEE evaluation should include the RA dimension, size and shunt magnitude of ASD, the morphology of tricuspid leaflets, the severity of TR, the presence of RVOT obstruction, ventricular function, and associated cardiac anomalies (Figure 16). Postoperatively, we should evaluate tricuspid valve function, residual intracardiac shunting, residual RVOT obstruction, and RV dysfunction.

Fig. 16. Ebstein's anomaly. The mid-esophageal four-chamber view demonstrates the "saillike" anterior leaflet (AL) of tricuspid valve and downward attachment (arrow) of septal leaflet (SL) of tricuspid valve. RA, right atrium; LV, left ventricle; MV, mitral valve.

#### **3.10 Transposition of great arteries / congenitally corrected transposition of great arteries**

Dextro-transposition of great arteries (d-TGA) stands for 5-7% in congenital heart disease. It is characterized by concordance of the AV connection and discordance of the ventriculoarterial (VA) connection. Without treatment, 30% of patients will die in one week, 50% of patients will die in one month, and 90% of patients will die in one year. Balloon atrial septostomy and prostaglandin E1 for PDA patency are usually given for flow communication. Preoperative TEE exam should include the assessment of the AV and VA connections, outflow tract obstruction, systemic to pulmonary communications, ventricular size and function, and the associated cardiac pathology (Figure 17).

Surgical treatment for d-TGA has changed significantly through the years. Before mid 1980, the favored approach for infants with d-TGA is atrial switch procedure (Mustard or Senning operation). Surgeons will redirect the blood flow from SVC and IVC through mitral valve, then to LV. The heart will pump the blood from LV to PA. Pulmonary vein flow will be

(Oechslin et al. 2000). The preoperative TEE evaluation should include the RA dimension, size and shunt magnitude of ASD, the morphology of tricuspid leaflets, the severity of TR, the presence of RVOT obstruction, ventricular function, and associated cardiac anomalies (Figure 16). Postoperatively, we should evaluate tricuspid valve function, residual

Fig. 16. Ebstein's anomaly. The mid-esophageal four-chamber view demonstrates the "saillike" anterior leaflet (AL) of tricuspid valve and downward attachment (arrow) of septal leaflet (SL) of tricuspid valve. RA, right atrium; LV, left ventricle; MV, mitral valve.

**3.10 Transposition of great arteries / congenitally corrected transposition of great** 

size and function, and the associated cardiac pathology (Figure 17).

Dextro-transposition of great arteries (d-TGA) stands for 5-7% in congenital heart disease. It is characterized by concordance of the AV connection and discordance of the ventriculoarterial (VA) connection. Without treatment, 30% of patients will die in one week, 50% of patients will die in one month, and 90% of patients will die in one year. Balloon atrial septostomy and prostaglandin E1 for PDA patency are usually given for flow communication. Preoperative TEE exam should include the assessment of the AV and VA connections, outflow tract obstruction, systemic to pulmonary communications, ventricular

Surgical treatment for d-TGA has changed significantly through the years. Before mid 1980, the favored approach for infants with d-TGA is atrial switch procedure (Mustard or Senning operation). Surgeons will redirect the blood flow from SVC and IVC through mitral valve, then to LV. The heart will pump the blood from LV to PA. Pulmonary vein flow will be

**arteries** 

intracardiac shunting, residual RVOT obstruction, and RV dysfunction.

directed to RV, aorta, and systemic circulation. This changes the parallel, noncommunicating circulation to serial connection with oxygenation. The intraoperative study mainly involves an assessment of systemic and pulmonary venous pathways. We should look for obstruction of systemic and pulmonary venous return, baffle leak, and ventricular function. Though atrial switch operation corrects hemodynamic abnormalities, it does not correct anatomical imperfections. Later complications include systemic RV failure, baffle obstruction, and arrhythmia.

Arterial switch operation, the Jatene procedure, has been performed for anatomical repair since 1980s (Skinner et al., 2008). The great arteries are transected above the sinus valsalva and anastomosed to their appropriate ventricular outflows. Coronary arteries are translocated to the systemic outflow. Perioperative TEE should evaluate the size and flow of two neo-arteries, and check for any valvular stenosis or regurgitation. Because coronary arteries are relocated, TEE becomes an important tool for segmental and global function evaluation, thus providing indirect evidence of coronary perfusion.

Fig. 17. Transposition of great arteries. The pulmonary artery (PA) arises from left ventricle (LV) and the aorta (Ao) arises from right ventricle (RV).

Levo-transposition of great arteries (l-TGA), also commonly referred to as congenitally corrected transposition of the great arteries (ccTGA), is an acyanotic congenital heart disease. In segmental analysis, this condition is described as AV discordance and VA discordance, with aorta anterior and to the left of the PA. RV serves as the systemic ventricle. Although the physiology of blood flow is correct, systemic RV may develop failure progressively.

Intraoperative Transesophageal Echocardiography for Congenital Heart Disease 133

anomalies, two-ventricle repair is not feasible and operation toward single ventricle

Postoperative complications generally fall into four groups: LV failure, RV failure, arrhythmia, and residual shunts. Because LV flow is baffled through VSD to great artery, obstruction occurs with poor configuration of the patch or insufficient enlarged VSD size. It is especially difficult in DORV with remote VSD. Aortic insufficiency may occur due to surgical damage. Residual RVOT obstruction can occur whether the repair acquired infundibulotomy, outflow tract patch, or some form of RV to PA conduit. Intracardiac baffle may compromise RVOT flow, especially in DORV with subpulmonary VSD, because the VSD is very close to pulmonary orifice and infundibular septal band. Tricuspid insufficiency may happen if chordae resection and reattachment is needed to accommodate baffle implantation. After arterial switch operation, neo-PA or branched PA obstruction should be carefully surveyed. Residual shunt may be caused by incomplete VSD repair, baffle detachment, and unrecognized multiple VSDs. It is prudent to carefully evaluate the repair

Fig. 18. Double-outlet right ventricle. The mid-esophageal long-axis view demonstrates both aorta (Ao) and pulmonary artery (PA) arises from right ventricle (RV) and the presence of pulmonary stenosis (arrow) and ventricular septal defect (D). LV, left ventricle; RV, right

The functionally univentricular circulation, or single-ventricle physiology, is a heterogenous group of cardiac abnormalities. In most patients, there is hypoplasia of either the RV or LV

physiology is needed.

ventricle.

**3.12 Single ventricular physiology** 

by TEE before leaving operation room.

Double switch operation may be performed for patients with l-TGA. It is a combination of atrial switch operation and arterial switch operation. The preoperative TEE exam should evaluate the relationship of great arteries, presence of outflow tract obstruction, ventricular and valvular function, and associated intracardiac anomalies. The post-repair TEE exam should focus on the systemic and pulmonary venous return pathway, ventricular and valvular function, and anatomy of outflow tract and neo-great arteries.
