Pediatric Ebstein Anomaly Workup

Updated: Aug 14, 2018
  • Author: Duraisamy Balaguru, MBBS, MRCP, FACC, FAAP, FSCAI; Chief Editor: Stuart Berger, MD  more...
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Workup

Imaging Studies

Chest radiography

Typical findings in severe cases of Ebstein anomaly consist of cardiomegaly and pulmonary oligemia. Right atrial enlargement accounts for most of the large size of the cardiac silhouette. Pulmonary vascular markings may be normal in some patients with minimal or no cyanosis. (See the following image.)

Chest radiograph of a newborn with severe Ebstein Chest radiograph of a newborn with severe Ebstein anomaly and patent ductus arteriosus. Most of the cardiomegaly is secondary to right atrial enlargement. The pulmonary vascular markings are normal in this newborn.

Echocardiography

Echocardiography is diagnostic in Ebstein anomaly. Typical findings include variable degrees of downward displacement of the septal and/or posterior leaflet of the tricuspid valve (see the image below), tricuspid valve regurgitation, and right atrial enlargement usually proportional to the degree of displacement of the septal leaflet. The large, sail-like anterior leaflet of the tricuspid valve is also usually noted.

In addition, echocardiography should define the following: (i) the chordal attachments of the tricuspid valve, (ii) an atrial septal defect (ASD) or patent foramen ovale (PFO), (iii) the status of the right ventricular (RV) outflow tract and the pulmonary valve size and orifice, (iv) a patent ductus arteriosus, (v) estimation of the RV systolic pressure, and (vi) ventricular systolic function. The presence of other associated cardiac defects should be ruled out. Fetal echocardiography identifies Ebstein anomaly well and is useful in determining prognosis. (See the Prognosis Assessment by Imaging section).

Echocardiogram in an apical four-chamber view. Thi Echocardiogram in an apical four-chamber view. This image reveals downward displacement of the insertion of the septal leaflet of the tricuspid valve (arrow) in a 3-year-old boy. The child has moderate tricuspid regurgitation and has not required surgical intervention so far. aRV = atrialized portion of right ventricle, LA = left atrium, LV = left ventricle, RA = right atrium, RV = functional portion of the right ventricle.

A case of prenatally diagnosed Ebstein anomaly of the mitral valve has been described. [12]  Fetal echocardiography revealed tethering of the mitral valve posterior leaflet to the lateral wall of the left ventricle (LV) with downward displacement into the LV cavity. The diagnosis was confirmed with postnatal transthoracic and transesophageal echocardiography, which showed apical displacement of the level of coaptation mitral valve into the LV cavity. [12]

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Prognosis Assessment by Imaging

Celermajer index:

An echcardiography-based scoring system is useful to assess the severity and outcome of Ebstein anomaly and, therefore, aid in counseling families. In this system, the ratio of the combined area of the right atrium and the atrialized portion of the right ventricle (RV) to the combined area of  the functional portion of of the RV, left atrium (LA), and left ventricle (LV) is calculated from an apical four-chamber view of an echocardiogram. Four grades are derived, as follows [13] :

  • Grade 1 (ratio < 0.5): 0% mortality
  • Grade 2 (ratio 0.5-1.0): Mortality of 10%
  • Grade 3 (ratio 1.0-1.49): Mortality of 44%
  • Grade 4 (ratio >1.5): Mortality of 100%.

This system has been used in fetal and postnatal echocardiography. [13]

Simpson-Andrews-Sharland (SAS) score for fetal echocardiography

The SAS score is calculated from a fetal echocardiogram. A value of 0, 1 or 2 is assigned for five parameters from the fetal echocardiogram, comprising the following [14] :

  • Cardiothoracic ratio
  • Celemajer index
  • RV-to-LV ratio
  • Reduced/absent pulmonary blood flow
  • Retrograde ductus arteriosus flow
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Other Tests

Electrocardiography (ECG)

Typical findings on the ECG are right atrial enlargement (tall, peaked P waves), a prolonged PR interval, right axis deviation, and a right bundle branch block. In the presence of Wolff-Parkinson-White syndrome (30%), a short PR interval and Delta wave are noted. Atrial arrhythmias may be seen, if present.

Holter monitoring

An ambulatory ECG recording may be performed to evaluate the possibility of occult arrhythmias or to verify symptomatology, such as palpitations over 24 or 48 hours.

Stress testing

Exercise testing may be performed both preoperatively and postoperatively to objectively evaluate exercise tolerance, oxygen consumption, systemic arterial oxygenation, and possible arrhythmia vulnerability during exercise. [15]

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Procedures

Cardiac catheterization

Cardiac catheterization is not routinely needed for presurgical evaluation. Pressure traces in the right atrium and right ventricle (RV) are useful however. RV angiography either in the posteroanterior or right anterior oblique view will demonstrate downward displacement of the tricuspid leaflet(s), RV outflow tract, and pulmonary valve and arteries. Rarely, balloon atrial septostomy of a restrictive atrial septal defect or patent foramen ovale may be needed to stabilize the hemodynamic status of a newborn or infant. However, septostomy may lead to worsening cyanosis from an increased right-to-left shunting, and thus it needs to be weighed in such decision making. 

Electrophysiologic studies (EPS)

EPS are performed in many patients suspected of having an arrhythmia secondary to paroxysmal supraventricular tachycardia (SVT) and Wolff-Parkinson-White (WPW) syndrome, both of which occur at a high incidence. During invasive EPS, an accessory pathway is most often identified along the abnormal tricuspid annulus. Manifest accessory pathways (WPW) and concealed pathways (unidirectional retrograde conducting accessory pathways) account for most supraventricular tachycardias (SVTs) mechanistically in patients with Ebstein anomaly. The frequency of multiple accessory pathways is significantly higher in those with Ebstein anomaly than in the general population of patients with SVT and normal tricuspid valve anatomy.

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