Atrial septal defect transesophageal echocardiography


 * Associate Editor(s)-In-Chief: Priyamvada Singh, M.B.B.S. [mailto:psingh@perfuse.org], ; Assistant Editor-In-Chief: Kristin Feeney, B.S. [mailto:kfeeney@perfuse.org]

For a full discussion on the usage of echocardiography for atrial septal defect diagnosis click here.

Overview
Transesophageal echocardiography (TEE) has had a notable positive impact on both, the care and management of a patient with congenital heart disease, such as an atrial septal defect patient. TEE has been evaluated in all age groups and is determined to be safe for pediatrics and adults. Trials have shown transesophageal echocardiography to be superior in diagnosing sinus venosus ASD compared to transthoracic echocardiography

TEE in atrial septal defects

 * Transesophageal echocardiography is the preferred diagnostic tool in atrial septal defect.
 * To accurately diagnose the different types of atrial septal defects and associated anomalies a two-dimensional imaging of the atrial septum from different views like parasternal, apical, and subcostal views should be used.
 * A color Doppler along with TEE helps to demonstrate amount and directions of shunting.
 * Atrial septal defects in adults could be best visualized by subcostal views with deep inspiration and high right parasternal views.
 * Ideally the entire atrial septum from the orifice of the superior vena cava to the orifice of the inferior vena cava should be visualized. This helps in detecting sinus venosus defects and large ostium secundum defects that might extends up-to that area.
 * It also helps in identifying pulmonary veins morphology that could be helpful in sinus type of atrial septal defects and assocaiated lesions.
 * In case of diagnostic dilemmas with adults with transthoracic echocardiography, TEE helps in exact localization, size of the ASD and measurement of septal rims. All these details also help in making surgical decisions.
 * The entire coronary sinus roof should be imaged to diagnose sinus atrial septal defect. A large coronary sinus orifice with evidence of atrial shunting may indicate a defect in the roof of the coronary sinus.
 * With pulmonary artery hypertension, the low velocity of the shunt flow across the coronary sinus defect may be difficult to distinguish from other low-velocity flow within the atria.

TEE in Pediatrics

 * Research has indicated that TEE is a considerably safe procedure in pediatric populations.
 * Caution is recommended in inserting a probe into a neonate weigh less than or equal to 3 kg.
 * The reported incidence of development of complications during TEE performance is between 1-3%.

Advantages
TEE is a highly recommended method of imaging modality for atrial septal defect. It can provide:
 * Precise identification of the location
 * Precise information regarding lesion morphology
 * Identification of:
 * Number of atrial septal defects
 * Extent of surrounding atrial septal tissue
 * Location of adjacent structures

This information allows an interventional cardiologist to determine the best method and devise for closure.

Complications

 * The most common complications include:
 * Hoarseness
 * Dysphagia
 * Esophageal perforation


 * Less common complications:
 * Perforation/laceration of the oropharynx, hypopharynx, esophagus and stomach
 * Arrhythmias
 * Pulmonary complications
 * Bronchospasm
 * Hypoxemia
 * Laryngospasm
 * Circulatory derangement
 * Endocarditis

The Task Force of the Pediatric Council of the American Society of Echocardiography recommendations
The Task Force of the Pediatric Council of the American Society of Echocardiography recommends the following.

A preoperative transthoracic echocardiogram be performed in every patient undergoing a transesophageal echocardiogram during congenital heart surgery. The results of the TTE should be evaluated prior to the TEE. A TEE is not recommended as the only diagnostic imagining method as there are limitations that are better identified in methods such as TTE. ==ACC / AHA Guidelines - Evaluation of the Unoperated Patient (DO NOT EDIT) == {{cquote|

Class I
1) ASD should be diagnosed by imaging techniques with demonstration of shunting across the defect and evidence of RV volume overload and any associated anomalies. (Level of Evidence: C) }}

Supportive Trial data
In a study done on forty one patients with clinical diagnosis of atrial septal defect, transesophageal echocardiography was able to diagnose all the patients whereas transthoracic echocardiography was only able to diagnose 80% of them. Interestingly, 3 out of the 4 undiagnosed cases with trans-thoracic echocardiography were sinus venosus ASD. Transesophageal echocardiography is recommended when an atrial septal defect is clinically suspected but cannot be visualized by transthoracic echocardiography.