Atrial septal defect transthoracic echocardiography


 * Associate Editor(s)-In-Chief: Priyamvada Singh, M.B.B.S. [mailto:psingh@perfuse.org], ; Assistant Editor(s)-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
Echocardiography is the preferred diagnostic tool in the evaluation of an atrial septal defect. Trans-thoracic echocardiography is an effective two-dimensional modality that can be used to identify suspected atrial septal defects.

Trans-thoracic echocardiography

 * Effective two-dimensional modality for visualizing an ostium secundum atrial septal defect.
 * Types:
 * Apical four chamber view
 * Subcoastal four chamber view


 * Provides imaging of:
 * Right ventricular enlargement
 * Paradoxical motion involving the ventricular septum
 * Right atrium enlargement

Advantages

 * Determines which type of defect exists.
 * Necessary to evaluate for anomalous pulmonary veins.
 * Evaluates for an atrial septal aneurysm.

Disadvantages

 * Apical four chamber view involves a parallel angle of the echocardiographic beams onto the atrial septum causing artifact in the echo
 * Subcostal four chamber view can be ineffective in overweight/obese patients.
 * Size of the defect seen in a TTE does not parallel the measurement of shunt flow from cardiac catheterization.

Sensitivity
==ACC / AHA Guidelines - Evaluation of the Unoperated Patient (DO NOT EDIT) == {{cquote|
 * One study found that subcostal approach could successfully visualize the majority of ostium primum and ostium secundum atrial septal defects.
 * Visualization of sinus venosus atrial septal defect is less successful, less than 50% of the cases were properly imaged.

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) }}