Coronary Sinus Atrial Septal Defects Workup

Updated: Jul 03, 2019
  • Author: Louis I Bezold, MD; Chief Editor: Syamasundar Rao Patnana, MD  more...
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Imaging Studies

The following imaging studies are helpful for the workup of isolated coronary sinus atrial septal defects (ASDs).

Chest radiography

Chest radiographic findings vary. Cardiac silhouette and pulmonary vascular markings are increased in proportion to the degree of left-to-right shunt. Pulmonary vascular markings may show peripheral extension with central prominence. Increased right atrial shadow and triangular-shaped cardiac silhouette may be observed.


Note the following:

  • Transthoracic echocardiographic findings are diagnostic in most cases.

  • Transesophageal echocardiography is useful during defect repair, and findings may be diagnostic in relatively old or large patients with limited transthoracic acoustic windows. [4, 5]

  • M-mode echocardiography shows right ventricular enlargement and flattened (sometimes paradoxical) septal motion. Two-dimensional imaging defines anatomic features well, and findings are diagnostic.

  • Subcostal views are most useful for defining the area of interatrial shunting characteristic of this defect and for assessing the degree of coronary sinus unroofing.

  • The apical 4-chamber view demonstrates the coronary sinus well but is unreliable for assessing the interatrial septum because of false septal drop-out.

  • The left superior vena cava (SVC) is best imaged from the suprasternal notch and subcostal views. Additional features include dilatation of the right atrium, right ventricle, and main pulmonary artery.

  • Care must be taken not to confuse either ostium primum ASD or sinus venosus defect of the inferior vena cava type with coronary sinus ASD.

  • Color and pulsed Doppler interrogation provides hemodynamic data regarding right-sided pressures, and the degree of shunting (Qp/Qs) can be estimated.

  • In infants and young children, echocardiography is the noninvasive method of choice to either rule out or further evaluate complex lesions in cases of heterotaxy associated with a coronary sinus defect.

  • Real-time 3-dimensional transthoracic echocardiography has been reported to be useful in diagnosing a surgically unroofed coronary sinus in a patient with poor acoustic windows; therefore, it may be useful in native coronary sinus ASD visualization. [6]

Magnetic resonance imaging (MRI)

MRI may be useful, particularly in patients with heterotaxy syndrome or other complex anomalies incompletely defined by echocardiography.


Optimal visualization of a coronary sinus ASD requires selective left SVC, right upper pulmonary vein, or left atrium contrast injection in the hepatoclavicular view. A coronary sinus defect may also be suggested by a catheter course through the coronary sinus into the left atrium and pulmonary vein. [4]


Other Tests

Electrocardiography (ECG)

ECG most commonly shows normal sinus rhythm in young patients, with an increasing frequency of sinus-node dysfunction with increasing age, beginning in childhood. Righ ventricular hypertrophy, manifest by rsR', may be seen in moderate to large shunts.

A prolonged PR interval is relatively uncommon but not unusual.

Common findings include right-axis deviation, right atrial enlargement, and mild right ventricular enlargement manifested by an RSr' or rsR' pattern in precordial leads V3R and V1.

Holter monitoring

Holter monitoring is indicated in patients with a history of arrhythmias and before surgery in adults with newly diagnosed arrhythmias.



Cardiac catheterization

Cardiac catheterization is generally not necessary for diagnosis but may be necessary to evaluate hemodynamics in complicated cases, in patients with auscultatory or Doppler evidence of elevated pulmonary artery resistance, and in patients in whom transthoracic and transesophageal echocardiography is inconclusive.