Atrial septal defect

(Redirected from ASD)

Background

Atrial septal defect
  • Many ASDs go undiagnosed in childhood
  • From superior to inferior, ASDs occur in[1]:
    • Sinus venosus (5%)
    • Ostium secundum (75%), ostium primum (15-20%)
    • Very rarely coronary sinus ASD
  • Spontaneous closure in up to 40% of patients within the first 5 years of life
  • By 40s, patients may develop symptoms[2]
    • Small ASDs < 5 mm in diameter may not generate symptoms
    • 5-10 mm defects lead to symptoms in 4th and 5th decade of life
    • > 10 mm defects present with symptoms in 3rd decade
  • LV stiffness increases as a part of normal aging, impairing left heart diastolic filling[3][4]
    • Increases left to right shunt across ASD
    • Produces RA and RV volume overload
  • May predispose to paradoxical embolus, causing stroke, TIA, acute limb ischemia, mesenteric ischemia, etc.[5]
    • Right to left shunt may occur during coughing, for example
    • Pulmonary hypertension produces this shunting pattern even at rest
  • Unlike ventricular septal defects, uncomplicated ASDs are not associated with high risk of bacterial endocarditis (lower turbulence and velocity of blood flow)

Clinical Features

A patient may be asymptomatic or have any of the following features:

Differential Diagnosis

Congenital Heart Disease Types

Evaluation

ECG Findings

Crochetage pattern on ECG for atrial septal defect

Echocardiography

Echo in subcostal view. The apex is towards the right, the atria are to the left. ASD secundum seen as a discontinuation of the white band of the atrial septum. The enlarged right atrium is below. The enlarged pulmonary veins are seen entering the left atrium above.
Positive Bubble Test in a pediatric patient demonstrating a Atrial Septal Defect [10]
  • Subcostal view preferred window, due to interatrial septum perpendicular to echo signal (apical four-chamber is parallel to ASD echo signal)
  • Clues to ASD
    • Hypermobile interatrial septum
    • Abrupt septal irregularity
    • RA and/or RV volume overload
    • Pulmonary artery dilation
    • High pulmonary artery pressures
  • TTE with Doppler can demonstrate most shunting
  • Agitated saline with Valsalva maneuver to increase right to left shunting is more diagnostic[11]

Management[12]

  • Medical management of complications (Afib, pulmonary HTN, etc.)
  • Avoid pregnancy and exertional activity in ASD complicated by pulmonary hypertension
  • Indications for ASD closure
    • Right heart overload with RA or RV enlargement
    • Complicated ASDs

Disposition

  • If no acute complications → discharge with outpatient follow-up

See Also

External Links

References

  1. Warnes CA, Williams RG, Bashore TM, et al. ACC/AHA 2008 guidelines for the management of adults with congenital heart disease. J Am Coll Cardiol. 2008;52:e143–263.
  2. Craig RJ, Selzer A. Natural history and prognosis of atrial septal defect. Circulation. 1968;37:805–15.
  3. Fleg JL, Shapiro EP, O’Connor F, Taube J, Goldberg AP, Lakatta EG. Left ventricular diastolic filling performance in older male athletes. JAMA. 1995;273:1371–5.
  4. Swinne CJ, Shapiro EP, Lima SD, Fleg JL. Age-associated changes in left ventricular diastolic performance during isometric exercise in normal subjects. Am J Cardiol. 1992;69:823–6.
  5. Ward R, Jones D, Haponik EF. Paradoxical embolism. An underrecognized problem. Chest. 1995;108:549–58.
  6. Gabriels C, De Meester P, Pasquet A, et al. A different view on predictors of pulmonary hypertension in secundum atrial septal defect. Int J Cardiol. 2014;176:833–40.
  7. Knipe K et al. Cyanotic congenital heart diseases. Radiopaedia. http://radiopaedia.org/articles/cyanotic-congenital-heart-disease
  8. Heller, J et al. “Crochetage” (Notch) on R wave in inferior limb leads: A new independent electrocardiographic sign of atrial septal defect. J Am Coll Cardiol. 1996;27(4):877-882 full text]
  9. Gatzoulis MA, Freeman MA, Siu SC, Webb GD, Harris L. N Engl J Med. 1999 Mar 18; 340(11):839-46.
  10. http://www.thepocusatlas.com/echocardiography/
  11. Shub C, Dimopoulos IN, Seward JB, et al. Sensitivity of two-dimensional echocardiography in the direct visualization of atrial septal defect utilizing the subcostal approach: experience with 154 patients. J Am Coll Cardiol. 1983;2:127–35.
  12. Martin SS et al. Atrial Septal Defects – Clinical Manifestations, Echo Assessment, and Intervention. Clin Med Insights Cardiol. 2014; 8(Suppl 1): 93–98.