eMedicine Specialties > Pediatrics: Cardiac Disease and Critical Care Medicine > Cardiology

Atrioventricular Septal Defect, Unbalanced: Differential Diagnoses & Workup

Author: Mark A Law, MD, Fellow, Department of Pediatric Cardiology, Baylor College of Medicine,Texas Childrens Hospital
Coauthor(s): Ameeta Martin, MD, Clinical Associate Professor, Department of Pediatric Cardiology, University of Nebraska College of Medicine
Contributor Information and Disclosures

Updated: Aug 27, 2008

Differential Diagnoses

Atrioventricular Septal Defect, Complete
Heterotaxy, Polysplenia
Atrioventricular Septal Defect, Partial and Intermediate
Hypoplastic Left Heart Syndrome
Atrioventricular Septal Defect: Surgical Perspective
Hypoplastic Left Heart Syndrome and the Staged Norwood Procedure
Heterotaxy, Asplenia
Single Ventricle

Other Problems to Be Considered

In the setting of abdominal heterotaxy, other abnormalities may include intestinal malrotation, renal anomalies, and asplenia.

Workup

Laboratory Studies

  • A CBC count with special attention to the peripheral smear to exclude Howell-Jolly bodies should be obtained in patients with heterotaxy syndrome. Howell-Jolly bodies may be noted in patients with functional asplenia.
  • Chromosome testing may be performed, although findings are usually normal, unless the patient has Down syndrome.

Imaging Studies

  • Chest radiography
    • Chest radiography may reveal abdominal situs inversus with heterotaxy. Abnormalities of bronchial anatomy may be evident in the setting of asplenia or polysplenia.
    • Generally, chest radiography reveals cardiomegaly with increased pulmonary vascular markings.
    • If significant subpulmonic obstruction is present, pulmonary markings may be decreased.
  • Two-dimensional echocardiography and Doppler analysis
    • Doppler-echocardiography is definitive and is the method of choice in making the diagnosis of unbalanced atrioventricular (AV) septal defect. Cardiac anatomy, hemodynamics, and ventricular function can be noninvasively assessed in detail. Doppler-echocardiography alone can generally provide sufficient anatomic and functional information before repair and/or palliation.6
    • The initial Doppler-echocardiogram should focus on the following:
      • Atrial and visceral situs
      • Presence and size of atrial-level defect and shunt (Common atria may be observed.)
      • Presence and size of ventricular-level defect and shunt
      • Anatomy of the atrioventricular valve (AVV), including annulus size, leaflet morphology, chordal attachments, and papillary muscle architecture (Assess the proportion of the AVV overlying each ventricle from the subcostal short-axis view as well as the degree of AVV regurgitation.)
      • Relative chamber sizes and functions
      • Relationship and sizes of the great arteries
      • Detailed attention to the anatomy of the left ventricular (LV) and right ventricular (RV) outflow tracts and the presence of obstruction
      • Systemic and pulmonary venous connections
      • Hypoplasia of aortic arch and/or status of ductus arteriosus
      • Presence or absence of RV and/or pulmonary artery (PA) hypertension
    • The greatest clinical challenge for the cardiologist is to determine the feasibility of the 2-ventricular repair in borderline cases. This depends on relative ventricular sizes, AVV structure and function, size of the ventricular septal defect (VSD), size of the LV outflow tract, and aortic arch hypoplasia.
      • No strict quantitative guidelines exist; qualitative and/or clinical impressions often provide accurate guidance in the feasibility of a 2-ventricular repair.
      • PA banding in infancy protects the pulmonary vascular bed and allows additional time before a commitment needs to be made for either a univentricular or biventricular repair. Additionally, many perform primary repair if a biventricular approach is considered, again to avoid the deleterious hypertrophy that can occur after PA banding.
      • Three-dimensional echocardiography may be useful in providing more detailed information about ventricular potential in borderline cases and has been described in evaluating the anatomy in AV septal defects and AVV regurgitation.7,8
  • MRI: MRI can be useful in delineating the intracardiac, PA, systemic and pulmonary venosum, and abdominal anatomy in patients with heterotaxy syndrome. MRI may also be useful in providing more detailed quantitative information about ventricular potential in borderline cases.
  • Abdominal ultrasonography: This study helps detect presence or absence of the spleen.

Other Tests

  • Electrocardiography often reveals left axis deviation, initial counterclockwise frontal loop, and RV hypertrophy.
  • In patients with heterotaxy, P-wave axis may assist in determining the location of the sinus node.

Procedures

  • Cardiac catheterization and angiography
    • Invasive studies are not always needed before surgical repair and/or palliation if all the anatomic and functional data can be obtained using echocardiography.
    • Catheterization may be helpful in borderline cases to assist with decision making about whether to proceed with univentricular or biventricular repair.
    • Catheterization may assist with defining systemic venous and pulmonary venous anatomy more completely.
    • If single-ventricular repair is chosen, catheterization is often used prior to creation of the bidirectional Glenn anastomosis to assess the pulmonary artery architecture and pressures. Catheterization may also be obtained prior to completion of a Fontan repair to assess systemic and PA structure and hemodynamics.

More on Atrioventricular Septal Defect, Unbalanced

Overview: Atrioventricular Septal Defect, Unbalanced
Differential Diagnoses & Workup: Atrioventricular Septal Defect, Unbalanced
Treatment & Medication: Atrioventricular Septal Defect, Unbalanced
Follow-up: Atrioventricular Septal Defect, Unbalanced
Multimedia: Atrioventricular Septal Defect, Unbalanced
References
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References

  1. Anderson RH, Mccartney FJ, Shinebourne EA. Atrioventricular septal defects. Pediatr Cardiol. 1987;1:571-609.

  2. VanPraagh R, Litovsky S. Pathology and embryology of common atrioventricular canal. Prog Pediatr Cardiol. 1999;10:115-27.

  3. Berger TJ, Blackstone EH, Kirklin JW, et al. Survival and probability of cure without and with operation in complete atrioventricular canal. Ann Thorac Surg. Feb 1979;27(2):104-11. [Medline].

  4. Somerville J, Revel-Chion R, Van Der Cammen T. Atrioventricular canal defects - natural and unnatural history. Pediatr Cardiol. 1981;404-416.

  5. Bull C, Rigby ML, Shinebourne EA. Should management of complete atrioventricular canal defect be influenced by coexistent Down syndrome?. Lancet. May 18 1985;1(8438):1147-9. [Medline].

  6. Levine JC, Geva T. Echocardiographic assessment of common atrioventricular canal. Prog Pediatr Cardiol. 1999;10:137-151.

  7. Toh N, Kanzaki H, Nakatani S, Kohyama K, Ohara T, Kim J. Partial atrioventricular septal defect assessed by real-time three-dimensional echocardiography: a case report. J Cardiol. Dec 2007;50(6):379-82. [Medline].

  8. Barrea C, Levasseur S, Roman K, Nii M, Coles JG, Williams WG. Three-dimensional echocardiography improves the understanding of left atrioventricular valve morphology and function in atrioventricular septal defects undergoing patch augmentation. J Thorac Cardiovasc Surg. Apr 2005;129(4):746-53. [Medline].

  9. van Son JA, Phoon CK, Silverman NH, Haas GS. Predicting feasibility of biventricular repair of right-dominant unbalanced atrioventricular canal. Ann Thorac Surg. Jun 1997;63(6):1657-63. [Medline].

  10. Cohen MS, Jacobs ML, Weinberg PM, Rychik J. Morphometric analysis of unbalanced common atrioventricular canal using two-dimensional echocardiography. J Am Coll Cardiol. Oct 1996;28(4):1017-23. [Medline].

  11. Foker JE, Berry J, Steinberger J. Ventricular growth stimulation to achieve two-ventricle repair in unbalanced common atrioventricular canal. Prog Pediatr Cardiol. 1999;10:173-86.

  12. Lillehei CW, Cohen M, Warden HE, Varco RL. The direct-vision intracardiac correction of congenital anomalies by controlled cross circulation; results in thirty-two patients with ventricular septal defects, tetralogy of Fallot, and atrioventricularis communis defects. Surgery. Jul 1955;38(1):11-29. [Medline].

  13. Daebritz S, del Nido PJ. Surgical management of common atrioventricular canal. Prog Pediatr Cardiol. 1999;10:161-71.

  14. Backer CL, Stewart RD, Bailliard F, Kelle AM, Webb CL, Mavroudis C. Complete atrioventricular canal: comparison of modified single-patch technique with two-patch technique. Ann Thorac Surg. Dec 2007;84(6):2038-46; discussion 2038-46. [Medline].

  15. Drinkwater DC, Laks H. Unbalanced atrioventricular septal defects. Semin Thorac Cardiovasc Surg. Jan 1997;9(1):21-5. [Medline].

  16. Journois D, Baufreton C, Mauriat P, et al. Effects of inhaled nitric oxide administration on early postoperative mortality in patients operated for correction of atrioventricular canal defects. Chest. Nov 2005;128(5):3537-44. [Medline].

  17. Emanuel R, Somerville J, Inns A, Withers R. Evidence of congenital heart disease in the offspring of parents with atrioventricular defects. Br Heart J. Feb 1983;49(2):144-7. [Medline].

  18. Apfel HD, Gersony WM. Clinical evaluation, medical management and outcome of atrioventricular canal defects. Prog Pediatr Cardiol. 1999;10:129-36.

  19. Bricker J, McNamara D, Garson A. Defects of the atrial septum including the atrioventricular canal. In: Science and Practice of Pediatric Cardiology. Lippincott Williams & Wilkins;1990:1036-1051.

  20. Kirklin JW, Barratt-Boyes BG. Atrioventricular canal defect. In: Cardiac Surgery. 2nd ed. Churchill Livingstone Inc; 1993:693-747.

  21. Nadas AS. Endocardial cushion defects. In: Flyer DC, ed. Nadas' Pediatric Cardiology. Hanley & Belfus Inc; 1992:577-86.

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Further Reading

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Keywords

unbalanced atrioventricular septal defect, AVSD, AV canal, AVC, unbalanced endocardial cushion defects, left ventricular–type septal defect, LV-type septal defect, left ventricular–type canal, LV-type canal, left ventricular–dominant AV septal defect, LV-dominant AV septal defect, left ventricular–dominant AV canal, LV-dominant AV canal, atrioventricular canal, atrioventricular septal defect, right ventricular–type septal defect, RV-type septal defect, right ventricular–type canal, RV-type canal, right ventricular–dominant AV septal defect, RV-dominant AV septal defect, right ventricular–dominant AV canal, RV-dominant AV canal, congestive heart failure, pulmonary artery banding, Down syndrome, tachypnea, failure to thrive, pulmonary outflow tract obstruction, coarctation of the aorta, trisomy 21

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Contributor Information and Disclosures

Author

Mark A Law, MD, Fellow, Department of Pediatric Cardiology, Baylor College of Medicine,Texas Childrens Hospital
Mark A Law, MD is a member of the following medical societies: Alpha Omega Alpha, American Academy of Pediatrics, American College of Cardiology, American College of Physicians, and American Heart Association
Disclosure: Nothing to disclose.

Coauthor(s)

Ameeta Martin, MD, Clinical Associate Professor, Department of Pediatric Cardiology, University of Nebraska College of Medicine
Ameeta Martin, MD is a member of the following medical societies: American College of Cardiology
Disclosure: Nothing to disclose.

Medical Editor

Paul M Seib, MD, Associate Professor of Pediatrics, University of Arkansas for Medical Sciences; Medical Director, Cardiac Catheterization Laboratory, Co-Medical Director, Cardiovascular Intensive Care Unit, Arkansas Children's Hospital
Paul M Seib, MD is a member of the following medical societies: American Academy of Pediatrics, American College of Cardiology, American Heart Association, Arkansas Medical Society, International Society for Heart and Lung Transplantation, and Society for Cardiac Angiography and Interventions
Disclosure: Nothing to disclose.

Pharmacy Editor

Mary L Windle, PharmD, Adjunct Assistant Professor, University of Nebraska Medical Center College of Pharmacy, Pharmacy Editor, eMedicine
Disclosure: Pfizer Inc Stock Investment from financial planner; Avanir Pharma Stock Investment from financial planner ; WebMD Salary and stock Employment and investment from financial planner

Managing Editor

Hugh D Allen, MD, Professor, Department of Pediatrics, Division of Pediatric Cardiology and Department of Internal Medicine, Ohio State University College of Medicine
Hugh D Allen, MD is a member of the following medical societies: American Academy of Pediatrics, American College of Cardiology, American Heart Association, American Pediatric Society, American Society of Echocardiography, Society for Pediatric Research, Society of Pediatric Echocardiography, and Western Society for Pediatric Research
Disclosure: Nothing to disclose.

CME Editor

Gilbert Z Herzberg, MD, Assistant Professor, Department of Pediatrics, Section of Pediatric Cardiology, New York Medical College; Consulting Staff, Department of Pediatrics, Sound Shore Medical Center
Gilbert Z Herzberg, MD is a member of the following medical societies: American Academy of Pediatrics
Disclosure: Nothing to disclose.

Chief Editor

Steven R Neish, MD, SM, Director of Pediatric Cardiology Fellowship Program, Associate Professor, Department of Pediatrics, Baylor College of Medicine
Steven R Neish, MD, SM is a member of the following medical societies: American Academy of Pediatrics, American College of Cardiology, and American Heart Association
Disclosure: Nothing to disclose.

 
 
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