Pediatric Partial and Intermediate Atrioventricular Septal Defects Clinical Presentation
- Author: M Silvana Horenstein, MD; Chief Editor: P Syamasundar Rao, MD more...
In the absence of moderate to severe mitral regurgitation (MR) and other associated congenital heart disease (CHD), partial atrioventricular septal defect (AVSD) is often discovered later in childhood when the patient is referred for evaluation of a heart murmur. Also, partial AVSD is less common in Down syndrome than in complete AVSD.
Note the following:
The clinical presentation of patients with partial AVSD depends on the degree of MR and on the associated cardiac defects.
Other cardiac anomalies that may be associated with partial AVSD include secundum atrial septal defect (ASD), persistent left superior vena cava draining to the coronary sinus, pulmonary stenosis, discrete subaortic stenosis, tricuspid stenosis, tricuspid atresia, coarctation of the aorta, patent ductus arteriosus (PDA), perimembranous ventricular septal defect (VSD), and hypoplastic left ventricle (LV).
Children with atrioventricular valve competence usually exhibit no significant symptoms. They are usually referred to a pediatric cardiologist if a heart murmur is detected during routine examination.
Substantial left-to-right shunting may exacerbate pulmonary disease and cause frequent lower respiratory infections in some patients. These patients may present with tachypnea, respiratory distress, and inadequate weight gain.
Infants with severe MR often demonstrate poor feeding, tachypnea, and labored breathing. Rarely, respiratory distress may be so severe as to require mechanical ventilation.
Progressive cardiac enlargement and LV dysfunction cause shocklike symptoms and eventually lead to mortality.
Adolescents and young adults may note progressive exercise intolerance.
Palpitations caused by atrial arrhythmia become more common in young adulthood, and sustained supraventricular tachycardia, atrial flutter, or atrial fibrillation may trigger the onset of congestive heart failure (CHF) in older patients with AVSD.
Hypervolemia of pregnancy may trigger CHF symptoms and complicate pregnancy.
Most children with partial AVSD and minimal MR appear healthy. Patients who have Down syndrome exhibit features typical of the condition.
Patients with severe MR in infancy can manifest tachypnea, retractions, and diaphoresis, especially during and immediately after feeding. Poor caloric intake and excessive metabolic demands lead to growth failure. Older children and adolescents with severe MR may display a prominent left chest as well as a slim (asthenic) build.
Pulmonary and cardiovascular examination
Palpation and auscultatory findings depend on the severity of the left-to-right shunt, the presence of MR, and associated defects (eg, LV outflow obstruction, PDA).
Fine rales or rhonchi, or both, may be heard in the lung fields of older patients with severe MR but are rare in infants.
The partial AVSD provides auscultatory findings that are indistinguishable from those created by any other large ASD. A prominent impulse along the right sternal border, consistent with a right ventricle (RV) lift, may be present. Alternatively, severe MR can cause a prominent apical impulse or thrill.
The classic auscultatory finding associated with an ASD is a constant or fixed splitting of the second heart sound (S2), frequently accompanied by a pulmonary ejection murmur audible at the upper left sternal border.
A large AVSD with substantial left-to-right shunting creates a mid-diastolic rumbling murmur, audible along the lower left sternal border. This often occurs in association with a prominent third heart sound (S3) in that location. These sounds are attributed to an abnormally high flow across the tricuspid component of the atrioventricular valve.
The apical murmur of MR occurs even with a small cleft in the atrioventricular valve. This murmur has a blowing quality and must be differentiated from the murmur caused by a VSD. However, when it occurs with a fixed split S2, this murmur is helpful in differentiating a partial AVSD from a secundum ASD.
Severe MR can also cause a diastolic murmur audible over the apical area, which, in association with the systolic murmur, produces a to-and-fro quality.
AVSDs are presumed to occur secondary to extracellular matrix abnormalities that produce faulty development of the endocardial cushions and the atrioventricular septum. It has been recently described that yet another structure, the dorsal mesenchymal protrusion, which derives from the second heart field, should also fully develop in order to have an intact 4-chambered heart; otherwise, an ASD or an AVSD occurs.
More detailed scientific theories interpret the normal development of the human heart as an orderly coordination of transcriptional programs. Therefore, the variety and range of anatomic malformations in CHD are believed to be caused by a faulty mechanism that disrupts the above.
AVSDs are often associated with genetic syndromes such as trisomy 21 or Down syndrome;Holt-Oram syndrome, which results from mutations in the TBX5 gene; and heterotaxy syndromes, which result from mutations in genes such as PITX2, SHH, and NODAL. A newly described CRELD1 gene is likely to be an AVSD-susceptibility gene, and CRELD1 mutations may increase the risk of developing a heart defect ; this mutation is believed to be associated with the 3p deletion syndrome characterized by low birth weight, varying degrees of mental retardation, ptosis, and micrognathia.
Genetic mutations may be also associated with nonsyndromic cardiac defects. For example, one of the most important factors for the differentiation of mesodermal progenitor cells is the homeobox protein Nkx-2.5. In humans, 28 germline Nkx-2.5 mutations have been associated with CHD. Studies have shown that mutations in the gene Nkx-2.5 are associated specifically with AVSDs and VSDs. Mutations in the GATA4 transcriptional factor may also cause AVSDs by disrupting its role during different stages in cardiogenesis.
To date, approximately 100 CHD "risk genes" have been described. Of these, 6 subphenotypes have been shown to be linked to partial AVSDs. Of note, these genes have also been linked to aortic valve stenosis, subaortic stenosis, AVSDs associated with tetralogy of Fallot, tetralogy of Fallot, and truncus arteriosus.
Miller A, Siffel C, Lu C, Riehle-Colarusso T, Frias JL, Correa A. Long-term survival of infants with atrioventricular septal defects. J Pediatr. 2010 Jun. 156(6):994-1000. [Medline].
Briggs LE, Kakarla J, Wessels A. The pathogenesis of atrial and atrioventricular septal defects with special emphasis on the role of the dorsal mesenchymal protrusion. Differentiation. 2012 Jul. 84(1):117-30. [Medline]. [Full Text].
Guo Y, Shen J, Yuan L, Li F, Wang J, Sun K. Novel CRELD1 gene mutations in patients with atrioventricular septal defect. World J Pediatr. 2010 Nov. 6(4):348-52. [Medline].
Robinson SW, Morris CD, Goldmuntz E, Reller MD, Jones MA, Steiner RD, et al. Missense mutations in CRELD1 are associated with cardiac atrioventricular septal defects. Am J Hum Genet. 2003 Apr. 72(4):1047-52. [Medline]. [Full Text].
Inga A, Reamon-Buettner SM, Borlak J, Resnick MA. Functional dissection of sequence-specific NKX2-5 DNA binding domain mutations associated with human heart septation defects using a yeast-based system. Hum Mol Genet. 2005 Jul 15. 14(14):1965-75. [Medline].
Moskowitz IP, Wang J, Peterson MA, Pu WT, Mackinnon AC, Oxburgh L, et al. Transcription factor genes Smad4 and Gata4 cooperatively regulate cardiac valve development. [corrected]. Proc Natl Acad Sci U S A. 2011 Mar 8. 108(10):4006-11. [Medline]. [Full Text].
Tomita-Mitchell A, Mahnke DK, Struble CA, Tuffnell ME, Stamm KD, Hidestrand M, et al. Human gene copy number spectra analysis in congenital heart malformations. Physiol Genomics. 2012 May 1. 44(9):518-41. [Medline]. [Full Text].
Kutty S, Smallhorn JF. Evaluation of atrioventricular septal defects by three-dimensional echocardiography: benefits of navigating the third dimension. J Am Soc Echocardiogr. 2012 Sep. 25(9):932-44. [Medline].
Cheng HL, Huang CH, Tsai HE, Chen MY, Fan SZ, Hsiao PN. Intraoperative assessment of partial atrioventricular septal defect with a cleft mitral valve by real-time three-dimensional transesophageal echocardiography. Anesth Analg. 2012 Apr. 114(4):731-4. [Medline].
Prifti E, Bonacchi M, Bernabei M, et al. Repair of complete atrioventricular septal defects in patients weighing less than 5 kg. Ann Thorac Surg. 2004 May. 77(5):1717-26. [Medline].
Jacobs JP, O'Brien SM, Pasquali SK, Jacobs ML, Lacour-Gayet FG, Tchervenkov CI, et al. Variation in outcomes for benchmark operations: an analysis of the Society of Thoracic Surgeons Congenital Heart Surgery Database. Ann Thorac Surg. 2011 Dec. 92(6):2184-91; discussion 2191-2. [Medline]. [Full Text].
Kaza AK, Colan SD, Jaggers J, Lu M, Atz AM, Sleeper LA, et al. Surgical interventions for atrioventricular septal defect subtypes: the pediatric heart network experience. Ann Thorac Surg. 2011 Oct. 92(4):1468-75; discussion 1475. [Medline]. [Full Text].
Ten Harkel AD, Cromme-Dijkhuis AH, Heinerman BC, et al. Development of left atrioventricular valve regurgitation after correction of atrioventricular septal defect. Ann Thorac Surg. 2005 Feb. 79(2):607-12. [Medline].
Murashita T, Kubota T, Oba J, Aoki T, Matano J, Yasuda K. Left atrioventricular valve regurgitation after repair of incomplete atrioventricular septal defect. Ann Thorac Surg. 2004 Jun. 77(6):2157-62. [Medline].
Aeba R, Kudo M, Okamoto K, Yozu R. Bridging annuloplasty for left atrioventricular valve of partial atrioventricular septal defect. Ann Thorac Surg. 2012 May. 93(5):e137-9. [Medline].
Manning PB. Partial atrioventricular canal: pitfalls in technique. Semin Thorac Cardiovasc Surg Pediatr Card Surg Annu. 2007. 42-6. [Medline].
Stulak JM, Burkhart HM, Dearani JA, Cetta F, Barnes RD, Connolly HM, et al. Reoperations after repair of partial atrioventricular septal defect: a 45-year single-center experience. Ann Thorac Surg. 2010 May. 89(5):1352-9. [Medline].
Abbruzzese PA, Napoleone A, Bini RM. Late left atrioventricular valve insufficiency after repair of partial atrioventricular septal defects: anatomical and surgical determinants. Ann Thorac Surg. 1990 Jan. 49(1):111-4. [Medline].
Aubert S, Henaine R, Raisky O, et al. Atypical forms of isolated partial atrioventricular septal defect increase the risk of initial valve replacement and reoperation. Eur J Cardiothorac Surg. 2005 Aug. 28(2):223-8. [Medline].
Najm HK, Williams WG, Chuaratanaphong S, Watzka SB, Coles JG, Freedom RM. Primum atrial septal defect in children: early results, risk factors, and freedom from reoperation. Ann Thorac Surg. 1998 Sep. 66(3):829-35. [Medline].
Jacobs JP, Jacobs ML, Mavroudis C, Chai PJ, Tchervenkov CI, Lacour-Gayet FG, et al. Atrioventricular septal defects: lessons learned about patterns of practice and outcomes from the congenital heart surgery database of the society of thoracic surgeons. World J Pediatr Congenit Heart Surg. 2010 Apr. 1(1):68-77. [Medline].
Cooper WO, Hernandez-Diaz S, Arbogast PG, et al. Major congenital malformations after first-trimester exposure to ACE inhibitors. N Engl J Med. 2006 Jun 8. 354(23):2443-51. [Medline].
Allwork SP. Anatomical-embryological correlates in atrioventricular septal defect. Br Heart J. 1982 May. 47(5):419-29. [Medline].
Ebels T, Ho SY, Anderson RH, Meijboom EJ, Eijgelaar A. The surgical anatomy of the left ventricular outflow tract in atrioventricular septal defect. Ann Thorac Surg. 1986 May. 41(5):483-8. [Medline].
Ferencz C, Rubin JD, Loffredo CA, eds. The Epidemiology of Congenital Heart Disease, The Baltimore-Washington Infant Heart Study (1981-1989),. Perspectives in Pediatric Cardiology. Mount Kisco, NY: Futura Publishing Co; 1993. Vol 4:
Freeman SB, Taft LF, Dooley KJ, et al. Population-based study of congenital heart defects in Down syndrome. Am J Med Genet. 1998 Nov 16. 80(3):213-7. [Medline].
Jacobstein MD, Fletcher BD, Goldstein S, Riemenschneider TA. Evaluation of atrioventricular septal defect by magnetic resonance imaging. Am J Cardiol. 1985 Apr 15. 55(9):1158-61. [Medline].
LaCorte MA, Cooper RS, Kauffman SL, et al. Atrioventricular canal ventricular septal defect with cleft mitral valve. Angiographic and echocardiographic features. Pediatr Cardiol. 1982. 2(4):289-95. [Medline].
Lipshultz SE, Sanders SP, Mayer JE, Colan SD, Lock JE. Are routine preoperative cardiac catheterization and angiography necessary before repair of ostium primum atrial septal defect?. J Am Coll Cardiol. 1988 Feb. 11(2):373-8. [Medline].
Neufeld HN, Titus JL, Dushane JW, BUrchell HB, Edwards JE. Isolated ventricular septal defect of the persistent common atrioventricular canal type. Circulation. 1961 May. 23:685-96. [Medline].
Parsons JM, Baker EJ, Anderson RH, et al. Morphological evaluation of atrioventricular septal defects by magnetic resonance imaging. Br Heart J. 1990 Aug. 64(2):138-45. [Medline].
Piccoli GP, Gerlis LM, Wilkinson JL, et al. Morphology and classification of atrioventricular defects. Br Heart J. 1979 Dec. 42(6):621-32. [Medline].
Portman MA, Beder SD, Ankeney JL. A 20-year review of ostium primum defect repair in children. Am Heart J. 1985 Nov. 110(5):1054-8. [Medline].
Portman MA, Beder SD, Cohen MH, et al. Conduction abnormalities detected by electrophysiologic testing following repair of ostium primum atrioventricular septal defect. Int J Cardiol. 1986 Apr. 11(1):111-9. [Medline].
Pretre R, Dave H, Kadner A. Direct closure of the septum primum in atrioventricular canal defects. J Thorac Cardiovasc Surg. 2004 Jun. 127(6):1678-81.
Sadeghi AM, Laks H, Pearl JM. Primum atrial septal defect. Semin Thorac Cardiovasc Surg. 1997 Jan. 9(1):2-7. [Medline].
Singh A, Romp RL, Nanda NC, Rajdev S, Mehmood F, Baysan O, et al. Usefulness of live/real time three-dimensional transthoracic echocardiography in the assessment of atrioventricular septal defects. Echocardiography. 2006 Aug. 23(7):598-608. [Medline].
van den Bosch AE, van Dijk VF, McGhie JS, et al. Real-time transthoracic three-dimensional echocardiography provides additional information of left-sided AV valve morphology after AVSD repair. Int J Cardiol. 2006 Jan 26. 106(3):360-4. [Medline].
Wang ZJ, Reddy GP, Gotway MB, et al. Cardiovascular shunts: MR imaging evaluation. Radiographics. 2003 Oct. 23 Spec No:S181-94. [Medline].