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 Table of Contents  
FOCUS ISSUE - CONGENITAL HEART DISEASE
Year : 2020  |  Volume : 4  |  Issue : 3  |  Page : 267-275

Assessment of Atrioventricular Septal Defect on Echocardiography


Consultant, Pediatric Cardiologist, Department of Pediatric, LLRM Medical College, Meerut, India

Date of Submission14-Oct-2020
Date of Acceptance18-Oct-2020
Date of Web Publication18-Dec-2020

Correspondence Address:
Dr. Munesh Tomar
LLRM Medical College, Garh Road, Jai Bhim Nagar, Meerut - 250 002, Uttar Pradesh
India
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Source of Support: None, Conflict of Interest: None


DOI: 10.4103/jiae.jiae_69_20

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  Abstract 

Atrioventricular septal defect comprise of 1.4-2.9% of congenital cardiac defect and is most common congenital cardiac defect in Trisomy 21. This anomaly is characterized by a common atrioventricular junction coexisting with atrial and/or ventricular septal defect , cleft of left atrioventriocular valve along with left ventricular outflow tract abnormality. Due to cleft of left atrioventricular valve ,valve regurgitation is almost invariably present leading to early onset of congestive cardiac failure in these patients. Other associated structural heart defects are pulmonary stenosis,ductal arteriosus,aortic arch anomalies,pulmonary and systemic venous anomalies and unbalaned atrioventricular valve connection leading to univentricular physiology. Echocardiography plays very crucial role in defning the anomaly and planning management In this article, I am going to focus on role of echocardiography in atrioventricular septal defect.

Keywords: Atrioventricular canal defect, cleft mitral valve, inlet ventricular septal defect, ostium primum atrial septal defect


How to cite this article:
Tomar M. Assessment of Atrioventricular Septal Defect on Echocardiography. J Indian Acad Echocardiogr Cardiovasc Imaging 2020;4:267-75

How to cite this URL:
Tomar M. Assessment of Atrioventricular Septal Defect on Echocardiography. J Indian Acad Echocardiogr Cardiovasc Imaging [serial online] 2020 [cited 2021 Apr 13];4:267-75. Available from: https://www.jiaecho.org/text.asp?2020/4/3/267/303951


  Introduction Top


Atrioventricular septal defect is characterized by the anatomical hallmark of a common atrioventricular junction coexisting with deficient atrioventricular septation.[1] The atrioventricular valves can have a common orifice (complete atrioventricular septal defect) or two separate orifices partial atrioventricular septal defect). The abnormal common atrioventricular junction is found irrespective of whether there are separate atrioventricular orifices for right and left ventricles or a common atrioventricular valve.


  Incidence Top


This anomaly occur in 0.19/1000 live birth and comprise of 1.4%–2.9% of patients with congenital heart defects,[1],[2] there is a strong association of deficient atrioventricular septum with trisomy 21. It has been found that 30%–50% of patients with atrioventricular septal defect have trisomy 21 and about one-third of patients with Down syndrome have atrioventriuclar canal defect.[3],[4],[5] Atrioventricular canal defect is one of the most commonly detected cardiac anomlay on fetal echocardiography.


  Classification Top


Patients with atrioventricular septal defect are classified into two groups:[1]

  1. Partial atrioventricular septal defect - when the two bridging leaflet are joined to each other by a tongue of tissue dividing the atrioventricular valve into two separate orifices, called as partial atrioventricular septal defect
  2. Complete atrioventricular septal defect - when the bridging leaflets are free, guarding the opening of both atria to respective ventricle as a common opening than it is called as complete atrioventricular septal defect.


Both categories can be further classified as:

  • With/without atrial septal defect (ASD)
  • With/without ventricular septal defect (VSD)
  • With/without cleft of left and/or right atrioventricular valve.


Depending upon the position of bridging leaflets, intermediate (incomplete) form of atrioventricular canal defect has also been described.[6],[7],[8]

In 1966, Rastelli et al., have further classified complete atrioventricular canal defect into three types:[9]

Rastelli A: When the superior bridging leaflet is attached firmly to the septal crest, there is no defect beneath it, more commonly this leaflet is attached to a normally positioned medial papillary muscle and is attached by multiple cords to the crest of the septum. There are then multiple interventricular communications through the intercordal spaces, and the flow can be recognized on color flow mapping.

Rastelli type B: The right ventricular medial papillary muscle is positioned in mid septal position, the degree of bridging is greater, and bridging leaflet is less well attached to the ventricular septal crest, and become free–floating.

Rastelli type C: When the papillary is located still further in right ventricle, a so-called Rastelli type C defect is produced. In this situation, almost always a large VSD is present, and is particularly frequent in Down's syndrome.


  Echocardiography Top


Echocardiography provides a reliable delineation of detailed morphology.[6],[10],[11],[12] Color flow Doppler interrogation compliments the anatomical investigation by demonstrating the sites of intracardiac shunting and atrioventricular regurgitation, as well as defining any outflow tract obstruction if present. Pulsed and continuous wave Doppler is used to assess pulmonary artery pressure, severity of left or right ventricular outflow tract obstruction or arch obstruction.

While evaluating a patient with atrioventricular septal defect, the things needs to be addressed are:

  1. Type of defect, partial or complete atrioventricular septal defect
  2. Extent of atrial shunting
  3. Extent of ventricular shunting
  4. Presence and degree of atrioventricular valve regurgitation
  5. Commitment of atrioventricular valves to respective ventricles, is there balanced atrioventricular connection or unbalanced atrioventricular connection, degree of ventricular hypoplasia if present
  6. Presence of straddling
  7. Potential for left or right ventricular outflow obstruction
  8. Pulmonary artery pressures
  9. Associated lesions.


Two-dimensional echocardiographic findings common to all patients of atrioventricular septal defect are:

  1. Loss of offsetting of atrioventricular valves
  2. Deficiency of inlet portion of ventricular septum
  3. Presence of common atrioventricular valve fibrous orifice
  4. Abnormal morphology of atrioventricular valve cusps
  5. Abnormal position of papillary muscles
  6. Longer left ventricular (LV) outflow, and anterior unwedged position of aorta.


The following basic views can define these anatomical features:

Subcostal coronal and sagittal views supplemented with apical four chambers, parasternal long axis and short axis can define the anatomy with great accuracy. Subcostal coronal view shows common atrioventricular junction, loss of offsetting of atrioventricular valves, scooped out inlet septum and inferior bridging leaflet of atrioventricular valve [Figure 1] and [Figure 2]. Subcostal sagittal view shows common atrioventricular junction, in addition to that both superior and inferior bridging leaflets and anterior unwedged position of aorta can be very well profiled. Subcostal long axis view of LV outflow tract defines “Goose neck” deformity of LV outflow tract (long left ventricle outflow with anterior position of aorta) [Figure 3]. Apical four-chamber view shows loss of offsetting, ostium primum ASD, inlet VSD, commitment of atrioventricular valve (s) to respective ventricle (s) [Figure 4]. Parasternal short axis view shows trileaflet left atrioventricular valve, presence of cleft; presence of common atrioventricular junction, and abnormal position of the papillary muscles in the left ventricle [Figure 5]. Parasternal long axis view shows discrepancy in the left ventricle inflow and outflow measurements [Figure 6], and presence of LV outflow tract obstruction.
Figure 1: Echocardiography from an infant with complete atrioventricular septal defect. Subcostal coronal view showing large atrial septal defect, common atrioventricular junction, ventricular septal defect (*), loss of offsetting of atrioventricular valves, and inferior bridging leaflet (arrow). RA: Right atrium, LA: Left atrium, RV: Right ventricle, LV: Left ventricle

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Figure 2: Subcostal coronal view from an infant with partial atrioventricular septal defect showing two atrial septal defects (ostium primum and additional fossa ovalis–thick arrows), common atrioventricular junction, loss of offsetting of AV valves, and inferior bridging leaflet (thin arrow). RV: Right ventricle, LV: Left ventricle, RA: Right atrium, LA: Left atrium

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Figure 3: Subcostal coronal view with anterior tilt (modified view) in diastole showing “goose neck deformity” of left ventricular outflow tract, i.e., left ventricular outflow tract in elongated with anterior unwedged position of aorta. Inferior bridging leaflet is seen (arrow). RV: Right ventricle, LV: Left ventricle, RA: Right atrium, Ao: Aorta

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Figure 4: Apical four-chamber view from a child with partial atrioventricular septal defect showing large ostium primum atrial septal defect, loss of offsetting of atrioventricular valve, common atrioventricular junction, and superior bridging leaflet (arrow). Right atrium and right ventricle are dilated. RV: Right ventricle, LV: Left ventricle, RA: Right atrium, LA: Left atrium

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Figure 5: Echocardiography from a 4 years old child with partial atrioventricular canal defect showing Trileaflet left atrioventricular valve, and presence of cleft (arrow) RV: Right ventricle, LV: Left ventricle, LAVV: Left atrioventricular valve

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Figure 6: Parasternal long axis view from an infant with complete atrio-ventricular septal defect showing discrepancy in left ventricular inflow (line-a) and outflow (line-b) measurements. RV: Right ventricle, LV: Left ventricle, LA: Left atrium, Ao: Aorta, *-descending aorta

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In addition atrioventricular valves need to be profiled in subcostal enface view (by rotating the transducer 30°–45° clockwise from subcostal four chamber view) [Figure 7]. From this view with tilting the plane of sound from anterior to posterior, all five leaflets, separate or common atrioventricular valve orifices, attachment of anterosuperior bridging leaflet to anterior muscular septum and posteroinferior septum to inlet septum can be defined.
Figure 7: Subcostal enface view from same child in [Figure 7] showing common atrioventricular junction, two separate atrioventricular valve orifices (Left and right), and cleft (arrow), superior and inferior bridging leaflets. RV-right ventricle, LV-left ventricle, PA: Pulmonary artery, SBL: Superior bridging leaflet, IBL: Inferior bridging leaflet, Lt: Left, Rt: Right

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  Potential for Shunting Top


This feature is perhaps, the most important anatomical factor along with atrioventricular valve regurgitation that influences clinical presentation. The anatomic variability depends on the relationship of the bridging leaflets, and of the connecting tongue if present, to the lower edge of atrial septum, on the one hand, and to the crest of the scooped out ventricular septum, on the other hand. If the leaflets are not attached to atrial and ventricular level than potential for shunting is there at both atrial and ventricular level. The extent of ventricular shunting depends on the proximity of the bridging leaflets to the septal crest. If there is free floating leaflets than there will be large ASD and VSD. When cords from septal crest tether to one or both bridging leaflet than ventricular shunting can be limited. When both superior and inferior bridging leaflet attached to septal crest than shunting occurs only at atrial level. Sometimes, the bridging leaflets, and a tongue, if present attached to the under surface of atrial septum, this arrangement permits shunting to occur only at the ventricular level.


  Type of Atrioventricular Septal Defect Top


Partial atrioventricular septal defect

The characteristic features of partial atrioventricular septal defect are two separate atrioventricular orifices within the common atrioventricular junction, abnormal valve leaflets with or without cleft, and usually the presence of ASD between lower part of atrial septum and the crest of the ventricular septum. Leaflets are attached to the crest of ventricular septum, so there will be loss of offsetting and usually VSD is not there or it is restrictive [Figure 8], though this is not a universal finding. Rarely, we can find only inlet VSD, intact interatrial septum when the bridging leaflets are attached to the lower part of interatrial septum [Figure 9]a,[Figure 9]b,[Figure 9]c,[Figure 9]d. VSD can be profiled from subcostal coronal and sagittal, apical four chamber and parasternal long axis with posterior tilt and short axis views. Here, trileaflet left atrioventricular valve guarding the left component of the common atrioventricular junction, seen in parasternal short axis and subcostal enface views [Figure 9]c, will be the hallmark features to differentiate it from isolated inlet muscular VSD. Rarely a left atrioventricular valve with three leaflets may be the only manifestation of an atrioventricular septal defect with intact atrial and ventricular septum. There will be only cleft of left or right atrioventricular valve (more commonly of left side). Cleft can be profiled in subcostal enface view, parasternal long axis and parasternal short axis views [Figure 5], [Figure 7], [Figure 10] and [Figure 11]. In parasternal short axis view the cleft (zone of apposition between superior and inferior bridging leaflets) is seen toward the ventricular septum to differentiate this anomaly from isolated cleft of mitral valve where the cleft will be oriented toward the LV outflow tract.[13] In this scenario other features of atrioventricular septal defect as longer left ventricle outflow tract, unwedged and anterior position of aorta as described earlier will be present. Less common variant is common atrium (virtual absence of atrial septum), usually found in setting of left or right isomerism [Figure 12]. Associated anomaly of atrioventricular valves as dual orifice atrioventricular valve with or without stenosis[10] and Ebstein's anomaly of right atrioventricular valve can sometimes be present and should be looked for on two-dimensional echocardiography [Figure 13]a and [Figure 13]b.
Figure 8: Apical four chamber with color flow mapping in a child with partial atrioventricular septal defect showing intact interatrial septum, common atrioventricular junction, and small inlet ventricular septal defect with left to right shunt. Ventricular septal defect is small due to attachment of superior bridging leaflet to crest of ventricular septum (arrow). RV: Right ventricle, LV: Left ventricle, RA: Right atrium, LA: Left atrium

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Figure 9: Echocardiography from a 1-year-old child with partial atrioventricular septal defect, intact interatrial septum, and large ventricular septal defect. (a) Apical four chamber view showing common atrioventricular junction with loss of offsetting of atrioventricular valve, intact atrial septum, large inlet ventricular septal defect, and superior bridging leaflet attached to lower part of interatrial septum. (b) Subcostal coronal view with anterior tilt showing common atrioventricular junction, inlet ventricular septal defect and anterior unwedged position of aorta. (c): Subcostal enface view showing two separate atrioventricular valve orifices (Lt and Rt), inlet ventricular septal defect (*), and superior and inferior bridging leaflets. (d) Subcostal sagittal view with color flow mapping showing non-restrictive inlet ventricular septal defect (laminar left to right shunt-arrow). RA: Right atrium, LA: Left atrium, RV: Right ventricle, LV: Left ventricle, PA: Pulmonary artery

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Figure 10: Subcostal sagittal view with color flow mapping from a child with partial atrioventricular septal defect showing left atrioventricular valve regurgitation through cleft (arrow). RV: Right ventricle, LV: Left ventricle

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Figure 11: Parasternal short axis view with color flow mapping at the level of atrioventricular valves from a child with partial atrioventricular septal defect showing regurgitation through the cleft (arrow). RV: Right ventricle, LV: Left ventricle

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Figure 12: Subcostal coronal view from an infant with right isomerism, common atrium showing large atrial septal defect (common atrium), common atrioventricular junction, loss of offsetting of AV valves, and inferior bridging leaflet (arrow). RV: Right ventricle, LV: Left ventricle

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Figure 13: Echocardiography from a child with partal atrioventricular septal defect with double orifice left atrioventricular valve. (a) Parasternal short axis view showing left atrioventricular valve is devided by aberrant tissue into two orifices (two stars) of the same size. (b) Apical four chamber view is diastole showing large atrial septal defect, loss of offsetting, and restricted movement (doming-arrow) of left atrioventricular valve. The common atrioventricular valve is displaced inferiorly in the heart and anchored to the crest of the ventricular septum. Right atrium and right ventricle are dilated. RA: Right atrium, LA: Left atrium, RV: Right ventricle, LV: Left ventricle

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Complete atrioventricular septal defect (atrioventricular septal defect with common valvar orifice)

The typical echocardiographic features of complete atrioventricular septal defect are ostium primum ASD, common atrioventricular valve guarding the common junction and an inlet interventricular communication of variable size [Figure 1], [Figure 14]a, [Figure 14]b, [Figure 15]a and [Figure 15]b. The VSD can be small or large depending upon the attachment of the bridging leaflets. As described earlier, inferior bridging leaflet is seen best in subcostal coronal view, it may be firmly attached by a midline raphae to the septum; as a result there will be no interventricular communication close to crux. The superior bridging leaflet is seen in apical four-chamber view with anterior tilt and most of the variations in ventricular component of shunting are seen beneath the superior bridging leaflet [Figure 15]b. Subcostal enface view shows both superior and inferior bridging leaflets [Figure 14]a and [Figure 14]b.
Figure 14: Subcostal enface view from a child with complete atrioventricular septal defect. (a) In diastole showing common atrioventricular valve orifice guarded by superior and inferior bridging leaflets. (b) In systole the atrioventricular valve is seen in closed position. RV: Right ventricle, PA: Pulmonary artery, SBL: Superior bridging leaflet, IBL: Inferior bridging leaflet

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Figure 15: Apical four-chamber view from a child with complete atrioventricular septal defect. (a) In diastole the, large atrial septal defect, large inlet ventricular septal defect can be seen. Common atrioventricular junction is displaced downward because of deficiency of inlet septum. (b) In systole, because the superior bridging leaflet is not tethered to the crest of ventricular septum, shunting occurs at both atrial and ventricular level. RA: Right atrium, LA: Left atrium, RV: Right ventricle, LV: Left ventricle

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Rarely with complete atrioventricular septal defect, there will be the absence of any interatrial shunt when the superior bridging leaflet attached to the lower end of atrial septum, and absence of VSD when it is firmly attached to ventricular septum as described with partial atrioventricular septal defect.

Commitment of atrioventricular valve to ventricle and relationship of atrioventricular valve leaflets to the septal structure

Apical four-chamber, subcostal coronal, and subcostal enface views are required to profile commitment of atrioventricular valves to respective ventricle, and to look for presence of overriding. These views allow simultaneous visualization of all four chambers, atrioventricular valves and atrial and ventricular septa. If the atrioventricular junction is shared equally then there is a balanced atrioventricular connection. When there is overriding of atrioventricular valve to one of the ventricle and malalignment between atrial and ventricular septum, then the condition is termed as unbalanced atrioventricular connection leading to hypoplasia of left or right ventricle depending upon the degree of overriding [Figure 16]a and [Figure 16]b. One of the atrioventricular valves can be atretic causing hypoplasia of respective ventricle [Figure 17]. Abnormal relation between atria and ventricle can also occur when the common atrioventricular junction is equally shared between both the ventricles but is committed exclusively to one or the other atrium. This condition is termed as double outlet atrium or uniatrial biventricular atrioventricular connection and can be defined in subcostal and apical four chamber views.
Figure 16: Apical four-chamber view from a child with complete atrioventricular septal defect, unbalanced atrioventricular connection with hypoplastic left ventricle. (a) In systole, malalignment of interatrial and interventricular septum is apparent, with commitment of common atrioventricular valve to right ventricle. Right ventricle is dilated and left ventricle is small. (b) In systole free floating superior bridging leaflet is seen with commitment of common atrioventricular valve to right ventricle. RA: Right atrium, LA: Left atrium, RV: Right ventricle, LV: Left ventricle

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Figure 17: Apical four-chamber view from a child with atrioventricular canal defect showing common atrium, atretic left component (arrow) of atrioventricular valve, and hypoplastic left ventricle. RV: Right ventricle, LV: Left ventricle

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Straddling of atrioventricular valve is also an issue, which needs to be defined. Straddling of the left atrioventricular valve is defined in parasternal long axis view while for right atrioventricular valve, it is the four-chamber view and subcostal enface view are required to profile the chordal attachment [Figure 18].
Figure 18: Apical four-chamber view in systole from a child with partial atrioventricular septal defect showing tethering of cordae (thin arrows) to free wall of right ventricle. There is mild hypoplasia of right ventricle. Thick arrow point to primum atrial septal defect. This child presented with history of cyanosis. Cyanosis occurred due to right to left shunt across the atrial septal defect with hyoplastic right ventricle. RA: Right atrium, LA: Left atrium, RV: Right ventricle, LV: Left ventricle

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Color flow mapping is required to define presence and direction of shunting across interatrial or interventricular septum [Figure 8] and [Figure 9]c, presence of atrioventricular valve regurgitation or stenosis, presence of left or right ventricular outflow tract obstruction. Direction of shunt across ASD or VSD can be profiled from views used to define the defects. Subcostal [Figure 10], apical four chamber [Figure 19] and parasternal short axis views are required to look for presence of atrioventricular valve regurgitation, presence of left ventricle-right atrial shunt, or right ventricle-left atrial shunt. Right ventricle-left atrial shunt could be a cause of cyanosis in a child with partial atrioventricular canal defect with normal pulmonary artery pressure. The quantitative assessment of valvar stenosis may not be accurate by Doppler echocardiography when there is large ASD. Hence, it is important to evaluate atrioventricular valve anatomy by two-dimensional echocardiography and look especially for dysplasia, tethering of leaflets and valve orifice. In such cases, valve stenosis may manifest after closure of the ASD.
Figure 19: Apical four-chamber view with color flow mapping from a child with partial atrioventricular canal defect showing mild regurgitation of both left and right atrioventricular valves. There is left ventricle to right atrial and right ventricle to left atrial shunt. RA: Right atrium, LA: Left atrium, RV: Right ventricle, LV: Left ventricle

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Left ventricular outflow tract obstruction

LV outflow tract is longer and narrow than normal in atrioventricular septal defect, though in most cases there is no overt stenosis. Any factor which causes further narrowing of LV outflow tract causes LV outflow tract obstruction. Causes of LV outflow tract obstruction are,[6],[14],[15],[16],[17],[18],[19],[20]

  1. Tight adherence of superior bridging leaflet to septal crest causing LV outflow tract to be longer and narrower. LV outflow tract obstruction is more common in partial atrioventricular septal defect and Rastelli type A of common atrioventricular septal
  2. Discrete subaortic membrane
  3. Septal hypertrophy
  4. Abnormal chordal attachment of superior bridging leaflet
  5. Prominent anterolateral muscle bundle.


LV outflow tract can be profiled from subcostal coronal view with anterior tilt, subcostal sagittal view, and parasternal long axis view.


  Complex Atrioventricular Septal Defect Top


Complex atrioventricular septal defect can be defined as atrioventricular septal defects morphology, which precludes two-ventricle correction or makes it difficult.[11] The following conditions can be the cause of such a situation.

  1. Right/LV dominant atrioventricular septal defect - Because of extreme straddling/overriding of the common atrioventricular valves across the VSD, one of the ventricles may be hypoplastic. This will prevent two-ventricle repair
  2. There is common association of hetrotaxy syndrome with atrioventricular canal defect. Anomalous systemic/pulmonary venous connection, hypoplasia of ventricles and abnormalities of ventricular arterial connection are frequently associated creating further complexity
  3. Abnormalities of ventricular arterial connections- atrioventricular septal defect can be associated with double outlet right ventricle making it difficult or impossible to route the VSD (which is remote from the aorta) to the aorta thus precluding a two ventricle repair.



  Associated Defects Top


Tetralogy of Fallot (Tet canal), double outlet right ventricle, malposed great vessels are frequently associated with complete atrioventricular septal defect especially in setting of isomerism.[6],[8] With unbalanced atrioventricular connection leading to hypoplastic left ventricle, aortic arch should be well profiled in suprasternal long axis view to rule out arch anomalies as coarctation of aorta and arch interruption. With hypoplastic right ventricle, pulmonary stenosis and pulmonary atresia may be the association.


  Hemodynamic Assessment of Atrioventricular Septal Defect Top


Without pulmonary stenosis

  1. Partial atrioventricular septal defect – These defects behave like ASD. In the absence of significant atrioventricular valve regurgitation and normal pulmonary artery pressure, the lesion is well tolerated and patients may present late like fossa ovalis ASDs. Significant atrioventricular valve regurgitation however may cause early congestive heart failure. Accurate assessment of pulmonary artery pressure and atrioventricular valve regurgitation is critical in decision-making in timing of surgery. Doppler assessment of pulmonary artery pressure is usually performed by assessing tricuspid regurgitation velocity. Care should be taken in not confusing left ventricle to right atrial shunt for tricuspid regurgitation as the former (LV- right atrium shunt) invariably produce high velocity signals and will wrongly overestimate pulmonary artery pressure.
  2. Complete atrioventricular septal defect: This is associated with large VSD and pulmonary arterial hypertension. Thus congestive heart failure develops in the first few months of life. Also, rapid progression of pulmonary vascular disease in infancy occurs in this condition. Thus there is need to correct these lesions early in infancy only. If correction is performed at the appropriate age, then echocardiography alone is enough for the assessment of this lesion and there is no need for invasive determination of pulmonary artery pressure and vascular resistance. Late presentation however may need more detailed evaluation in the form of cardiac catheterization.


With pulmonary stenosis

Patients with pulmonary stenosis present as tetralogy of Fallot. However, the morphology is much more complicated. The VSD, which is predominantly of the inlet type, may extend into the outlet septum. Anterior malalignment of the outlet septum causes right ventricular outflow obstruction and other morphological abnormality associated with tetralogy. These children presents as tetralogy of Fallot if there is no significant atrioventricular valve regurgitation. The presence of significant atrioventricular valve leads to early presentation with cyanosis and features of congestive cardiac failure.


  Postoperative Assessment Top


Because of the complexity of the repair, echocardiographic assessment in immediate post-operative period and in long term is mandatory to detect any important imperfections in the repair. Following lesions should be sought for in patients following atrioventricular septal defect repair.

Residual atrial or ventricular septal defects

Doppler color flow mapping is particularly useful as a rapid screening technique for residual septal defects.

Inadequate repair of common atrioventricular valve

It is by far the most common postoperative problem. This will result in left/right atrioventricular valve regurgitation or left/right atrioventricular valve stenosis.

  1. Left atrioventricular valve regurgitation: This is more common in patients with complete form of atrioventricular septal defect than partial. Most commonly it occurs at the commissure between anterior and posterior bridging leaflets– cleft mitral valve. Larger mural leaflet is also more common in patients with significant residual left atrioventricular valve regurgitation. Echocardiography helps in assessment of severity of regurgitation and its hemodynamic significance. Serial postoperative echocardiographic studies are needed to assess the need of further medical or surgical intervention (Valve replacement/repair).
  2. Left atrioventricular valve Stenosis: It can result from excessive suture closure of cleft, congenital anomaly of atrioventricular valve or inappropriate surgical division of common atrioventricular valve between two ventricles. Doppler echocardiography helps in assessment of severity and need for reintervention.
  3. Right atrioventricular valve stenosis or regurgitation: It is less common and has less serious hemodynamic consequences than left atrioventricular valve regurgitation. It can be accurately diagnosed by careful Doppler evaluation.


Left ventricular outflow tract obstruction

Subaortic stenosis occurs more frequently after repair of partial atrioventricular septal defect. Underlying mechanisms producing stenosis include, adherence of anterior bridging leaflet to the crest of ventricular septum, membranes or chordae crossing LV outflow tract or redundant atrioventricular valve tissue protruding into LV outflow tract. Echocardiography helps in identifying the cause and severity of obstruction.

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Conflicts of interest

There are no conflicts of interest.

 
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    Figures

  [Figure 1], [Figure 2], [Figure 3], [Figure 4], [Figure 5], [Figure 6], [Figure 7], [Figure 8], [Figure 9], [Figure 10], [Figure 11], [Figure 12], [Figure 13], [Figure 14], [Figure 15], [Figure 16], [Figure 17], [Figure 18], [Figure 19]



 

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Abstract
Introduction
Incidence
Classification
Echocardiography
Potential for Sh...
Type of Atrioven...
Complex Atrioven...
Associated Defects
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