Congenital Heart Disease

8 Congenital Heart Disease



Denise Joffe



• There are now more adults than children with congenital heart disease (CHD).

• Many present for reoperative procedures; they were treated in an era when there was a long interval between palliative procedures and complete repair. Their hearts were exposed to prolonged pressure and volume loads, cyanosis, abnormal rhythms, and other physiologic stresses.

• A smaller number of adult patients require surgery for unrepaired simple or complex CHD.

• Patients with CHD also require noncardiac surgery.

• In order to interpret an intraoperative transesophageal echocardiography (TEE) examination, it is critical to have a detailed appreciation of the patient’s history, including all cardiac surgical/interventional procedures. The echocardiographer must understand the long-term risks and complications of the defect and treatments.

• For optimal management, most of these procedures including noncardiac surgery should be performed in centers with the expertise and resources to care for these complex patients.

• Many of these patients have had exhaustive studies to delineate their anatomy and residual defects before elective surgery. Intraoperative TEE can confirm the preoperative diagnosis, assess the surgical repair, and help guide the hemodynamic management of the patient.


Atrial Septal Defects




Key Points



All Atrial Septal Defects (ASD) (Tables 8-1 and 8-2)



• Adult presentation is not uncommon.

• Presentation may be shortness of breath (SOB), congestive heart failure (CHF), arrhythmias, and/or right heart enlargement.

• Symptoms worsen with age because the decrease in left ventricular (LV) compliance increases left to right (L→R) shunt.

TABLE 8-1 BASIC ECHOCARDIOGRAPHIC PRINCIPLES WHEN IMAGING PATIENTS WITH AN ATRIAL SEPTAL DEFECT











Defect What to Look for on 2D CF and Spectral Doppler
All ASDs
• Measure ASD size.

• Examine MV structure and function. Look for prolapse/cleft.

• Examine TV for prolapse. Measure annulus.

• Examine PV drainage especially right-sided PVs.

• Assess for RAE, RVE.

• Assess biventricular function.

• Examine morphology/function of PulmV. Look for number of leaflets, doming leaflets, commissural fusion, restricted motion (ME AV SAX, ME asc aortic SAX, ME RV inflow-outflow, UE aortic arch, SAX).

• Elevated PAP, RVH, R→L shunt, flat or leftward orientation of IAS in systole may indicate Eisenmenger’s.

• Look for an LSVC, located between the LUPV and the LAA (see Figure 8-5) (ME 2C, ME 4C).
• CF/PW Doppler for direction of flow (L→R in uncomplicated ASDs) (Figure 8-6).

• CF/CW Doppler to grade MR, TR.

• PW of PVs may show higher baseline velocities second to high PBF but pulsatility is preserved and peak and mean velocities are not significantly elevated.

• Estimate PAP if TR is present RVP = PAP = 4VTR2 + RAP (ME inflow-outflow, ME 4C).

• CF/CW Doppler to assess for PS. Velocities up to 2.5 m/s may result from ASD flow alone.

asc, ascending; ASD, atrial septal defect; AV aortic valve; 4C, four-chamber; CF, color flow; IAS, interatrial septum; L, left; LAA, left atrial appendage; LSVC, left superior vena cava; LUPV, left upper pulmonary vein; ME, midesophageal; MR, mitral regurgitation; MV, mitral valve; PAP, pulmonary artery pressure; PBF, pulmonary blood flow; PS, pulmonic stenosis; PulmV, pulmonary valve; PV, pulmonary vein; PW, pulsed wave; R, right; RAE, right atrial enlargement; RV, right ventricular; RVE, right ventricular enlargement; RVH, right ventricular hypertrophy; RVP, right ventricular pressure; SAX, short axis; TR, tricuspid regurgitation; TV, tricuspid valve; 2C, two-chamber; 2D, two-dimensional; UE, upper esophageal.



TABLE 8-2 BASIC ECHOCARDIOGRAPHIC PRINCIPLES WHEN IMAGING SPECIFIC ATRIAL SEPTAL DEFECTS

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Primum Atrial Septal Defects (Figure 8-1A)



• Cleft mitral valve (MV) is almost always present (see Figure 8-1B).

• Secondary changes to the MV from prolonged mitral regurgitation (MR) can result in annular dilatation, thickened leaflets, and restricted motion and complicate the repair.

• Left ventricular outflow tract obstruction (LVOTO) can develop because of:
• A deficient LV inlet compared with the LV outlet causing long tunnel-like LVOTO (“gooseneck deformity”).

• A discrete membrane causing stenosis (Figure 8-2A).

• Aberrant chords inserting into the interventricular septum (IVS) obstructing outflow (see Figure 8-2B).

• Reoperations for new/recurrent MR/LVOTO.

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Figure 8-1 A, Primum ASD. ME 4C view with CF Doppler demonstrates a defect in the inferior part of the IAS and two jets of MR. More imaging suggested that the medial jet originated from the medial aspect of the cleft and the second, more central jet of MR was likely a coaptation defect from annular dilatation. Note also that both AVVs originate at the same level from the center (crux) of the heart. B, TG basal SAX view showing a large cleft (asterisk) in the anterior mitral leaflet (AML). C, Secundum ASD. Deep TG view at 90 degrees with rightward rotation (deep TG bicaval equivalent) shows a defect in the area of the fossa ovalis (FO).


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Figure 8-2 A, ME AV LAX view in a patient with a primum ASD shows a chord inserting into the ventricular septum. B, ME AV LAX in a patient 2 years post primum ASD repair shows a long segment tunnel-like LVOTO that required surgical repair.



Secundum Atrial Septal Defects (see Figure 8-1C)



• Associated defects include MV prolapse, left superior vena cava (LSVC), pulmonic stenosis (PS), and partial anomalous pulmonary venous drainage (PAPVD).

• If left untreated, approximately 5% develop Eisenmenger’s syndrome (irreversible pulmonary vascular disease).


Sinus Venosus Atrial Septal Defects (Figure 8-3)



• Most are superior sinus venosus (SV) ASDs and are associated with anomalous right pulmonary vein drainage into the right atrium (RA) or superior vena cava (SVC).

• Inferior defects are very rare.

• Scimitar syndrome is anomalous pulmonary vein (PV) drainage of part or all of the right lung to the inferior vena cava (IVC). Associated defects include secundum ASD, right lung hypoplasia, and aortopulmonary collaterals supplying the right lung.

• Reoperations for obstruction of the SVC/PVs/ASD baffle.

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Figure 8-3 A, Superior SV ASD. 2D and CF Doppler ME 4C view with the probe withdrawn slightly demonstrates a defect in the superior aspect of the IAS. The RUPV is seen to drain into the RA and flow is left to right through the ASD. B, Inferior SV ASD. 2D ME bicaval view shows a defect in the inferior part of the IAS. Note the enlarged IVC. C, Schematic drawing with the SV ASD straddling the right upper and lower pulmonary veins (arrows). In the right hand frame, the defect was closed using a double-patch repair technique, while assuring that the right pulmonary veins drained into the left atrium.


Courtesy of Starr Kaplan.



Coronary Sinus Atrial Septal Defects (Figure 8-4)



• The coronary sinus (CS) opens into the floor of the left atrium (LA) causing a L→R shunt. The defect may involve part or the whole CS.

• There is a high association with an LSVC and it alters the surgical repair (Figure 8-5).

• Associated defects: PAPVD, LSVC.

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Figure 8-4 A, CS ASD. ME AV LAX shows the CS opening into the LA (asterisk). The extent of the defect cannot be determined in this view. B, Flow is going left to right through the defect.


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Figure 8-5 A, ME modified 2C view shows an enlarged CS in the atrioventricular groove (enlarged CS marked with an asterisk). B, ME modified 5C view shows the LSVC. Always rule out an LSVC in the presence of a dilated CS (>1 cm).



Principles of Surgical/Interventional Management



• Concomitant tricuspid valve (TV) repair may be necessary if right ventricular (RV) dilatation/hypertension has caused moderate to severe tricuspid regurgitation (TR).


Secundum Atrial Septal Defects



• Defect closed with a device in catheterization laboratory or with surgical closure using a pericardial patch or simple stitch closure.


Primum Atrial Septal Defects



• Surgical patch closure of the primum ASD.

• The MV cleft is usually stitch closed even if there is no MR.

• If the MR is more complex or in cases of re-operation, repair may involve annular reduction, commissurotomy, or patch augmentation of deficient leaflet tissue. If the valve cannot be repaired a MVR (mitral valve replacement) is performed in the older patient.


Sinus Venosus Atrial Septal Defects



• Patch closure of defect with anomalous PV baffled to the LA (see Figure 8-3C).

• SVC-RA junction may require augmentation with a pericardial patch to avoid SVC obstruction: “two-patch technique,” one to baffle the PV and one to augment the SVC.

• A Warden procedure may be necessary when the PVs drain into the high SVC or if there is difficulty making an unobstructed baffle. The SVC is disconnected and reattached to the right atrial appendage (RAA). The PV “stump” (cardiac end of the SVC containing the anomalous PV) is baffle closed to the LA.


Scimitar Syndrome



• Several surgical techniques can be used.
1 The scimitar vein is baffled from its origin in the IVC to the LA through an existing patent foramen ovale (PFO)/ASD or a surgically created ASD. The baffle is usually long and makes a sharp turn at its origin with a risk of obstruction.

2 The preceding procedure is employed except that the vein is reattached to the RA before the intracardiac baffle. The baffle is shorter and the baffle angle is less.

3 A direct anastomosis to the LA. It is not always possible to mobilize the vein for this approach.


Coronary Sinus Atrial Septal Defects



• Simple patch closure of the CS orifice. The CS drains into the LA, resulting in minimal cyanosis (R→L shunt).

• With an LSVC, the roof of the CS is covered and allowed to drain into the RA. If an LSVC is not recognized, simple patch closure of the CS ostium will result in unacceptable cyanosis.

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Figure 8-6 PW Doppler of ASD flow in a ME 4C view with rightward rotation. A, There is mostly left to right flow. B, PW Doppler shows bidirectional flow through an ASD. There is right to left flow during systole and left to right flow during diastole. Although it is not possible to calculate PVR by echocardiography, a careful examination of the heart for signs of pulmonary hypertension (PHTN) should be performed (see note on Eisenmenger’s).


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Figure 8-7 CF Doppler view at 97 degrees with insertion of the probe to the level of the liver shows the scimitar vein joining the IVC slightly inferior to the RA.



Postoperative TEE Assessment after Atrial Septal Defect Repair



Step 1: Verify ASD closure
• Bubble contrast study is often a helpful adjunct to visualize residual shunts.

Step 2: Assess MV function
• After a primum repair, MR can be eccentric and composed of multiple jets. Grading can be difficult. Less than mild MR is necessary for a durable repair but more significant MR is often tolerated in children to avoid early mitral valve repair (MVR).

Step 3: Assess TV function
• If a repair/annuloplasty ring was performed, mild residual TR is ideal.

Step 4: Specific ASDs
• SV ASD. Confirm appropriate drainage of PVs into the LA without narrowing of PV/SVC/SVC baffle/SVC-RAA anastomosis (Figure 8-8). PV flow should be pulsatile and of low velocity.

• CS ASD. In patients without an LSVC, confirm closure of the CS. In those with an LSVC, the CS drains into the RA and the CS appears normal (covered) in the midesophageal (ME) two-chamber (2C) view.

• Scimitar syndrome. Confirm unobstructed drainage of the scimitar vein to the LA after repair. If a baffle was used, assess for obstruction at the baffle origin and along its course to the LA.

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Figure 8-8 2D and CF Doppler ME bicaval view shows the PV baffle directing RUPV flow to the LA. It is important to verify unobstructed PV and SVC flow.



Ventricular Septal Defects




Key Points



All Ventricular Septal Defects (Tables 8-3 to 8-5)



• Adult presentation is rare unless the ventricular septal defect (VSD) is small or there are coexisting defects that restrict pulmonary blood flow (PBF). A high incidence of Eisenmenger’s occurs in unrepaired moderate to large VSDs.

• Cardiac catheterization must be performed when there is PHTN to evaluate pulmonary vascular resistance (PVR) and suitability for VSD closure.

• Associated lesions: ASDs, double-chamber right ventricle (DCRV), coarctation, subaortic obstruction, other complex CHDs (see Video 8-2 on the Expert Consult website).

• PHTN may occasionally progress even in those with early repair.

TABLE 8-3 SURGICAL APPROACH TO VENTRICULAR SEPTAL DEFECT CLOSURE



























Most Common Surgical Approach Defect Additional Facts
RA
• Inlet, perimembranous, anterior malaligned VSD.
• Preferable because it is the most innocuous approach.

• Retraction of TV necessary. Occasionally partial removal and then resuspension of TV is employed.
RV
• Anterior malaligned (TOF)

• Perimembranous/inlet if cannot be closed via RA approach.
• Division/resection of muscle bundles easily performed from RV.

• Risk of RV dysfunction or dysrhythmias.
Transpulmonary
• Outlet
  
Transaortic
• VSD associated with DORV or when concomitant aortic valve repair (valvuloplasty) or subaortic resection is needed.
• Higher incidence of heart block when VSD closed via this approach.
LV
• Rarely muscular
• Risk of LV dysfunction or dysrhythmias.

DORV, double-outlet right ventricle; LV, left ventricle; LV, left ventricular; RA, right atrium; RA, right atrial; RV, right ventricle; RV, right ventricular; TOF, tetralogy of Fallot; TV, tricuspid valve; VSD, ventricular septal defect.


TABLE 8-4 BASIC ECHOCARDIOGRAPHIC PRINCIPLES WHEN IMAGING PATIENTS WITH A VENTRICULAR SEPTAL DEFECT


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TABLE 8-5 BASIC ECHOCARDIOGRAPHIC PRINCIPLES WHEN IMAGING SPECIFIC VENTRICULAR SEPTAL DEFECTS

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Perimembranous Defects (Figure 8-9A)



• Also known as infracristal, subaortic, paramembraneous, conoventricular.

• Owing to the Venturi effect from VSD flow, the right coronary cusp (RCC) and noncoronary cusp (NCC) are at risk of prolapse with the development of aortic insufficiency (AI).

• Defect may be partially/completely closed with TV tissue that appears aneurysmal (see Video 8-3 on the Expert Consult website).

• Reoperations for residual VSD, AI.

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Figure 8-9 A, Perimembranous VSD. 2D and CF Doppler ME AV LAX with the probe turned rightward. There is a high-velocity restrictive VSD adjacent to the RCC in the LV and the TV in the RV. Note that the RCC is prolapsing into the defect. Ao, aorta. B, Outlet VSD. 2D and CF Doppler modified ME AV SAX demonstrates a VSD immediately underneath the PulmV. The RCC is prolapsing into the defect, although there is no AI seen (clip taken in diastole).



Inlet Defects (Figure 8-10)



• Also known as AV canal type, inlet muscular.

• Often part of an atrioventricular canal (AVC) defect or a component of heterotaxy syndrome.

• Adult presentation is rare unless PS is present.

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Figure 8-10 A, Inlet VSD. ME 4C view shows a defect immediately underneath the AVV. There is an overriding TV with more than 50% of the TV opening into the LV (the stippled yellow line marks where the crest of the septum would line up with the AVV). There are also straddling chords that are not well seen in this image (see text). B, Inlet VSD as part of an AVC defect. 2D and CF Doppler ME 4C views show an inlet VSD and the associated primum ASD and common AVV. The direction of flow through the VSD is away from the LV (L→R).



Outlet Defects (see Figure 8-9B)



• Also known as subpulmonary, supracristal, doubly committed subarterial, infundibular, conal.

• Owing to the Venturi effect from VSD flow, the RCC is at risk of prolapse with the development of AI.

• Reoperations for AI.


Muscular Defects (Figure 8-11)



• May be difficult to locate especially if there are multiple defects in the trabeculated RV apex.

• Defect may partially/completely close with surrounding muscle.

• Reoperations for residual VSD.

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Figure 8-11 A, Muscular VSD. CF Doppler ME AV LAX view shows a muscular VSD in a heavily trabeculated part of the mid septum. There is a left to right shunt and it is likely large given the low-velocity flow. Note also there is LV enlargement. B, CF Doppler ME 4C view shows a high-velocity restrictive VSD in the mid septum.



Malalignment Type (Figure 8-12)



• Outlet (infundibular) septum is deviated anteriorly or posteriorly and fails to join the IVS, resulting in a VSD and outflow tract obstruction.

• Anterior deviation, typical in TOF, causes VSD and right ventricular outflow tract obstruction (RVOTO).

• Posterior deviation, typical of interrupted aortic arch, causes VSD and LVOTO.

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Figure 8-12 A, Anterior malaligned VSD. ME AV LAX shows the outlet septum deviated anteriorly resulting in a VSD and RVOTO. This patient had TOF. B, Posterior malaligned VSD. ME AV LAX view shows the outlet septum deviated posteriorly into the LVOT resulting in a VSD and LVOTO. This patient had an interrupted aortic arch.



Principles of Surgical Management



• TV repair/annuloplasty ring may be necessary if RV dilation/hypertension has caused moderate to severe TR.

• Aortic prolapse can usually be repaired but occasionally requires valve replacement.

• Surgical closure of VSD is with a synthetic patch via a right atrial (RA), RV, infundibular (transpulmonary), transaortic, and rarely, LV approach (see Table 8-3).

• Devices are not yet approved for routine closure of VSDs, although devices for closure of muscular and perimembranous defects are available. Hybrid approach with catheter access through a right ventriculotomy with TEE guidance is useful in some cases of apical muscular VSD.

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Figure 8-13 CW Doppler of ME AV LAX view in a patient with a perimembranous VSD. CW is aligned as parallel as possible to the direction of the jet and the peak velocity is used to calculate RVP = LVP – 4Vvsd2. SBP is used as LVP, assuming there is no LVOTO. As RVP nears LVP, the defect becomes unrestrictive and the velocity decreases.



Postoperative TEE Assessment after Primary or Revision Ventricular Septal Defect Repair



Step 1: Look for evidence of a residual VSD
• Residual VSD flow should be high velocity with right ventricular pressure (RVP)/left ventricular pressure (LVP) less than 0.5 to 0.6 and a size less than 25% of the diameter of the aortic annulus are ideal. Reexamine the entire IVS because the decrease in RVP can “unmask” another VSD or DCRV.

Step 2: Examine the TV apparatus, PulmV and aortic valve (AV) for evidence of injury or inadequate repair
• Look for prolapse, perforation of a cusp, or poor resuspension of TV around annulus. Less than mild AI, TR is ideal after repair.

Step 3: Examine biventricular function especially after ventriculotomies
• New or worsening ventricular dysfunction can be secondary to the ventriculotomy or injury to a coronary artery.

Step 4: Measure pulmonary artery pressure (PAP)


Atrioventricular Canal Defects (Table 8-6)



TABLE 8-6 BASIC ECHOCARDIOGRAPHIC PRINCIPLES WHEN IMAGING PATIENTS WITH REPAIRED OR UNREPAIRED ATRIOVENTRICULAR CANAL DEFECTS


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Key Points



Primum ASD



• Also called a partial AVC (see “Atrial Septal Defects” section)


Transitional Canal



• Adult presentation possible.

• Includes primum ASD, cleft MV, restrictive VSD (Figure 8-14).

• Reoperations for atrioventricular valve repair (AVVR), LVOTO

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Figure 8-14 Schematic of the AVVs. A, A normal heart. B, CAVC defects. In the most common configuration, there is a common AVV with five leaflets including two right-sided lateral leaflets, one left-sided lateral leaflet, and superior and inferior leaflets that bridge the IVS. During surgical repair, the atrial and ventricular defects are closed and are fashioned to separate the valves. In addition, the cleft is closed. C, Primum and transitional AVC defects. There is a cleft in the left-sided AVV, which is usually closed during repair. IVS, interventricular septum; Lt AVV, left atrioventricular valve; Rt AVV, right atrioventricular valve; PL, posterior leaflet (of the MV).


A and B, Modified and reprinted with permission from Seale A, Shinebourne EA. Cardiac problems in Down’s syndrome. Curr Paediatr. 2004;14:33-38.



Common Atrioventricular Canal



• Includes a primum ASD, a large inlet VSD, and a common atrioventricular valve (AVV).

• Common in trisomy 21. Surgery between 4 and 6 months of age. Early development of Eisenmenger’s in nonoperated patients. Adult presentation only if patient has concomitant RVOTO.

• Single AVV has multiple leaflets: an anterior (superior) and posterior (inferior) leaflet that bridge the IVS and several lateral leaflets (see Figure 8-14; see Video 8-4 on the Expert Consult website).

• AVV is often described as right- or left-sided AVV.

• SV repair is necessary in patients with straddling chords or in patients with an unbalanced AVC (the VSD separates the heart unevenly so that one ventricle, usually the LV, is too small).

• Associated lesions: tetralogy of Fallot (TOF), heterotaxy syndrome.

• Reoperations for residual VSD, AVVR, LVOTO.


Principles of Surgical Management



• A one- or two-patch technique or the so-called Australian technique (stitch closure of VSD with patch closure of ASD) is used to close the septal defects and bridge the anterior and posterior leaflets.

• The atrial patch is usually placed so that the CS drains into the LA. An LSVC draining to the CS would preclude that.

• MV clefts are usually closed unless it would result in significant mitral stenosis (MS).

• When repaired in infancy, may have to accept even moderate residual regurgitation in order to avoid AVV stenosis or early valve replacement because morbidity/mortality is significantly increased when MVR is performed at less than 2 years. Approximately 15% of patients require reoperations for AVVR. Complex techniques often required for revision MVR (see section on “Primum Atrial Septal Defect”). MVR may be necessary in older patients.

• Significant LVOTO may require a simple resection or more aggressive intervention (see section on “Left Ventricular Outflow Tract Obstruction”).


Postoperative TEE Assessment after Atrioventricular Canal Repair



Step 1: Visualize the ASD/VSD patch
• Verify the absence of atrial/ventricular level shunts.

• AVV without stenosis or regurgitation. At most, trace regurgitation is ideal.

Step 2: Measure PAP if TR is present

Step 3: Assess biventricular function
• LVOTO without significant stenosis.


Tetralogy of Fallot




Key Points



All Tetralogy of Fallot (Tables 8-7 and 8-8)



• Consists of RVOTO, an anterior malaligned VSD, right ventricular hypertrophy (RVH), and overriding aorta (<50% overrides the VSD). The VSD is almost always large and unrestrictive. There may be additional muscular VSDs (Figure 8-15).

• RVOTO may be multifactorial including a subpulmonary component, infundibular narrowing, PulmV annular hypoplasia, PS, and PA or branch PA hypoplasia. Rarely, there is also DCRV.

• Associated defects: PFO, ASD, additional muscular VSDs, aortopulmonary collateral arteries (APCs).

• There is a 25% incidence of right aortic arch (the arch goes over the right bronchus, but this is not seen by TEE).

• Coronary artery anomalies are common. In approximately 3%, the left anterior descending (LAD) comes from the right coronary artery (RCA) and crosses the RVOTO.

• Patients with conotruncal abnormalities (TOF, transposition of the great arteries [TGA], truncus arteriosus) can develop dilatation of the ascending aorta, which may progress and become a risk for rupture or dissection. It may also cause AI.

TABLE 8-7 PRINCIPLES OF SURGICAL/INTERVENTIONAL MANAGEMENT





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Jun 11, 2016 | Posted by in CARDIOLOGY | Comments Off on Congenital Heart Disease

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