Approach Considerations
Provide routine medical care with special attention to signs of congestive heart failure (CHF) or increased pulmonary vascular resistance (PVR). Most patients with an atrial septal defect (ASD) are asymptomatic and require only routine well-child care until they undergo elective surgical repair or transcatheter device placement for their defects.
Most children with uncomplicated atrial septal defects are followed up by their primary care provider and receive follow-up with a pediatric cardiologist every year or every other year. Children who require medical intervention or who have other comorbidities are seen by a cardiologist more frequently.
Transfer
An isolated atrial septal defect almost never causes clinically significant problems in the neonatal period or in infancy. Refer a child who is to have elective atrial septal defect surgical repair or transcatheter intervention to a pediatric center with experience in performing cardiopulmonary bypass and surgical atrial septal defect closure or catheter based procedures in young children.
A patient with an ostium primum atrial septal defect may have associated clinically significant AV valve insufficiency and may require earlier surgical intervention. Refer this patient to a center with experience in the evaluation and repair of this problem.
Any attempt at closure with a transcatheter device should be performed at a center with experience in pediatric interventional cardiology with surgical support. Additionally, since some atrial septal defects are detected outside of childhood, transcatheter interventions in adults are often performed by adult interventionalists with the assistance of a pediatric interventionalist. Adult interventionalists may be very comfortable with transcatheter patent foramen ovale closure, but not as familiar with the nuances of true atrial septal defect device closure, especially larger defects.
Medical Care
Medical therapy is of no benefit in children with asymptomatic atrial septal defects (ASDs). With the exception of ostium secundum types, atrial septal defects are structural defects that do not spontaneously close. Surgical closure is ultimately required for most atrial septal defects, other than ostium secundum atrial septal defects. Occasionally, small primum ASDs may not require closure, but due to their association with mitral valve abnormalities, they may be closed at the time of mitral valve repair, if such a repair is indicated. An ostium secundum atrial septal defect that measures 6 mm in diameter or smaller in the patient's first year of life is likely to spontaneously close; however, such closure is substantially slower than that of a typical small, muscular ventricular septal defect.
Infants who are severely affected with an atrial septal defect and who develop congestive heart failure (CHF) may be treated as any other child with CHF from a left-to-right shunt. This treatment, which includes diuretics, afterload reduction, and less commonly, digoxin, is covered in other articles. As noted previously, it is of particular importance to rule out other etiologies of symptoms in these infants, especially those with secundum ASDs, due to the typical paucity of symptoms associated with this lesion in infancy and early childhood.
Arrhythmias associated with atrial septal defect are similarly uncommon in childhood become increasingly common with age. In fact, the development of atrial fibrillation may trigger CHF in adults with atrial septal defect who are younger than 40 years. Arrhythmias may result from atrial distention, and these individuals may require antiarrhythmic therapy until the atrial septal defect is repaired. In some cases, arrhythmias may persist after repair due to the chronicity of the right atrial dilation.
Some children with an atrial septal defect present with recurrent respiratory tract infections, which may be poorly tolerated. If immunologically normal, these children are not at a higher risk for infection in general, but the chronically increased pulmonary blood flow, when combined with the inflammatory changes associated with lower respiratory tract infections, can lead to prolonged symptoms and altered cardiopulmonary interactions.
Bacterial endocarditis prophylaxis is not necessary for the typical patient with an isolated atrial septal defect, although the ostium primum type of atrial septal defect may need subacute bacterial endocarditis prophylaxis because of the associated mitral valve abnormality. Prophylaxis is recommended prior to surgical repair if the atrial septal defect is part of complex cyanotic congenital heart disease (CCHD). Endocarditis prophylaxis is recommended for 6 months following either surgical or percutaneous repair of atrial septal defects and, in some instances, may be recommended for longer in patients with residual mitral valve abnormalities after surgical repair of primum atrial septal defects. Additionally, endocarditis prophylaxis is recommended indefinitely for any persistent residual shunting detected by echocardiography after surgical or device closure. For more information see Antibiotic Prophylactic Regimens for Endocarditis.
Surgical Care
Definitive therapy for an atrial septal defect (ASD) has historically been limited to surgical closure. However, with the advent of transcatheter techniques, [23, 24, 25] many children undergo successful treatment in the cardiac catheterization laboratory. [26]
The most common surgical approach to the defect is primary repair with suture closure or with patch repair (generally with glutaraldehyde treated autologous pericardium, Gore Tex patch or fabric made of polyester fiber [Dacron]).
Not all children with an atrial septal defect are candidates for surgery, which is only indicated for those children with clinically significant left-to-right shunting. In general, a pulmonary-to-systemic flow ratio of 1.5:1 or more is considered the principal indication for surgical repair. Shunting less than this in children with small defects and in those with existing pulmonary hypertension may be observed. Because cardiac catheterization is rarely necessary, echocardiographic evidence of right atrial and right ventricular enlargement is usually considered evidence of a clinically significant left-to-right shunt and an indication for surgical closure of the atrial septal defect.
Surgery is ideally performed in children aged 2-4 years and has a very low mortality rate. However, surgery may be performed earlier than this if the child has evidence of CHF. Surgery can be deferred until later in childhood if there is a specific family preference without adding any substantial risk by delaying intervention.
Newer, minimally invasive surgical techniques have been developed. These improve cosmetic appearances and decrease hospital stays. These techniques are ideally suited for simple closure of a secundum atrial septal defect. [27]
The surgical mortality rate is low in patients with uncomplicated atrial septal defects. In an experienced pediatric center, the mortality rate should be less than 1%.
Postoperative morbidity in individuals with atrial septal defects is almost exclusively due to accumulation of pericardial fluid (postpericardiotomy syndrome), which occurs in approximately one third of patients. On occasion, tamponade occurs and requires pericardiocentesis. Pericardial effusion should be suspected in any pediatric patient who undergoes postsurgical repair of an atrial septal defect and who presents with chest pain, fever, shortness of breath, or general malaise. In young children, symptoms may be nonspecific and include irritability and decreased appetite.
Transcatheter approaches to atrial septal defect closure are well accepted in the pediatric population. Secundum atrial septal defects are currently the only subtype of atrial septal defect that are amenable to this approach. The preference for timing of catheter-based closure is institution/interventionalist specific, but generally around age 4-6 years with a known, hemodyanmically significant defect. Catheter-based intervention has been successful in smaller children. [28]
Such techniques require individuals with considerable expertise in the field of interventional pediatric cardiology and cooperation between the interventionalist and the noninvasive imaging specialists. For a detailed description of the procedure and results in children [3, 29, 30] and adults, [31] the reader is referred to these publications in the References section.
Benefits of the transcatheter approach include its minimal invasiveness, the lack of median sternotomy, the avoidance of cardiopulmonary bypass, and the relatively quick recovery time. Potential drawbacks and concerns include residual shunting around the device, embolization during placement requiring surgical intervention, lack of adequate septal rims to properly seat the device and the need for specific technical expertise and equipment.
Long-term safety concerns are noted because device placement in smaller children is still relatively new. There has been some recent concern regarding device erosion of surrounding tissue, which is not limited to the pediatric population. [32] Further follow-up should provide additional information regarding optimal patient selection, as well as longer-term prognosis of the catheter-based approach. Overall however, the medium- to long-term outcomes of atrial septal defect closure, either surgically or percutaneously, appear very good. [33]
For patients with ostium primum atrial septal defects and sinus venosus atrial septal defects, surgical closure is necessary owing to the need to address mitral valve cleft and anomalous pulmonary venous return, respectively. Surgery is also the procedure of choice for most coronary sinus atrial septal defects, although very small defects may be addressed by transcatheter methods. [34]
Consultations
Diagnosis of an atrial septal defect (ASD) in a newborn or an older child should prompt consultation with a pediatric cardiologist.
Almost all newborns have a small left-to-right shunt at the foramen ovale, as detected during echocardiography in the neonatal period. In the absence of a murmur or other signs of a true atrial septal defect on subsequent well-child care visits, consultation with a cardiologist is probably not necessary, although review of the initial echocardiogram report is prudent to verify the description of the defect.
When closure of the atrial septal defect is considered, an interventional pediatric cardiologist should be consulted.
Activity
Children with atrial septal defects (ASDs) generally have no restrictions on their activity. Children with compensated congestive heart failure with an atrial septal defect are candidates for surgical or catheter-based intervention and should be able to resume normal activity after the defect is corrected. Following transcatheter occlusion, restriction of physical activity for several months after occlusion is suggested.
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Subcostal echocardiographic view of a child with a secundum atrial septal defect (ASD). Note the position of the defect in the atrial septum. LA = left atrium; RA = right atrium; SVC = superior vena cava.
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Subcostal long-axis view of the same child as in the previous image with a secundum atrial septal defect (ASD). LA = left atrium; RA = right atrium; RUPV = right upper pulmonary vein.
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Parasternal short axis view of a child with a secundum atrial septal defect (ASD). AO = aorta; LA = left atrium; RA = right atrium.
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Apical echocardiographic view of a primum atrial septal defect (ASD). Note the position of the defect when compared with a secundum ASD. LA = left atrium; LV = left ventricle; RA = right atrium; RV = right ventricle.
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Apical echocardiographic view of a primum atrial septal defect (ASD). Note that the atrioventricular valves are at the same level (instead of mild apical displacement of the tricuspid valve), which is seen in the spectrum of atrioventricular canal defects. LA = left atrium; LV = left ventricle; RA = right atrium; RV = right ventricle.
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Apical color Doppler echocardiographic view of a primum atrial septal defect (ASD). Note the flow across the defect from the left atrium to the right atrium (RA), and note the mitral regurgitation (MR) through a cleft in the anterior leaflet of the mitral valve. LV = left ventricle; MV = mitral valve.
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Subcostal short-axis view of a child with a sinus venosus atrial septal defect (ASD). Note the position of the defect compared with that of a secundum or primum ASD. Also note the anomalous position of the right upper pulmonary vein (RUPV). LA = left atrium; RA = right atrium.
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Electrocardiographs (ECGs) from a child with a secundum atrial septal defect (ASD). Note the right-axis deviation and rSR' pattern in lead V1.
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Electrocardiogram (ECG) from a child with a primum atrial septal defect (ASD). Note the left-axis deviation with a counterclockwise vector of depolarization (small q waves in leads I and aVL) and right ventricular hypertrophy and/or volume overload (rSR' pattern and upright T wave in lead V1).
