Congenital heart disease Flashcards
What is the incidence and prevalence of ASD?
approximately 10 to 15 percent of congenital heart disease, with a reported birth prevalence of approximately 1 to 2 per 1000 live births
How are ASDs classified?
ASDs are classified based on their anatomic location, which generally reflects the abnormality of embryogenesis that led to the anomaly :
●Primum ASD
●Secundum ASD
●Sinus venosus ASD
●Coronary sinus ASD
Patent foramen ovale (PFO) is also an open communication between the right and left atria; however, a PFO is not considered an ASD, because no septal tissue is missing
Describe the development of the right atrial septum
The septation of the atria begins as early as the fifth week of gestation and involves three structures: septum primum, septum secundum, and the atrioventricular (AV) canal septum, which is made up in part by the superior and inferior endocardial cushion.
Describe the normal development of the atrial septum
- septation of the atria begins as early as the fifth week of gestation and involves three structures: septum primum, septum secundum, and the atrioventricular (AV) canal septum, which is made up in part by the superior and inferior endocardial cushion.
- The septum primum arises from the superior portion of the common atrium and grows caudally towards the AV canal septum (eg, the endocardial cushions) located between the atria and ventricles. The fusion between the septum primum and the endocardial cushions closes the orifice (ostium primum) separating the right and left atria.
- A second orifice (the ostium secundum) develops in the septum primum; this orifice is covered by the septum secundum that arises on the right atrial side of the septum primum. The septum secundum grows caudally and covers the ostium secundum forming the fossa ovalis. However, the septum secundum does not completely divide the atria in the fetus; it leaves an oval orifice (the foramen ovale) that is covered (but not sealed) on the left side by the flexible flap of the septum primum
Describe primum defects
The primum-type ASD develops if the septum primum does not fuse with the endocardial cushions, leaving a defect at the base of the interatrial septum that is usually large. This type of defect accounts for 15 to 20 percent of ASDs. Primum ASDs are usually not isolated, typically being associated with AV canal defects that include anomalies of the AV valves and ventricular septal defects
Describe secundum defects
Secundum ASDs are typically located within the fossa ovalis (remnant of the foramen ovale in the right atrium). This type of ASD can result from arrested growth of the secundum septum or excessive absorption of the primum septum. Multiple defects can be seen if the floor of the fossa ovalis is fenestrated. The defects vary greatly in size, from less than 3 mm to greater than 20 mm. Secundum ASDs typically present as an isolated cardiac defect, though they may be contiguous with other ASDs, such as a sinus venosus defect or a primum defect. Some patients with secundum ASD have functional mitral valve prolapse, perhaps related to a change in the left ventricular geometry associated with right ventricular volume overload.
Secundum defects account for approximately 70 percent of all ASDs and occur twice as often in females as in males. The familial recurrence rate has been estimated to be approximately 7 to 10 percent. In a comprehensive literature review, the median reported incidence was 5.64 per 10,000 live births. However, the true incidence of secundum ASD may be substantially higher because many ASDs are commonly undiagnosed in infancy and childhood, and spontaneously resolve.
What is Holt-Oram syndrome? What genetic mutation is most commonly involved?
autosomal dominant disorder characterized by upper limb defects (deformities of the radius, carpal bones, and/or thumbs) and cardiac septal defects, most commonly a secundum ASD. Cardiac conduction disturbances, including complete heart block, are also common.
Holt-Oram syndrome is genetically heterogeneous; mutations in the TBX5 gene are the most common cause.
What genes other than TBX 5 have been linked to familial isolated ASDs?
GATA4, MYH6, and NKX2-5
What congenital syndomes other than Holt-Oram syndrome are associated with secundum ASDs?
Noonan syndrome, Treacher Collins syndrome, and the thrombocytopenia-absent radii syndrome
Describe sinus venosus defects (ASDs)
Sinus venosus ASDs are characterized by malposition of the insertion of the superior or inferior vena cava straddling the atrial septum. The interatrial communication is within the mouth of the overriding vein and is outside the area of the fossa ovalis. Sinus venosus defects account for approximately 5 to 10 percent of ASDs.
Describe superior sinus venosus defects
●Superior sinus venosus defects (sometimes called superior vena caval defects) are located in the atrial septum immediately caudal to the orifice of the superior vena cava. The right upper lobe and middle lobe pulmonary veins often connect to the junction of the superior vena cava and right atrium, resulting in a partial anomalous pulmonary venous connection
Describe inferior sinus venosus defects
●Inferior sinus venosus defects, also known as inferior vena caval defects, are less common. They are located in the atrial septum immediately cranial to the orifice of the inferior vena cava. Inferior sinus venosus defects are often associated with partial anomalous connection of the right pulmonary veins.
Describe coronary sinus defects (ASDs)
In coronary sinus ASDs (unroofed coronary sinus), part or the entire common wall between the coronary sinus and the left atrium is absent. This rarer form accounts for less than 1 percent of all ASDs. Many such patients also have a persistent left superior vena cava.
Describe patent foramen ovale
PFOs are identified on autopsy in approximately 30 percent of the adult population. The size of a PFO can range from 1 to 10 mm in maximal potential diameter. A PFO is not considered an ASD, because no septal tissue is missing. Interatrial shunting generally does not occur as long as left atrial pressure exceeds right atrial pressure and the flap valve remnant of septum primum of the foramen ovale is competent. However, persistent left-to-right shunting frequently occurs in the first few weeks of life. Mild shunting during the neonatal period is common, particularly in premature infants, and is usually considered a normal finding.
What are some cardiovascular defects associated with ASDs?
ASDs are often associated with other congenital cardiac anomalies. Often the associated defect is clinically more important than the ASD itself. However, in some cases, the ASD may contribute substantially to the physiology of the condition. As examples, an ASD permits mixing between the pulmonary and systemic circulations in complete transposition of the great arteries, while in tricuspid atresia, the entire cardiac output passes across the ASD
How are ASDs classified according to size?
●Trivial – <3 mm in diameter
●Small – 3 to <6 mm in diameter
●Moderate – 6 to 8 mm in diameter
●Large – >8 mm in diameter
These absolute measurements are not exact and the relative size of the defect (related to overall heart size) may be more clinically relevant. For example, a 6 mm ASD would be insignificant in an adult but would be of moderate size in a newborn.
Describe the pathophysiology of ASDs with regards to perinatal physiology
In utero, pulmonary arterial blood flow in the fetus is limited by high pulmonary vascular resistance, which results in decreased right ventricular diastolic filling. Instead of traversing the tricuspid valve, much of the blood that flows into the right atrium is shunted across the isolated ASD into the left atrium, similar to the blood flow through the normal patent foramen ovale. At birth, left atrial pressure becomes greater than right atrial pressure, resulting in left-to-right shunting across the defect. Initially, the volume of blood shunted from left to right is small because the right ventricle is still relatively thick-walled and noncompliant. As the right ventricle remodels in response to the decreased pulmonary vascular resistance, its compliance increases and the mean right atrial pressure decreases. As a result, the left-to-right shunting increases in volume.
In some neonates, transient right-to-left shunting may also occur during the cardiac and respiratory cycles, resulting in mild cyanosis. In these patients, there is a drop in atrial pressure at the onset of ventricular contraction due to atrial relaxation that is more rapid in the left than the right atrium. During inspiration, the decrease in intrathoracic pressure results in an increase in systemic venous return and a decrease in pulmonary venous return, decreasing left atrial pressure and increasing right atrial pressure, which results in right-to-left shunting.
Describe the pathophysiology of ASDs with regards to postnatal physiology
With a small ASD, left atrial pressure is slightly higher than right atrial pressure, resulting in continuous flow of oxygenated blood from the left to the right atrium across the defect. The pressure gradient between the two atria and the amount of shunt flow depend upon the size of the defect and the relative distensibility of the right and left sides of the heart. Left-to-right shunting occurs primarily in late ventricular systole and early diastole, with some augmentation during atrial systole. Even when the right and left atrial pressures are equal, as will be seen with a large defect, left-to-right shunting still occurs because of the greater compliance of the right ventricle compared with the left ventricle.
The shunt flow consists of fully oxygenated blood from the left atrium, and constitutes a “useless circuit” of ineffective pulmonary blood flow through the right atrium and ventricle, pulmonary circulation, left atrium and back to the right atrium. Thus, the volume of blood flow in the pulmonary circulation is greater than that in the systemic circulation. The pulmonary flow to systemic flow ratio (Qp/Qs) can be over 3:1 in patients with large defects.
The increased flow leads to right-sided dilatation evident on chest radiograph and echocardiographic imaging. Right ventricular function is also occasionally decreased. The main pulmonary arteries dilate and the pulmonary vascularity is increased. These pulmonary vascular changes may be evident on the chest radiograph, and large vessels in both the lower and upper lobes may be seen.
The right-sided volume overload is usually well tolerated for years. Heart failure is unusual before age 30, but the prevalence increases substantially in older uncorrected patients over time. Other complications in older patients include atrial arrhythmias such as flutter and fibrillation, thought to result from chronic stretching of the atrial muscle and, occasionally, pulmonary arteriopathy leading to progressive pulmonary hypertension resulting in right-to left shunting of blood (ie, Eisenmenger syndrome).
Describe the likelihood of spontaneous closure of ASDs. What ASDs are unlikely to spontaneously close
Spontaneous closure is most likely to occur in patients with small secundum ASDs that are diagnosed during infancy or early childhood. Secundum defects of moderate and large size, types of ASDs other than secundum, and those that are detected later in childhood or adolescence are unlikely to close spontaneously, and some may increase in size over time
Describe the natural history of persistent moderate to large ASDs. What symptoms and signs may they have?
In patients with uncorrected moderate to large ASDs, left-to-right shunting may increase with age, leading to volume overload, heart failure, atrial arrhythmia, and/or pulmonary hypertension. Most patients become symptomatic before 40 years of age. Common symptoms include palpitations reflecting atrial arrhythmias (the most frequent presenting symptom), exercise intolerance, dyspnea, and fatigue. Arrhythmias are thought to result from stretching of the atria by the increased shunting. In some patients, exercise intolerance may develop as early as the second decade of life.
The right-sided volume overload associated with an ASD is usually well tolerated for years. Pulmonary vascular disease develops in approximately 10 percent of older patients with isolated ASDs, but this complication is rare in childhood and adolescence. Elevated pulmonary vascular resistance in infants with ASDs is almost always reversible with correction, unlike the rare complication of fixed pulmonary vascular disease seen in affected adults.
In uncorrected older patients, severe irreversible pulmonary hypertension (Eisenmenger syndrome) may develop and presents with signs of right ventricular failure resulting in right-to-left shunting. Clinical findings include cyanosis, dyspnea with exertion, hepatomegaly, and clubbing of the fingers and toes. These patients are also at risk for paradoxical embolization of clot from the venous system or right atrium via right-to-left shunting into the arterial system.
How might ASDs present overall? is paradoxical embolisation common?
Most ASDs are small and do not cause symptoms in infancy and childhood. They most commonly come to attention because a murmur is detected on physical examination or as an incidental finding on echocardiogram obtained for other reasons
Infants with large ASDs occasionally present with symptoms of heart failure, recurrent respiratory infections, or failure to thrive. Failure to thrive in infants with ASDs may be associated with extracardiac pathology
Paradoxical embolization and resultant embolic stroke is a rare complication of ASDs in pediatric patients
What might be seen on physical exam in ASD?
Depend on size of the defect, degree of shunting, and pulmonary arterial pressure. Characteristic findings include a midsystolic pulmonary flow or ejection murmur accompanied by a fixed split second heart sound (S2)
Describe the murmurs that may be heard with ASD
low velocity shunt flow across the ASD produces insufficient turbulence to be audible itself. However, several other murmurs may be heard
- A midsystolic pulmonary flow or ejection murmur, resulting from the increased blood flow across the pulmonic valve, is classically present with moderate to large left-to-right shunts and may be louder than that attributed to the usual functional murmur. This murmur is loudest over the second intercostal space and is usually not associated with a thrill. The presence of a thrill typically indicates a very large shunt or pulmonic stenosis.
- A murmur of mitral regurgitation may be heard and is due to a cleft mitral valve in ostium primum defects, and mitral valve prolapse in secundum defects. In the latter setting, an apical late or holosystolic murmur of mitral regurgitation radiating to the axilla may be heard.
- A middiastolic murmur of low to medium frequency due to high flow across the tricuspid valve may be heard with careful auscultation in patients with a left-to-right shunt greater than 2:1. A low-pitched diastolic murmur of pulmonic regurgitation may result from dilatation of the pulmonary artery.
Describe the classic S2 component of murmur in ASD
In contrast to the normal variation in S2 splitting during the respiratory cycle, patients with ASDs typically have a wide fixed split. The fixed split of S2 occurs because the atrial defect equalizes the respiratory effect on both right and left ventricular output. The widening of the split is due to prolonged emptying of the enlarged right ventricle which delays pulmonic closure. A relatively wide (though not fixed) S2 split is common in healthy individuals in the supine position. Therefore S2 should be evaluated in both the supine and sitting or standing position.
What signs of heart failure might be seen with ASDs?
In patients with large ASDs, signs of heart failure (eg, tachypnea, rales, failure to thrive, hepatomegaly) may be seen
What signs of right atrial enlargement might be seen in ASDs?
- A large left-to-right shunt may result in a precordial bulge due to atrial enlargement.
- In some, atrial enlargement leads to chest deformity with transverse depressions along the sixth and seventh costal cartilages at the site of attachment of the anterior part of the diaphragm, known as Harrison grooves.
- Patients with large left-to-right shunts also may have a hyperdynamic right ventricular impulse that results in a right ventricular heave. This is most pronounced along the left sternal border and in the subxiphoid area.
Can pulmonary hypertension occur in ASDs?
Pulmonary hypertension (PH) is unusual in pediatric patients with ASDs but can occur. Patients with PH usually have an accentuated pulmonic component of S2
What are some ECG findings in ASD?
- may be normal in a child with an uncomplicated ASD and a small shunt.
- moderate to large degree of shunting –> the QRS complex is often slightly prolonged and has a characteristic rSr’ or rsR’ pattern in V1 (often described as incomplete right bundle branch block). This pattern is thought to result from enlargement of the right ventricular outflow tract, which is the last portion of the ventricle to depolarize. Alternatively, it may result from stretching of peripheral specialized conduction fibers secondary to right ventricular outflow tract distension.
- Patients with increasing PH tend to lose the rSr’ and develop a tall monophasic R wave with a deeply inverted T wave.
- Notching of the peak of the R wave in the inferior leads (a pattern called “crochetage”) has been described in patients with an ASD.
What P wave changes might you see on ECG in ASD?
P wave is typically normal with secundum ASDs. In comparison, sinus venosus ASDs are often associated with a leftward frontal plane P wave axis (ie, negative in leads III and aVF, and positive in lead aVL). This leftward shift is caused by an ectopic pacemaker resulting from an ASD located near the sinus node. Right atrial enlargement may be reflected by increased P wave voltage. Sinus node dysfunction may develop in early childhood
What PR interval changes might you see on ECG in ASD?
The PR interval may be prolonged and increases with increasing age. First degree atrioventricular (AV) block can occur in any type of ASD but is classically present in ostium primum defects in association with complete right bundle branch block and left anterior fascicular block. The rim of the ostium primum defect is in close spatial relationship to the His bundle, accounting for abnormalities of impulse conduction through this area.
What QRS changes might you see on ECG in ASD?
The frontal plane QRS axis often ranges from +95° to +135° (right axis deviation) with a clockwise loop. Left axis deviation of the QRS axis with a counterclockwise frontal plane loop can occur with uncomplicated secundum ASD, although it usually suggests the presence of an AV canal defect.
What CXR findings might you see in patients with ASD?
- With small ASDs, the chest radiograph is typically normal.
- In patients with an isolated secundum ASD with a large left-to-right shunt, chest radiography findings include cardiac enlargement and increased pulmonary vascularity. The increase in pulmonary vascularity typically extends to the periphery of the lung fields, and the pulmonary trunk and central branches appear dilated. The heart often has a characteristic triangular appearance because the enlarged pulmonary arteries prevent the normal-diameter ascending and transverse aorta from forming the heart border. The right atrium and ventricle are usually enlarged, while the left atrium and left ventricle are normal.
Describe prenatal diagnosis of primum ASD
●Primum ASD – Prenatal ultrasounds by experienced fetal echocardiographers (Level III Fetal Ultrasound) can usually diagnose primum ASDs in the fetus at 18 to 22 weeks gestation. Advances in technology have enabled some specialized centers to identify primum ASDs in the first trimester, but the accuracy of detection remains low even in these centers.
Describe prenatal diagnosis of secundum ASD
●Secundum ASD – The more common secundum ASD cannot be reliably detected by fetal echocardiography, since the normal fetus has a sizable patent foramen ovale (PFO), and distinguishing between a small to moderate size secundum ASD and a PFO with right-to-left flow is usually not possible. However, the presence of very large secundum ASD may be suspected on fetal echocardiography but must be confirmed by postnatal echocardiograms.
Describe the prenatal diagnosis of sinus venosus and coronary sinus ASDs
●Sinus venosus and coronary sinus ASDs – Experienced fetal echocardiographers may be able to detect sinus venosus ASDs and coronary sinus ASDs. However, the sensitivity and specificity of fetal ultrasound for identification of these more unusual types of atrial septal defect is not known.
Describe the postnatal diagnosis of ASDs
An isolated ASD may be clinically suspected based upon findings on physical examination (midsystolic pulmonary flow or ejection murmur and fixed splitting of the second heart sound and electrocardiogram (incomplete right bundle branch block. The diagnosis is confirmed by echocardiography.
What is the role of echo in ASD diagnosis. Compare and contrast TTE vs. TOE
test of choice for the diagnosis of ASD. Transthoracic echocardiography (TTE) is usually definitive in diagnosing secundum ASDs. Shunt volume, shunt ratios, and pulmonary artery pressures can be estimated with Doppler flow echocardiography
Although TTE is usually adequate to identify the presence of an ASD and determine its overall size, transesophageal echocardiography (TEE) is often necessary to precisely measure ASD margins at the time of catheter closure of secundum ASDs. TEE is generally superior to TTE in measuring the size and position of ASDs, diagnosing sinus venosus defects (image 5), and assessing for other abnormalities such as anomalous venous connection.
In addition, TEE more precisely measures ASD margins and, on occasion, may determine that the ASD rims are inadequate for catheter device closure.
Finally, not all patients have good acoustic windows for adequate TTE visualization. False dropout of the thin fossa ovalis region of the atrial septum can occur even in childhood. Thus, TEE prior to planned surgical or percutaneous closure can provide an additional level of diagnostic assurance and sometimes prevent unnecessary therapeutic procedures.
What is the role of MRI in diagnosing ASD?
Magnetic resonance imaging (MRI) can be helpful in selected cases with suspected associated defects such as partial anomalous pulmonary venous connection or in patients in whom there are inconclusive echocardiographic findings. MRI can also provide accurate quantitation of ventricular volumes, and of pulmonary and systemic flow when this information is required
What is the differential diagnosis of ASDs?
The differential diagnosis of isolated ASDs includes other cardiac conditions that present as an incidental finding of a cardiac murmur in asymptomatic children. Although other physical findings (eg, fixed second heart sound) and electrocardiographic findings of incomplete right bundle branch block suggest ASD, echocardiography conclusively distinguishes these conditions from ASD.
●Pulmonic stenosis
●Innocent or functional murmurs
●Aortic stenosis
●Ventricular septal defect
●Patent ductus arteriosus
●Mitral stenosis
Describe the physiology of the foramen ovale
In the fetus, the foramen ovale is held open by the pressure gradient between the right and left atria. Right atrial pressure is higher than that on the left and pushes the flexible septum primum aside, permitting right to left flow of oxygenated blood from the inferior vena cava into the left ventricle. At birth, expansion of the lungs lowers right heart pressures at the same time that systemic vascular resistance rises, causing reversal of the atrial gradient. The septum primum is then held against the septum secundum and the interatrial shunt ceases.
In approximately 70 percent of individuals, the septum primum and septum secundum fuse during infancy or early childhood, creating an intact interatrial septum; the remnant of the foramen ovale in the right atrium is termed the fossa ovalis. However, in a significant minority of the population, the septae do not fuse. If the foramen ovale is completely covered, but not sealed, it is called a PFO, indicating that the foramen can be opened (by a reversal of the interatrial pressure gradient or by an intracardiac catheter)
What factors impact the functional consequences of ASDs?
- anatomic location of the defect
- size
- presence or absence of other cardiac anomalies
- systolic and diastolic function of the ventricles
What are some important consideration when managing a child with an isolated ASD?
●Size, degree of shunting, and persistence of the ASD
●Likelihood of spontaneous closure
●When closure is indicated, deciding between surgical and percutaneous transcatheter closure
Describe measurement of shunt ratio and how this is important in managing ASD patient
The main indication for ASD closure has been the presence of a left-to-right shunt sizable enough to result in clinically significant right heart overload. This typically occurs in patients with moderate to large ASDs. The usual clinical standard for repair is a measured shunt ratio of pulmonary to systemic flow (Qp/Qs) >2:1, though high quality evidence supporting this threshold is generally lacking. Other experts in the field have advocated lower thresholds of 1.7:1 and 1.5:1
How do you measure shunt ratio?
- Cardiac catheterization is considered the gold standard for measuring Qp/Qs
- Phase contrast magnetic resonance imaging (MRI) in experienced hands appears to be at least as good as the standard Fick technique for measuring shunt flow with blood samples obtained at catheterization
- Pulsed Doppler echocardiography is now routinely used in sites that have established an acceptable correlation between echocardiographic and catheterization laboratory or MRI estimates of shunt flow.
- Because echocardiography and MRI are noninvasive, these techniques easily permit serial monitoring.
How do you manage ASD if Qp/Qs isnt available?
- echocardiographic evidence of substantial right heart enlargement
- qualitative color and spectral Doppler findings of a large amount of left-to-right shunting through the ASD, can be sufficient to justify ASD closure. In addition, the following findings support ASD closure, though these are not sufficient in isolation:
●Evidence of right ventricular hypertrophy on electrocardiogram
●Auscultatory finding of a tricuspid flow rumble by an experienced clinician
●Increased heart size and pulmonary vascularity on chest radiograph
Do small isolated secundum ASDs close? When? Should these defects be closed?
- majority of isolated small secundum ASDs close spontaneously by two years, and some as late as five years of age
- in the absence of associated symptoms, early closure is not indicated for these defects
because there is a a small possibilityof spontaneous closure during the first two years of life, intervention to close even moderate and large isolated secundum ASDs is generally deferred until after the age of two years in asymptomatic patients
What types of ASDs are unlikely to close spontaneously?
- Secundum defects of moderate and large size
- types of ASDs other than secundum
Should small persistent ASDs w/o symptoms be closed?
- do not suggest closure.
- evidence supporting a benefit of ASD closure in this setting is generally lacking.
- risk of paradoxical embolism through a small ASD or valve-competent patent foramen ovale (PFO) is uncertain.
- The benefit of ASD closure in reducing the risk of embolism must be weighed against the short- and long-term risks of the procedure for closure. Procedure risks are changing as closure techniques continue to improve with decreasing morbidity.
- Closure is recommended by many clinicians in older adult patients with a small ASD or PFO who have experienced embolic strokes or transient ischemic attacks
When is closure of ASDs typically recommended?
In patients with a persistent moderate or larger defect, left-to-right shunting usually increases with age if the defect is not corrected. In these patients, we recommend closure if there is significant shunting
How do we differentiate between ASD and PFO?
- presence or absence of a tissue flap partially occluding the opening of the atrial septum. Openings with a tissue flap are defined as PFO, and those without a tissue flap are defined as secundum ASD.
- defect size or position in the atrial septum to differentiate between ASD and PFO. Caution should be employed when using absolute defect diameter for classification in premature infants, because the physiologic effect of defect size varies with patient size.
Because of the lack of uniformity in subjective interpretations of echocardiograms, and because pediatric cardiology practice standards differ, primary care clinicians should seek pediatric cardiology advice regarding the necessity for follow-up when receiving an echocardiographic report identifying an ASD or a borderline classification such as “PFO/ASD.”
Does PFO need to be followed up?
- follow-up is generally not necessary.
- medical follow-up of asymptomatic patients with PFO does not appear to have any benefit.
- Many PFOs spontaneously close during childhood and adolescence, and most of the PFOs that persist into adulthood never cause problems.
- Requiring routine follow-up for such children may cause undue anxiety regarding rare complications that can be associated with PFO later in adulthood (eg, paradoxical embolus and decompression illness).
- Furthermore, given the high prevalence of PFO, medical follow-up of all PFOs would be burdensome on a population basis.
Do trivial ASDs need to be followed up? What defines a trivial ASD?
children with trivial secundum ASDs (<3 mm) do not require specific follow-up.
Which ASDs require follow-up?
- The child in whom a clinically significant ASD is detected should be followed regularly by a pediatric cardiologist.
- Clinically significant ASDs include:
- secundum ASDs with a maximal diameter of ≥3 mm, since secundum ASDs of this size can increase substantially with patient growth
What examination and investigations are performed when following up ASD patients?
detecting any signs or symptoms of increased shunting. Signs suggestive of increased shunting include:
- failure to gain weight appropriately
- increased frequency of respiratory infections
- signs of heart failure such as hepatomegaly or auscultatory evidence of pulmonary congestion
Echocardiography is indicated when there is concern that the shunt may be increasing or to confirm spontaneous closure.
When is ASD closure recommened (clinical indications)?
- right heart enlargement
- pulmonary overcirculation
- evidence of substantial left-to-right shunting through an ASD (ie, ratio of pulmonary to systemic flow [Qp/Qs] >2:1 or other evidence of large amount of left-to-right shunting)
These findings are typically associated with moderate to large ASDs. Such defects are unlikely to close spontaneously, and observational data suggest that left-to-right shunting may increase with age, resulting in heart failure, exercise intolerance, and increased risk of arrhythmia and pulmonary hypertension
ASD closure is generally deferred until after the age of two years in asymptomatic patients because there is a possibility, albeit small, of spontaneous closure during the first two years of life
Is there benefit in closing persistent ASD without significant L-R shunt?
- no definitive evidence that ASD closure is beneficial for patients with a persistent ASD without a significant left-to-right shunt and without symptoms directly attributable to the ASD (including paradoxical embolism or platypnea-orthodeoxia, which is shortness of breath and hypoxemia that occurs when sitting or standing and that is relieved when lying down).
- Most pathologic consequences of ASD, such as atrial arrhythmias and (rarely) pulmonary hypertension, are secondary to right heart volume overload or pulmonary overcirculation.
- No studies have shown that prospective closure of asymptomatic small ASDs prevents paradoxical embolization, and the risk of endocarditis with isolated small ASDs appears to be negligible. Since all closure techniques have risk, closure of asymptomatic small ASDs does not appear to be warranted at this time.
Describe the aims of preprocedure echo evaluation for ASD
●Accurately measuring the size of the defect and degree of left-to-right shunting
●Identifying other cardiac defects
●Assessing for pulmonary hypertension
The preprocedural echocardiogram helps to determine the optimal choice of intervention. For example, severe fixed pulmonary hypertension is a contraindication for ASD closure, though this is a rare finding in children with ASDs.
Describe indications for percutaneous closure for ASDs
- usually possible for secundum ASDs that are not excessively large (ie, <30 mm in diameter) and with a rim of tissue around the defect sufficient for effective closure without obstruction or impingement on adjacent cardiac structures (at least 5 mm). For patients with secundum ASDs that meet these criteria, suggest percutaneous closure rather than surgical closure.
- Percutaneous closure should not be used in sinus venosus, primum or coronary sinus ASD, or in infants with large defects and heart failure.
- Although successful percutaneous closure can be performed in young infants, the complication rate appears to be higher in infants and young children, compared with older patients in the three- to five-year age range who weigh at least 15 kg.
- Furthermore, spontaneous closure of even large ASDs can occur in infants and young children. As a result, the benefits of closure in infants and young children (weight <15 kg) must be weighed against the increased risk of complication and possibility of spontaneous closure.
Surgical closure is reserved for all other patients or based on family preference.
Describe overall post-procedure care in ASD
- Clinical evaluation subsequent to closure should assess for signs of embolic events, arrhythmia, and chest pain.
- Echocardiographic surveillance is essential to detect complications including:
- residual shunting
- pericardial effusion
- ventricular function
- pulmonary artery pressure
- in patients who underwent percutaneous device closure, device migration, and thrombosis.
Electrocardiographic monitoring is also performed to detect any evidence of atrial arrhythmia.
Describe post-procedure care following percutaneous ASD closure
Patients are typically treated with aspirin, clopidogrel, or another anticoagulant agent subsequent to percutaneous ASD defect closure for six months to reduce the chance of thrombus formation on the ASD device before the device has become endothelialized.
In addition, temporary limitations on highly vigorous physical activity during the weeks immediately subsequent to ASD device implantation are usually advised. Specific recommendations on such temporary exercise limitations vary among interventional cardiologists.
Describe post-procedure care for surgical ASD closure
In the immediate postoperative period, patients are monitored for complications including:
- pericardial and pleural effusions
- postpericardiotomy syndrome.
- Fevers, chest pain, abdominal pain, and vomiting in postoperative ASD patients suggest the possible presence of clinically significant effusions and/or postpericardiotomy syndrome.
Percutaneous closure of ASD should not be used in patients with…?
- sinus venosus ASD
- primum ASD
- coronary sinus ASD
- infants with large defects and heart failure.
Periprocedural complications associated with percutaneous ASD closure include…?
device embolization or malposition, and arrhythmias (usually atrial)
What are indications for surgical correction of ASDs?
- sinus venosus defects
- coronary sinus defects
- primum ASDs
- complex congenital lesions including partial anomalous pulmonary venous connection
- infants with large secundum defects who present with heart failure generally cannot be adequately treated with percutaneous closure and typically undergo surgical correction
What are some post-op complications of ASD closure?
Postoperative complications occur in 25 to 30 percent of patients and include:
●Pericardial effusion
●Pleural effusions
●Arrhythmias
●Bleeding
●Pneumothorax
●Wound infection
Complications are usually transient and often do not require intervention. They may occur because of the standard surgical technique, which requires sternotomy or thoracotomy, atriotomy, and cardiopulmonary bypass, with its potentially deleterious consequences.
What is the typical overall outcome in surgical correction for ASD?
Outcomes following surgical closure of ASD in childhood are excellent with almost no difference in long-term mortality compared with age-matched controls. Long-term morbidities such as stroke, heart failure, arrhythmia, heart block, and pulmonary hypertension are also rare
Percutaneous vs. surgical correction? Differences in outcome and need for reintervention?
Observational data suggest that procedural success rates are similarly high for both surgery and percutaneous closure, but complication rates and length of hospital stay are lower with the percutaneous approach. There may be a slightly increased risk of needing reintervention with percutaneous closure.
Long-term cardiology follow-up is indicated following surgical or percutaneous ASD closure if there are…?
- other cardiac lesions
- preoperative or postoperative atrial arrhythmias
- if the patient had pulmonary artery hypertension preoperatively
- ASD was repaired during adulthood.
Describe the long term management of surgically closed ASDs
Patients who have had ASDs surgically repaired during childhood and who have uncomplicated early postoperative courses generally are free of late complications and activity restrictions. Patients with surgically repaired ASDs are at increased risk of developing late atrial arrhythmias compared with the general population. Routine surveillance is generally not necessary since the incidence is relatively low overall and the nature of these atrial arrhythmias is typically benign
Describe the long term follow up of percutaneously closed ASDs
Long-term outcomes following percutaneous ASD closure are less certain, and generally follow these children longitudinally.
Describe long term guidelines for sport participation in children with ASDs
●Patients with untreated ASDs and normal pulmonary pressure can participate in all competitive sports.
●Patients with untreated ASDs and pulmonary hypertension may participate in low-intensity (class IA) sports.
●Patients with untreated ASDs and associated pulmonary vascular obstructive disease with cyanosis and large right-to-left shunt should be restricted from participation in all competitive sports.
●Patients with repaired ASD can participate in all competitive sports three to six months after closure if they have normal pulmonary pressure and ventricular function, and no arrhythmias.
When is endocarditis prophylaxis recommened in children with isolated ASD?
The 2007 guidelines of the AHA recommend no antibiotic prophylaxis in children with an isolated ASD, except in the following circumstances:
●In children with a repaired ASD which required the use of prosthetic material or device, prophylactic antibiotics are recommended for dental and respiratory tract procedures during the first six months after the repair.
●In children with repaired ASD with a residual defect at the site or adjacent to the site of a prosthetic device, antibiotic prophylaxis is recommended for dental and respiratory tract procedures
Isolated secundum defects account for what percentage of CHD?
7%
What part of the artrial septum can ASDs occur?
any part of atrial septum - secundum, primum, or sinus venosus
What are the five most common congenital heart lesions and what percentage of total do they each make?
VSD 30-35%
ASD (secundum) 6-8 %
PDA 6-8%
Coarctation of aorta 5-7%
TOF 5-7%
What chromosome location, gene and cardiac defect is associated with Digeorge syndrome (velocardiofacial syndrome)?
22q11.2, 11p13p14
TBX1
TOF, IAA, TA, VSD
What chromosome location, gene and cardiac defect is associated with familial ASD with heart block?
5q35
NKX2.5
ASD, heart block
What chromosome location, gene and cardiac defect is associated with familial ASD without heart block?
8p22-23
GATA4
ASD
What chromosome location, gene and cardiac defect is associated with Alagille syndrome (bile duct hypoplasia etc.)
20p12, 1p12
JAGGED1, NOTCH2
Peripheral pulmonary hypoplasia, PS, TOF
What chromosome location, gene and cardiac defect is associated with Holt Oram syndrome (limb defects etc.)
12q24
TBX5
ASD, VSD, PDA
What chromosome location, gene and cardiac defect is associated with trisomy 21 (Down syndrome)?
21q22
Not known
AVSD
What chromosome location, gene and cardiac defect is associated with isolated familial AV septal defect (without trisomy 21)?
1p31-p21, 3p25
CRELD1
AVSD
What chromosome location, gene and cardiac defect is associated with Familial TAPVR?
4p13-q12
Not known
TAPVR
What chromosome location, gene and cardiac defect is associated with Noonan syndrome?
Multiple
PTPN11, KRAS, SOS1, SOS2, RAF1, BRAF, MEK1, HRAS, NRAS, SHOC2, CBL, NF1
PS, ASD, VSD, PDA, Hypertrophic cardiomyopathy
What chromosome location, gene and cardiac defect is associated with Ellis-van Creveld syndrome (polydactyly)
4p16
ECV, EVC2
ASD, common atrium
What chromosome location, gene and cardiac defect is associated with Char syndrome (craniofacial, limb defects etc)?
6p12-21.5
TFAP2B
PDA
What chromosome location, gene and cardiac defect is associated with Williams-Beuren syndrome?
7q11.23
ELN (Elastin)
Supravalvular AS, peripheral PS
What chromosome location, gene and cardiac defect is associated with Marfan syndrome?
15q11
Fibrillin
Aortic aneurysm, mitral valve disease
What chromosome location, gene and cardiac defect is associated with familial laterality abn?
Xq24-2q7, 1q42, 9p13-21
ZIC3, DNAI1
Situs inversus, complex congenital heart disease
What chromosome location, gene and cardiac defect is associated with Turner syndrome
X
Not known
Corctation of the aorta, aortic stenosis
What chromosome location, gene and cardiac defect is associated with Trisomy 13 (Patau)
13
Not known
ASD, VSD, PDA, valve abn
What chromosome location, gene and cardiac defect is associated with Trisomy 18 (edward)
18
Not known
ASD, VSD, PDA, valve abn
What chromosome location, gene and cardiac defect is associated with Cri du chat syndrome?
5p15.2
CTNND2
ASD, VSD, PDA, TOF
What chromosome location, gene and cardiac defect is associated with cat-eye syndrome?
22q11
Not known
TAPVR, TOF
What chromosome location, gene and cardiac defect is associated with Jacobson syndrome?
11q23
JAM3
HLHS
What chromosome location, gene and cardiac defect is associated with Costello syndrome?
11p15.5
HRAS
PS, hypertrophic cardiomyopathy, arrhythmias
What chromosome location, gene and cardiac defect is associated with CHARGE syndrome?
8p12, 7q21.11
CHD7, SEMA3E
ASD, VSD, TOF
What chromosome location, gene and cardiac defect is associated with Kabuki syndrome
12q13.12
MILL2
ASD, VSD, TOF, coarctation, TGA
What chromosome location, gene and cardiac defect is associated with Carney syndrome?
2p16
PRKAR1A
Atrial; and ventricular myxomas
What is the most common cardiac malformation and what percentage of congenital heart disease does it account for?
VSD. 25% of congenital heart disease
What is the most common type of VSD.
Membranous type. These defects are in a posterio-inferior position, anterior to the septal leaflet of the tricuspid valve.
VSDs between the crista supventricularis and the papillary muscle of the conus may be associated with…?
pulmonary stenosis and other manifestation of TOF
Supracristal VSDs are how common and where are they found?
less common. found just beneath the pulmonary valve and may impinge on an aortic sinus and cause aortic insufficiency
What race are supracristal VSDs are common in?
Asian
What is the major determinant of size of L-R shunting with VSD?
Physical size of VSD
In large defect VSDs, what is the major determinant of shunt magnitude?
Level of pulmonary vascular resistance in relation to systemic vascular resistance is the major determinant of shunt magnitude
What pressure differences are noted in the LV vs. RV in pressure restrictive VSDs?
In small communications (usually <5mm), VSD is deemed pressure restrictive, meaning that RV pressure is normal or only slightly elevated. The higher pressure in the left ventricle drives the shunt left to right, and the size of the defect limits the magnitude of the shunt
What pressure changes in LV and RV are noted in nonrestrictive VSDs?
In larger, nonrestrictive VSDs (usually >10mm), RV and LV pressure are equalised. In these defects the direction of shunting and shunt magnitude are determined by PVR/SVR ratio
What is the typical murmur feature in VSDs?
Loud, harsh, or blowing holosystolic murmur is presented and heard best over the left lower sternal border, frequently accompanied by a thrill. In a few cases the murmur ends before the second heart sounds (S2), presumably because of closure of the defect during late systole
How might a VSD present in a neonate?
Short, loud, harsh, systolic murmur over the apex –> tiny VSD in the apical muscular septum
In premature infants the murmur may be heard earlier as PVR descreases more rapidly
How do large VSDs present?
Excessive pulm BF and PHTN –> signs of CHF such as dyspnea, poor feeding, poor growth, profuse perspiration, recurrent pulm infections in infancy.
Cyanosis often absent, but duskiness is sometimes noted during infections or crying
Prominent L precordium, palpable parasternal lift, laterally displaced apical impulse and apical thrust, systolic thrill
Holosystolic murmur of large VSD is less harsh than that of a small VSD and more blowing in nature due to lack of significant pressure gradient
Pulmonic component of S2 may be increased as a result of PHTN
Mid-diastolic, low-pitched rumble at apex is caused by inc BF across the MV and usually indicates a Qp:Qs ration of > 2:1
CXR findings for VSD?
Small VSD: usually normal, but minimal cardiomegaly and a borderline inc in pulmonary vasculature may be observed
Large VSD: cardiomegaly w/ prominence of both ventricles, L atrium and pulm artery. pulm vasc markings are inc, and frank pulm oedema, including pleural effusions, may be present
ECG findings for VSD?
Small VSD: generally normal but may suggest LV hypertrophy. RV hypertrophy is sign that defect is not small and that pt has pulm HTN or an associated lesion such as pulmonic stenosis
Large VSD: biventricular hypertrophy; P waves may be notched (indicating LA enlargement)
Normal right-sided heart pressure and PVR are seen in?
Small, restrictive VSDs
equal or near-equal pulm and systemic systolic pressure and variable elevations in PVR are seen in?
Large, non-restrictive VSDs
What percentage of small defect VSDs close spontaneously? When does this occur?
30-50%. Occurs in first 2 years of life
Are muscular vs. membranous VSDs more likely to close?
Small muscular VSDs are more likely to close (up to 80%) than membranous VSDs (up to 35%)
Most defects that close do so before age 4, although spontaneous closure has been reported in adults
VSDs that close often have […] that limits the magnitude of the shunt
ventricular septal aneurysm (accessory tricuspid valve) tissue
Most children with small restrictive VSDs …
They are at long-term risk for?
remain asymptomatic, w/o evidence of an increase in heart size, PAP, or PVR
Long-term risk is infective endocarditis
Do Moderate-large VSDs close spontaneously? What percentage of them?
Less common for moderate or large VSDs to close spontaneously, although even defects large enough to result in HF may get smaller, and up to 8% may close completely
Infants with large VSDs present with?
repeated episodes of respiratory infection and HF despite optimal medical management. HF may be manifested in many of these infants primarily as failure to thrive
PHTN occurs as a result of high pulm BF. These pts are high risk for pulm vascular disease if defect is not repaired during early infancy
Pts with VSD are at risk for developing what valve pathology?
The greatest risk occurs in what type of VSD?
Aortic valve regurgitation
Supracristal VSD - position of the defect undermines support for the aortic valve R coronary or noncoronary leaflet
What can develop in pts with VSDs which protects the pulm circulation from the short-term effects of pulm overcirculation and the long-term effects of pulm vascular disease?
acquired infundibular pulmonary stenosis
Clinical picture changes from VSD with a large L-R shunt to a VSD with pulmonary stenosis. Shunt may diminish in size, becoem balanced, or even become net R-L. These pts must be distinguished from those with Eisenmenger physiology
In pts w/ small VSDs, what can you tell parents? Is there exercise restrictions? are prophylactic Abx needed for IE? Is surgery recommended? What follow up?
Reassure that it is a bening lesion
Can live a normal life, no restrictions on physical activity
Surgy not recommended
Integrity of primary and permanent teeth should be maintained, but Abx prophylaxis is not recommended for dental visits or surgical procedures
Monitor with clinical exam and TTE to estimate PAP, screen for development of LVOT pathology (subaortic membran or aortic regurgitation), and to confirm spontaneous closure
In pts w/ large VSDs, what are management goals?
Control symptoms of HF
Prevent development of pulm vascular disease
What is the role of surgical closure in infants with large VSDs?
Surgical closure can be carried out at low risk in most infants –> medical management should not be pursued in symptomatic infants after an initial unsuccessful trial
As pulm vascular disease can be prevented when surgery is performed within the first year of life, even infants with well-controlled HF should not have surgery delayed inordinately unless there is evidence that the defect is becoming pressure restrictive
Describe the physiology of a large VSD
Indications for surgical closure of a VSD?
Pts at any age with large defects in whom symptoms and FTT can’t be controlled medically
infants bet 6m-12m w/ moderate to large defects assoc w/ PHTN, even if Sx are controlled by medication
Pts older than 24m with a Qp:Qs ratio greater than 2:1
Pts w/ supracristal VSD of any size are typcically referred for surgery due to higher risk for developing aortic valve regurgitation
What is a major contraindication to closure of a VSD?
Severe pulm vascular disease nonresponsive to pulmonary vasodilators
What are some complications leading to long-term problems of surgical repair of VSD?
Residual ventricular shunts requiring reoperation
Heart block
What types of VSD defects have higher risk when surgically closed?
Muscular septum defects, particularly apical defects and multiple (swiss cheese-type) VSDs
Pts may need pulmonary arterial banding if symptommatic, with subsequent debanding and repair of multiple VSDs at an older age
After surgical obliteration of the L-R shunt in VSDs, what changes occur in the patient?
Hyperdynamic heart becomes quiet
Cardiac size decreases toward normal
Thrills and murmurs are abolished
Pulmonary artery hypertension regresses
What can a supracristal VSD be complicated by?
prolapse of the aortic valve into the defect and aortic insufficiency –> can eventually develop in 50-90% of these pts
What pertentage of all VSDs do supracristal VSDs make?
Supracristal VSDs are more common in what demographic group?
Although supracristal VSD accounts for about 5% of all pts with VSD, the incidence is higher in asian children and in males
Describe the location of the VSD in supracristal VSDs
anterior to and directly below the pulmonary valve in the outlet septum, superior to the muscular ridge known as the crista supraventricularis, which separates the trabecular body of the RV from the smooth outflow portion
What type of VSDs are associated with aortic insufficiency?
Most common with supracristal VSDs, aortic insufficiency is occasionally associated with VSDs located in the membranous septum
Describe the heart failure that can occur in supracristal VSDs
HF 2ndry to large L-R shunt rarely occurs, but w/o surgery, moderate-severe aortic insufficiency and LV failure can occur
Describe the murmur heard clinically with supracristal VSDs
mid- to upper left sternal border, as opposed to the LLSB, and it is sometimes confused with that of pulmonic stenosis
A decrescendo diastolic murmur will be appreciated at the upper right or mid-left sternal borders if there is aortic insufficiency
More advanced degrees of aortic insufficiency will be associated with a wide pulse pressure and a hyperdynamic precordium
These clinical findings must be distinguished from PDA or other defects associated with aortic run-off
What are the clinical manifestations of supracristal VSD with aortic insufficiency?
vary widely, from trivial AR and small L-R shunts in asymptommatic children to florid aortic insufficiency and massive cardiomegaly in symptomatic adolescents
How do you manage supracristal VSDs?
Closure of all supracristal VSDs is recommended to prevent the development of AR, even in an asymptommatic child
Pts who have significant aortic insufficiency require surgical intervention to prevent irreversible LV dysfunction
What is the function of the ductus arteriosus?
During fetal life, most of the pulmonary arterial blood is shunted R-L through the ductus arteriosus into the aorta
Describe the anatomy of the ductus arteriosus
The aortic end of the ductus is just distal to the origin of the left subclavian artery, and the ductus enter the pulmonary artery at its bifurcation
Is PDA more common in males or females?
Female patients with PDA outnumber males 2:1
PDA is associated with what infection during early pregnancy?
Maternal rubella infection during early pregnancy, an uncommon occurrence in the vaccination era
Why is PDA a common problem in premature infants?
The smooth muscle in the wall of the preterm ductus is less responsive to high PO2 and therefore less likely to constrict after birth. In these infants the shunt through a PDA can cause severe haemodynamic derangements
What is different in term infants with PDA compared to preterm infants?
In term infants with PDA, wall of the ductus is deficient in both the mucoid endothelial layer and the muscular media, whereas in the premature infant the PDA usually has a normal structure. Thus a PDA persisting beyond the 1st few weeks of life in a term infant rarely closes spontaneously or with pharmacologic intervention, whereas if early pharmacologic or surgical intervention is not required in a premature infant, spontaneous closure occurs in most instances
How is PDA related to other congenital heart defects?
PDA is seen in 10% of pts w/ other congenital heart lesions and often plays a critical role in providing a source of pulmonary blood flow when the RV outflow tract is stenotic or atretic or in providing systemic BF in the presence of aortic coarctation or interruption
Describe the pathophysiology of PDA
Due to higher aortic pressure postnatally, L-R shunt occurs through the ductus. Extent of shunt depends on size of the ductus and on the PVR/SVR ratio. If PDA is small, pressures within the pulmonary artery, RV and RA are normal. If PDA is large, PAP may be elevated to systemic levels during both systole and diastole. Thus pts with large PDA are at high risk for developing pulmonary vascular disease if left unoperated
What are the clinical manifestation of a small PDA?
usually asymptommatic and dx by presence of a heart murmur
- machine like murmur, 2nd left intercostal space
normal peripheral pulses
What are the clinical manifestations of a large PDA?
HF similar to that in infants with a large VSD
Retardation of physical growth may be a major manifestation in infants with large shunts
bounding peripheral arterial pulses and a wide pulse pressure, caused by runoff of blood into the pulmonary artery during diastole
heart is moderately or grossly enlarged in cases with a large communication; in these pts the apical impulse is prominent and, with cardiac enlargement, is heaving
Thrill: maximal in the 2nd left IC space, may radiate towarwd the left clavicle, down the left sternal border, or toward the apex. usually systolic but can be palpated throughout the cardiac cycle
Machine-like murmur beginning soon after onset of S1, reaching maximal intensity at end of systole, and wanes in late diastole. Localised to the 2nd IC space or radiate down the left sternal border or left clavicle
When PVR is increased, the diastolic component of murmur may be less prominent or absent
Large L-R shunt - low-pitched mitral mid-diastolic murmur may be heard at apex as a result of increased volume of blood flow across the mitral valve
What ECG findings might be seen with PDA?
if L-R shunt is small, ECG is normal. If the ductus is large, LV or biventricular hypertrophy is present
Diagnosis of uncomplicated, isolated PDA is untenable when RV hypertrophy is spresent on ECG
What radiographic findings might be seen with PDA
prominent pulm atery w/ increased pulmonary vascular markings
cardiac size depends on degrees of L-R shunting; may be normal or moderately to greatly enlarged
Chambers involved are LA and LV
Aortic knob may be normal or prominent
What TTE findings are seen with PDA?
if ductus small: cardiac chambers will be normal size
large shunts: LA and LV dimensions are increased.
Ductus can easily be visualised directly and its size estimated. Color and pulsed doppler examination demonstrate systolic or diastolic (or both) retrograde turbulent flow in the pulmonary artery, and aortic retrograde flow in diastole in the presence of a large shunt
What conditions can be confused for a PDA?
Aorticopulmonary window defect may be clinically indistinguishable from a patent ductus, though in most cases the murmur is only systolic and loudest at the right rather than LUSE
A sinus of valsalva aneurysm that has ruptured into the right side of the heart or pulmonary artery, a coronary AV fistula, and an aberrant left coronary artery with massive collaterals from the right coronary display dynamics similar to that of a PDA with a continuous murmur and a wide pulse pressure
Truncus arteriosus w/ torrential pulmonary flow also can present with an aortic runoff physiology
Peripheral AV fistula also results in a wide pulse pressure, but the distinctive precordial murmur of PDA is not present
VSD w/ aortic insufficiency , repaired TOF, and combined aortic and mitral insufficiency (usually from rheumatic fever) can be confused with a PDA, but the murmurs should be differentiated by their to-and-fro rather than continuous nature
Describe the difference with to-and-fro and continuous murmurs
In a to-and-fro murmur there is a quiet segment between the systolic and diastolic components, whereas in a continuous murmur there is flow disturbance throughout the cardiac cycle (even if the murmur is louder during systole than diastole)
How often does spontaneous closure of the ductus after infancy occur?
rare
Prognosis for small PDA?
may live a normal life span with few or no cardiac symptoms, but late manifestations may occur
Prognosis of large PDA?
cardiac failure most often occurs in early infancy but may occur later in life, even with a moderate-sized communication
What are some complications of PDA?
IE may be seen at any age. pulm or systemic embolic may occur. rare complications include aneurysmal dilation of the pulm artery or the ductus, calcification of the ductus, noninfective thrombosis of the ductus with embolisation, and paradoxical emboli
PHTN (eisenmenger syndrome) usually develops in patients with a large PDA who do not undergo ductal closure
what are the treatment strategies for PDA?
Irrespective of age, pts with PDA needs either catheter or surgical closure
Small PDA - closure to prevent bacterial endocarditis or other late complications
Moderate/Large PDA - closure to treat heart failure or prevent the development of pulm vascular disease, or both
Once diagnosis of moderate/large PDA is made, Tx should not be unduly postponed after adequate medical therapy for cardiac failure has been instituted
Is PHTN a contraindication to surgery for PDA closure?
PHTN not a contraindication to surgery at any age if it can be demonstrated at cardiac catheterization that the shunt flow is still predominantly L-R and that severe pulm vascular disease is not present
What surgical possibilities exist for PDA closure?
Transcatheter PDA closure is routinely performed.
Small PDA - generally closed with intravascular coils
Moderate/Large PDA may be closed with an umbrella-like device or with a catheter-introduced sac into which several coils are released
Surgical closure of a PDA - left thoracotomy or using thoracoscopic minimally invasive techniques
Congenital aortic stenosis accounts of what percentage of cardiac malformations recognised in childhood?
5%
Is there a sex predominance for aortic stenosis?
more frequent in males (3:1)
What genes have been implicated in bicuspid aortic stenosis?
There are families with multiple individuals affected with bicuspid aortic valve, and several genes have been implcated, including NOTCH1 on chromosome 9q34.4
Describe the pathophysiology with the most common form of aortic stenosis - valvular aortic stenosis
Leaflets are thickened and commissures are fused to varying degrees
LV systolic pressure is increased as a result of obstruction to outflow
LV wall hypertrophies in compensation - as its compliance decreases, end-diastolic pressure increases also
Where is the lesion in subvalvular (subaortic stenosis)?
discrete fibromuscular shelf below the aortic valve
Subvalvular aortic stenosis is an important form of..?
LVOT
subvalvular aortic stenosis is frequently associated with which other forms of congenital heart disease?
mitral stenosis and coarctation of the aorta (Shone syndrome)
When might subvalvular aortic stenosis be noted?
may become apparent after successful surgery for other CHD (coarctation, PDA, VSD), may develop in association with mild lesions that have not been surgically repaired, or may occur as an isolated abn
may be caused by markedly hypertrophied ventricular septum in association with hypertrophic cardiomyopathy
What syndrome is supravalvular aortic stenosis associated with?
least common type of aortic stenosis
may be sporadic, familial, or associated with williams syndrome (dev delay, elfin facies, as well as idiopathic hypercalcaemia of infancy)
Williams: loquacious personality, hypersensitivity to sound, spasticity, hypoplastic nails, dental anomalies (partial anodontia, microdontia enamel hypoplasia), joint hypermobility, nephrocalcinosis, hypothyroidism, and poor weight gain
Williams associated with deletion involving the elastin gene on chromosome 7q11.23
what significant pathology can be caused by supravalvular aortic stenosis?
narrowing of the coronary artery ostia can occur
needs to be carefully evaluated
stenosis of other arteries, particularly the branch pulm arteries may also be present
symptoms of aortic stenosis?
depend on severity of obstruction
severe AS occuring in early infancy - critical aortic stenosis –> LV failure and signs of low CO. HF, cardiomegaly, pulm oedema, weak pulses in all extremities, skin may be pale or grayish. UO may be diminished. If CO is significantly decreased, intensity of murmur at RUSB may be minimal
Less severe AS - asymptomatic and display normal growth and development. murmur usually noted during routine review. rarely fatigue, angina, dizziness or syncope may develop in older child with previously undiagnosed severe obstruction to LV outflow
sudden death can occur with severe LVOT obstruction in whom surgical relief has been delayed
Physical exam findings in aortic stenosis?
dependent on degree of LVOT
mild stenosis - pulse, heart size, apical impulse are normal
Inc degrees of severity, pulses become diminished in intensity and heart may be enlarged with an LV apical thrust
Mild/moderate valvular AS usually assoc w/ early systolic ejection click, best heard at apex and left sternal edge. intensity of slick does not vary with respiration (unlike PS)
severe stenosis: S1 may be diminished due to dec compliance of thickened left ventricle
normal splitting of S2 is present in mild-mod obstruction. Severe obs - intensity of aortic valve closure is diminished and rarely in children, S2 may be split paradoxically (becoming wider in expiration)
4th heart sound (S4) may be audible when obstruction is severe as result of dec LV compliance
louder, harsher (higher pitch), and longer the murmur –> greater degree of obstruction
murmur audible maximally at RUSB and radiated to neck and L midsternal border. usually accompanied by thrill in suprasternal notch
Subvalvular AS - murmur may be maximal along the LSB or even at the apex
soft, decrescendo diastolic murmur indicative of aortic insufficiency is often present when obstruction is subvalvular or in pts w/ bicuspid aortic valve
occasionally an apical, shoft mid-diastolic rumbling murmur is audible –> suspicious of associated MV stenosis
ECG findings in aortic stenosis?
If pressure gradient across aortic valve is mild - ECG likely normal
LVH and LV strain (inverted T waves in left precordial leads) –> severe stenosis and long-standing
CXR findings in aortic stenosis?
prominent ascending aorta, but aortic knob is normal
Heart size typically normal
Associated anomalies on TTE in pts with aortic stenosis?
anomalies of MV, aortic arch, or VSD or PDA are present in up to 20% of cases
What do doppler studies show in aortic stenosis?
Shows specific site of obstruction and determines peak and mean systolic LVOT gradients
When severe aortic obs is assoc w/ LV dysfunction, doppler-derived valve gradient may greatly underestimate the severity of the obstruction due to the low cardiac output across the valve
What is the utility of heart catheterisation in aortic stenosis?
L-sided heart catheterisation, usually done in conjunction with aortic balloon valvuloplasty, demonstrates the magnitude of the pressure gradient from the left ventricle to the aorta
aortic pressure curve is abn if obs is severe
In pts w/ severe obs and dec LV compliance, L atrial pressure is inc and P-HTN may be present
Treatment for aortic stenosis?
Balloon valvuloplasty - moderate to severe valvular AS to prevent progressive LV dysfunction and risk of syncope and sudden death
Valvuloplasty advised when peak-to-peak systolic gradient bet LV and aorta exceeds 60-70mmHg at rest, assuming normal CO, or for lesser gradients when Sx or ECG changes are present
for more rapidly progressive subaortic obstructive lesions, a gradient of 40-50mmHg or presence of aortic insufficiency is considered an indication for surgery
balloon valvuloplasty is procedure of choice even in neonates
Surgical Tx reserved for extremely dysplastic aortic valves that are not amenable to balloon therapy or in pts who also have subvalvar or valvar (AKA supravalvar) stenosis
Treatment for subaortic stenosis?
discrete subaortic stenosis can be resected w/o damage to aortic valve, anterior leaflet of MV, or conduction system. This type of obs is not usually amenable to catheter treatment
Treatment for supravalvular aortic stenosis?
surgical treatment
results are excellent if area of obstruction is discrete and not assoc w/ a hypoplastic aorta
Complications of treatment (catheter or surgical) or aortic stenosis?
Aortic insufficiency or calcification with restenosis is likely to occur years or even decades later and eventaully require reoperation and often aortic valve replacement
Signs of recurrent stenosis include ECG signs of LVH, increase in Doppler echocardiographic gradient, deterioration in echo indices of LV function, and recurrence of signs or symptoms during graded treadmill exercise
evidence of significant aortic regurgitation includes sx of HF, cardiac enlargement on CXR, LV dilation on echo
choice of reparative procedure depends on relative degree of stenosis and regurgitation
Prognosis of critical aortic stenosis in neonates?
Have severe HF and deteriorate rapidly to a low-output shock state
emergency surgery or balloon valvuloplasty is lifesaving, but has significant mortality risk
neonates who die of critical AS frequently have sig LV endocardial fibroelastosis
those who surgive may develop signs of LV diastolic muscle dysfunction (restrictive cardiomyopathy) and require cardiac transplantation
Prognosis of mild-moderate aortic stenosis in older infants and children?
reasonably good, although disease progression over 5-10 yr is common
Usually respond well to tx (either surgery or valvuloplasty), although reoperation on the aortic valve are often needed later in childhood or adult life, and many pts eventually require valve replacemen
In unoperated pts w/ severe obs, sudden death is sig risk and often occurs during or immediately after exercise. AS is one of the causes of sudden cardiac death in the paediatric age-group
Gradient classification of mild vs. moderate aortic stenosis?
Mild disease: aortic valve gradients of <40-50 mmHg
Moderate disease: aortic valve gradients of 40-70mmHg
Can kids with aortic stenosis play sports? doe they need prophylaxis for IE?
Moderate/severe AS –> should not participate in active competitive sports
milder disease –> sports participation is less severely restricted
status should be reviewed annually
prophylaxis against IE is no longer recommended unless a prosthetic valve has been inserted
Older children and adults with isolated bicuspid aortic valves are at inc risk for developing…?
dilation of their ascending aorta, even in absence of significant stenosis
risk inc with age, and rate of inc is greatest in those with largest aortic roots
In kids, this dilation is usually mild and remains stable over many years of observation, but in older pts the aorta can dilate substantially and progressively
this form of dilation is similar to that seen in marfan syndrome
Where does coarctation of the aorta occur?
Is there a sex predominance?
may occur at any point from the transverse arch to the iliac bifurcation, but 98% occur just below the origin of the L subclavian artery at origin of the ductus arteriosus (juxtaductal coarctation)
twice as often in males as in females
Coarctation of the aorta may be a feature of what syndrome?
Turner syndrome
Coarctation of the aorta is assoc with a bicuspid aortic valve in what percentage of patients?
70%
What is shone syndrome/complex?
- coarctation of the aorta
- MV abn (supravalvular mitral ring or parachute mitral valve)
- valvular or subvalvular aortic stenosis
Describe the types of coarctation of the aorta?
Can occur as discrete juxtaductal obstruction or as tubular hypoplasia of the transverse aorta starting at one of the head of neck vessels and extending to the ductal area (prevously referred to as preductal or intantile-type coarctation
Often both components are present
Describe the pathophysiology of coarctation of the aorta
may be initiated in fetal life by presence of a cardiac abn that results in dec blood flow anterograde through the aortic valve (e.g. bicuspid aortic valve, VSD). Alternatively, coarctation may be caused by abn extension of contractile ductal tissue into the aortic wall
Discrete juxtaductal coarctation - ascending aortic blood flows through the narrowed segment to reach the descending aorta, although LV HTN and hypertrophy result
1st few days of life, PDA may serve to widen the juxtaductal area of the aorta and provide temporary relief from obstruction. Net L-R shunting occurs in these acyanotic infants
with more-severe juxtaductal coarctation or in the presence of transverse arch hypoplasia, RV blood is ejected through the ductus to supply the descending aorta
perfusion of the lower part of the body is then dependent on RV output - in this situation femoral pulses are palpable and differential BPs may not be helpful in making the diagnosis
How is ductal R-L shunting in coarctation observed clinically?
manifests as differential cyanosis, with upper extremities being pink and lower extremities being blue
may have severe P-HTN and high PVR
Signs of HF are prominent
severely hypoplastic segments of the aortic isthmus may become completely atretic and result in an interrupted aortic arch, with the left subclavian artery arising either proximal or distal to the interruption
Coarctation assoc w/ arch hypoplasia was once referred to as […] because its severity usually led to recognition of the condition in early infancy
infantile type
[…] referred to isolated juxtaductal coarctation, which, if mild, was not usually recognised until later childhood
Adult type
How does blood pressure differ above and below coarctation of the aorta?
what vessults contribute to collateral circulation?
BP is elevated in vessels that arise proximal to the coarctation; BP as well as pulse pressure is lower below the constriction
HTN not caused by mechanical obs alone, but also involves neurohumoral mechanisms
cheifly branches of the subclavian, superior intercostal, and internal mammary arteries are involved in collateral circulation
Clinical manifestations of coarctation of the aorta?
if recognised after infancy - not usually associated with significant symptoms
some kids have weakness or pain/claudication (or both) in legs after exercise, but in many cases, even pts with severe coarctation are asymptomatic
older kids usually picked up when noted to be hypertensive on routine exam
classic sign: disparity in pulsation and BP in arms and legs. femoral/popliteal/PT and DP pulses are weak (or absent in up to 40% of pts), in contrast to bounding pulses of the arms and carotid vessels
radial and femoral pulses should be palpated simultaneously for presence of a radial-femoral delay. normally femoral pulse occurs slightly before the radial pulse. radial-femoral delay occurs when BF to descending aorta is dependent on collaterals, in which case femoral pulse is felt after the radial pulse
In kids (except neonates), systolic BP in legs obtained by the cuff method is 10-20mmHg higher than that in the arms. In coarctation, BP in the legs is lower than that in the arms; frequently it is difficult to obtain
BP higher in right than left arm suggests involvement of L subclavian artery in the area of coarctation
occasionally R subclavian may arise anomalously from below the area of coarctation and result in a left arm BP that is higher than the right
with exercise, more prominent rise in systemic BP occurs, and the upper-to-lower extremity pressure gradient will increase
Physical exam findings in coarctation of the aorta?
precordial impulse and HS are usually normal
systolic ejection click or thrill in the suprasternal notch suggests a bicuspid aortic valve (present in 70% of cases)
short systolic murmur often heard along LSB at 3rd/4th intercostal spaces. murmur well transmitted to left infrascapular area and occasionally to the neck
often, typical murmur of mild aortic stenosis can be heard in the 3rd right IC space
low-pitched mid-diastolic murmur at apex suggests MV stenosis
older kids with well-developed collateral BF: systolic or continuous murmurs may be heard over the L and R sides of the chest laterally and posteriorly. In these pts, a palpable thrill can occasionally be appreciated in the IC spaces on the back
How might neonates or infants with severe coarctation present with?
usually includes some degree of transverse arch hypoplasia
initially have signs of lower body hypoperfusion, acidosis and severe HF
these signs may be delayed by days or weeks until after closure of the ductus arteriosus
if detected before ductal closure, patient may exhibit differential cyanosis, best demonstrated by simultaneous oximetry of the upper and lower extremities
On exam the heart is large, and a systolic murmur is heard along the left sternal border with a loud S2
CXR findings for coarctation of the aorta?
Depend on age and effects of HTN and the collateral circulation
infants w/ severe coarctation: cardiac enlargement and pulmonary congestion
in childhood, findings are not striking until after the 1st decade, when heart is mildly/moderately enlarged due to LV prominence
Enlarged L subclavian artery typically produces a prominent shadow in the left superior mediastinum
notching of the inferior border of the ribs from pressure erosion by enlarged colateral vessels is common by late childhood
descending aorta may have area of poststenotic dilation
ECG findings in coarctation of the aorta?
normal in young children but reveals evidence of LV hypertrophy in older pts
neonate and yound infants display right or biventricular hypertrophy
What imaging modality is preferred to diagnose coarctation of the aorta?
Segment of coarctation can generally be visualised by 2D echo
assoc anomalies of the MV and aortic valve can also be demonstrated
The descending aorta is hypopulsatile
color doppler is useful for demonstating the specific site of the obstruction
pulsed and continuous wave doppler studies determine the pressure gradient directly at the area of coarctation; in the presence of a PDA the severity of the narrowing may be underestimated
if echo equivocal - CT and MRI can be used
CT, MRI or diagnostic catheterisation is not needed before surgery in cases well defined by echo
Treatment of neonates with severe coarctation of the aorta?
closure of the ductus often results in hypoperfusion, acidosis and rapid deterioration.
Should have infusion of PGE1 to reopen the ductus and reestablish adequate lower-extremity blood flow
Surgical repair should be eventually performed
How should older infants (older than neonates) with heart failure secondary to coarctation be treated?
if good perfusion can be manged with anticongestive measures to improve their clinical status prior to surgical intervention
usually no reason to delay surgical repair waiting for patient growth; successful repairs have been performed in small premature infants
How should older children with significant coarctation be treated?
treat relatively soon after diagnosis
delay is unwarranted, esp after the 2nd decade of life - operation may be less successful due to dec LV function and degenerative changes in the aortic wall
if cardiac reserve is sufficient, satisfactory repair is possible well into mid-adult life
In the immediate postoperative period for coarctation, what needs to be managed?
What are some complications of operative interventions?
Rebound hypertension can occur and requires medical management. This exaggerated acute hypertension gradually subsides and in most patients, antihypertensives can be discontinued
spinal cord injury from aortic cross-clamping (if collaterals are poorly developed), chylothorax, diaphragm injury, laryngeal nerve injury
if the left subclavian flap approach is used, the radial pulse and BP in the left arm are diminished or absent
What is postcoarctectomy syndrome?
postop mesenteric adenitis can be assoc with acute HTN and abdominal pain in the immediate postop period
pain varies in severity and may occur in conjunction with anorexia, n/v, leukocytosis, intestinal hemorrhage, bowel necrosis, and SBO
relief usually obtained with antihypertensive drugs (e.g. nitroprusside, esmolol, captopril) and intestinal decompression; surgical exploration is rarely required for bowel obstruction or infarction
Prognosis of pts with coarctectomy?
although restenosis in older pts is rare, sig no. of infants operated on before 1yr of age require revision in later childhood
All pts need to be monitored for development of recoarctation and an aortic anastomotic aneurysm
If recoarctation occurs after coarctectomy, what management should be used
balloon angioplasty is procedure of choice
scar tissue from previous surgery may make reoperation more difficult yet makes balloon angioplasty safer due to lower incidence of aneurysm formation
in adolescents and young adults, intravascular stents are typically used, generally with excellent results
Describe neurological complications of coractation?
neurological damage or even death may rarely occur from associated cerebrovascular disease
subarachnoid or intracerebral hemorrhage may result from rupture of congenital aneurysms in the circle of Willis, rupture of other vessels with defective elastic and medial tissue, or rupture of normal vessels
These all occur secondary to hypertension
What is PHACE syndrome?
PHACE syndrome (Posterior brain fossa anomalies, facial hemangiomas, arterial anomalies, cardiac anomalies, and aortic coarctation, eye anomalies syndrome) kids may have strokes
abn of the subclavian arteries may include involvement of the left subclavian artery in the area of coarctation, stenosis of the orifice of the left subclavian artery, and anomalous origin of the R subclavian artery
What can untreated coarctation of the aorta lead to?
majority of older pts with coarctation would die between 20-40 years of age
common serious complications are related to systemic HTN, which may result in premature CAD, HF, hypertensive encephalopathy, or intracranial haemorrhage
HF may be worsened by assoc anomalies
IE or endarteritis is a sig complicaiton in adults
aneurysms of the descending aorta or the enlarged collateral vessels may develop
What is the most common form of RVOT with an intact ventricular septum?
Pulmonary stenosis
Isolated valvular pulmonary stenosis accounts for what percentage of all congenital heart defects?
7-10%
What is pulmonary stenosis?
Pulmonary valve cusps are deformed to various degrees and as a result, valve opens incompletely during systole
valve may be bicuspid or tricuspid and leaflets partially fused together with an eccentric outlet
fusion may be so severe that only a pinhole central opening remains
If valve not severely thickened, it produces a domelike obstruction to RV outflow during systole.
Isolated infundibular or subvalvular stenosis, supravalvular pulmonary stenosis, and branch pulmonary artery stenosis are also encountered
PS and an ASD are also occasionally seen as associated defects
What is the most common cardiac anomaly in Noonan syndrome?
PS as a result of valve dysplasia is the most common cardiac abn in Noonan syndrome
Mechanism of PS in Noonan syndrome?
unknown
maldevelopment of the distal portion of the bulbis cordis and the sequelae of fetal endocarditis have suggested as etiologies
What is Leopard syndrome?
Lentigines
ECG abn
ocular hypertelorism
PS
abn of genetalia
retardation of growth
deafness syndrome
What is Leopard syndrome often associated with?
hypertrophic cardiomyopathy
What genetic mutations have been implicated in LEOPARD syndrome?
PTPN11
RAF1
BRAF
What valve lesion is associated with Alagille syndrome?
PS, either of the valve or branch pulmonary arteries is a common finding
What gene is implicated in Alagille syndrome?
JAGGED1 gene mutation
Describe the pathophysiology of pulmonary stenosis?
Obstructed RV outflow –> inc RV systolic pressure and wall stress –> hypertrophy of the RV
severity of abn depend on size of restricted valve opening
Severe cases - RV pressure may be high than systemic arterial systolic pressure
PAP is normal or decreased
Arterial O2 sats will be normal even in severe stenosis, unless an intracardiac communicaiton such as VSD or ASD allows blood to shunt from right to left
severe PS in neonates –> dev RV complicance often leads to cyanosis as a result of R-L shunt through a PFO, a condition termed critical pulmonic stenosis
What is termed critical pulmonic stenosis?
severe PS in neonates –> dev RV complicance often leads to cyanosis as a result of R-L shunt through a PFO, a condition termed critical pulmonic stenosis
Clinical features of PS?
mild-moderate –> usually nil Sx. Growth and dev often normal
severe stenosis –> signs of RV failure such as hepatomegaly, peripheral oedema, exercise tolerance may be present
neonate/young infant w/ critical PS –> signs of RV failure may be more prominent and cyanosis often present due to R-L shungint at foramen ovale
Clinical features of mild PS?
venous pressure and pusle are normal
heat nor enlarged, apical impulse is normal, PV impulse not palpable
Sharp pulmonic ejection click immediatedly after S1 heard at LUSB during expiration. S2 is split, with pulmonary component of normal intensity thay may become slightly delayed
short, low/medium pitched systolic ejection murmur is maximally audible over pulmonic area and radiates minimally to lung fields bilaterally
ECG features mild PS?
Normal, or mild RVH may be present
inverted T waves in R precordial leads may be seen
T-wave in lead V1 should normally be inverted until at least 6-8yr of age
a positive T wave in V1 in a young child is a sign of RVH even in the absence of voltage criteria
Imaging features mild PS?
only abn demonstrable radiographically is usually poststenotic dilation of the pulmonary artery
2D TTE shows RVH and a slightly thickened pulmonic valve, which domes in systole
Dippler studies demonstrate a RV-pulmonary artery pressure gradient of <30mmHg
Clinical features of moderate PS?
venous pressure slightly elevated
in older kids, prominent a wave may be noted in the jugular pulse
RV lift may be palpable at LLSB
S2 is split, with delayed and soft pulmonic component
as valve motion becomes more limited with more severe degrees of stenosis, both the pulmonic ejection click and pulmonic S2 may become inaudible
with inc degrees of stenosis, peak of systolic ejection murmur is prolonged later into systole, and its quality becomes louder and harsher (higher frequency). Murmur radiated more prominently to both lung fields
ECG features moderate PS?
RVH, sometimes with prominent spiked P wave
CXR features of moderate PS?
heart can vary from normal size to mildly enlarged with uptilting of the apex due to prominence of the RV; pulmonary vascularity may be normal or slightly decreased
TTE features moderate PS?
TTE shows thickend pulmonic valve with restricted systolic motion
Doppler RV-PA pressure gradient of 30-60mmHg. Mild TR may be present and allows doppler confirmation of RV systolic pressure
Clinical features severe PS?
mild-moderate cyanosis may be noted in pts with an interatrial communication (ASD or PFO). In absence of intracardiac shunt, cyanosis is absent
hepatic enlargement and peripheral oedema are an indication of RV failure
elevation of venous pressure is common an dis caused by a large presystolic jugular a wave
hear is moderately or greatly enlarged, parasternal RV lift is present and frequently extends to the left midclavicular line
pulmonary component of S2 usually inaudible
loud, long harsh systolic ejection mumur usually accompanied by a thrill, is maximally audible in the pulmonic area and may radiate over the entire precordium, to both lung fields, into the neck, and to the back
peal of the mumur occurs later in systole as valve opening becomes more restricted.
Murmur frequently encompasses the aortic component of S2 but is not preceded by an ejection click
ECG findings in PS?
- The electrocardiogram (ECG) findings are normal in mild cases.
- Right-axis deviation (RAD) and right ventricular hypertrophy (RVH) are present in
moderate PS. - Right atrial hypertrophy (RAH) and RVH with “strain” may be seen in severe PS.
- Neonates with critical PS may show left ventricular hypertrophy (LVH) because of a hypoplastic RV and relatively large left ventricle (LV).
Radiographic findings in PS?
- Heart size is usually normal, but the main PA segment may be prominent with valvular
stenosis (caused by poststenotic dilatation). Cardiomegaly is present only if
CHF develops. - Pulmonary vascular markings are usually normal but may decrease with severe PS.
- In neonates with critical PS, lung fields are oligemic with a varying degree of cardiomegaly.
Echo findings in PS?
- Two-dimensional echocardiography in the parasternal short-axis view shows thick pulmonary valve cusps with restricted systolic motion (doming). The subcostal long-axis view may show similar findings. The size of the pulmonary valve annulus can be estimated. The main PA is often dilated (poststenotic dilatation).
- The instantaneous pressure gradient estimated by Doppler echo is slightly greater than the peak-to-peak systolic pressure gradient obtained by cardiac catheterization. The severity of PS (by Doppler gradient) may be classified as follows.
a. Mild: A pressure gradient less than 35 to 40 mm Hg (or RV systolic pressure <50% of the LV pressure).
b. Moderate: A valve pressure gradient of 40 to 70 mm Hg (or RV pressure 50%–75% of the LV pressure).
c. Severe: A pressure gradient greater than 70 mm Hg (or RV pressure ≥ 75% LV pressure). - Dysplastic valves are characterized by a noticeably thickened and immobile leaflet and hypoplasia of the pulmonary valve annulus.
- In neonates, Doppler pressure gradient may underestimate the severity of PS because the PA pressure may be higher than normal, especially in those with PDA with a left-to-right shunt.
Describe the natural history of PS?
- severity of stenosis not usually progressive in mild PS
- moderate/severe PS –> severity progresses with age
- CHF may develop in severe stenosis. Sudden death possible in pts w/ severe stenosis during heavy physical exercise
- w/o appropriate mgmt, most neonates w/ critical PS die
Describe the different anatomic subtypes of PS?
Medical management of PS?
- Newborns with critical PS and cyanosis
- PGE1 infusion reopens the ductus arteriosus and may temporarily improve baby
- balloon valvuloplasty procedure of choice in critically ill neonates
- if infant unable to maintain forward flow through PV due to noncompliant or hypoplastic RV –> prolong PGE1 infusion (3 weeks), ductal stenting, or systemic-to-pulm shunt surgery
- neonatal complication rate of balloon valvuloplasty is higher than in older pts, mortality up to 3%, major complicaiton rate of 3.5%, minor complication rate of 15%
- 15% need reintervention (repeat valvuloplasty or surgery for infundibular stenosis or dysplastic valve) at a later time
Indications for balloon valvuloplasty in PS?
- resting pressure gradient of >40mmHg with pt sedated in the cath lab
- if catherterisation gradient is 30-39mmHg, balloon procedure may be reasonable
- symptoms attributalbe to PS with a catheterisation gradient >30mmHg. Sx may include angina, syncope or presyncope, and exertional dyspnoea
- procedure useful and reasonable in pts w/ dysplastic PV, as seen in Noonan syndrome. Has a lower success rate with valvuloplasty (65%). If balloon valvuloplasty unsuccessful
–> surgery is indicated
Describe the pressure gradient definitions of mild/moderate/severe PS?
a. Mild: A pressure gradient less than 35 to 40 mm Hg (or RV systolic pressure <50%
of the LV pressure).
b. Moderate: A valve pressure gradient of 40 to 70 mm Hg (or RV pressure 50%–75%
of the LV pressure).
c. Severe: A pressure gradient greater than 70 mm Hg (or RV pressure ≥ 75% LV
pressure).
What results can be expected from balloon valvuloplasty?
extremely low risk, painless, less costly than surgery, shorter hospital stay
Good outcome in 85% of pts w/ valvular stenosis. Restenosis after balloon dilatation is very rare
PR after dilatation is common, occuring in 10-40% of pts. Usually well tolerated, some pts rartely become candidates for PV implantation
After relief of severe PS (either balloon or surgery), a hypertrophied dynamic infundibulum may cause a persistent pressure gradient, with rare occurrences of fatal outcome (‘suicidal RV”). Propranolol may reduce hyperdynamic infundibular obstruction. reduction of this gradient occurs gradually over weeks
Are activity restrictions required in pts with PS?
Restriction of activity is not necessary in child with PS except in cases of severe PS (doppler gradient of >70mmHg)
Indications for surgery in PS?
- Surgical valvotomy should be limited to patients with more complex lesions or those in whom balloon procedure is contraindicated or failed.
- Other types of obstructions (e.g., infundibular stenosis, anomalous RV muscle bundle) with significant pressure gradients require surgery on an elective basis.
- If balloon valvuloplasty is unsuccessful or unavailable, infants with critical PS and CHF require surgery on an urgent basis.
What is the incidence of tetralogy of fallot (TOF)?
Tetralogy of Fallot occurs in 5% to 10% of all CHDs. This is probably the most common
cyanotic heart defect
Describe the abn associated with TOF?
The original description of TOF included the following four abnormalities: a large VSD, RVOT obstruction, RVH, and overriding of the aorta. In actuality, only two abnormali-
ties are required, a VSD large enough to equalize pressures in both ventricles and an RVOT obstruction. The RVH is secondary to the RVOT obstruction, and the overriding of the aorta varies
Describe the VSD associated with TOF?
The VSD in TOF is a large perimembranous defect with extension into the subpulmonary region.
Describe the RVOT obstruction in TOF?
The RVOT obstruction is most frequently in the form of infundibular stenosis (45%). The obstruction is rarely at the pulmonary valve level (10%). A combination of the two may also occur (30%). The pulmonary valve is atretic in the most severe
form of the anomaly (15%)
Describe the abn of the pulmonary annulus and main PA in TOF patients?
The pulmonary annulus and main PA are variably hypoplastic in most patients. The PA branches are usually small, although marked hypoplasia is uncommon. Stenosis at the origin of the branch PAs, especially the left PA, is common. Occasionally, systemic collateral arteries feed into the lungs, especially in severe cases of TOF.
Is right aortic arch common in pts with TOF?
Right aortic arch is present in 25% of cases, with some of them having symptoms of
vascular ring
How common are abnormal coronary arteries present in TOF? What is the most common abnormality?
In about 5% of TOF patients, abnormal coronary arteries are present. The most common abnormality is the anterior descending branch arising from the right coronary artery and passing over the RVOT, which prohibits a surgical incision in the
region
How common is AV canal defects in pts with TOF?
Complete AV canal defect occurs in approximately 2% of patients with TOF, more commonly among patients with Down syndrome, called “canal tet.” In these patients, the VSD has a large outlet component in addition to the inlet portion associated with the AV canal
History findings in pts with TOF?
- A heart murmur is audible at birth.
- Most patients are symptomatic with cyanosis at birth or shortly thereafter. Dyspnea on exertion, squatting, or hypoxic spells develop later even in mildly cyanotic infants
- Occasional infants with acyanotic TOF may be asymptomatic or may show signs of CHF from a large left-to-right ventricular shunt
Physical examination findings in pts with TOF?
- Varying degrees of cyanosis, tachypnea, and clubbing (in older infants and children)
- An RV tap along the left sternal border and a systolic thrill at the upper and mid-left sternal borders are commonly present (50%).
- An ejection click that originates in the aorta may be audible. The S2 is usually single because the pulmonary component is too soft to be heard. A long, loud (grade 3 to 5 of 6) ejection-type systolic murmur is heard at the mid-and upper left sternal borders. This murmur originates from the PS but may be easily confused with the holosystolic regurgitant
murmur of a VSD. The more severe the obstruction of the RVOT, the shorter and softer the systolic murmur - acyanotic form: long systolic murmur, resulting from VSD and infundibular stenosis, is audible along the entire left sternal border, and cyanosis is absent. Thus, auscultatory findings resemble those of a small-shunt VSD (but, unlike VSD, the ECG
shows RVH or BVH)
ECG findings in TOF?
- Right-axis deviation (RAD) (+120 to +150 degrees) is present in cyanotic TOF. In the acyanotic form, the QRS axis is normal.
- RVH is usually present, but the strain pattern is unusual (because RV pressure is not suprasystemic). BVH may be seen in the acyanotic form. RAH is occasionally present
CXR findings in cyanotic TOF?
- The heart size is normal or smaller than normal, and pulmonary vascular markings are decreased. “Black” lung fields are seen in TOF with pulmonary atresia.
- A concave main PA segment with an upturned apex (i.e., “boot-shaped” heart or coeur en sabot) is characteristic
- RA enlargement (25%) and right aortic arch (25%) may be present.
CXR findings in acyanotic TOF?
Radiographic findings of acyanotic TOF are indistinguishable from those of a small to moderate VSD (but patients with TOF have RVH rather than LVH on the ECG).
Echo findings in TOF?
- A large, perimembranous infundibular VSD and overriding of the aorta are readily imaged in the parasternal long-axis view
- Anatomy of the RVOT, the pulmonary valve, the pulmonary annulus, and the main PA and its branches is imaged in the parasternal short-axis and subcostal short-axis views. These views allow systematic evaluation of the severity of obstruction at different levels.
- Doppler studies estimate the pressure gradient across the RVOT obstruction.
- Anomalous coronary artery distribution can be imaged accurately by echocardiographic studies. The major concern is to rule out any branch of the coronary artery crossing the RVOT. Thus, preoperative cardiac catheterization solely for the diagnosis of coronary artery anatomy is not necessary.
- Associated anomalies such as ASD and persistence of the left superior vena cava (LSVC) can be imaged.
Describe the natural history of TOF (9)?
- Infants with acyanotic TOF gradually become cyanotic. Patients who are already cyanotic become more cyanotic as the infundibular stenosis worsens and polycythemia
develops. - Polycythemia develops secondary to cyanosis.*
- Physicians need to watch for the development of relative iron-deficiency states (i.e.,
hypochromia) - Hypoxic spells may develop in infants
- Growth retardation may be present if cyanosis is severe.*
- Brain abscess and cerebrovascular accident rarely occur
- Subacute bacterial endocarditis (SBE) is occasionally a complication.*
- Some patients, particularly those with severe TOF, develop aortic regurgitation (AR).
- Coagulopathy is a late complication of a long-standing cyanosis.*
What is a hypoxic (tet) spell?
Hypoxic spells are characterized by a paroxysm of hyperpnea (i.e., rapid and deep respiration), irritability and prolonged crying, increasing cyanosis, and decreasing intensity of
the heart murmur. Hypoxic spells occur in infants, with a peak incidence between 2 and 4 months of age. These spells usually occur in the morning after crying, feeding, or defecation. A severe spell may lead to limpness, convulsion, cerebrovascular accident, or even death. There appears to be no relationship between the degree of cyanosis at rest and the
likelihood of having hypoxic spells
Management of a tet spell?
- The infant should be picked up and held in a knee–chest position.
- Morphine sulfate, 0.2 mg/kg administered subcutaneously or intramuscularly, suppresses the respiratory center and abolishes hyperpnea (and thus breaks the vicious cycle).
- Oxygen is usually administered, but it has little demonstrable effect on arterial oxygen saturation.
- Acidosis should be treated with sodium bicarbonate (NaHCO 3 ), 1 mEq/kg administered IV. The same dose can be repeated in 10 to 15 minutes. NaHCO 3 reduces the respiratory center–stimulating effect of acidosis.
With the preceding treatment, the infant usually becomes less cyanotic, and the heart murmur becomes louder, which indicates an increased amount of blood flowing through the stenotic RVOT. If the hypoxic spells do not fully respond to these measures, the following medications can be tried:
- Ketamine, 1 to 3 mg/kg (average, 2 mg/kg) administered IV over 60 seconds, works well. It increases the systemic vascular resistance (SVR) and sedates the infant.
- Propranolol, 0.01 to 0.25 mg/kg (average, 0.05 mg/kg) administered by slow IV push, reduces the heart rate and may reverse the spell.
Medical management of TOF?
- Physicians should recognize and treat hypoxic spells. It is important to educate parents to recognize the spells and know what to do.
- Oral propranolol therapy, 0.5 to 1.5 mg/kg every 6 hours, is occasionally used to prevent hypoxic spells while waiting for an optimal time for corrective surgery in the regions where open heart surgical procedures are not well established for small infants.
- Balloon dilatation of the RVOT and pulmonary valve, although not widely practiced,
has been attempted to delay repair for several months. - Relative iron-deficiency states should be detected and treated. Iron-deficient children are more susceptible to cerebrovascular complications. Normal hemoglobin or hematocrit values or decreased red blood cell indices indicate an iron-deficiency state in cyanotic patients.
When would a shunt operation be chosen rather than primary repair in TOF pts?
Many institutions prefer primary repair without a shunt operation regardless of the patient’s age. However, when
the following situations are present, a shunt operation may be chosen rather than primary repair:
- Neonates with TOF and pulmonary atresia
- Infants with hypoplastic pulmonary annulus, which requires a transannular patch for complete repair
- Children with hypoplastic PAs
- Unfavorable coronary artery anatomy
- Infants younger than 3 to 4 months old who have medically unmanageable hypoxic spells
- Infants weighing less than 2.5 kg
What primary surgical operation are often performed in TOF?
Although several other procedures were performed in the past, a modified BT (Gore-Tex interposition) shunt is the only procedure performed at this time.
- Classic BT shunt, anastomosed between the subclavian artery and the ipsilateral PA, is usually performed for infants older than 3 months because the shunt is often thrombosed in young infants. A right-sided shunt is performed in patients with left aortic arch; a left-sided shunt is performed for right aortic arch.
- With a modified BT shunt, a Gore-Tex interposition shunt is placed between the subclavian artery and the ipsilateral PA. This is the most popular procedure for any age, especially for infants younger than 3 months of age. Whereas a left-sided shunt is preferred for patients with left aortic arch, a right-sided shunt is preferred for patients with a right aortic arch. The surgical mortality rate is 1% or less.
- The Waterston shunt, anastomosed between the ascending aorta and the right PA, is no longer performed because of a high incidence of surgical complications. Complications resulting from this procedure included too large a shunt leading to CHF or pulmonary hypertension and narrowing and kinking of the right PA at the site of the anastomosis. This created difficult problems in closing the shunt and reconstructing the right PA at the time of corrective surgery.
- The Potts operation, anastomosed between the descending aorta and the left PA, is no longer performed either. It may result in heart failure or pulmonary hypertension, as in
the Waterston operation. A separate incision (i.e., left thoracotomy) is required to close the shunt during corrective surgery, which is performed through a midsternal incision
Indications for complete repair surgery of TOF?
- Oxygen saturation less than 75% to 80% is an indication of surgery by most centers. The occurrence of hypoxic spells is generally considered an indication for operation.
- Symptomatic infants who have favorable anatomy of the RVOT and PAs may have primary repair at any time after 3 to 4 months of age, with some centers performing it even before 3 months of age. Most centers prefer primary elective repair by 1 to 2 years of age even if they are asymptomatic, acyanotic (i.e., “pink tet”), or minimally cyanotic.
Advantages cited for early primary repair include diminution of hypertrophy and fibrosis of the RV, normal growth of the PAs and alveolar units, and reduced incidence of postoperative ventricular arrhythmias, and sudden death.
- Mildly cyanotic infants who have had previous shunt surgery may have total repair 1 to 2 years after the shunt operation.
- Asymptomatic children with coronary artery anomalies may have the repair after 1 year of age, because a conduit placement may be required between the RV and the PA.
Complications for complete repair surgery for TOF?
- Bleeding problems may occur during the postoperative period, especially in older polycythemic patients.
- Pulmonary valve regurgitation may occur, but mild regurgitation is well tolerated.
- Right bundle branch block (RBBB) on the ECG caused by right ventriculotomy, which occurs in more than 90% of patients, is well tolerated.
- Complete heart block (i.e., <1%) and ventricular arrhythmia are both rare.
Incidence of TGA? Is there a sex predominance?
5% to 7% of all CHDs.
It is more common in males than in females (male-to-female ratio of 3:1
What is complete TGA?
In complete TGA, the aorta arises anteriorly from the RV carrying desaturated blood to
the body, and the pulmonary artery (PA) arises posteriorly from the LV carrying oxygen-
ated blood back to the lungs. In the classic complete TGA, the aorta is located anteriorly
and to the right (dextro) of the PA. This is why the prefix D is used and thus the condi-
tion is called D-transposition (D-TGA). (When the transposed aorta is located to the left
of the PA, it is called L-transposition)
Result of D-TGA with regards to circulation?
The result of D-TGA is complete separation of the pulmonary and systemic circulations. This results in hypoxemic blood circulating throughout the body and hyperoxemic blood circulating in the pulmonary circuit, which is not compatible with survival (see Fig. 11-4). Defects that permit mixing of the two circulations (e.g., atrial septal defect [ASD], VSD, and patent ductus arteriosus [PDA]) are necessary for survival.
What is the most common defect associated with TGA?
About half of these infants do not have associated defects other than a patent foramen ovale (PFO) or a small PDA (i.e., simple TGA)
Describe LVOT in TGA?
In about 5% of the patients, left ventricular outflow tract (LVOT) obstruction (or subpulmonary stenosis) occurs. The obstruction may be dynamic or fixed. Dynamic obstruction of the LVOT, which occurs in about 20% of such patients, resultsfrom bowing of the interventricular septum to the left because of a high RV pressure. Anatomic (or fixed) subpulmonary stenosis or abnormal mitral chordal attachment rarely causes obstruction of the LVOT
Describe association of VSD with TGA?
VSD is present in 30% to 40% of patients with D-TGA and may be located anywhere in the ventricular septum. A combination of VSD and significant LVOT obstruction (or PS) occurs in about 10% of all patients with D-TGA. Infants with TGA and VSD more
commonly have associated defects than those without associated VSD. Such associated defects may include COA, interrupted aortic arch, pulmonary atresia, and an overriding
or straddling of the atrioventricular (AV) valve.
Describe overriding in TGA?
Overriding is an abnormal relationship between the AV valve annulus and the ventricular septum. The AV valve annulus commits to both ventricular chambers, and it is the result
of malalignment of the atria and ventricular septa. Straddling is present when the chordae tendineae insert into the contralateral ventricle through a septal defect. Type A straddling is a mild form in which the chordae insert near the crest of the ventricular septum. In type B, the insertion is along the ventricular septum. In type C straddling, the chordae insert into the free wall of the contralateral ventricle. Overriding and straddling may occur independently or coexist in the same valve
History findings in TGA?
- History of cyanosis from birth is always present.
- Signs of congestive heart failure (CHF) with dyspnea and feeding difficulties develop
during the newborn period.
Physical exam findings in TGA?
- Moderate to severe cyanosis is present, especially in large male newborns. Such an infant is tachypneic but without retraction unless CHF supervenes.
- The S2 is single and loud. No heart murmur is heard in infants with an intact ventricular septum. An early or holosystolic murmur of VSD may be audible in less cyanotic
infants with associated VSD. A soft midsystolic murmur of PS (LVOT obstruction) may be audible. - If CHF supervenes, hepatomegaly and dyspnea develop.
Lab findings in TGA?
- Severe arterial hypoxemia usually with acidosis is present. Hypoxemia does not respond to oxygen inhalation.
- Hypoglycemia and hypocalcemia are occasionally present.
ECG findings in TGA?
- Right ventricular hypertrophy (RVH) is usually present after the first few days of life. The QRS voltages and the QRS axis may be normal in many newborns with the defect. After 3 days of life, an upright T wave in V1 may be the only abnormality suggestive of RVH
- Biventricular hypertrophy (BVH) may be present in infants with large VSD, PDA, or pulmonary vascular obstructive disease because all of these conditions produce an addi-
tional left ventricular hypertrophy (LVH). - Occasionally, right atrial hypertrophy (RAH) is present.
CXR findings in TGA?
- Cardiomegaly with increased pulmonary vascularity is typically present.
- An egg-shaped cardiac silhouette with a narrow, superior mediastinum is characteristic
Echo findings in TGA?
- In the parasternal long-axis view, the great artery arising from the posterior ventricle (LV) has a sharp posterior angulation toward the lungs, which suggests that this artery
is the PA. In contrast to the normal intertwining of the great arteries, the proximal portion of the great arteries runs parallel. Unlike in a normal heart, there is a fibrous continuity between the pulmonary and mitral valves, and subaortic conus is present. (In normal hearts, there is aortic–mitral fibrous continuity with subpulmonary conus.) - In the parasternal short-axis view, the “circle and sausage” appearance of the normal great arteries is not visible. Instead, the great arteries appear as “double circles”. The PA is in the center of the heart, and the coronary arteries do not arise from this great artery. The aorta is usually anterior and slightly to the right of the PA, and the coronary arteries arise from the aorta.
- In the apical and subcostal five-chamber views, the PA (i.e., the artery that bifurcates) is seen to arise from the LV, and the aorta arises from the RV.
- The status of atrial communication, both before and after balloon septostomy, is best evaluated in the subcostal view. Doppler examination and color-flow mapping should aid in the functional evaluation of the atrial shunt.
- Frequently, associated defects such as VSD, LVOT obstruction (dynamic or fixed), or pulmonary valve stenosis are found. Subaortic stenosis or COA rarely occurs.
- The coronary arteries can be imaged in most patients in the parasternal and apical views
When is cardiac catheterisation performed in pts with TGA?
Cardiac catheterization is performed only for the purpose of balloon atrial septostomy to improve mixing at the atrial level. Rarely, it is performed to look for associated anomalies such as abnormal coronary artery, collateral circulation, or a small aortic isthmus.
Describe the natural history of pts with TGA?
- Progressive hypoxia, acidosis, and heart failure result in death in the newborn period. Without surgical intervention, death occurs in 90% of patients before they reach
6 months of age. - Infants with an intact ventricular septum are the sickest group but demonstrate the most dramatic improvement after Rashkind balloon atrial septostomy.
- Infants with VSD are the least cyanotic group but the most likely to develop CHF and pulmonary vascular obstructive disease. Many infants with TGA and a large VSD
develop moderate pulmonary vascular obstructive disease by 3 to 4 months of age. Thus, surgical procedures are recommended before that age. - Infants with a significant PDA are similar to those with a large VSD in terms of their development of CHF and pulmonary vascular obstructive disease.
- The combination of VSD and PS allows considerably longer survival without surgery because the pulmonary vascular bed is protected from developing pulmonary hypertension, but this combination carries a high surgical risk for correction.
What measures should be done to stabilise pts before an emergency cardiac catheterisation (if performed) or a surgical procedure is carried out in pts with TGA?
a. Arterial blood gases and pH should be obtained, and metabolic acidosis should be corrected. Hypoglycemia and hypocalcemia, if present, should be treated.
b. PGE 1 infusion should be started to improve arterial oxygen saturation by reopening the ductus. This should be continued throughout the cardiac catheterization or until the time of surgery.
c. Oxygen should be administered for severe hypoxia. Oxygen may help lower pulmonary vascular resistance (PVR) and increase pulmonary blood flow (PBF), which in turn increases systemic arterial oxygen saturation.
CHF may be treated with diuretics (and digoxin)
When might cardiac catheterisation and a balloon atrial septostomy be performed in pts with TGA?
Before surgery, cardiac catheterization and a balloon atrial septostomy (i.e., the Rashkind procedure) are often carried out to have some flexibility in planning surgery. If adequate interatrial communication exists and the anatomic diagnosis of TGA is clear by echocardiographic examination, the patient may go to surgery without cardiac catheterization or the balloon atrial septostomy. The need for the balloon septostomy may be determined by inadequate atrial mixing through the PFO (evidenced with a high Doppler flow velocity of >1 m/sec) or a lack of readiness for surgical intervention.
In the balloon atrial septostomy, a balloon-tipped catheter is advanced into the left atrium (LA) through the PFO. The balloon is inflated with diluted radio-opaque dye and abruptly and forcefully withdrawn to the right atrium (RA) under fluoroscopic or echocardiographic monitoring. This procedure creates a large defect in the atrial septum through which an improved intracardiac mixing occurs. An increase in the oxygen saturation of 10% or more and a minimal interatrial pressure gradient are considered satisfactory results of the procedure.
Describe the overall surgical approaches to TGA?
Palliative Procedure. No palliative procedure is performed unless an arterial switch operation (ASO) cannot be performed early in life.
Definitive Repair. Historically, definitive surgeries performed for TGA were procedures that switched right- and left-sided blood at three levels: the atrial level (intraatrial repair surgeries such as the Senning or Mustard operation), the ventricular level (i.e., Rastelli operation), and the great artery level (ASO). At this time, ASO is clearly the procedure of choice, and intraatrial repair surgeries are very rarely performed only under unusual
situations. The Damus-Kaye-Stansel operation in conjunction with the Rastelli operation can be performed in patients with VSD and subaortic stenosis. Because of a relatively poor
long-term result of the Rastelli operation, other options such as the Nikaidoh operation or REV (réparation à I’étage ventriculare) procedure have become more popular recently
What postop follow up is typical for post-TGA repair patients?
- Follow-up every 6 to 12 months is required for a possible progression of AV conduction disturbances, arrhythmias, or worsening of anatomic tricuspid valve regurgitation.
- Routine pacemaker care, if a pacemaker is implanted, should be conducted.
- Activity restriction is indicated if significant hemodynamic abnormalities persist.
