CME-SAM ARTICLE
Adult Congenital Heart Disease A Practical Approach Larry Latson, Jr, MD, MS,*w Jeffrey M. Levsky, MD, PhD,z and Linda B. Haramati, MD, MSy
Abstract: Adults with congenital heart disease (CHD) represent an increasing population both because anomalies that might have remained undiagnosed in the past are now being diagnosed later in life on imaging and because significant therapeutic advances have resulted in survival to adulthood of patients with complex CHD. In this article, we discuss simple and common complex congenital anomalies that are encountered in general practice including their incidence, associations, and expected postoperative appearances. We will describe an approach to segmental anatomy and situs evaluation and details of some of the common vascular anomalies, simple shunts, and complex CHDs to refine the imaging strategies and diagnostic acumen of radiologists interested in CHD who may not be practicing in specialized adult CHD centers. Key imaging appearances on chest radiography, protocoling tips for answering clinically relevant questions on computed tomography and magnetic resonance imaging, and the specific imaging appearances and common complications related to long-standing CHD in the adult and complications of treatment are reviewed for each entity. Key Words: adult congenital heart disease, heterotaxy, vascular anomalies, cardiac shunts, complex congenital heart disease
(J Thorac Imaging 2013;28:332–346)
LEARNING OBJECTIVES After completion of this activity, physicians should be better able to: 1. Identify the segmental anatomic classification system for congenital heart disease. 2. Describe late complications of repaired coarctation of the aorta. 3. Use the clinical information and imaging findings to diagnose simple cardiac shunts in adults. 4. Describe the two main operative techniques for repairing complete transposition of the great arteries (D-TGA).
*Cardiothoracic Radiology Fellow, Albert Einstein College of Medicine, Montefiore Medical Center, Bronx, NY; wCurrent affiliation: Assistant Professor, Department of Radiology, New York University, Langone Medical Center, New York, NY; zAssociate Director of Research, Research Assistant Professor, Department of Radiology, Albert Einstein College of Medicine, Montefiore Medical Center, Bronx, NY; and yProfessor of Clinical Radiology and Medicine, Division Head, Cardiothoracic Imaging-Radiology, Albert Einstein College of Medicine, Montefiore Medical Center, Bronx, NY. All authors and staff in a position to control the content of this CME activity and their spouses/life partners (if any) have disclosed that they have no financial relationships with, or financial interests in, any commercial organizations pertaining to this educational activity. Reprints: Linda B. Haramati, MD, MS, Department of Radiology, Albert Einstein College of Medicine/Montefiore Medical Center, 211 East 210th Street, Bronx, NY 10467 (e-mail:
[email protected]). Copyright r 2013 by Lippincott Williams & Wilkins
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INTRODUCTION The prevalence of congenital heart disease (CHD) in adults has been estimated at 3 to 4/10001,2 or about 800,000 people in the United States.2,3 Adult CHD encompasses a broad spectrum of diseases, including complex cardiac and vascular anomalies diagnosed and treated in infancy that now reach adulthood due to therapeutic advances, incidental anomalies demonstrated on imaging of asymptomatic patients, and various intermediate conditions.1,4 Adults with repaired CHD have complex anatomy and physiology.5–12 To properly assess these patients, one must foremost understand the original congenital abnormality and its pathophysiology. Second, one must recognize the surgery performed and its expected postoperative appearance. Finally, one must vigilantly search for the expected complications of repair or residual abnormality that may only be detected with specialized protocols. In the United States and other industrialized countries, most newly diagnosed adults with CHD have mild disease, having escaped detection in childhood. These patients can present clinically because of the hemodynamic consequences of long-standing disease that may become symptomatic due to comorbidities associated with aging, such as acquired pulmonary and cardiovascular disease. In addition, greater imaging utilization has led to incidental discovery of CHD. This review will focus on forms of adult CHD that radiologists can expect to see in routine practice. For each entity, we describe the clinical presentation, imaging appearance, techniques and protocols for analysis with computed tomography (CT) and magnetic resonance imaging (MRI), and the usual management, including indications for further evaluation or intervention. Although adults with CHD ought to be treated in specialized centers,12 they are frequently cared for in the community by nonspecialists, especially for acute symptoms. Radiologists may be in a position to make the initial diagnosis of CHD or detect important complications. It is crucial for radiologists to seize the opportunity to provide incremental value in the care of this enlarging group of patients.
THE ANATOMY OF CHD Knowledge of the segmental approach to cardiac anatomy, initially described by Van Praagh,13,14 allows the radiologist to speak in a language familiar to the cardiologist. This method succinctly conveys the relationships between the atria, ventricles, and great vessels. Although the terminology can initially be confusing, use of a standardized system ultimately facilitates communication. Attention to cardiac and visceral organ orientation can also be an important clue for detection of CHD. J Thorac Imaging
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Atrial sidedness or situs can be (S)olitus—right atrium on the right, (I)nversus—right atrium on the left, or (A)mbiguous. Atrial situs cannot be directly determined with radiographs; however, it can be predicted by assessment of the closely related bronchial situs. The morphologic right bronchus has a more vertical orientation with an upper lobe branch that arises close to the carina and a long bronchus intermedius. The right mainstem bronchus is above the pulmonary artery (eparterial). In contrast, the left bronchus is longer, more horizontal, and courses below the left pulmonary artery (hyparterial). Ventricular looping, which determines ventricular sidedness, can be D—right ventricle on the right; L—right ventricle on the left; or X—in a single ventricle. Great artery orientation can be (S)olitus—aorta posterior and to the right of the pulmonary artery; (I)nversus—aorta posterior/left, (D)-malposed—aorta anterior/right; or (L)malposed—aorta anterior/left. Atrial, ventricular, and arterial sidedness is conveyed segmentally, in order. Thus, a normal patient is {S, D, S}—atrial situs solitus, ventricular D-looping, and normally related great arteries. Patients with situs solitus and complete transposition of the great arteries (D-TGA) are {S, D, D}, whereas those with congenitally corrected transposition of the great arteries (L-TGA) are {S, L, L}. A detailed contemporary review of the segmental approach has recently been published.15 Visceral situs and the position of the cardiac apex are easily assessed on plain radiographs. In abdominal situs solitus the liver is on the right, and the spleen and stomach are on the left. The rate of CHD in infants with visceral situs solitus and levocardia (normal left-sided cardiac apex) is 0.8%16; the rate is even lower in adults. The rate is similar in patients with situs solitus and mesocardia (midline cardiac apex). In situs inversus the abdominal viscera are reversed, the morphologic right atrium is on the left, and the cardiac apex is on the right. The rate of CHD in situs inversus is 3% to 5%.16 When the situs is neither solitus nor inversus, it is termed situs ambiguous or heterotaxy. The 2 major forms of heterotaxy are asplenia and polysplenia. Asplenia is strongly associated with severe, cyanotic CHD (>90%) such as total anomalous pulmonary venous return and single ventricle.16,17 Adults with asplenia have almost always been diagnosed and treated in childhood.
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Polysplenia is also associated with CHD (B75%) but typically has less severe anomalies, including atrial septal defect (ASD), partial anomalous pulmonary venous return (PAPVR), and pulmonic stenosis.16,17 Patients with polysplenia may be discovered incidentally after childhood. Venous anomalies, such as azygous continuation of the inferior vena cava (IVC), are common and may complicate catheter placement or interventional procedures17 (Fig. 1).
VASCULAR ANOMALIES Aortic Coarctation The hallmark of aortic coarctation is upper extremity hypertension due to congenital narrowing of the aorta. This anomaly accounts for approximately 5% of all CHD,18 with a prevalence in adults of 0.07/1000.1 Historically, coarctation was thought to be a localized defect of the aortic isthmus. Newer studies, however, suggest that coarctation is part of a systemic cardiovascular anomaly of unknown pathogenesis.8,19,20 This is supported by the high prevalence of associated anomalies, the most common of which is bicuspid aortic valve (> 50%).8,17,19,21 Complications of coarctation include the sequelae of longstanding hypertension and can be life threatening (eg, acute aortic syndromes, aortic and cerebral aneurysms). Aortic coarctation includes a wide spectrum of diseases ranging from mild narrowing of the aorta to complete occlusion, with variability in the site of narrowing and degree of involvement of the great vessels. This anatomic variability leads to varied clinical presentations. Patients with “early” disease presentation were classically diagnosed in infancy during workup of symptoms of congestive heart failure (due to obstruction of systemic blood flow) and are now commonly detected by routine fetal sonography. “Early” coarctations have more severe anatomic defects, such as hypoplasia of the aortic arch, and associated anomalies such as ventricular septal defects (VSDs), which obligate intervention early in life.17 Cardiac anomalies associated with coarctation include ASDs and VSDs.22 Some patients have coarctation as part of a more complex disorder, including Shone, Williams, PHACES, and Turner syndromes. Shone syndrome is associated with 4 levels of left heart obstruction: supravalvar mitral ring, subaortic stenosis, parachute mitral
FIGURE 1. A 31-year-old woman with heterotaxy, polysplenia, and an endocardial cushion defect who underwent Fontan palliation. A, Contrast-enhanced axial CT of the upper abdomen demonstrating multiple spleens (*) consistent with polysplenia. There is an azygous continuation of the IVC (arrow), which is commonly associated with polysplenia. The liver demonstrates heterogenous enhancement due to congestion, common in patients with Fontan circulation. B, Coronal minimum intensity projection reconstruction demonstrating bilateral hyparterial (left-sided) bronchi (*) that course below the pulmonary arteries. Note the rightsided aortic arch (arrow) indenting the trachea. The left-sided paratracheal opacity that does not indent the trachea is the dilated azygous arch. r
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FIGURE 2. An 85-year-old man who presented for evaluation for bronchiectasis. Noncontrast oblique sagittal CT image demonstrating a focal narrowing in the proximal descending thoracic aorta (arrow) with a “kink,” or buckling, at the aortic isthmus. There were no collateral vessels to suggest a hemodynamically significant coarctation. These findings are typical of aortic pseudocoarctation.
valve, and coarctation.23 Williams syndrome is frequently associated with multiple stenoses of the aorta, systemic branch arteries, and peripheral pulmonary arteries. Turner syndrome has a high frequency of aortic anomalies including coarctation in up to 15%.24,25 Coarctation is also a part of a rare constellation of anomalies denoted by the acronym PHACES (posterior fossa malformations, hemangiomas of the face and neck, arterial anomalies, cardiac defects or coarctation of the aorta, eye or endocrine anomalies, and sternal defects). Late presentation of aortic coarctation occurs in older children and adults.17 The diagnosis may be made during a workup for hypertension or discovered incidentally on imaging performed for other reasons. The aortic narrowing is usually juxtaductal, beyond the origin of the left subclavian artery, at the site of the ligamentum arteriosum. The aortic arch is characteristically elongated, with an increased separation between the left common carotid artery and the posteriorly displaced left subclavian artery.26,27 Pseudocoarctation is the presence of an elongated aorta with kinking at the isthmus but without hemodynamically significant stenosis (Fig. 2). Absence of arterial collateral vessels is a significant pertinent negative finding. Pseudocoarctation has been described in families with true coarctation and has similar associations including bicuspid aortic valve, aortic aneurysm, and dissection. It likely represents a mild form of coarctation.28,29 There are a number of classic chest radiographic findings of coarctation in children and adults. The “3” sign results from deformity of the aorta and arch vessels30 (Fig. 3). The superior curve represents the dilated left subclavian artery or dilated aortic arch proximal to the coarctation. The inferior curve represents the poststenotic dilation of the proximal descending aorta, and the central
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indentation represents the site of coarctation.17 A network of collateral arteries develops to bypass the coarctation and to supply blood distal to the coarctation. The collaterals become enlarged and tortuous later in childhood and may cause bony findings on chest radiographs. Retrosternal scalloping reflects hypertrophied internal mammary collaterals. Rib notching, due to erosions of the undersurfaces of the ribs by intercostal arteries, typically involves the third or fourth through eighth ribs, which have reversed flow and supply the descending aorta distal to the coarctation. The first and second ribs are not involved because their intercostal arteries are branches of the subclavian arteries, which arise proximal to the coarctation.17 Unilateral right-sided rib notching occurs when the coarctation occurs proximal to the origin of the left subclavian artery, and unilateral left-sided rib notching occurs when the coarctation is proximal to an aberrant right subclavian artery; in both cases the artery that arises distal to the coarctation is unable to supply collaterals, and rib notching does not develop on that side.17,31 The American College of Cardiology 2008 guidelines recommend that every patient with coarctation (repaired or not) should undergo at least 1 CT or MRI for evaluation of the thoracic aorta and intracranial vessels.12 For adults with unrepaired coarctation, the guidelines recommend intervention when the gradient across the coarctation is >20 mm Hg or when there are radiographically substantial collateral vessels indicating hemodynamic significance.12 Treatment of coarctation can be by means of a variety of different open and transcatheter procedures, including direct end-to-end anastomosis or graft placement, balloon angioplasty, or stenting.21,32,33 The choice of treatment depends on the patient’s specific anatomy and institutional expertise. Patients require life-long follow-up after repair with at least yearly physical examinations including measurements of blood pressures in the upper and lower extremities and CT or MRI at least every 5 years.12,20 Complications after coarctation repair include persistent hypertension, recoarctation or residual stenosis, dissection, aneurysm or pseudoaneurysm formation, or frank rupture at the site of repair.21,32–35 Interestingly, patients are also at increased risk for premature coronary artery disease related to long-standing proximal hypertension.18,21,35 Potential associated anomalies are assessed at the time of imaging, including bicuspid aortic valve, which is frequently dysfunctional and may require intervention. Imaging of coarctation with CT angiography has several advantages, including speed and patient tolerability. CT provides high-resolution, detailed evaluation of the coarctation site and the formation of collaterals. Limitations include the use of ionizing radiation, which is a significant concern considering that coarctation patients undergo multiple studies over the course of their lives, and the use of iodinated contrast agents, whose use may be limited in patients with renal insufficiency and which rarely can result in a severe contrast reaction. CT also incompletely evaluates the aortic valve, especially when retrospective electrocardiogram (ECG)-gating is not used. MRI offers the advantage of no ionizing radiation and no iodinated contrast agent but involves a longer examination time and requires a cooperative patient capable of performing multiple breath-holds. MRI is limited by patient claustrophobia and is unsafe in patients with incompatible implants. MRI offers detailed anatomic imaging including systolic phase measurements. MRI is used to depict the r
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FIGURE 3. A 44-year-old woman with a history of aortic coarctation repair in childhood. A, Posteroanterior chest radiograph demonstrating an abnormal descending aortic contour (arrow). The classic “3” configuration indicates the dilated aorta proximal and distal to the coarctation with nipping in at that level of the narrowing. B, Oblique contrast-enhanced maximum intensity projection CT reconstruction demonstrating a juxtaductal coarctation of the aorta (white *) just distal to the origin of a dilated left subclavian artery. Surgical repair with a bypass graft (black arrow) was complicated decades later by dilatation of the proximal and distal anastomoses (black *) and distal pseudoaneurysm formation. C, 3D, volume rendered CT image after repeat surgical repair of the distal aortic arch and proximal descending aorta (*). The left subclavian artery was distally reimplanted (arrow).
anatomy and function of the aortic valve and quantify regurgitant volume and stenosis related flow acceleration with phase contrast imaging. A flow volume increase along the descending aorta documents the contribution of collateral vessels and suggests hemodynamically significant recurrent or residual coarctation.36,37
PAPVR PAPVR is defined as abnormal drainage of 1 or more pulmonary veins into a systemic vein or the right atrium.38 It represents a left-to-right shunt as oxygenated (left-sided) pulmonary venous blood drains into a deoxygenated (rightsided) systemic venous structure or cardiac chamber. The clinical effect of PAPVR depends on the volume of shunted blood and is often mild. In contradistinction, the embryologically similar total anomalous pulmonary venous return, when all pulmonary venous blood is shunted to the right heart, results in neonatal cyanosis. Cases of PAPVR diagnosed in childhood are more severe and complex than those detected in adults. In children, PAPVR is usually right-sided (80%), often involving r
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the right upper lobe vein, and is usually associated with other anomalies.39 Right upper lobe PAPVR is an integral component of the sinus venosus-type ASD.40 Pulmonary venolobar (scimitar) syndrome refers to anomalous pulmonary venous drainage of much or all of the right lung inferiorly into the IVC, hepatic veins, or right atrium. The anomalous draining vein resembles a Turkish sword, hence the term scimitar.30 Other components of the syndrome include hypoplasia of the right lung and right pulmonary artery and dextroposition of the heart.17,41,42 Sinus venosus defects and pulmonary venolobar syndrome may also be detected in adults, either after treatment or as an initial presentation. More commonly, adults present with isolated PAPVR of the left upper lobe vein, which drains through a persistent vertical vein into the left brachiocephalic vein.38,40,43 The incidence of unsuspected PAPVR on CT scans performed for unrelated indications is up to 0.3%.38,40,43 The hemodynamic consequences of PAPVR range from none to development of right ventricular volume overload and heart failure.41,44 Pulmonary hypertension is www.thoracicimaging.com |
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FIGURE 4. A 29-year-old man who presented to the emergency department with chest pain. A, Posteroanterior chest radiograph demonstrating a characteristic contour abnormality in the left superior mediastinum (arrows), lateral to the aortic arch, typical for a vertical vein in a patient with PAPVR of the left upper lobe. B, Oblique coronal reconstruction from a contrast-enhanced CT showing the left upper lobe vein arising from the lung and forming the vertical vein (arrows) that courses cephalad to join the left brachiocephalic vein, which is dilated. C, Axial contrast-enhanced CT at the level of the aortic arch demonstrating an abnormal vessel to the left of the aortic arch (arrow). The SVC is dilated. On axial cross-sectional imaging, the differential diagnosis includes a duplicated SVC and a vertical vein related to PAPVR of the left upper lobe. Understanding the origin and drainage of the anomalous vein is key to ascertaining the correct diagnosis. On this axial image alone, the diagnosis of a vertical vein is favored; PAPVR is a left-to-right shunt that results in dilatation of the SVC and right heart chambers. Patients with duplicated SVC have bilateral small SVCs, typically without shunting. Ao indicates aorta; LPA, left pulmonary artery.
uncommon because PAPVR is a low-pressure shunt, unlike VSD and patent ductus arteriosus (PDA).5 Right heart enlargement in an adult without a readily apparent cause warrants further evaluation for shunts including PAPVR,
as anomalous pulmonary veins may be undetectable on echocardiography.12,45 Surgical correction of PAPVR is considered when there are symptoms, such as dyspnea on exertion, in the
FIGURE 5. A 74-year-old man with a history of cardiomegaly who presented to the emergency department with atypical chest pain. A nongated CT was performed for suspected pulmonary embolism. A, Oblique coronal contrast-enhanced CT reconstruction image showing PAPVR from the right upper and middle lobes into the SVC (arrows). The right atrium (RA) is dilated. B, Oblique sagittal contrast-enhanced CT image showing the typical appearance of a sinus venosus atrial septal defect (*). Blood from the SVC directly enters both the right and left (LA) atria at the level of the sinus venosus, in an inverted “Y” configuration.
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presence of significant dysrhythmia, or when the pulmonary to systemic blood flow ratio (Qp:Qs) exceeds 1.5 to 2:1.41,46 The type of surgical repair depends on the anatomy. The possibilities include baffling the anomalous vein through a surgical ASD to the left atrium (for right-sided anomalies), reimplantation of the vein on the left atrium or the left atrial appendage, and anastomosis of the anomalous vein to a normally draining pulmonary vein (usually for leftsided anomalies).41,42,44,46 Patients with concomitant sinus venosus ASD may undergo repair by caval division (Warden procedure). The cranial (systemic) portion of the superior vena cava (SVC) is attached to the right atrial appendage. The caudal part of the SVC, which includes the anomalous pulmonary vein drainage, remains connected to the left atrium through the sinus venosus defect and no longer communicates with the right atrium.12,47 Chest radiographic findings depend on the location of the anomalous vein and the degree of shunting. PAPVR of the left upper lobe drains into a vertical vein, which creates a subtle but characteristic abnormal contour of the left superior mediastinum (Fig. 4).38 When pulmonary venolobar syndrome is present, the typical curved “scimitar” vein will be evident along with a small right lung. Other types of PAPVR can present with normal radiographs when there is mild shunting or with right heart enlargement and overcirculation (shunt vascularity) when the shunt is greater.17 Cross-sectional imaging of PAPVR should clearly define the anatomy of the anomalous and normal pulmonary veins, demonstrate associated cardiac anomalies, assess right and left ventricular volumes and function, and calculate the ratio of pulmonary to systemic flow (Qp:Qs). CT and MRI play major roles in determining the need for intervention and planning surgery. CT and MR angiography are the noninvasive diagnostic modalities of choice for pulmonary venous anatomy given their excellent correlation with surgical findings.48 The venous anomalies are readily detected by either modality without ECG-gating. Associated cardiac anomalies, such as ASD, are better demonstrated with MRI or ECG-gated CT. Sinus venosus ASD may be difficult to perceive on axial images but it has a characteristic appearance on oblique sagittal reconstructions. The SVC has an inverted “Y” shape as it drains directly into both atria (Fig. 5). In addition to the lack of ionizing radiation, MRI has several advantages over CT that make it optimal for evaluating patients with PAPVR. Qp:Qs can be directly measured with phase contrast imaging of the proximal pulmonary artery and aorta, with good correlation with catheterization measurements.48,49 CT typically has superior spatial resolution to MRI; however, it cannot directly measure flow. Although both ECG-gated CT and cine bright blood MRI can be used to measure right and left ventricular volumes and function, MRI is currently considered the “gold standard.” When MRI is not feasible, comparison of right and left ventricular stroke volumes on CT can be used to estimate Qp:Qs in patients without significant valvular insufficiency. A recent study of patients who were referred for MRI for evaluation of unexplained right ventricular enlargement demonstrated PAPVR in 36/37 patients with the anomaly, confirming high sensitivity.45 Care must be taken to distinguish PAPVR of the left upper lobe from a persistent left SVC. Both entities have an “extra” vessel to the left of the aortic arch.50,51 The key difference is the origin and drainage pathway of the anomalous vein. PAPVR of the left upper lobe drains the r
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lung superiorly through the vertical vein into a dilated left brachiocephalic vein. A left-sided or duplicated SVC arises from the confluence of the jugular and subclavian veins and most commonly drains inferiorly into a dilated coronary sinus. Patients with a duplicated SVC may, or may not, have a small connecting vein between the cavae.
SIMPLE SHUNTS ASD ASDs are the most prevalent form of adult CHD, occurring in approximately 0.88 of 1000 adults.1 There are 3 major types of ASD: ostium secundum, ostium primum, and sinus venosus. Ostium secundum defects are the most common form (75%), whereas ostium primum ASD is associated with endocardial cushion/atrioventricular canal defects, a complex CHD that is repaired early in life. Atrioventricular canal is commonly associated with trisomy 21 (Down syndrome) and heterotaxy.17 Superior sinus venosus defects account for about 10% of ASDs5,12,52 and have a strong association with PAPVR (see above). Inferior sinus venosus ASDs occur at the IVC to right atrial junction and are rare. Secundum ASDs occur at the fossa ovalis. In contrast to ostium primum ASDs, they are often well-tolerated, isolated anomalies that can present in adulthood or can be detected incidentally on imaging.12,17 The pathophysiology of the shunt flow in ASD is complex and depends on a number of factors, including the size of the defect and the capacity and compliance of the ventricles.5 In a patient with an otherwise normal heart, the compliance of the thinner right ventricle, which pumps blood to the low-resistance pulmonary circulation, is greater than the thicker left ventricle, which pumps blood to the high-resistance systemic circulation. This results in higher left atrial pressure than right atrial pressure. Thus, flow through the ASD is typically from left to right.50 As patients age, the left ventricular compliance naturally decreases, increasing the left-to-right shunt.5 Perhaps this explains why many patients with ASD are asymptomatic in childhood and early adulthood and become symptomatic later in life. In addition, the onset of agingrelated diseases such as hypertension and chronic obstructive pulmonary disease change the hemodynamics and may unmask a previously well-tolerated, low-pressure shunt. The most common signs and symptoms of ASD are progressive shortness of breath with exertion, fatigue, syncope, and heart murmur on auscultation.5 Other presenting events include atrial dysrhythmia, due to dilation of the atria causing conduction abnormalities, and paradoxical embolism from the systemic venous circulation to the systemic arterial circulation.5,53,54 The development of irreparable pulmonary hypertension with shunt reversal and cyanosis or Eisenmenger syndrome occurs in up to 15% of patients with unrepaired ASD.5 This is in contrast to higher-pressure left-to-right shunts, such as PDA and VSD, which more frequently lead to pulmonary hypertension.12 Chest radiography has characteristic findings in adults with ASD (Fig. 6). Most radiologists who interpret chest radiographs in clinical practice will have the opportunity to correctly suggest the diagnosis of ASD in an adult. However, familiarity with the findings is crucial. Cardiomegaly, particularly dilation of the right atrium and right ventricle, is notable and may be better appreciated on the lateral view as filling of the retrosternal clear space. The main and peripheral pulmonary arteries are often strikingly dilated.50 www.thoracicimaging.com |
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FIGURE 6. A 64-year-old woman with a history of asthma who presented with shortness of breath. Posteroanterior chest radiograph showing an enlarged heart. The central and peripheral pulmonary arteries are dilated consistent with overcirculation (shunt vascularity). The patient subsequently underwent echocardiography, which demonstrated a large atrial septal defect.
The pulmonary blood flow pattern is overcirculation (shunt vascularity), which must be differentiated from pulmonary arterial hypertension, a more common cause of enlarged central pulmonary arteries and right ventricular dilation in adults. In pulmonary hypertension, the peripheral pulmonary arteries are attenuated or “pruned,” and the lungs are hyperlucent due to diminished perfusion.17,55 In patients with shunts, the peripheral arteries are enlarged. When a shunt progresses to Eisenmenger syndrome, the overcirculated peripheral pulmonary vasculature becomes less pronounced; however, “pruning” is rarely evident, and the lungs are typically not hyperlucent. The American College of Cardiology 2008 guidelines suggest that repair of ASD is indicated when it is 10 mm or more in diameter and there is right atrial and ventricular enlargement or when the Qp:Qs exceeds 1.5:1.12,54 History of a paradoxical embolism is also an indication for closure.12 ASD closure is contraindicated in patients with severe pulmonary hypertension and Eisenmenger syndrome.12,54 Echocardiography is the standard modality for assessing ASD. It capitalizes on the echogenicity of soft
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tissue-fluid interfaces to provide visualization even when the tissue is extremely thin, like the intact atrial septum. Cardiac MRI is a useful adjunctive tool in some cases and directly shows ASDs on cine bright blood images without limitations due to acoustic windows and most body shapes. The flap of tissue at the floor of the fossa ovalis is often very thin and poorly demonstrated on MRI due to volume averaging. Therefore, it is necessary to see a dephasing jet extending directly through a defect from the left into the right atrium to make a sure diagnosis. When an ASD is suspected, ventricular volumes and ejection fraction, as well as phase contrast imaging in the aorta and main pulmonary artery (to estimate Qp:Qs), should be measured with MRI. MR angiography detects anomalous pulmonary veins, which can alter the treatment strategy. ECG-gated CT also gives high-resolution images of the interatrial septum and performs excellently in depicting secundum ASD. It is important to differentiate a secundum ASD from patent foramen ovale (PFO), which occurs in the same location and may be considered a normal variant, as it is present in up to 25% of adults.56 PFO is an oblique flap valve that is usually closed but permits bidirectional communication between the atria, especially during periods of increased pressure such as those due to the Valsalva maneuver or contrast injection. The oblique orientation of the tissue flap distinguishes PFO from a small secundum ASD, which is a straight communication between the atria. PFO is correlated with stroke and migraines57,58; however, to date no clinical trials have demonstrated an outcome benefit to closure, even in patients with stroke.59,60 This is in contrast to ASD closure, which is supported by evidence. Although one would hope that ASD closure would return a patient’s morbidity and mortality risk to baseline, this does not appear to be the case in adults. In an outcomes study of 123 patients who underwent surgical repair and had multidecade follow-up, there was significantly increased mortality, stroke, heart failure, and atrial fibrillation in patients repaired at 25 years of age or older as compared with age-matched controls. The rate of these complications in patients repaired earlier in life was not statistically different from that of the age-matched controls.53 This suggests that despite elimination of the shunt, irreversible cardiovascular injury has occurred by early adulthood.8,53 Multiple methods of ASD closure are available, including conventional and minimally invasive surgery, either with direct suturing or with a pericardial or synthetic patch.54 The latter is often necessary for larger defects.
FIGURE 7. A 24-year-old woman with chest pain and dyspnea on exertion was found to have a secundum atrial septal defect with a dilated right heart on echocardiography. A, Magnified posteroanterior chest radiograph obtained after placement of an Amplatzer septal occluder device. The device is faintly visible as 2 radiopaque markers surrounded by the 2 metal disks. B, Magnified lateral chest radiograph more clearly demonstrates the conspicuous appearance of the device with 2 apposed radiopaque disks in the expected location of the interatrial septum.
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More recently, percutaneous transcatheter closure has become an important treatment option for patients with secundum ASD. When used appropriately, device closure has been shown to be as safe and effective as surgery.58,61 Several devices are available, including the Gore HELEX (W.L. Gore and Associates) and Amplatzer Septal Occluder (AGA Medical Corporation) devices, which have distinctive radiographic appearances. Before device placement, the remaining atrial septal tissue around the defect (rims) must be evaluated to ensure that there is adequate space to anchor the occluder.50,58,61,62 The rims are assessed by measuring the length of the septal tissue in the 4 quadrants around the defect: anterior superior (ASD to aortic valve), anterior inferior (ASD to tricuspid valve), posterior superior (ASD to SVC), and posterior inferior (ASD to IVC). The minimum acceptable rim is typically 5 mm.58,61 When MRI or CT are performed for secundum ASD, the rims should be detailed in order to assess the feasibility of device closure.62 ASD occluder devices are not without complications. Device malpositioning, migration, embolization,63,64 and infection have been described and may be demonstrated on imaging. Devices can lead to clinically significant dysrhythmia.64 In rare cases, devices have eroded into the aorta; this occurs in adults who had device placement despite a deficient anterior superior rim.65 In patients with septal occlusion devices, the location of the device within the heart can be evaluated on radiographs. For example, the Amplatzer septal occluder can be inconspicuous on the frontal view, appearing most often as 2 small, metallic dots.66,67 The metallic disks are better visualized on the
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FIGURE 9. A 53-year-old woman who underwent ECG-gated CT for evaluation of suspected coronary artery disease. Multiplanar reformatted contrast-enhanced CT image in the ventricular short axis demonstrating an incidental, small restrictive muscular ventricular septal defect (*). Small restrictive ventricular septal defects are relatively common findings on coronary CT angiograms performed for other indications, generally do not lead to a hemodynamically significant shunt, and do not require further treatment. LV indicates left ventricle; RV, right ventricle.
lateral radiograph.66 The device should parallel the orientation of the interatrial septum (Fig. 7).
VSD
FIGURE 8. A 45-year-old man who presented to the emergency department with abdominal pain. Posteroanterior chest radiograph showing cardiomegaly with dilated central and peripheral pulmonary arteries consistent with overcirculation (shunt vascularity). The main pulmonary artery is calcified indicative of systemic pulmonary artery pressures. Echocardiography confirmed a large membranous ventricular septal defect with severe pulmonary arterial hypertension consistent with Eisenmenger syndrome. r
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VSDs are the second most common form of adult CHD after ASD, with a prevalence of 0.78/1000 adults.1 VSDs can occur as a solitary lesion or in combination with other forms of simple and complex CHD. There are multiple forms of VSD, including perimembranous, subarterial, inlet, and muscular.68 The 2 most common forms of isolated VSD are perimembranous (membranous or subaortic) and muscular.5,69 Patients with a large VSD and a significant left-toright shunt classically present in infancy or childhood with congestive heart failure. They may also be diagnosed by neonatal auscultation of a murmur or fetal sonography. As with other shunts, the presentation and hemodynamic effects depend on the size of the defect, degree of shunting, and presence of other coexisting defects. Patients with large VSDs only rarely present in adulthood, and when they do they often have irreversible pulmonary hypertension (Eisenmenger syndrome), at which point they are no longer candidates for repair5,17,69 (Fig. 8). In contrast, small, restrictive VSDs are often not clinically significant. As imaging utilization has increased, these VSDs are more commonly detected incidentally on imaging performed for other indications (Fig. 9). Closure of a VSD can be either through surgery or, more recently, with device closure similar to those used for ASD closure.12,69
PDA Most patients with PDA are diagnosed early in life either with congestive heart failure or by auscultation of the typical, continuous machine-like murmur. Associated defects include ASD and VSD.12 Occasionally, a small www.thoracicimaging.com |
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PDA will escape detection until adulthood. A large PDA is a rare cause of pulmonary hypertension in an adult but is sometimes seen in patients who did not have earlier access to adequate health care. Eisenmenger syndrome due to PDA has a classical clinical presentation described as “differential” cyanosis.70 When right-sided pressure is high enough to cause reversal of the shunt at the ductus, there is cyanosis of the lower extremities (distal to the PDA) but not of the upper extremities (proximal to the PDA).5,17 When diagnosed in adulthood, small PDAs without evidence of left heart volume overload or pulmonary hypertension can be observed.12 Patients with PDA and signs of left heart failure or endocarditis should undergo closure unless irreversible pulmonary hypertension has developed.12 PDA closure in adults is usually performed with a transcatheter device, as it is less invasive than open surgical closure, and the ductus is often heavily calcified rendering surgical repair more difficult.12,50 Normal structures that should not be mistaken for PDA include calcified ligamentum arteriosum,71 which is frequently present on CT in adults, and a ductus diverticulum, which is a normal smooth outpouching of the undersurface of the aorta at the level of the ligamentum arteriosum.
COMPLEX CHD Optimizing treatment paradigms to improve outcomes of adults with previously repaired complex CHD is an area of active investigation. The population of adults with complex CHD has markedly increased in the past few decades as successful surgical repairs in childhood have become commonplace. Complex CHD is a broad topic. In this review, we focus on a few common lesions that may be encountered with some frequency even in practices that do not specialize in adult CHD.
Tetralogy of Fallot Tetralogy of Fallot (TOF), the most common cyanotic CHD, is due to malalignment of the conal septum, which leads to the 4 originally described components of the anomaly: subaortic VSD, overriding aorta, right ventricular outflow tract obstruction, and right ventricular hypertrophy.9,17,72,73 Septal malalignment causes infundibular stenosis; thus, there is obstruction of blood flow from the right ventricle into the pulmonary artery. Right ventricular outflow obstruction causes deoxygenated blood to shunt from the right ventricle across the VSD and into the aorta (right to left) producing cyanosis. The clinical severity of TOF is related to the size of the VSD and the degree of right ventricular outflow tract obstruction. The spectrum ranges from mild pulmonary stenosis to pulmonary atresia.72 The classic appearance of TOF on chest radiography is “coeur en sabot” (boot-shaped heart).17,30 This shape is due to an elevated cardiac apex from right ventricular hypertrophy. The pulmonary artery segment is concave due to right ventricular outflow obstruction and/or pulmonic stenosis. In repaired adults, the pulmonary artery segment is commonly dilated or aneurysmal secondary to surgical augmentation. Approximately 25% of patients with TOF have a right aortic arch, which usually has mirror-image branching.17 The presence of a right aortic arch and poststernotomy wires in an adult should raise suspicion of TOF. Most cases of TOF are diagnosed and repaired in infancy by closure of the VSD and relief of the right ventricular outflow obstruction.11,74 Transventricular repair
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involves an incision in the right ventricular infundibulum, resection of obstructing right ventricular muscle bundles, and placement of a right ventricular outflow tract patch, which may extend across the pulmonary valve annulus.11,75 This almost inevitably leaves the patient with significant pulmonary regurgitation, which leads to chronic volume overload, dilatation, and failure of the right ventricle over decades.8 Recognition of this complication led to the development of annulus sparing approaches, sometimes performed through right atrial and pulmonary artery incisions.11 The benefits of these methods include relative preservation of pulmonic valve function and prevention of a right ventricular surgical scar that may cause dysrhythmia.76 As the population of patients with repaired TOF lives longer, MRI has become a primary method for follow-up.77 Indications for MRI in TOF patients include the need for estimation of the right ventricular function and volume, as well as quantitation of pulmonary stenosis and/or regurgitation. Cine bright blood images obtained in the short axis plane provide accurate and reproducible measurements of ventricular volumes.78 Phase contrast imaging is used to assess the pulmonary regurgitant fraction, Qp:Qs, split perfusion of each lung, and pulmonary artery flow acceleration suggestive of residual stenosis.77 Stenosis is estimated by noting the peak velocity in the proximal pulmonary artery and applying the modified Bernoulli equation, which states that the pressure gradient (DP) is equal to 4 times the velocity (n, in m/s) squared9: DP ¼ 4n2 Patients with repaired TOF, severe pulmonic insufficiency, and either clinical symptoms or marked dilation of the right ventricle on imaging may undergo repair of the pulmonary valve in an effort to prevent right ventricular failure and sudden death.76,79,80 Traditional surgical valve replacement has been the treatment of choice; however, prosthetic valves have finite life spans, and multiple repeat thoracotomies are undesirable. Percutaneous valve replacement using the Melody valve (Medtronic Inc.) has become a viable option, although experience with the device is largely limited to patients with preexisting right ventricle to pulmonary artery conduits.81 Multiple repeat pulmonic valve replacements have already been performed using this technology. Complications of the Melody valve include stent fracture and embolization.81,82 Delayed gadolinium enhancement of either the right or left ventricle has been shown to correlate with worse clinical outcomes but is not yet used to guide therapy.83 In addition to right ventricular outflow tract obstruction, TOF patients may have stenosis of the right and left branch pulmonary arteries or the peripheral pulmonary arteries. These areas of stenosis can lead to differences in lung perfusion, which manifest on CT as mosaic attenuation of the pulmonary parenchyma.84 Proximal stenoses are often amenable to percutaneous angioplasty and stenting. About 10% of TOF patients have associated coronary artery anomalies that should be mapped before attempting surgical and catheter-based interventions.
TGA TGA occurs in 2 classically described forms, complete (D-TGA) and congenitally corrected (L-TGA).17,85 In D-TGA, the aorta arises from the right ventricular conus and the pulmonary artery from the left ventricle (ventriculoarterial discordance). In patients with situs solitus there r
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FIGURE 10. A 28-year-old man with a history of complete D-TGA who underwent an atrial switch as a child. A, Axial T1-weighted black blood image demonstrating the characteristic abnormal position of the ascending aorta anterior (AAo) and slightly to the right of the pulmonary artery (MPA). B, Axial T1-weighted black blood image demonstrating marked hypertrophy of the systemic right ventricle (*) after an atrial switch procedure. Note that the interventricular septum is bowed toward the left ventricle (arrows), consistent with elevated right ventricular pressure. C, Contrast-enhanced multiplanar reformatted image from a late phase MR angiographic acquisition demonstrating opacification of both the superior (SVC) and inferior (IVC) limbs of the systemic venous pathway coursing toward the left (or “pulmonary”) ventricle (black *). The pulmonary venous pathway is also partially visible (white *). D, Contrast-enhanced multiplanar reformatted MR angiographic image in the pulmonary venous phase demonstrating baffling of the pulmonary venous blood toward the “systemic” right ventricle (RV) (white *).
is ventricular D-looping, and the aorta is anterior, superior, and to the right of the pulmonary artery. D-TGA presents in infancy and is repaired early because the systemic and pulmonary circuits run in parallel, and the patient is therefore dependent on shunting from a septal defect and/or PDA.17 There are 2 main surgical techniques for D-TGA repair: the atrial switch and the arterial switch. The atrial switch (Mustard or Senning) creates systemic and pulmonary venous pathways that connect the systemic veins (cavae) and the pulmonary veins through baffles to the left ventricle and right ventricle, respectively10 (Fig. 10). Thus, deoxygenated blood reaches the left ventricle and exits into the pulmonary artery, whereas oxygenated blood reaches the right ventricle and proceeds into the aorta. Baffle leaks and stenoses are common complications of the atrial switch.75 MRI and CT may be used to demonstrate the patency and flow through the entire pulmonary and systemic venous pathways, which may be difficult to assess on echocardiography. Intravenous contrast is typically administered through an upper extremity vein, therefore the superior (SVC) portion of the systemic venous pathway opacifies early, whereas the inferior limb (flow from the IVC) opacifies much later. Delayed imaging is required to completely evaluate the systemic venous pathway. In addition, atrial switch patients have a systemic right ventricle that may be poorly suited to supply systemic demand over the long-term and required evaluation.8,85 The arterial switch (Jatene) procedure involves disconnecting the great arteries above the semilunar valves r
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and connecting the aorta to the left ventricle and the pulmonary artery to the right ventricle (Fig. 11). This requires transfer of the coronary arteries to the neoaortic
FIGURE 11. A 20-year-old man with a history of D-TGA who underwent an arterial switch procedure with a LeCompte maneuver in infancy. Axial T1-weighted black blood MR image demonstrates the main pulmonary artery (MPA) to be anterior to the ascending aorta (AAo). The right (RPA) and left (LPA) pulmonary arteries characteristically “drape” over the ascending aorta.
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root and often involves repositioning the distal pulmonary artery and its branches anteriorly (LeCompte maneuver).10,75 The advantage of the arterial switch is that the left ventricle is the systemic ventricle. Complications of surgery include coronary artery stenosis/occlusion, pulmonary artery stenosis, right ventricular outflow tract obstruction, and neoaortic valve insufficiency. In L-TGA there is both atrioventricular and ventriculoarterial discordance, which results in pulmonic and systemic circuits in series.85,86 The left atrium connects to the right ventricle, which in turn gives rise to the aorta, whereas the right atrium connects to the left ventricle, which gives rise to the pulmonary artery. With situs solitus these patients have ventricular L-looping, and the aorta is anterior, superior, and to the left of the pulmonary artery. Most patients with L-TGA have associated anomalies, including ASD, VSD, PDA, and valve or outflow tract disease, which lead to symptoms.17,85 Their conduction pathways are abnormal, and they frequently have arrhythmias. In the absence of associated cardiac anomalies, L-TGA patients may initially present in adulthood because of failure of the systemic right ventricle or may be detected incidentally on imaging studies performed for other reasons. In patients with known CHD, the finding of visceral situs solitus and mesocardia on a radiograph is highly suggestive of L-TGA.
CONCLUSIONS The population of adults with CHD is increasing and is composed of 2 major groups. The first includes those with mild anomalies that may present in adulthood or can be diagnosed incidentally on imaging performed for nonspecific or unrelated indications. These patients often are imaged in general practice without forewarning. Radiologists should take advantage of the opportunity to use characteristic and suggestive imaging signs to render the correct diagnosis. This requires familiarity with imaging appearances on all modalities including chest radiography. The second group includes patients who were diagnosed and treated for more severe CHD in childhood that now live into adulthood and even old age because of improved surgical techniques and medical management. In these patients, the underlying disease is surely known; however, its identity is often not conveyed or only vaguely mentioned in a clinical request for urgent imaging. We have highlighted some of the most useful chest radiographic, CT, and MRI findings for making a diagnosis of CHD, including expected postoperative appearances. This information should help radiologists add value to assessment of patients with known or undiscovered CHD. REFERENCES 1. Marelli AJ, Mackie AS, Ionescu-Ittu R, et al. Congenital heart disease in the general population: changing prevalence and age distribution. Circulation. 2007;115:163–172. 2. Van der Bom T, Bouma BJ, Meijboom FJ, et al. The prevalence of adult congenital heart disease, results from a systematic review and evidence based calculation. Am Heart J. 2012;164:568–575. 3. Warnes CA, Liberthson R, Danielson GK, et al. Task force 1: the changing profile of congenital heart disease in adult life. J Am Coll Cardiol. 2001;37:1170–1175. 4. Gilboa SM, Salemi JL, Nembhard WN, et al. Mortality resulting from congenital heart disease among children and adults in the United States, 1999 to 2006. Circulation. 2010;122: 2254–2263.
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5. Sommer RJ, Hijazi ZM, Rhodes JF. Pathophysiology of congenital heart disease in the adult: Part I: shunt lesions. Circulation. 2008;117:1090–1099. 6. Rhodes JF, Hijazi ZM, Sommer RJ. Pathophysiology of congenital heart disease in the adult, Part II: simple obstructive lesions. Circulation. 2008;117:1228–1237. 7. Sommer RJ, Hijazi ZM, Rhodes JF. Pathophysiology of congenital heart disease in the adult: Part III: complex congenital heart disease. Circulation. 2008;117:1340–1350. 8. Warnes CA. The adult with congenital heart disease: born to be bad? J Am Coll Cardiol. 2005;46:1–8. 9. Zwany SK, Lui GK, Scheinfeld MH, et al. Making complex adult congenital heart disease a little simpler. Semin Roentgenol. 2012;47:289–301. 10. Gaca AM, Jaggers JJ, Dudley LT, et al. Repair of congenital heart disease: a primer—Part 1. Radiology. 2008;247:617–631. 11. Gaca AM, Jaggers JJ, Dudley LT, et al. Repair of congenital heart disease: a primer—Part 2. Radiology. 2008;248:44–60. 12. Warnes CA, Williams RG, Bashore TM, et al. ACC/AHA 2008 guidelines for the management of adults with congenital heart disease: a report of the American College of Cardiology/ American Heart Association Task Force on Practice Guidelines. Circulation. 2008;118:e714–e833. 13. Van Praagh R. The importance of segmental situs in the diagnosis of congenital heart disease. Semin Roentgenol. 1985;20:254–271. 14. Van Praagh R. Diagnosis of complex congenital heart disease: morphologic-anatomic method and terminology. Cardiovasc Intervent Radiol. 1984;7:115–120. 15. Schallert EK, Danton GH, Kardon R, et al. Describing congenital heart disease by using three-part segmental notation. Radiographics. 2013;33:E33–E46. 16. Ghosh S, Yarmish G, Godelman A, et al. Anomalies of visceroatrial situs. Am J Roentgenol. 2009;193:1107–1117. 17. Spindola-Franco H, Fish BG, Eisenberg R. Radiology of the Heart: Cardiac Imaging in Infants, Children, and Adults. 1st ed. New York: Springer-Verlag; 1985. 18. Jenkins NP, Ward C. Coarctation of the aorta: natural history and outcome after surgical treatment. Q J Med. 1999;92: 365–371. 19. Perloff JK. The variant associations of aortic isthmic coarctation. Am J Cardiol. 2010;106:1038–1041. 20. Celermajer DS, Greaves K. Survivors of coarctation repair: fixed but not cured. Heart. 2002;88:113–114. 21. Webb G. Treatment of coarctation and late complications in the adult. Semin Thorac Cardiovasc Surg. 2005;17:139–142. 22. Nozaki T, Nosaka S, Miyazaki O, et al. Syndromes associated with vascular tumors and malformations: a pictorial review. Radiographics. 2013;33:175–195. 23. St Louis JD, Bannan MM, Lutin Wa, et al. Surgical strategies and outcomes in patients with Shone complex: a retrospective review. Ann Thorac Surg. 2007;84:1357–1363. 24. Ho VB, Bakalov VK, Cooley M, et al. Major vascular anomalies in Turner syndrome: prevalence and magnetic resonance angiographic features. Circulation. 2004;110:1694–1700. 25. Kim HK, Gottliebson W, Hor K, et al. Cardiovascular anomalies in Turner syndrome: spectrum, prevalence, and cardiac MRI findings in a pediatric and young adult population. Am J Roentgenol. 2011;196:454–460. 26. Smith LH. Pathogenesis of coarctation of the aorta. Vasc Endovasc Surg. 1978;12:30–46. 27. Aluquin VPR, Shutte D, Nihill MR, et al. Normal aortic arch growth and comparison with isolated coarctation of the aorta. Am J Cardiol. 2003;91:502–505. 28. Wang W-B, Lin G-M. Pseudocoarctation and coarctation. Int J Cardiol. 2009;133:e62–e64. 29. Sebastia C, Quiroga S, Boye R, et al. Aortic stenosis: spectrum of diseases depicted at multi-section CT. Radiographics. 2003;23:S79–S91. 30. Ferguson EC, Krishnamurthy R, Oldham SAA. Classic imaging signs of congenital cardiovascular abnormalities. Radiographics. 2007;27:1323–1334. r
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31. Kaplan S. The adult with congenital heart disease. Semin Roentgenol. 1985;20:151–159. 32. Forbes TJ, Kim DW, Du W, et al. Comparison of surgical, stent, and balloon angioplasty treatment of native coarctation of the aorta: an observational study by the CCISC (Congenital Cardiovascular Interventional Study Consortium). J Am Coll Cardiol. 2011;58:2664–2674. 33. Shih M-CP, Tholpady A, Kramer CM, et al. Surgical and endovascular repair of aortic coarctation: normal findings and appearance of complications on CT angiography and MR angiography. Am J Roentgenol. 2006;187:W302–W312. 34. Oliver JM, Gallego P, Gonzalez A, et al. Risk factors for aortic complications in adults with coarctation of the aorta. J Am Coll Cardiol. 2004;44:1641–1647. 35. Toro-Salazar OH, Steinberger J, Thomas W, et al. Long-term follow-up of patients after coarctation of the aorta repair. Am J Cardiol. 2002;89:541–547. 36. Muzzarelli S, Meadows AK, Ordovas KG, et al. Prediction of hemodynamic severity of coarctation by magnetic resonance imaging. Am J Cardiol. 2011;108:1335–1340. 37. Muzzarelli S, Meadows AK, Ordovas KG, et al. Usefulness of cardiovascular magnetic resonance imaging to predict the need for intervention in patients with coarctation of the aorta. Am J Cardiol. 2012;109:861–865. 38. Haramati LB, Moche IE, Rivera VT, et al. Computed tomography of partial anomalous pulmonary venous connection in adults. J Comput Assist Tomogr. 2003;27:743–749. 39. Senocak F, O¨zme S, Bilgic A, et al. Partial anomalous pulmonary venous return: evaluation of 51 cases. Jpn Heart J. 1994;35:43–50. 40. Ho M-L, Bhalla S, Bierhals A, et al. MDCT of partial anomalous pulmonary venous return (PAPVR) in adults. J Thorac Imaging. 2009;24:89–95. 41. Brown JW, Ruzmetov M, Minnich DJ, et al. Surgical management of scimitar syndrome: an alternative approach. J Thorac Cardiovasc Surg. 2003;125:238–245. 42. Vida VL, Padalino Ma, Boccuzzo G, et al. Scimitar syndrome: a European Congenital Heart Surgeons Association (ECHSA) multicentric study. Circulation. 2010;122:1159–1166. 43. Berko NS, Jain VR, Godelman A, et al. Variants and anomalies of thoracic vasculature on computed tomographic angiography in adults. J Comput Assist Tomogr. 2009;33: 523–528. 44. Majdalany DS, Phillips SD, Dearani JA, et al. Isolated partial anomalous pulmonary venous connections in adults: twentyyear experience. Congenit Heart Dis. 2010;5:537–545. 45. Kafka H, Mohiaddin RH. Cardiac MRI and pulmonary MR angiography of sinus venosus defect and partial anomalous pulmonary venous connection in cause of right undiagnosed ventricular enlargement. Am J Roentgenol. 2009; 192:259–266. 46. Alsoufi B, Cai S, Van Arsdell GS, et al. Outcomes after surgical treatment of children with partial anomalous pulmonary venous connection. Ann Thorac Surg. 2007;84:2020–2026. 47. Park CS, Kwak JG, Lee C, et al. Partial anomalous pulmonary venous connection to the superior vena cava: the outcome after the Warden procedure. Eur J Cardiothorac Surg. 2012;41: 261–265. 48. Festa P, Ait-Ali L, Cerillo AG, et al. Magnetic resonance imaging is the diagnostic tool of choice in the preoperative evaluation of patients with partial anomalous pulmonary venous return. Int J Cardiovasc Imaging. 2006;22:685–693. 49. Debl K, Djavidani B, Buchner S, et al. Quantification of leftto-right shunting in adult congenital heart disease: phasecontrast cine MRI compared with invasive oximetry. Br J Radiol. 2009;82:386–391. 50. Berko NS, Haramati LB. Simple cardiac shunts in adults. Semin Roentgenol. 2012;47:277–288. 51. Martinez-Jimenez S, Heyneman LE, Mcadams HP, et al. Nonsurgical extracardiac vascular shunts in the thorax: clinical and imaging characteristics. Radiographics. 2010; e41:1–33. r
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52. Brickner ME, Hillis LD, Lange RA. Congenital heart disease in adults: first of two parts. N Engl J Med. 2000;342: 256–263. 53. Murphy JG, Gersh BJ, McGoon MD, et al. Long-term outcome after surgical repair of isolated atrial septal defect: follow-up at 27 to 32 years. N Engl J Med. 1990;323: 1645–1650. 54. Webb G, Gatzoulis MA. Atrial septal defects in the adult: recent progress and overview. Circulation. 2006;114: 1645–1653. 55. Green CE, Gottdiener JS, Goldstein HA. Atrial septal defect. Semin Roentgenol. 1985;20:214–225. 56. Meissner I, Khandheria BK, Heit JA, et al. Patent foramen ovale: innocent or guilty? Evidence from a prospective population-based study. J Am Coll Cardiol. 2006;47:440–445. 57. Volman M, Mojadidi MK, Gevorgyan R, et al. Incidence of patent foramen ovale and migraine headache in adults with congenital heart disease with no known cardiac shunts. Catheter Cardiovasc Interv. 2013;81:643–647. 58. Tobis J, Shenoda M. Percutaneous treatment of patent foramen ovale and atrial septal defects. J Am Coll Cardiol. 2012;60:1722–1732. 59. Carroll JD, Saver JL, Thaler DE, et al. Closure of patent foramen ovale versus medical therapy after cryptogenic stroke. N Engl J Med. 2013;368:1092–1100. 60. Furlan AJ, Reisman M, Massaro J, et al. Closure or medical therapy for cryptogenic stroke with patent foramen ovale. N Engl J Med. 2012;366:991–999. 61. Du ZD, Hijazi ZM, Kleinman CS, et al. Comparison between transcatheter and surgical closure of secundum atrial septal defect in children and adults: results of a multicenter nonrandomized trial. J Am Coll Cardiol. 2002;39: 1836–1844. 62. Ko S-F, Liang C-D, Yip H-K, et al. Amplatzer septal occluder closure of atrial septal defect: evaluation of transthoracic echocardiography, cardiac CT, and transesophageal echocardiography. Am J Roentgenol. 2009;193:1522–1529. 63. Son J-W, Park J-S. Subacute, silent embolization of amplatzer atrial septal defect closure device to the pulmonary artery. J Cardiovasc Ultrasound. 2012;20:201–204. 64. Chessa M, Carminati M, Butera G, et al. Early and late complications associated with transcatheter occlusion of secundum atrial septal defect. J Am Coll Cardiol. 2002;39: 1061–1065. 65. Amin Z, Hijazi ZM, Bass JL, et al. Erosion of Amplatzer septal occluder device after closure of secundum atrial septal defects: review of registry of complications and recommendations to minimize future risk. Catheter Cardiovasc Interv. 2004;63: 496–502. 66. Kim J-H, Siegel MJ, Goldstein JA, et al. Radiologic findings of 2 commonly used cardiac septal occluders with clinical correlation. J Thorac Imaging. 2003;18:183–189. 67. Lee T, Tsai I-C, Fu Y-C, et al. MDCT evaluation after closure of atrial septal defect with an Amplatzer septal occluder. Am J Roentgenol. 2007;188:W431–W439. 68. Rojas CA, Jaimes C, Abbara S. Ventricular septal defects: embryology and imaging findings. J Thorac Imaging. 2013;28: W28–W34. 69. Minette MS, Sahn DJ. Ventricular septal defects. Circulation. 2006;114:2190–2197. 70. Schneider DJ, Moore JW. Patent ductus arteriosus. Circulation. 2006;114:1873–1882. 71. Wimpfheimer O, Haramati LB, Haramati N. Calcification of the ligamentum arteriosum in adults: CT features. J Comput Assist Tomogr. 1996;20:34–37. 72. Bashore TM. Adult congenital heart disease: right ventricular outflow tract lesions. Circulation. 2007;115:1933–1947. 73. Taussig B. Tetralogy of Fallot: early history and late results. Am J Roentgenol. 1979;133:423–431. 74. Pigula FA, Khalil PN, Mayer JE, et al. Repair of tetralogy of Fallot in neonates and young infants. Circulation. 1999;100: II–157–II–161.
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75. Frank L, Dillman JR, Parish V, et al. Cardiovascular MR imaging of conotruncal anomalies. Radiographics. 2010;30:1069–1094. 76. McElhinney DB. Recent progress in the understanding and management of postoperative right ventricular outflow tract dysfunction in patients with congenital heart disease. Circulation. 2012;125:e595–e599. 77. Geva T, Sandweiss BM, Gauvreau K, et al. Factors associated with impaired clinical status in long-term survivors of tetralogy of Fallot repair evaluated by magnetic resonance imaging. J Am Coll Cardiol. 2004;43:1068–1074. 78. Bonello B, Kilner PJ. Review of the role of cardiovascular magnetic resonance in congenital heart disease, with a focus on right ventricle assessment. Arch Cardiovasc Dis. 2012;105:605–613. 79. Therrien J, Siu SC, McLaughlin PR, et al. Pulmonary valve replacement in adults late after repair of tetralogy of fallot: are we operating too late? J Am Coll Cardiol. 2000;36: 1670–1675. 80. Therrien J, Provost Y, Merchant N, et al. Optimal timing for pulmonary valve replacement in adults after tetralogy of Fallot repair. Am J Cardiol. 2005;95:779–782.
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81. Khambadkone S, Coats L, Taylor A, et al. Percutaneous pulmonary valve implantation in humans: results in 59 consecutive patients. Circulation. 2005;112:1189–1197. 82. Nordmeyer J, Khambadkone S, Coats L, et al. Risk stratification, systematic classification, and anticipatory management strategies for stent fracture after percutaneous pulmonary valve implantation. Circulation. 2007;115: 1392–1397. 83. Babu-Narayan SV, Kilner PJ, Li W, et al. Ventricular fibrosis suggested by cardiovascular magnetic resonance in adults with repaired tetralogy of fallot and its relationship to adverse markers of clinical outcome. Circulation. 2006;113:405–413. 84. Gartner RD, Sutton NJ, Weinstein S, et al. MRI and computed tomography of cardiac and pulmonary complications of tetralogy of fallot in adults. J Thorac Imaging. 2010; 25:183–190. 85. Warnes CA. Transposition of the great arteries. Circulation. 2006;114:2699–2709. 86. Van Praagh R, Van Praagh S. Anatomically corrected transposition of the great arteries. Br Heart J. 1967;29:112–119.
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CME-SAM EXAM INSTRUCTIONS FOR OBTAINING AMA PRA CATEGORY 1 CREDITSTM The Journal of Thoracic Imaging includes CME-certified content that is designed to meet the educational needs of its readers. This article is certified for 1.5 AMA PRA Category 1 CreditsTM. This activity is available for credit through October 31, 2014.
Accreditation Statement Lippincott Continuing Medical Education Institute, Inc., is accredited by the Accreditation Council for Continuing Medical Education to provide continuing medical education for physicians.
Credit Designation Statement Lippincott Continuing Medical Education Institute, Inc., designates this journal-based CME activity for a maximum of one and a half (1.5) AMA PRA Category 1 CreditsTM. Physicians should only claim credit commensurate with the extent of their participation in the activity. To earn CME credit, you must read the article in The Journal of Thoracic Imaging and complete the quiz, answering at least 70 percent of the questions correctly. Mail the Answer Sheet to Lippincott CME Institute, Inc., Wolters Kluwer Health, Two Commerce Square, 2001 Market Street, 3rd Floor, Philadelphia, PA 19103. Only the first entry will be considered for credit, and must be postmarked by the expiration date. Answer sheets will be graded and certificates will be mailed to each participant within 6 to 8 weeks of participation. Questions marked with an asterisk are ABR Self-Assessment Module (SAM) questions. Participants can claim credit for the SAM regardless of the test outcome. Notify the ABR of the SAM completion, or visit the ABR website at www.theabr.org to set up or log in to your personal database to record the number of SAMs you completed. The SAM ID number will be printed on the CME certificate for your records. If you wish to include the ID number in your ABR database, contact a MOC Specialist at the ABR office for instruction by calling 520-519-2152.
CME-SAM EXAMINATION Please mark your answers on the ANSWER SHEET found on page W126 of the Web Exclusive Content in the November 2013 issue of the Journal of Thoracic Imaging located at www.thoracicimaging.com. After completing this CME activity, physicians should be better able to: Identify the segmental anatomic classification system for congenital heart disease Describe late complications of repaired coarctation of the aorta Use the clinical information and imaging findings to diagnose simple cardiac shunts in adults Describe the two main operative techniques for repairing complete transposition of the great arteries (D-TGA) *1. The segmental anatomic classification system of Van Praagh is a concise way of describing the anatomy of the: (a) systemic venous return, pulmonary venous return, ventricles (b) atria, ventricles, great vessels (c) systemic venous return, ventricles, great vessels (d) atria, atrioventricular valves, ventricles Please see the following references for further study: 1. Schallert EK, Danton GH, Kardon R, Young DA. Describing congenital heart disease by using three-part segmental notation. RadioGraphics. 2013;33:E33–E46. 2. Van Praagh R. The importance of segmental situs in the diagnosis of congenital heart disease. Semin Roentgenol. 1985;20:254–271. *2. Which complication can develop even years after aortic coarctation repair? (a) Aortic pseudoaneurysm (b) Pulmonary artery aneurysm (c) Lower extremity hypertension (d) Vertebral scalloping Please see the following references for further study: 1. Celermajer D, Greaves K. Survivors of coarctation repair: fixed but not cured. Heart. 2002;88:113–114. 2. Warnes C. The adult with congenital heart disease: born to be bad? J Am Coll Cardiol. 2005;46:1–8. *3. What is the key differential diagnosic consideration for an incidental CT or MR finding of an “extra” vascular structure located lateral to the aortic arch in an adult? (a) Vertical Vein versus scimitar vein (b) Vertical Vein versus azygous continuation of the inferior vena cava (c) Vertical vein versus persistant left superior vena cava (d) Vertical vein verusus persistant right superior vena cava
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Please see the following references for further study: 1. Ho M-L, Bhalla S, Bierhals A, Gutierrez F. MDCT of partial anomalous pulmonary venous return (PAPVR) in adults. J Thorac Imaging. 2009;24:89–95. 2. Haramati LB, Moche IE, Rivera VT, et al. Computed tomography of partial anomalous pulmonary venous connection in adults. J Comput Assist Tomogr. 2003;27:743–749. *4. In adults with atrial septal defect (ASD), what is the risk of developing severe pulmonary hypertension and Eisenmenger syndrome? (a) 15% (b) 40% (c) 75% (d) 99% Please see the following references for further study: 1. Sommer R, Hijazi Z, Rhodes J. Pathophysiology of congenital heart disease in the adult: Part 1: Shunt lesions. Circulation. 2008;117:1090–1099. 2. Green CE, Gottdiener JS, Goldstein HA. Atrial septal defect. Semin Roentgenol. 1985;20:214–225. *5. What is the pulmonary flow pattern on chest radiographs of adults with an atrail septal defect (ASD)? (a) Overcirculation (b) Undercirculation (c) Redistribution (d) Mosaic Please see the following references for further study: 1. Spindola-Franco H, Fish BG, Eisenberg R. Radiology of the Heart: Cardiac Imaging in Infants, Children, and Adults. 1st ed. New York: Springer-Verlag; 1985. 2. Berko NS, Haramati LB. Simple cardiac shunts in adults. Semin Roentgenol. 2012;47:277–288. *6. Adults with repaired tetralogy of Fallot nearly always have which of the following? (a) Tricuspid regurgitation (b) Mitral regurgitation (c) Aortic regurgitation (d) Pulmonary regurgitation Please see the following references for further study: 1. Gartner RD, Sutton NJ, Weinstein S, Spindola-Franco H, Haramati LB. MR and CT of Cardiac and Pulmonary Complications of Tetralogy of Fallot in Adults. J Thorac Imaging. 2010;25:183–190. 2. Zwany SK, Lui GK, Scheinfeld MH, Levsky JM. Making Complex Adult Congenital Heart Disease a Little Simpler. Semin Roentgenol. 2012;47:289–301. *7. When evaluating an adult with a history of D-TGA who underwent an atrial switch procedure, what type of CT protocol is required to evaluate the baffle? (a) Bilateral upper extremity contrast injections (b) Bilateral lower extremity contrast injections (c) Early and late post contrast imaging (d) Pre and early post contrast imaging Please see the following references for further study: 1. Frank L, Dillman JR, Parish V, et al. Cardiovascular MR Imaging of Conotruncal Anomalies. RadioGraphics. 2010;30:1069–1094. 2. Warnes CA. Transposition of the great arteries. Circulation. 2006;114:2699–2709. *8. What is the major advantage of the arterial switch procedure over the atrial switch procedure in patients with D-TGA? (a) The risk of pulmonary vein stenosis is low (b) The left ventricle is the systemic ventricle (c) The risk of pulmonary artery stenosis is low (d) The right ventricle is the systemic ventricle Please see the following reference for further study: 1. Sommer RJ, Hijazi ZM, Rhodes JF. Pathophysiology of congenital heart disease in the adult: Part III: Complex congenital heart disease. Circulation. 2008;117:1340–1350. Answer sheet can be found on page W134 of the Web Exclusive Content in the November 2013 issue of the Journal of Thoracic Imaging located at www.thoracicimaging.com.
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