Ellen Mayer Sabik
Congenital heart disease is by definition an abnormality in cardiac structure that is present at birth, even if it is not diagnosed until later in life. These defects are usually the result of altered embryonic development of a normal structure or failure of development. Four categories of etiologic agents may be responsible for this abnormal development, and these are the same influences that may cause cancers. They include hereditary and chromosomal defects (Table 24.1), viruses (rubella with patent ductus arteriosus [PDA]), chemicals (thalidomide with truncus arteriosus or tetralogy of Fallot), and radiation (x-irradiation with ventricular septal defects [VSDs]). Although these agents cause certain known defects, most defects have no specific cause and the etiology may in fact be multifactorial. The incidence of congenital heart disease (excluding bicuspid aortic valve and myxomatous mitral valve (MV) disease with mitral valve prolapse [MVP]) is approximately 0.5% to 0.8% of live births. Congenital cardiac malformations are much more common in stillbirths than in live births. Some congenital lesions have a high rate of survival without surgery and may be seen in the unoperated adult with different relative frequencies (Table 24.2). Other lesions, with worse prognosis, are usually not seen in adults. However, as both diagnosis and treatment (both medical and surgical) improve, more of these patients are surviving into adulthood and are more likely to be seen in a cardiology office as adults. Thus, all cardiologists should be familiar with the lesions discussed in this chapter.
TABLE
24.1 Chromosomal Anomalies and Their Congenital Syndromes Associated with Heart Defects
VSD, ventricular septal defect; PDA, patent ductus arteriosus; PS, pulmonic stenosis; AV atrioventricular; AS, aortic stenosis; ASD, atrial septal defect.
TABLE
24.2 Congenital Heart Defects in the Unoperated Adult
ATRIAL SEPTAL DEFECTS
Atrial septal defect (ASD) accounts for 22% of adult congenital defects. Excluding bicuspid aortic valves and MVP, ASDs are the most common form of adult congenital heart disease. They make up 10% of all congenital heart defects and demonstrate a female-to-male preponderance of 3:2. Diagnosis of ASD is aided by the following features:
On auscultation, a wide fixed split S2 with a pulmonary flow murmur is heard.
On electrocardiogram (ECG), ostium primum (OP) ASD shows marked left-axis or right bundle branch block (RBBB) with signs of right ventricular (RV) enlargement. There may be first-degree atrioventricular (AV) block. Ostium secundum (OS) ASD is marked by RSR or rSR in V1, QRS <0.11 seconds, right axis deviation, right ventricular hypertrophy (RVH), and possibly first-degree AV block and right atrial enlargement (RAE).
Shunt can be visualized by echocardiography with color Doppler and agitated saline contrast.
Shunt at the atrial level is a potential source of paradoxical embolus.
The locations of types of ASD are shown in Figure 24.1. The four types of ASD are:
FIGURE 24.1 Location of types of ASD. SV, sinus venosus ASD; OP, ostium primum ASD; OS, ostium secundum ASD; CS, coronary sinus ASD.
Primum ASD
Secundum ASD
Sinus venosus (SV)
Unroofed coronary sinus (CS)
Primum Atrial Septal Defect
Primum ASD accounts for 20% of cases of ASD (Fig. 24.2A–C) and is part of an AV canal defect in which embryonic endocardial cushions fail to meet normally and partition the heart (Figs. 24.3 and 24.4).
FIGURE 24.2 A: Apical four-chamber view of a patient with AV canal defect. Note the primum ASD (arrow) and the dilated right side. B: Magnified apical four-chamber view with color Doppler demonstrating the left-to-right flow (arrow) across the primum ASD. C: Parasternal short axis-view demonstrating the cleft anterior mitral leaflet with a gap (arrow) representing the cleft in the anterior mitral leaflet (AML).
FIGURE 24.3 Apical four-chamber view of partial AV canal defect (left) and complete AV canal defect (right). The partial AV canal defect has a primum ASD, cleft MV, and widened anteroseptal tricuspid commissure. The complete AV canal defect has all of these and a VSD.
FIGURE 24.4 Parasternal short-axis view showing complete AV canal defect (right) compared to a normal heart (left). Note the cleft anterior mitral leaflet and VSD in the complete AV canal defect.
A complete AV canal defect consists of four components:
Inlet VSD
Primum ASD
Cleft MV
Widened anteroseptal tricuspid commissure
A partial AV canal defect is as above without the VSD.
Secundum Atrial Septal Defect
Secundum ASD is an ASD at the fossa ovalis (Fig. 24.5A–D). It is the most common form of ASD (75% of cases). The following features distinguish a secundum ASD:
FIGURE 24.5 A: Four-chamber midesophageal view of a TEE demonstrating a secundum ASD (arrow). B: TEE with color Doppler demonstrating the left-to-right flow across the secundum ASD. Note that although there is one larger shunt, there are multiple defects with shunting through the atrial septum. C: TEE with agitated saline contrast demonstrating the intermittent right-to-left shunting across the secundum ASD. D: TEE with agitated saline contrast demonstrating the intermittent left-to-right shunting across the secundum ASD and the unopacified blood from the left side of the heart (specifically the leftatrium [LA]) displacing the contrastwithin the RA. The combination of this image and the prior image demonstrates the bidirectional shunting across this ASD.
Left-to-right shunt, because the right ventricle (RV) is thin walled and fills more easily than the left ventricle and pulmonary vascular resistance is lower than systemic
Pulmonary blood flow is often two to four times normal.
Dilated right side due to right atrial (RA) and RV volume overload
The pulmonary artery (PA) is often dilated.
Sinus Venosus Atrial Septal Defect
Sinus venosus ASD accounts for 5% of ASD (Fig. 24.6). The following are typical features:
FIGURE 24.6 Bicaval TEE view with color Doppler demonstrating a sinus venosus ASD with left-to-right shunting. This ASD is located near the connection between the SVC and the RA.
Defect near the junction of the superior vena cava (SVC) or the inferior vena cava (IVC) with the RA (posterior to fossa ovalis)
Often difficult to detect (typically requires transesophageal echocardiography [TEE])
If unexplained right-sided dilatation is seen on the echocardiogram, echocardiography should be performed with agitated saline contrast to look for a shunt, with follow-up TEE if needed.
Superior sinus venosus ASD is almost always associated with partial anomalous pulmonary venous (PV) return: right PV to either SVC or high RA.
Coronary Sinus Atrial Septal Defect
Coronary sinus ASD is very rare. A distinguishing feature is that the roof of the CS is absent.
VENTRICULAR SEPTAL DEFECT
VSD is the most common form of congenital abnormality at birth but accounts for only 10% cases of congenital heart disease in adults (Fig. 24.7). Distinguishing features include the following:
FIGURE 24.7 Locations of types of VSD: membranous, muscular (may be multiple), supracristal, or “subpulmonic” AV canal defects.
At least 50% to 80% of VSDs close spontaneously.
Perimembranous VSD is the most common form of VSD.
VSD carries a risk of endocarditis.
Perimembranous VSD is often associated with a ventricular septal aneurysm formed by septal leaflet of tricuspid valve (TV) closing defect (the defect may be larger than appears).
Restrictive VSDs have high-velocity jets with a large pressure difference between the right and left ventricles (larger defects are associated with a low-velocity jet). Recall the modified Bernoulli equation: ΔP = 4V2.
Types of VSDs include the following:
Membranous VSD: accounts for 80% of cases of congenital VSD, has the highest rate of spontaneous closure (Fig. 24.8A,B)
Muscular VSD: accounts for 10% of VSD and may be multiple (Fig. 24.9)
Supracristal VSD: accounts for 5% of VSD (Fig. 24.10A,B), involves left ventricular outflow track (LVOT)/right ventricular outflow track (RVOT), and carries a high incidence of aortic insufficiency (AI) due to prolapse of right coronary cusp (RCC) or left coronary cusp (LCC) into the VSD
AV canal defect: discussed in relation to ASD
FIGURE 24.8 A Inverted apical four-chamber view (pediatric convention) demonstrating a perimembranous VSD with a ventricular septal aneurysm formed as the septal leaflet of the TV attempts to close the defect. The big arrow denotes the VSD and the region enclosed by the smaller arrows demonstrates the extent of the ventricular septal aneurysm. B: Parasternal short-axis views (two-dimensional (2-D) images on the left and color Doppler images on the right) demonstrate a perimembranous VSD with a 2-D defect noted near the RV inflow region near the TV, with left-to-right shunting seen in that location.
FIGURE 24.9 Apical four-chamber view demonstrating a large muscular VSD in the midseptum. Note the dilated right side as a result of long-term left-to-right shunting and right-sided volume overload.
FIGURE 24.10 A: Parasternal short-axis view demonstrating the 2-D defect of a supracristal VSD located near the RVOT. B: Parasternal short-axis view with color Doppler demonstrating a fine jet of left-to-right flow through the supracristal VSD.
BICUSPID AORTIC VALVE
Bicuspid aortic valve occurs in 1% to 2% of the general population. The most common form is a fusion of the RCC and the LCC. Congenital abnormalities of aortic cusp anatomy are shown in Figure 24.11A–G. Characteristics of bicuspid aortic valve include the following:
FIGURE 24.11 A: Midesophageal short-axis view of the aortic valve demonstrating a bicuspid aortic valve with fusion of the right coronary cusp (RCC) and the left coronary cusp (LCC). The leaflets are somewhat thickened and there is a combination of aortic regurgitation as well as a component of stenosis. B: Long-axis midesophageal view demonstrating doming of a bicuspid aortic valve. Because of the significant leaflet doming, it is very important to obtain an on-axis, short-axis view. Off-axis images may cause overestimation of a planimetered aortic valve area (therefore underestimating the degree of AS). C: Midesophageal short-axis view of the aortic valve demonstrating a bicuspid aortic valve with non-coronary cusp (NCC) and right coronary cusp (RCC) fusion. D: Midesophageal short-axis view of the aortic valve demonstrating a unicuspid aortic valve. Note the eccentric opening with a single commissure at the 11:00 position. E: Gross pathologic specimen of a unicuspid aortic valve. F: Magnified midesophageal short-axis view of the aortic valve demonstrating a quadricuspid valve in diastole. G: Magnified midesophageal short-axis view of the aortic valve demonstrating a quadricuspid valve in systole. Note the presence of four separate cusps.
The mechanism of AI is prolapse of the conjoined cusp.
The long-axis view shows asymmetric closure of the AV with doming leaflets.
It may be associated with coarctation of the aorta. At least 50% of patients with coarctation have bicuspid AV; fewer with bicuspid valves have coarctation.
Early (typically ages 30s to 40s), affected individuals have problems with AI. RCC and LCC fusion produces a posteriorly directed jet.
Later (typically, ages 50s to 60s), they have problems with aortic stenosis (AS).
AI may be amenable to valve repair.
Patients with bicuspid aortic valves have an aortopathy which may cause aortic dilatation with increased risk of dissection. Typically indications for aortic surgery based on size of the aorta are the same as those used for Marfan patients
Helpful hint: To identify and name cusps, look for the interatrial septum. The leaflet closest to the interatrial septum is the noncoronary cusp (NCC). The LCC is always at the right of the screen.
SUBAORTIC AORTIC STENOSIS
Subaortic aortic stenoses, or subaortic membrane, is shown in Figure 24.12A,B and involves the following features:
FIGURE 24.12 A: Magnified midesophageal long-axis view of the aortic valve and LVOT demonstrating a subaortic membrane 1 mm beneath the aortic valve. B: Magnified long-axis view of the aortic valve and LVOT with color Doppler demonstrating a subaortic membrane with the color disturbance/acceleration occurring in the LVOT at the site of the membrane. It is important to note that the color acceleration occurs before the aortic valve, which should alert the cardiologist to the presence of a membrane (by transthoracic echocardiography [TTE] or transeophageal echocardiography (TEE), even if the membrane is not seen by 2-D imaging alone).
The membrane is usually 1 to a few millimeters below the AV.
It may be associated with perimembranous VSD, coarctation of the aorta, or valvular AS.
Eccentric turbulent flow through the AV often traumatizes and causes scarring, leading to development of AI.
Patients are at risk for endocarditis; however, antibiotic prophylaxis is no longer recommended.
Patients can develop left ventricular hypertrophy (LVH) in response to high gradients.
A small percentage of membranes grow back postresection.
Surgical excision is appropriate for patients with symptoms, LVH with strain, or significant outflow gradients. It may or may not be appropriate for patients who are asymptomatic with low gradient. Resection may prevent trauma to the AV and help prevent the development of AI.
PATENT DUCTUS ARTERIOSUS
In the fetus, the ductus diverts blood flow from the non-functioning pulmonary circuit into the aorta and back to the placenta. It normally closes within 24 to 48 hours of birth. PDA is found in 2% of adults with congenital heart disease (Figs. 24.13A,B and 24.14A,B). It is distinguished by the following:
FIGURE 24.13 A: Parasternal short-axis view demonstrating the opening of a PDA into the PA (arrow). B: Parasternal short-axis view with color Doppler demonstrating flow from the descending aorta into the PA (arrow).
FIGURE 24.14 A: Diagram of PDA. Aortic arch view with great vessels arising superiorly off the aorta, with the patent ductus arising from the aorta across from the origin of the subclavian artery, with flow into the PA. B: Continuous-wave Doppler pattern of flow in PDA.
It is usually isolated, but it can occur with complex lesions, coarctations, or VSD.
When the ductus remains patent after birth, there is left-to-right shunting through the ductus arteriosis. Therefore, there is an abnormal persistent fetal connection between the left PA and the descending aorta.
Auscultation reveals a machinery-type murmur.
Applying a modified Bernoulli equation, one can use the peak systolic velocity of the PDA jet to determine the systolic gradient between the aorta and the PA.
If PDA is left untreated, patients may develop congestive heart failure (CHF) from chronic left heart volume overload. Rarely, they can develop endocarditis and therefore need antibiotic prophylaxis. Typically, antibiotic prophylaxis is continued for 6 months after surgical or percutaneous closure.
COARCTATION OF THE AORTA
Coarctation of the aorta in adults involves a discrete ridge or focal narrowing of the descending aorta opposite the ligamentum arteriosus of the ductus arteriosus (Fig. 24.15A). Characteristics of this condition include the following:
FIGURE 24.15 A: Diagram of coarctation of the aorta. Aortic arch view showing narrowing immediately distal to the takeoff of the subclavian artery. B: Continuous-wave Doppler in the proximal descending aorta across the coarctation, with classic “sawtooth” flow pattern.
Clinical presentation includes hypertension, a decrease in femoral pulses, and LVH.
Fifty percent of adults with coarctation have bicuspid aortic valves.
Continuous-wave Doppler through the proximal descending aorta displays high peak velocity in systole and a gradient that persists into diastole (Fig. 24.15B).
Alternative imaging modalities may be needed to define the anatomy of coarctation exactly.
Chest radiography shows rib notching due to development of collaterals (intercostal arteries) (Fig. 24.16).
FIGURE 24.16 Chest radiograph demonstrating rib notching (arrow) that is characteristic of coarctation of the aorta, resulting from the markedly increased blood flow through the intercostal arteries.
Coarctation of the aorta is further illustrated in Figure 24.17A–D.
FIGURE 24.17 A: TEE long-axis view of the proximal descending aorta demonstrating the coarctation narrowing. B: TEE long-axis view of the proximal descending aorta with color Doppler demonstrating flow acceleration across the coarctation narrowing. C: Aortography demonstrating aortic coarctation narrowing in the descending aorta. D: MRI sagittal view of the thoracic aorta demonstrating coarctation narrowing.
PULMONIC STENOSIS
Pulmonic stenosis (PS) can be valvular, subvalvular (infundibular), or supravalvular (Fig. 24.18A–C). The following features distinguish PS:
FIGURE 24.18 A: Parasternal short-axis view demonstrating doming of the stenotic pulmonic valve. B: Parasternal short-axis view with color Doppler demonstrating flow acceleration across the stenotic pulmonic valve. There is a relatively large proximal flow convergence zone proximal to the pulmonic valve, due to the high transvalvular gradient. C: Continuous-wave Doppler across the pulmonic valve with traced peak and mean pressure gradients. (Peak/mean gradients are 33/18 mm Hg.)
ECG findings may be normal in mild cases.
Right-axis deviation and RVH are seen on ECG in moderate cases.
The degree of RVH correlates with the severity of the PS.
On chest radiograph, the heart size is usually normal, but the main PA is prominent.
Pulmonary vascular marking are usually normal but may be decreased in severe cases.
Balloon valvuloplasty is often the procedure of choice for treatment (with RV pressure ≥50 mm Hg). Surgery is often reserved for cases of failed percutaneous intervention.
Although patients are at increased risk for endocarditis, subacute bacterial endocarditis (SBE) prophylaxis is no longer recommended.
TETRALOGY OF FALLOT
The four elements of tetralogy of Fallot are:
1. VSD (large and nonrestrictive)
2. Overriding aorta
3. Infundibular PS
4. RVH
Defects in this condition result from abnormal conotruncal septation (anterior deviation of the infundibular septum). About 15% of patients also have ASD, making the condition “pentalogy” of Fallot. Other associated defects may include valvular PS (50% to 60%), right aortic arch (25%), muscular VSD (2%), and coronary anomalies (5%).
Early in life, mild PS may be present with no significant shunting, known as “pink tetralogy.” As subvalvular PS increases with time, pulmonary blood flow decreases and patients develop significant right-to-left shunting, causing cyanosis, or “blue tetralogy.”
Tetralogy of Fallot is illustrated in Figure 24.19A–D.
FIGURE 24.19 A: Parasternal short-axis view demonstrating a large, nonrestrictive VSD (thickarrow) and infundibular PS (thin arrows) with hypertrophy of the RVOT. B: Parasternal short-axis view with color Doppler showing a large VSD with significant left-to-right shunting (thickarrow) and the color acceleration/high-velocity flow associated with subpulmonic PS (long thin arrow). C: Parasternal long-axis view demonstrating a large perimembranous VSD and an overriding aorta. D: Continuous- wave Doppler through the RVOT/pulmonic valve demonstrating the high pressure gradients of the infundibular PS. The peak gradient across the stenosis is 76 mm Hg.
EBSTEIN ANOMALY OF THE TRICUSPID VALVE
Ebstein’s anomaly of the TV is characterized by apical displacement of the TV into the RV (Fig. 24.20). The following features distinguish this condition:
FIGURE 24.20 Apical four-chamber view (pediatric view) demonstrating apical displacement of the TV with apical tethering of the leaflets causing severe tricuspid regurgitation (TR). Note the severe RA dilatation.
TV tissue is dysplastic, with portions of the septal and inferior cusps adherent to RV away from the AV junction.
Clinical manifestations are variable, depending on associated manifestations.
Patent foramen ovale (PFO) or secundum ASD is present in >50% cases.
A common important associated defect is PS or atresia.
Other associations include primum ASD and VSD or congenitally corrected transposition.
Wolf–Parkinson–White syndrome (WPW) is found in 10% to 15% of patients with Ebstein anomaly.
ECG commonly shows RBBB or WPW. Most common is giant P waves and prolonged P–R interval with variable degrees of RBBB.
The presence of WPW increases the risk of paroxysmal supraventricular tachycardia.
Chest radiography shows a large RA and small RV with decreased pulmonary vascularity if a large right-to-left shunt is present.
TRANSPOSITION OF THE GREAT ARTERIES
Transposition of the great arteries (D-TGA) is defined as “ventriculoarterial discordance,” with the aorta connected to the RV and the PA connected to the left ventricle (Fig. 24.21A,B). It is caused by abnormal conotruncal septation in development, with “D-transposition” denoting that the direction of septal rotation is in a dextro, or rightward, direction (Fig. 24.22).
FIGURE 24.21 A: Apical four-chamber view with baffles (arrows) at the atrial level directing blood from the pulmonary veins to the RA and caval flow directed to the LA. Note that the pacemaker wire is within the LA (a clue to the presence of D transposition). B: Parasternal short-axis view of both the aortic and pulmonic valves showing the parallel course of the great vessels in D-TGA. In D transposition, the aorta (with the left coronary artery marked by arrows) is located anterior and to the right of the PA.
FIGURE 24.22 Diagram of d transposition both with and without VSD.
TGA may or may not have associated lesions. There must be mixing of venous and systemic blood at some level for survival (ASD, VSD, or PDA). Otherwise, the pulmonic circulation and the systemic circulation would be two separate and parallel circuits, which is not compatible with life. Common associated defects include ASD, perimembranous VSD, coarctation of the aorta, PS, and PDA. Further features of this condition include the following:
The aorta is anterior and to the right of the PA, because the aorta arises from the RV. The two great arteries run parallel (Fig. 24.23).
There is fibrous continuity between the anterior mitral leaflet and the pulmonic valve compared to the normal relationship with continuity between the anterior mitral leaflet and the aortic valve.
FIGURE 24.23 Relative position of great arteries in TGA. Normal position of great arteries (center): the PA wraps anteriorly around the aorta. d transposition (left): great arteries run parallel, with the aorta anterior and to the right of the PA. l transposition (right): great arteries run parallel with the aorta anterior and to the left of the PA.
CONGENITALLY CORRECTED TRANSPOSITION OF THE GREAT ARTERIES
Congenitally corrected D-TGA is defined as levotransposition, or L-transposition, in which the great arteries are transposed and the ventricles are inverted as well (Fig. 24.24A,B).
FIGURE 24.24 Normal blood flow versus blood flow and anatomy in congenitally corrected transposition. In congenitally corrected transposition (right), systemic venous return → RA → LV → PA → lungs. Pulmonary venous return → LA → RV → Aorta → body.
There is a “double switch” that allows a physiologically appropriate flow of blood. Atria are in normal position and are connected to the “opposite ventricle.” Systemic venous return is pumped to the lungs by the morphologic left ventricle and PV return is pumped to the aorta by the morphologic RV. Echocardiographic features include the following (Fig. 24.25A–C):
FIGURE 24.25 A: Apical four-chamber view of a patient with congenitally corrected D-TGA with an apically placed TV on the left side of the heart with the systemic RV. Note the location of the moderator band within the systemic ventricle. The LV pumps blood to the lungs. B:TEE demonstrating the parallel course of the great arteries with the anterior mitral leaflet contiguous with the pulmonic valve with a separation between the atrial mitral leaflet and the aortic valve. C: Deep transgastric view demonstrating the systemic RV with the left-sided TV (arrows).
The TV is the apically displaced AV valve with respect to the MV.
The morphologic RV is identified by the presence of a moderator band and the presence of trabeculations. Recall that AV valves always feed the appropriate ventricle (i.e., TV always feeds the RV).
The left ventricular (LV) is identified by its smooth walls, absence of moderator band, and continuity between the AV and semilunar valves.
There is discontinuity between the left-sided AV valve and the semilunar valve (aortic).
The PA and aorta run parallel (as opposed to normal orthogonal position). The aorta lies anterior to the PA.
Several associated lesions can be found in patients with congenitally corrected D-TGA. Abnormalities of left-sided TV occur in 90% of patients. Ebstein-type abnormality is the most common of these, with apical displacement of the valve and the septal leaflet typically being most deformed. VSD occurs in 70% of patients, most commonly perimembranous. Pulmonic outflow obstruction (i.e., LVOT obstruction) occurs in 40% of patients, sometimes in conjunction with VSD. Patients have an increased risk of acquired complete heart block due to the abnormally placed AV node.
On chest radiograph, because the aorta is anterior and to the left, the left heart border is straightened. The left PA is not well defined. If there is PS, there may be decreased lung markings; and if there is a VSD, there may be increased lung markings.
On ECG, typically one can see left-axis deviation. A variety of AV node conduction abnormalities may be seen and over time progress to complete heart block.
OPERATIONS FOR CONGENITAL HEART DISEASE
Surgical techniques to treat congenital heart disease have evolved over the last 50 years. Early techniques were predominantly palliative, providing temporary relief of symptoms or of a clinical condition. Over time, with improvement in diagnostic as well as surgical capabilities, corrective techniques were developed. Corrective operations can achieve “normal anatomy,” “normal hemodynamics,” and/or normal physiology. Some surgical approaches may require staged procedures. The trend has been toward performing corrective procedures earlier, with fewer palliative procedures being performed. Many acronyms are used to describe the various surgical techniques (Table 24.3). As more of these surgical techniques are performed, more of these patients will survive into adulthood and will transition to the care of specialists in adult cardiology. Having a basic knowledge of simple congenital heart disease as well as of classic postoperative conditions will be useful for all cardiologists.
TABLE
24.3 Palliative and Corrective Operations for Congenital Heart Lesions
LV left ventricle; RV, right ventricle; PA, pulmonary artery; SVC, superior vena cava; MV, mitral valve.
SUGGESTED READINGS
Child SJ. Echocardiographic evaluation with postoperative congenital heart disease. In: Otto CM, ed. The Practice of Clinical Echo. Philadelphia: WB Saunders; 1997:719–752.
King ME. Echocardiographic evaluation of the adult with un-operated congenital heart disease. In: Otto CM, ed. The Practice of Clinical Echo. Philadelphia: WB Saunders; 1997:697–728.
Marelli AJ, Moodie DS. Adult congenital heart disease. In: Topol EJ, ed. Textbook of Cardiovascular Medicine. Lippincott Williams & Wilkins; 2002:707–731.
Moore JD, Moodie DS. Adult congenital heart disease. In: Marso SP, Griffin BP, Topol EJ, eds. Manual of Cardiovascular Medicine. Philadelphia: Lippincott Williams & Wilkins; 2000:387–407.
QUESTIONS AND ANSWERS
Questions
1. A cleft mitral valve (MV) is associated with which of the following conditions?
a. Secundum atrial septal defect (ASD)
b. Primum ASD
c. Coarctation of the aorta
d. Sinus venosus (SV) ASD
e. Tetralogy of Fallot
2. All of the following regarding bicuspid aortic valves are true except:
a. May be associated with coarctation of the aorta
b. Often associated with posteriorly directed jets of aortic insufficiency (AI)
c. Commonly seen with congenitally corrected transposition of the great vessels
d. May be amenable to aortic valve repair
e. Most common type involves fusion of the right coronary cusp (RCC) and left coronary cusp (LCC)
3. A sinus venosus ASD is most often associated with which of the following?
a. Coarctation of the aorta
b. Marfan syndrome
c. Partial anomalous pulmonary venous (PV) drainage
d. Tetralogy of Fallot
4. All of the following regarding Ebstein’s anomaly are true except:
a. A portion of the right ventricular (RV) is atrialized.
b. Tricuspid valve (TV) leaflets are dysplastic and adherent to the RV.
c. Common important associated defects include pulmonic stenosis (PS) or atresia.
d. A patent foramen ovale (PFO) or secundum ASD is associated in >50% of cases.
e. A common associated defect is coarctation of the aorta.
5. Complications associated with a subaortic membrane include all of the following except:
a. AI
b. Left ventricular hypertrophy (LVH)
c. Atrial arrhythmias
d. May recur postresection
6. Which of the following lesions are associated with an aortopathy which may increase a patient’s risk for developing an aortic dissection?
a. Hypertrophic obstructive cardiomyopathy (HOCM)
b. Bicuspid Aortic Valve
c. PS
d. Sinus Venosus ASD
e. Mitral valve prolapse (MVP)
7. The most common form of ASD seen in adults is:
a. Secundum ASD
b. Primum ASD
c. Unroofed coronary sinus (CS)
d. Sinus venosus ASD
e. Supracristal ASD
8. All of the following are features of Tetralogy of Fallot except:
a. Right ventricular hypertrophy (RVH)
b. Ventricular septal defect (VSD)
c. ASD (primum)
d. Infundibular PS
e. Overriding aorta
9. Which statement is true regarding patients with coarctation of the aorta?
a. Fifty percent of patients with bicuspid aortic valves have coarctation of the aorta.
b. Patients typically have asymmetric septal hypertrophy.
c. PW Doppler in the descending aorta demonstrates pan diastolic flow reversal..
d. CW Doppler through the proximal descending aorta displays a high peak velocity in systole and a gradient that persists into diastole.
10. All of the following may be true for a patient with PS except:
a. Balloon valvuloplasty is often the procedure of choice for treatment (for RV pressures >50mm Hg).
b. EKG may show right axis deviation and RVH.
c. Pulmonary Artery may be dilated on chest X-ray (CXR).
d. Pulmonary vascular markings may be increased in severe cases.
e. The degree of RVH correlates with the severity of PS.
Answers
1. Answer B: A cleft MV is part of an atrioventricular (AV) canal defect, which is due to failure of the embryonic endocardial cushions to meet and partition the heart normally. A complete endocardial cushion defect has four components: primum ASD, cleft MV, inlet VSD, and a widened anteroseptal tricuspid commissure. A partial AV canal defect does not have the VSD.
2. Answer C: The most common form is fusion of the RCC and LCC, and the mechanism of AI in those patients is prolapse of the conjoined cusp. The conjoined cusp in the case of RCC and LCC fusion is anterior, and thus the AI is directed posteriorly. At least 50% of patients with coarctation of the aorta have a bicuspid valve. A bicuspid aortic valve with severe AI can often be surgically repaired, depending on the expertise of the surgical center.
3. Answer C: A sinus venosus ASD is a defect located near the junction of the inferior vena cava (IVC) or superior vena cava (SVC) and the right atrial (RA). It is typically difficult to see by surface echocardiogram, often requiring a transesophageal echocardiography (TEE) for diagnosis. It is usually associated with drainage of the right pulmonary veins to the RA.
4. Answer E: Ebstein’s anomaly of the TV is characterized by apical displacement of the TV into the RV. As a result, a portion of the RV becomes atrialized. TV tissue is dysplastic, with portions of the septal and inferior leaflets becoming adherent to the RV. Clinical manifestations depend on associated conditions. An important associated defect is PS or atresia. Other associations include primum ASD and VSD, and congenitally corrected transposition of the great vessels.
5. Answer C: The turbulent, high-velocity jets produced by the membrane damage the aortic valve over time, and patients often develop AI that requires surgery. The subaortic membrane is a fixed obstruction, which requires the left ventricle to develop high intracavitary pressures for ejection. As the left ventricular (LV) pumps against the fixed obstruction, LVH develops (similar to what is seen with valvular AS). Subaortic membranes are known to recur occasionally postresection, although the frequency with which this occurs is unknown.
6. Answer B: Patients with a bicuspid aortic valve have an aortopathy involving cystic medial necrosis and decreased expression of fibrillin-1 with a tendency toward aneurysm formation and an increased risk for aortic dissection. The guidelines used for timing of aortic surgery for a dilated aorta in a patient with a bicuspid aortic valve are the same as those used in Marfan’s patients.
7. Answer A: Secundum ASDs are the most common form of ASD at 75% with primum ASD representing 20%, sinus venosus ASDs in 5% and unroofed coronary sinus ASDs being rare. Supracristal is a type of VSD, not ASD.
8. Answer C: A primum ASD is part of either a partial or complete AV canal defect. The other features of a complete AV canal defect include inlet VSD, cleft MV, and Widened anteroseptal tricuspid commissure. The features of Tetralogy of Fallot include VSD, RVH, Infundibular PS, and overriding aorta.
9. Answer D: Fifty percent of patients with coarctation of the aorta have a bicuspid AV; however, the percentage of patients with bicuspid AVs who have a coarct is much smaller. CW Doppler through the proximal descending aorta in a patient with a coarctation of the aorta does show a high peak gradient as well as a gradient that persists into diastole. Pan diastolic flow reversal in the descending aorta by PW Doppler is characteristic of severe AI, not a coarctation of the aorta.
10. Answer D: All of the above are true in a patient with PS except answer d. In fact pulmonary vascular markings may be decreased in patients with severe PS due to decreased flow to the lungs due to the severe obstruction to flow at the level of the pulmonic valve. There is not an increase in lung markings in these patients.