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CHAPTER 20
Congenital Heart Disease
FIG. 20-11. Barium esophagogram showing posterior indentation
of the esophagus caused by a vascular ring (right aortic arch,
aberrant left subclavian artery, and left ligamentum).
22. In the setting of tricuspid atresia without a concurrent
ventricular septal defect (VSD), which of the following
interventions is likely to stabilize an infant who presents
with worsening cyanosis?
A. Pulmonary artery banding
B. Ligation of a patent ductus arteriosus
C. Closure of atrial septal defect
D. Prostaglandin E (PGE) administration
Answer: D
The main pathophysiology in tricuspid atresia is that of a univentricular heart of left ventricular morphology. That is, the
left ventricle (LV) must receive systemic blood via the interatrial communication and then distribute it to both the pulmonary circulation and the systemic circulation. Unless there
is a ventricular septal defect (VSD) (as is found in some cases),
pulmonary flow is dependent on the presence of a patent ductus arteriosus (PDA). As the ductus begins to close shortly
after birth, infants become intensely cyanotic. Reestablishing ductal patency (with PGE1) restores pulmonary blood
flow and stabilizes patients for surgical intervention. Pulmonary hypertension is unusual in tricuspid atresia. However,
occasional patients have a large VSD between the LV and the
infundibular portion of the right ventricle (RV) (just below
the pulmonary valve). If there is no obstruction at the level
of this VSD or at the valve, these infants may actually present with heart failure from excessive pulmonary blood flow.
Regardless of whether these infants are “ductal-dependent” for
pulmonary blood flow or have pulmonary blood flow provided across a VSD, they will be cyanotic since the obligatory
right-to-left shunt at the atrial level will provide complete
mixing of systemic and pulmonary venous return so that the
LV ejects a hypoxemic mixture into the aorta. (See Schwartz
11th ed., pp. 770–772.)
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23. Which of the following best describes the approach to
surgical palliation of hypoplastic left heart syndrome?
A. Separation of the systemic and pulmonary circula-
tions along with progressive off-loading of the right
ventricle (RV)
B. Elimination of intracardiac shunting
C. Relief of hypoxia through patent ductus arteriosus
(PDA) closure
D. Augmentation of left ventricular outflow obstruction
to increase coronary blood flow
Answer: A
The main pathophysiology in tricuspid atresia is that of a univentricular heart of left ventricular (LV) morphology. That is,
the LV must receive systemic blood via the interatrial communication and then distribute it to both the pulmonary circulation and the systemic circulation. Unless there is a ventricular
septal defect (VSD) (as is found in some cases), pulmonary
flow is dependent on the presence of a PDA. As the ductus
begins to close shortly after birth, infants become intensely
cyanotic. Reestablishing ductal patency (with PGE1) restores
pulmonary blood flow and stabilizes patients for surgical
intervention. Pulmonary hypertension is unusual in tricuspid atresia. However, occasional patients have a large VSD
between the LV and the infundibular portion of the RV (just
below the pulmonary valve). If there is no obstruction at the
level of this VSD or at the valve, these infants may actually present with heart failure from excessive pulmonary blood flow.
Regardless of whether these infants are “ductal-dependent”
for pulmonary blood flow or have pulmonary blood flow
provided across a VSD, they will be cyanotic since the obligatory right-to-left shunt at the atrial level will provide complete
mixing of systemic and pulmonary venous return so that the
LV ejects a hypoxemic mixture into the aorta. (See Schwartz
11th ed., pp. 773–5.)
CHAPTER 20
Congenital Heart Disease
24. Wolff-Parkinson-White (WPW) is a conduction abnormality commonly associated with which form of congenital heart defect (CHD)?
A. Tricuspid Atresia
B. Hypoplastic left heart syndrome
C. Ebstein Anomaly
D. Aortic stenosis
Answer: C
A WPW syndrome (Fig. 20-12) type of accessory pathway
with associated preexcitation is present in 15% of patients.
The surgical approach in widespread use today for patients
surviving infancy was described by Danielson and colleagues in 1992. This procedure entails excision of redundant right atrial tissue and patch closure of any associated
atrial septal defect (ASD), plication of the atrialized portion
FIG. 20-12. EKG of a newborn with Ebsteins anomaly and WPW syndrome. Note the pre-excitation (arrow).
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CHAPTER 20
of the ventricle with obliteration of the aneurysmal cavity, posterior tricuspid annuloplasty to narrow the tricuspid
annulus, reconstruction of the tricuspid valve if the anterior leaflet is satisfactory, or replacement of the tricuspid
valve if necessary. If the tricuspid valve is not amenable to
reconstruction, valve replacement should be considered.
Care must be taken when performing the posterior annuloplasty, or during the conduct of tricuspid valve replacement,
to avoid the conduction system, because complete heart
block can complicate this procedure. In addition, patients
who demonstrated preoperative evidence of preexcitation
should undergo electrophysiologic mapping and ablation.
(See Schwartz 11th ed., pp. 777–779.)
25. After accounting for size and location of the accompa-
Congenital Heart Disease
nying ventricular septal defect (VSD), which additional
factor is a critical determinant of the clinical presentation and management of double-outlet right ventricle
(DORV)?
A. Left ventricular hypertrophy
B. Posterior location of the aorta
C. Anterior location of the aorta
D. Presence of right ventricular outflow tract (RVOT)
obstruction
26. Which anatomic consideration may complicate relief of
severe right ventricular outflow tract (RVOT) obstruction in a patient with tetralogy of Fallot (TOF)?
A. Large ratio of pulmonary artery diameter to aorta
B. Posterior location of the aorta
C. Small ventricular septal defect (VSD)
D. Left anterior descending artery originating from the
right coronary
Answer: D
Patients with DORV typically present with one of the following three scenarios: (a) those with doubly committed or subaortic VSD present with congestive heart failure and a high
propensity for pulmonary hypertension, much like infants
with a large single VSD; (b) those with a subaortic VSD and
pulmonary stenosis present with cyanosis and hypoxia, much
like infants with tetralogy of Fallot; and (c) those with subpulmonic VSD present with cyanosis, much like those with
D-TGA, because streaming directs desaturated systemic
venous blood to the aorta and oxygenated blood to the pulmonary artery. Thus, the three critical factors influencing the
clinical presentation and subsequent management of infants
with DORV are the size and location of the VSD, the presence
or absence of important RVOT obstruction, and the presence
of other anomalies (especially associated hypoplasia of leftsided structures sometimes seen with subpulmonic VSD).
(See Schwartz 11th ed., p. 783.)
Answer: D
The morphology of TOF is markedly heterogeneous and
includes an absent pulmonary valve, concomitant atrioventricular (AV) septal defects, and pulmonary atresia with
major aortopulmonary collaterals. The present discussion
will focus only on the so-called classic presentation of TOF
without coexisting intracardiac defects.
Anomalous coronary artery patterns, related to either origin or distribution, have been described in TOF. However, the
most surgically important coronary anomaly occurs when the
left anterior descending artery arises as a branch of the right
coronary artery. This occurs in approximately 3% of cases of
TOF and may preclude placement of a transannular patch,
as the left anterior descending coronary artery crosses the
RVOT at varying distances from the pulmonary valve annulus.
(See Schwartz 11th ed., pp. 784–785.)
CHAPTER 21
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Acquired Heart Disease
1. New York Heart Association Classification (NYHA) is:
A. A functional classification system that is strongly
correlated with mortality.
B. A functional classification system that does not cor-
relate with mortality.
C. Is an angina classification system similar to that of
the Canadian Cardiovascular Society (CCS) angina
classification.
D. Only calculated after cardiac catheterization.
Answer: A
The NYHA functional class is a widely used classification
system in categorizing patients based on their functional
status (Table 21-1). The NYHA classification has become
one basis by which to compare patient populations in many
studies. Although less commonly used, the CCS angina classification is also used to incorporate anginal symptoms into
the functional assessment for prognostic value (Table 21-2).
(See Schwartz 11th ed., p. 803.)
TABLE 21-1 New York Heart Association (NYHA)
functional classification
Class Description
I Physical activity not limited by symptoms: fatigue,
palpitations, or dyspnea.
II Comfortable at rest. Slight limitation of physical activity.
Fatigue, palpitations, or dyspnea with ordinary
physical activity.
III Comfortable at rest. Marked limitation of physical
activity. Fatigue, palpitations, or dyspnea with less
than ordinary physical activity.
IV Inability to carry out any physical activity. Symptoms
may be present at rest and increase with activity.
TABLE 21-2 Canadian Cardiovascular Society (CCS)
angina classification
Class Description
I Ordinary physical activity (walking, climbing stairs) does
not cause angina. Angina occurs with strenuous, rapid,
or prolonged exertion during work or recreation.
II Slight limitation of ordinary activity. Angina occurs with
climbing stairs rapidly, walking uphill in the wind,
under emotional stress, in the cold, or after meals.
Walking more than 2 blocks or climbing one flight of
stairs causes angina.
III Marked limitation of ordinary physical activity
(climbing a flight of stairs or walking 1 to 2 blocks
at a normal pace).
IV Inability to carry out any physical activity without
discomfort. Angina may be present at rest.
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2. Patients undergoing noncardiac surgery should be
assessed for their risk of cardiovascular complication.
A. Perioperative risk of major adverse cardiac events
(MACE) is a function of preexisting cardiac disease
alone.
B. American College of Surgeons NSQUIP Risk Calcu-
lator or the Revised Cardiac Risk Index can estimate
patient specific risk.
CHAPTER 21
C. Risk assessment requires stress testing and
echocardiography.
D. Patients with recent percutaneous coronary interven-
tion are at lower risk.
Acquired Heart Disease
Answer: B
Patient characteristics can be classified by the status of the
patient’s cardiac disease, comorbid conditions, and functional
capacity. Patients are considered to be at major perioperative
clinical risk if they have one or more of the following active
cardiac conditions: acute coronary syndrome, decompensated heart failure, significant arrhythmias, or severe valvular heart disease. In these patients, intensive evaluation and
treatment prior to surgery (unless emergent) are warranted,
prior to proceeding with the noncardiac surgery.
If the patient does not have any of the previously mentioned active cardiac conditions, the perioperative risk of
MACE should be estimated. Both the operation performed
and the patient’s risk factors are predictive of MACE, and
the ACC/AHA guidelines recommend the use of either the
American College of Surgeons’ NSQIP risk calculator or the
Revised Cardiac Risk Index for the estimation of patientspecific risk. Patients at low (<1%) risk or patients at elevated
risk with functional capacity ≥4 metabolic equivalents (METs)
should proceed to surgery without further testing. It is reasonable to perform pharmacologic stress testing in patients
with poor or unknown functional capacity if this testing will
impact decision-making or perioperative care. Patients with
abnormal stress test results should undergo confirmatory test
such as coronary angiography, if indicated, before an elective
noncardiac surgery. The previous guidelines included intermediate and low cardiovascular risk profiles, but this has
been replaced by cardiovascular risk factors in the update.
These risk factors are: history of ischemic heart disease, history of prior or compensated heart failure, history of cerebrovascular disease, diabetes mellitus, and renal insufficiency.
Based on the number of present risk factors and the surgeryspecific risk, the guidelines recommend pathways for further
evaluation and risk management. The most recent guidelines from ACC/AHA were published in 2014. One important subgroup of patients at elevated risk are those who have
recently undergone percutaneous coronary intervention. In
these patients, elective noncardiac surgery should be delayed
until the risk of stent thrombosis decreases (30 days for bare
metal stents and 180 to 365 days for drug-eluting stents),
and dual antiplatelet therapy should be continued unless
the risk of bleeding exceeds the risk of stent thrombosis.
(See Schwartz 11th ed., p. 804.)
3. In comparing transthoracic echocardiography (TTE)
and transesophageal echocardiography (TEE):
A. Both TEE and TTE require sedation.
B. TTE provides excellent view of mitral valve and
posterior cardiac structures.
C. TEE is often performed intraoperatively during car-
diac surgery to assess repairs and cardiac function.
D. TTE cannot see all four chambers of the heart, so
TEE is preferred.
Answer: B
TTE requires no sedation and is generally performed with
the patient in a slight left lateral decubitus position. Standardized views are obtained with the ultrasound probe placed in
the apical, parasternal, subcostal, and suprasternal positions.
The apical four-chamber view is a useful window for visualizing all four cardiac chambers simultaneously as well as the
tricuspid and mitral valves. Other windows can be obtained
to assess specific structures such as the individual valve anatomy or myocardial wall segments. Dobutamine-stress echocardiography is a study similar in idea to the stress ECG that
utilizes a pharmacologic agent to assess the patient for ischemia or stress-induced valvular abnormalities.
TEE, on the other hand, is performed using a special endo-
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scope with an ultrasound probe mounted on its end that is
introduced orally into the esophagus under sedation. Posterior structures such as the mitral valve and left atrium are
particularly well visualized. TEEs are frequently used intraoperatively during cardiothoracic surgery to assess global
cardiac function, integrity of valve repairs and replacements,
intracavitary thrombus and/or air, and aortic atherosclerosis
or dissections that can have significant influences on operative strategy. (See Schwartz 11th ed., p. 804.)
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CHAPTER 21
4. Which of the following is FALSE regarding the deleterious effects of cardiopulmonary bypass (CPB)?
A. Classic and alternative complement pathways are
activated and generate powerful chemotactic molecules and anaphylatoxins.
B. Deleterious effects can be ameliorated with periop-
erative heparin and steroid administration.
C. Heparin-induced thrombocytopenia (HIT) occurs in
1% to 5% of patients.
D. End-organ dysfunction occurs because of hypoper-
fusion, embolization, and whole body inflammatory
response.
5. The bypass conduit with the highest patency rate is the:
A. Radial artery.
B. Internal thoracic artery.
C. Greater saphenous vein.
D. Radial artery.
Answer: B
The responses of the humoral and cellular immune systems
partly overlap with the hemostatic pathways. The classic and
alternative complement pathways are activated by CPB generating powerful chemotaxic molecules and anaphylatoxins.
Monocytes, platelets, and neutrophils are activated releasing
acute inflammatory mediators and cytokines that persist even
after conclusion of CPB. These inflammatory cells also produce reactive oxidants that may have cytotoxic and cardiovascular effects, such as vasodilation and hypotension.
The large quantity of unfractionated heparin used during
cardiac surgery predisposes patients to developing HIT with
an incidence of 1% to 5%. Platelet factor-4 (PF4) is produced
by platelets and avidly binds to heparin to form a heparin-PF4
complex that can be antigenic in some patients binding IgG.
The IgG-heparin-PF4 complex can bind to platelets, which
causes release of more PF4, perpetuating the process.
Answer: B
Bypass Conduit Selection. The most important criterion in
conduit selection is graft patency. The conduit with the highest patency rate (98% at 5 years and 85%–90% at 10 years)
is the internal thoracic artery which is most commonly left
attached proximally to the subclavian artery (although occasionally used as a free graft) and anastomosed distally to
the target coronary artery. The use of both internal thoracic
arteries has been shown to increase event-free survival in a
number of studies. (See Schwartz 11th ed., p. 811.)
Acquired Heart Disease
6. An absolute contraindication to a coronary artery bypass
operation is:
A. Acute coronary artery insufficiency with persistent or
progressive angina despite optimal medical therapy.
B. Acute subendocardial infarction with multivessel
coronary artery disease.
C. Cardiogenic shock after myocardial infarction.
D. Chronic congestive failure and ischemic cardiomy-
opathy with no signs of angina.
Answer: D
Patients with ischemic cardiomyopathy are a heterogeneous
group, and, as with any surgery, appropriate patient selection
is central to success. In one retrospective study of 96 patients
with ischemic cardiomyopathy (ejection fraction [EF] ≤ 25%),
age, and poor distal vessel quality were predictors of poor
outcomes. Mortality in patients with poor vessel quality was
100%, compared with 90% when vessel quality was fair and
10% when it was good. Therefore, poor vessel quality should
be considered a contraindication to surgical revascularization even in the presence of angina. (See Schwartz 11th ed.,
p. 810.)
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7. Which of the following is true regarding the choice of
using mechanical or tissue valves in valve replacement?
A. Long-term systemic anticoagulation is required for
patients receiving both mechanical and tissue valves.
B. Mechanical valves are recommended for all young
men and women because of durability.
C. ACC/AHA guidelines recommend a shared process
between patient and physician to determine the best
CHAPTER 21
choice of valve prosthesis.
D. Bioprosthetic valves have similar rates of thrombosis
compared to mechanical valves.
Acquired Heart Disease
8. Which of the following is FALSE regarding mitral stenosis (MS)?
A. Acquired MS is most commonly caused by rheumatic
heart disease (60%).
B. MS is associated with increased valve flow velocity
and increased size of the left atrium, and elevated
pulmonary artery pressures.
C. MS is associated with atrial fibrillation (AF) with left
atrial thrombus and embolism.
D. Pulmonary edema occurs due to left ventricular
failure.
Answer: C
Although mechanical valves are highly durable, they require
permanent anticoagulation to mitigate the risk of valve
thrombosis and thromboembolic sequelae. Due to the concordant risk of hemorrhagic complications, patient characteristics such as debility, lifestyle, and contraindications to
systemic anticoagulation therapy may preclude mechanical
valve replacement. Moreover, young women who are planning future pregnancies cannot take warfarin due to its teratogenic potential. Conversely, patients with other indications
for systemic anticoagulation, such as other risk factors for
thromboembolism (ie, atrial fibrillation), or the presence of
a mechanical prosthetic valve in place in another position,
may benefit from mechanical valve replacement. Current
ACC/AHA guidelines recommend a shared-decision-making
process between patient and physician when determining the
choice of valve prosthesis, with the use of bioprosthetic valves
in all patients who have a contraindication to lifelong anticoagulation or who are unwilling to receive it. (See Schwartz
11th ed., p. 814.)
Answer: D
Acquired MS is most often caused by rheumatic fever, with
approximately 60% of patients with pure MS presenting with
a clinical history of rheumatic heart disease. Rarely, other
conditions can cause obstruction to filling of the left ventricle
(LV), mimicking MS. Acquired causes of mitral valve (MV)
stenosis include left atrial myxoma, prosthetic valve thrombosis, mucopolysaccharidosis, previous chest radiation, and
severe annular calcification.
The increased left atrial pressure is subsequently transmitted to the pulmonary venous system, causing pulmonary edema as the hydrostatic pressure in the vessels exceeds
the plasma oncotic pressure. Decreased pulmonary venous
compliance exacerbates the pulmonary venous hypertension, though a concomitant decrease in microvascular permeability may preclude pulmonary edema in the chronic
setting. Patients may also develop pulmonary arterial hypertension, owing to vasoconstriction, intimal hyperplasia, and
medial hypertrophy of the pulmonary arterioles in response
to the increased pulmonary venous pressure. The secondary obstruction to flow caused by reactive pulmonary arterial hypertension may serve to protect against pulmonary
edema, but it also exacerbates the intractable decrease in cardiac output that develops as stenosis worsens. Throughout
the process, the left atrium becomes dilated and hypertrophied due to increased work in filling the ventricle against a
fixed obstruction. AF may develop, exacerbating the patient’s
symptoms and increasing the risk of left atrial thrombus and
subsequent embolization. Left ventricular structure and function are typically preserved owing to the protective effect of
the stenotic valve. (See Schwartz 11th ed., p. 818.)
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9. The most common cause of acquired mitral stenosis
(MS) is:
A. Rheumatic disease.
B. Left atrial myxoma.
C. Ball valve thrombus.
D. Previous chest radiation.
10. Patients undergoing mechanical mitral valve
replacement:
A. Have a target INR of 4 to 5 times normal.
B. Have increased left atrial size.
C. Have atrial fibrillation.
D. Are at lower risk for thromboembolism.
Answer: A
Acquired MS is most often caused by rheumatic fever, with
approximately 60% of patients with pure MS presenting with
a positive clinical history of rheumatic heart disease. Rarely,
other conditions can cause obstruction to filling of the left ventricle (LV), mimicking MS. Acquired causes of MV obstruction
include left atrial myxoma, ball valve thrombus, mucopolysaccharidosis, previous chest radiation, and severe annular calcification. (See Schwartz 11th ed., p. 818.)
Answer: B
Although mechanical valves necessitate systemic anticoagulation, careful monitoring of the international normalized ratio
(INR) reduces the risk of thromboembolic events andhemorrhagic complications, and improves overall survival. Patients
undergoing mechanical aortic valve replacement generally
have a target INR of 2 to 3 times normal. Patients undergoing mechanical mitral valve replacement frequently have
increased left atrial size, concomitant atrial fibrillation, and
are at higher risk for thromboembolism than those undergoing mechanical aortic valve replacement, and are thus recommended to have a target INR 2.5 to 3.5 times normal. When
managed appropriately, the yearly thromboembolic and
bleeding risks in these patients are 1% to 2%, and 0.5% to 2%,
respectively. (See Schwartz 11th ed., p. 816.)
CHAPTER 21
Acquired Heart Disease
11. What valvular lesion is most commonly found in a
patient with Marfan syndrome?
A. Mitral stenosis
B. Mitral insufficiency
C. Aortic stenosis
D. Aortic insufficiency
12. Age-related calcific aortic stenosis (AS) causes some
degree of aortic insufficiency (AI) in approximately:
A. 55%.
B. 65%.
C. 75%.
D. 85%.
Answer: D
The most common cause of isolated aortic insufficiency (AI)
in patients undergoing aortic valve replacement (AVR) is aortic root disease and represents over 50% of such patients in
some studies. Other common causes of AI include congenital
abnormalities of the aortic valve such as bicuspid aortic valve,
calcific degeneration, rheumatic disease, infective endocarditis, systemic hypertension, myxomatous degeneration, dissection of the ascending aorta, and Marfan syndrome. Less
common causes of AI include traumatic injuries to the aortic
valve, ankylosing spondylitis, syphilitic aortitis, rheumatoid
arthritis, osteogenesis imperfecta, giant cell aortitis, EhlersDanlos syndrome, Reiter syndrome, discrete subaortic stenosis, and ventricular septal defects with prolapse of an aortic
cusp. Although most of these lesions produce chronic AI,
rarely acute severe aortic regurgitation can result, often with
devastating consequences. (See Schwartz 11th ed., p. 825.)
Answer: C
There are also many primary valvular diseases that cause AI,
generally in association with AS. One such disorder is agerelated calcific AS, which causes some degree of AI in up to
75% of patients. Infective endocarditis may involve the aortic
valve apparatus and cause AI through direct destruction of the
valve leaflets, perforation of a leaflet, or formation of vegetations that interfere with proper coaptation of the valve cusps.
Rheumatic disease causes fibrous infiltration of the valve
cusps and subsequent retraction of the valve leaflets, inhibiting apposition of the cusps during diastole and producing a
central regurgitant jet. Patients with large ventricular septal
defects or membranous subaortic stenosis may develop progressive AI, owing to a Venturi effect that results in prolapse
of the aortic valve leaflets. (See Schwartz 11th ed., p. 823.)
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13. Tricuspid stenosis is:
A. Caused by secondary dilation of the tricuspid annu-
lus due to pulmonary hypertension and/or right
heart failure.
B. Commonly the result of organic disease, such as
rheumatic heart disease and endocarditis.
C. Commonly caused by mitral valve disease.
D. Commonly associated with Marfan syndrome.
CHAPTER 21
14. A holosystolic murmur that is accompanied by a ventricular septal defect is associated with which of the following etiologies?
Acquired Heart Disease
A. Ventricular filling that follows atrial contraction
B. Crescendo-decrescendo; occur as blood is ejected
into the left and right ventricular outflow tracts
C. Flow between chambers that have widely different
pressures throughout systole
D. A relative disproportion between valve orifice size
and diastolic blood flow volume
15. Which of the following statements is TRUE of left ventricular (LV) aneurysms?
A. Rupture is uncommon.
B. It usually occurs 4–8 weeks after myocardial infarct.
C. 1 year mortality is <5%.
D. Generally, it requires >40% necrosis of the
myocardium.
Answer: B
Acquired tricuspid valve (TV) disease can be classified as
either organic or functional, and affects approximately 0.8%
of the general population. Tricuspid stenosis is almost always
a result of organic disease, namely rheumatic heart disease
and endocarditis. In the case of rheumatic disease, tricuspid
stenosis with or without associated insufficiency is invariably associated with mitral valve disease. Other less common
causes of obstruction to right atrial emptying include congenital tricuspid atresia, right atrial tumors, and endomyocardial
fibrosis. (See Schwartz 11th ed., p. 829.)
Answer: C
See Schwartz 11th ed., p. 813, Table 21-7.
Answer: B
A transmural infarction of approximately 5% to 10% of the
myocardium may result in formation of an LV aneurysm
as necrotic myocardium is replaced by fibrous tissue. This
usually occurs 4 to 8 weeks following the infarct. In the last
decade, prompt revascularization of the culprit artery by
either surgical or interventional techniques generally results
in sparing of the subepicardial muscle while the subendocardial muscle remains necrotic. Therefore, it is not uncommon for the LV wall to show both living myocardium during
thallium testing and an akinetic zone on echocardiogram or
angiogram. It has been demonstrated that once >20% of the
myocardium is necrosed, there is irreversible progression to
ventricular dilation and failure. Once heart failure develops
after postinfarction remodeling, the 1-year mortality reaches
32% despite current therapies. The classic aneurysm is a 4 to
6 mm thick scar, which bulges outward in paradoxical motion
as the LV contracts during systole. More than 80% develop in
the anteroseptal and apical portions of the left ventricle as a
result of left anterior descending artery occlusion. The rest
are inferior in location and the result of circumflex or right
coronary occlusion. (See Schwartz 11th ed., p. 833.)
16. The most common arrhythmia worldwide is:
A. Atrial flutter.
B. Paroxysmal supraventricular tachycardia (PSVT).
C. Wolff-Parkinson-White (WPW) syndrome.
D. Atrial fibrillation.
Answer: D
Atrial fibrillation (AF) remains the most common arrhythmia in the world with an overall incidence of 0.4% to 1%
that increases to 8% in those older than 80 years. The most
serious complication of AF is thromboembolism with resultant stroke, but serious morbidity and mortality may also
result from hemodynamic compromise due to loss of atrial
contraction, exacerbations of congestive heart failure from
atrioventricular asynchrony and tachycardia-induced cardiomyopathy. (See Schwartz 11th ed., p. 838.)
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17. Which of the following is FALSE regarding the CoxMaze IV procedure?
A. It is indicated for ventricular tachycardia.
B. It is indicated for treatment of Atrial Fibrillation
(AF).
C. It includes surgical management of left atrial append-
age and radiofrequency or cryotherapy ablation.
D. It is indicated in patients who are poor candidates for
catheter-based ablation, including patients with large
left atria and long-standing persistent AF.
Answer: A
The Cox-Maze IV uses a combination of bipolar radiofrequency (RF) ablation and cryoablation to effectively replace
the majority of incisions that comprise the Cox-Maze III
while significantly shortening cross-clamp time and reducing
operative complexity.
The Cox-Maze IV is performed on cardiopulmonary
bypass through either a median sternotomy, often in combination with other cardiac surgery or a right minithoracotomy.
In most cases, the right atrial lesion set performed on the
beating heart, whereas the left atrial lesions are performed
during cardioplegic arrest (Fig. 21-1). (See Schwartz 11th ed.,
p. 838.)
CHAPTER 21
Acquired Heart Disease
FIG. 21-1. The Cox-Maze IV Lesion Set. A. The left atrial lesion set is comprised of right and left
pulmonary vein isolation, connecting lesions between the left and right superior and inferior
pulmonary veins, a lesion from the left atrial appendage excision site to the pulmonary vein, and a
lesion to the mitral valve annulus. B. The right atrial lesion set consists of lines of ablation along the
superior and inferior vena cavae, the free wall of the right atrium, and down to the tricuspid valve
annulus. (Reproduced with permission from Damiano RJ Jr, Schwartz FH, Bailey MS, et al: The Cox maze IV
procedure: predictors of late recurrence. J Thorac Cardiovasc Surg. 2011;141(1):113–21.)
18. Which of the following is not TRUE in comparing CoxMaze IV and pulmonary vein isolation (PVI)?
A. Both procedures require cardiopulmonary bypass.
B. PVI has poorer results than Cox-Maze IV procedure.
C. PVI has been shown to be superior to catheter-based
ablation procedures.
D. PVI is performed thoracoscopically.
Answer: A
PVI is an attractive therapeutic option because it can be performed off of cardiopulmonary bypass (CPB) through small
or thoracoscopic incisions. The results of PVI have been variable and highly dependent on patient selection since outcomes
are consistently worse in patients with long-standing persistent atrial fibrillation (AF). In a study from Edgerton et al,
only 56% of patients were free from AF at 6 months (35%
off antiarrhythmic drugs), and with concomitant procedures,
the success rate of PVI has been even lower. Several devices
are available to close the left atrial appendage (LAA) at the
time of PVI. These include staplers and epicardial clips that
can be placed without the need for CPB.
procedure, it has had superior results to catheter-based PVI.
The Atrial Fibrillation Catheter Ablation Versus Surgical
Ablation Treatment (FAST) Trial, which was a two-center,
randomized clinical trial, compared catheter-based ablation
to thoracoscopic PVI in patients with antiarrhythmic drugrefractory AF and either left atrial dilatation and hypertension or failed prior catheter-ablation. (See Schwartz 11th ed.,
p. 839.)
While surgical PVI has had poorer results than a Cox-Maze
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