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CHAPTER 6 Congenital Heart Disease
63
of patients). Guideline-directed recommendations for aortic valve
replacement are reasonable to follow for patients with d-TGA and
severe neo-aortic valve regurgitation.
Prognosis
Long-term follow-up studies after the atrial switch procedure show
a small but ongoing attrition rate, with numerous intermediate- and
long-term complications. Long-term complications include systemic
RV dysfunction and tricuspid valve regurgitation, loss of sinus rhythm
with the development of atrial arrhythmias (50% incidence by age 25),
endocarditis, baffle leaks, baffle obstruction, and sinus node dysfunction requiring pacemaker placement. Intermediate-term complications related to the arterial switch procedure include coronary artery
compromise, pulmonary outflow tract obstruction (at the supravalvular level or takeoff of the peripheral pulmonary arteries), neo-aortic
valve regurgitation, endocarditis, and neo-aorta dilation.
As a result of the long-term complications associated with the atrial
switch procedure, the arterial switch operation has been the procedure
of choice since 1985. Long-term data on the survival after the arterial
switch operation do not exist, but intermediate-term results are promising: 88% at 10 and 15 years.
For a deeper discussion on this topic, please see Chapter 61,
“Congenital Heart Disease in Adults,” in Goldman-Cecil Medicine,
26th Edition.
SUGGESTED READINGS
Bradley EA, Ammash N, Martinez SC: “Treat to close”: Non-repairable ASD-
PAH in the adult, Int J Card 291:127–133, 2019.
Campbell M: Natural history of atrial septal defect, Br Heart J 32:820–826,
1970.
Cohen M, Fuster V, Steele PM, et al: Coarctation of the aorta. Long-term
follow-up and prediction of outcome after surgical correction, Circulation
80:840–845, 1989.
Cohen SB, Ginde S, Bartz PJ, et al: Extracardiac complications in adults with
congenital heart disease, Congenit Heart Dis 8:370–380, 2013.
Co-Vu JG, Ginde S, Bartz PJ, et al: Long-term outcomes of the neoaorta after
arterial switch operation for transposition of the great arteries, Ann Thorac
Surg 95:1654–1659, 2013.
Cramer JW, Ginde S, Bartz PJ, et al: Aortic aneurysms remain a significant
source of morbidity and mortality after use of Dacron patch aortoplasty to
repair coarctation of the aorta: results from a single center, Pediatr Cardiol
34:296–301, 2013.
Crumb SR, Dearani JA, Fuller S, et al: 2018 AHA/ACC guideline for the man-
agement of adults with congenital heart disease, J Am Coll Cardiol 1–175.
Earing MG, Connolly HM, Dearani JA, et al: Long-term follow-up of patients
after surgical treatment for isolated pulmonary valve stenosis, Mayo Clin
Proc 80:871–876, 2005.
Earing MG, Webb GD: Congenital heart disease and pregnancy: maternal and
fetal risks, Clin Perinatol 32:913–919, 2005.
Gatzoulis MA, Freeman MA, Siu SC, et al: Atrial arrhythmia after surgical
closure of atrial septal defects in adults, N Engl J Med 340:839–846, 1999.
Gunther T, Mazzitelli D, Haehnel CJ, et al: Long-term results after repair of
complete atrioventricular septal defects: analysis of risk factors, Ann Thorac Surg 65:754–759, 1998, discussion 759-760.
Hickey EJ, Gruschen V, Bradely TJ, et al: Late risk of outcomes for adults
with repaired tetralogy of Fallot from an inception cohort spanning four
decades, Eur J Cardiothorac Surg 35:156–164, 2009.
Khairy P, Van Hare GF, Balaji S: PACES/HRS expert consensus statement on
the recognition and management of arrhythmias in adult congenital heart
disease, Can J Cardiol e1–e63, 2014.
Losay J, Touchot A, Serraf A, et al: Late outcome after arterial switch operation
for transposition of the great arteries, Circulation 104(Suppl 1):I121–
I1126, 2001.
Perloff JK, Warnes CA: Challenges posed by adults with repaired congenital
heart disease, Circulation 103:2637–2643, 2001.
Soto B, Becker AE, Moulaert AJ, et al.: Classification of ventricular septal
defects, Br Heart J 43:332–343, 1980.
Stout KK, Daniels CJ, Aboulhosn JA, et al.: Transposition of the great arteries,
Circulation 114:2699–2709, 2006.
7
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Valvular Heart Disease
Christopher Song
INTRODUCTION
In developing countries, rheumatic heart disease (RHD) remains a
common cause of valvular heart disease (VHD). In industrialized
countries, the burden of rheumatic disease has significantly decreased,
and the most common etiology is degenerative disease. The prevalence
of VHD in the US adult population is 2.5%. Prevalence increases with
age to as high as 13.3% in those 75 years and older. Moderate or severe
VHD is associated with excess mortality. Therefore, with an aging population, valvular heart disease is and will continue to be a major public
health problem.
The “2014 AHA/ACC Guideline for the Management of Patients
with Valvular Heart Disease” provides a classification of the progression of VHD with 4 stages, A through D (Table 7.1). Timing of intervention for most VHD is guided by the onset of symptoms, severity
of VHD, and evidence of adverse cardiac remodeling. Therefore, a
thorough history and physical examination along with a comprehensive transthoracic echocardiogram (TTE) are essential in the evaluation of patients with known or suspected VHD. Other cardiac testing
modalities can help to determine the severity of VHD and the presence of symptoms. Once intervention is contemplated, each individual
patient’s surgical risk should be assessed. If surgical risk is high or prohibitive, transcatheter approaches may be an option.
AORTIC STENOSIS
Definition and Etiology
Valvular aortic stenosis (AS) is defined by restriction in leaflet motion
resulting in left ventricular (LV) outflow obstruction. Less common
causes of LV outflow obstruction include lesions at the supravalvular
or subvalvular level. There are three primary etiologies of valvular AS:
congenital, rheumatic, and calcific disease.
The etiology often dictates age at presentation. Patients with congenital aortic stenosis and unicuspid aortic valves usually present
before the age of 30. Those with a bicuspid aortic valve or rheumatic
valve disease typically present between the age of 40 and 60. Patients
with calcific trileaflet valve typically present after age 70. However,
patients with Paget disease or end-stage renal disease may present at
a younger age.
Pathophysiology
The initiation phase of calcific aortic valve disease is similar to atherosclerosis. The process is thought to begin with mechanical stress and
endothelial damage leading to inflammation and lipid deposition. The
propagation phase is dominated by calcification leading to progressive
restriction of the valve leaflets and eventual LV outflow obstruction.
In bicuspid aortic valves there is an associated increase in mechanical stress which leads to accelerated calcification of the valve leaflets.
Bicuspid aortic valve occurs in about 1% of the population and it is
twice as common in males as in females. Patients with a bicuspid aortic
valve often have an associated aortopathy such as coarctation or aortic
aneurysm.
Once AS becomes hemodynamically significant, it leads to resistance in LV ejection and an increase in LV systolic pressure and
wall stress. In order to maintain normal wall stress, wall thickness
increases resulting in concentric hypertrophy. The left ventricle can
remain in this compensated state for a prolonged period. However,
as valvular stenosis and hypertrophy progress, LV end-diastolic pressure increases and, eventually, LV dilation and systolic dysfunction
ensue.
Natural History and Clinical Presentation
Patients with AS are usually asymptomatic for a prolonged period.
Symptom onset occurs when valve obstruction is severe and usually
prior to the onset of LV systolic dysfunction. In fact, LV chamber size
and systolic function can remain normal until the AS is end-stage. The
onset of symptoms in AS indicates a significant increase in mortality
risk. This was first described by Ross and Braunwald in their seminal
paper in 1968. They also found that specific symptoms were associated with different survival rates. The average survival of patients with
symptoms of angina, syncope, and heart failure was 5, 3, and 2 years,
respectively (Fig. 7.1).
These “classic” symptoms are now thought to be symptoms of
end-stage disease. With the advent of echocardiography and close follow-up of patients, the most common presenting symptoms are dyspnea on exertion or decreased exercise tolerance, exertional dizziness,
and exertional angina. Given the nonspecific nature of these symptoms
along with the prognostic and therapeutic implications of diagnosing a
patient with severe symptomatic AS, one must be thorough in screening patients for these symptoms but also be cautious in attributing
these symptoms to AS.
Physical Examination
The physical examination is useful in the initial detection of AS and
correlates with severity (Table 7.2). However, no physical examination
findings can reliably exclude severe AS.
When palpating the carotid artery, a delayed, low amplitude pulse
may be appreciated (pulsus parvus et tardus). With precordial palpation, a heaving and sustained apical impulse may be noted due to LV
hypertrophy or systolic dysfunction. A fourth heart sound (S4) can be
palpable in the setting of a noncompliant left ventricle. In addition, a
64
CHAPTER 7 Valvular Heart Disease
Age, years
Percent survival
Latent period Onset severe symptoms
80
TABLE 7.1 Stages of Progression of VHD
Stage Definition Description
A At risk Patients with risk factors for development of VHD
B Progressive Patients with progressive VHD (mild-moderate severity and asymptomatic)
C Asymptomatic severe Asymptomatic patients who have the criteria for severe VHD:
C1: asymptomatic patients with severe VHD in whom the left and right ventricle remain compensated
C2: asymptomatic patients with severe VHD with decompensation of the left or right ventricle
D Symptomatic severe Patients who have developed symptoms as a result of VHD
Data from Nishimura R, Otto C, Bonow RO, et al: 2014 AHA/ACC guideline for the management of patients with valvular heart disease. J Am Coll
Cardiol 2014;63:e57-e185.
65
Fig. 7.1 Natural history of severe aortic stenosis without surgery once
symptoms develop. (Data from Ross J Jr, Braunwald E: Aortic stenosis,
Circulation 38:61, 1968.)
precordial thrill may be appreciated due to turbulent blood flow across
a stenotic aortic valve.
and delayed closure of the aortic valve leaflets and resistance to flow. The
aortic component (A2) of the second heart sound (S2) becomes delayed
to occur simultaneously with the pulmonic component (P2) forming a
single S2. In severe AS, A2 may become inaudible or paradoxical S2 can
be observed. An aortic ejection click can be heard in mild to moderate
AS, when the leaflets are stiff but still mobile. The classic murmur AS is
described as a harsh crescendo-decrescendo systolic murmur that is best
heard at the right upper sternal border that radiates to the carotid arteries.
The murmur begins after the first heart sound (S1) and ends before S2.
Like the carotid pulse, the timing of the murmur correlates with severity
of AS. An early peaking murmur is indicative of mild or moderate AS
whereas a late peaking murmur is typically a sign of severe AS. The murmur may also radiate to the apex where a distinct musical quality can be
appreciated. This is known as Gallavardin’s phenomenon and often mistaken as the presence of concomitant mitral regurgitation (MR).
Diagnosis
An electrocardiogram (ECG) and chest radiograph are commonly
obtained and can have nonspecific findings such as LV hypertrophy
or cardiomegaly, respectively. The primary tool for diagnosing AS is
echocardiography. TTE can accurately assess the aortic valve structure, the severity of AS, and the effects of AS on the cardiac chambers.
Doppler imaging can be used to estimate the gradients across a stenotic
aortic valve and calculate an aortic valve area. Criteria for mild, moderate, and severe AS are well established (Table 7.3).
evaluation. If there is a discrepancy, further testing can be considered.
100
(Increasing obstruction,
80
myocardial overload)
60
40
20
40
50 60
63 70
Angina
Syncope
Failure
23
AV. survival, years
Average age death
5
The findings on cardiac auscultation are reflective of reduced mobility
In most cases the severity of AS by TTE correlates with the clinical
An exercise treadmill study can be done to objectively assess functional
capacity. A cardiac catheterization with hemodynamic measurements
provides an alternative assessment of the severity of AS. Computed
tomography can quantify aortic valve calcium, which has been shown
to correlate with AS severity by TTE and with clinical outcomes.
In patients with LV systolic dysfunction, it may be unclear if a
patient has true severe AS or pseudosevere AS. A low-dose dobutamine stress echocardiogram can help to differentiate between the two.
In true severe AS the valve area is fixed, regardless of dobutamine. In
pseudosevere AS the aortic valve opening is limited by the low LV
outflow and the valve area will increase with dobutamine. This test
can also provide information about the contractile reserve of the left
ventricle, which has prognostic implications when considering valve
replacement.
Treatment
The management of asymptomatic AS involves close monitoring, early
detection of symptoms, and treatment of cardiovascular risk factors
and comorbidities such as hypertension, hyperlipidemia, and coronary
artery disease. No treatments have been shown to prevent the progression of AS.
Once a patient develops severe symptomatic AS, medical therapy
has limited benefit and aortic valve replacement (AVR) is recommended. Medical therapy should focus on preventing and optimizing concomitant cardiovascular conditions and treating symptoms.
Nonetheless, AVR has been shown to improve symptoms and survival
and it is the only effective treatment in severe symptomatic AS. Those
with severe asymptomatic AS may also meet indications for AVR if
they have concurrent LV systolic dysfunction, very severe AS, rapidly
progressing AS, or if they are undergoing another cardiac surgery.
There are two broad approaches to AVR: surgical and transcatheter.
For decades, surgical AVR was the mainstay of therapy for severe AS.
With surgical AVR, either a mechanical or bioprosthetic valve can be
considered. With favorable flow characteristics, mechanical valves can
last for the patient’s lifetime (Fig. 7.2). However, these valves require
anticoagulation with warfarin. While bioprosthetic valves, made from
bovine or porcine material, do not require anticoagulation, they are
less durable and typically require re-replacement after 10 to 20 years
(Fig. 7.3).
Rather than an open procedure requiring sternotomy, transcatheter aortic valve implantation (TAVI) most commonly involves accessing the femoral artery and using a catheter to deliver a bioprosthetic
valve into position by expanding a balloon and effectively crushing
the native aortic valve against the aortic wall (Fig. 7.4). Less common
approaches include transapical, transaortic, and subclavian. The role of
TAVI was initially established in patients with severe symptomatic AS
and prohibitive surgical risk. TAVI led to significant mortality benefit
66 SECTION II Cardiovascular Disease
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TABLE 7.2 AS Exam Findings by Severity
Exam Finding Mild Moderate Severe
Carotid pulse Normal Slow rising Parvus et tardus
Apical impulse Normal Heaving Heaving and sustained
S4 gallop Absent May be present Present
Systolic ejection click Present May be present Absent
Systolic murmur peak Early systole Mid systole Mid or late systole
S
2
Normal Normal or single Single or paradoxical
TABLE 7.3 Measures of AS Severity on Echocardiography
Indicator Normal Mild Moderate Severe
Aortic valve area (cm2) >2.0 1.5-2.0 1.0-1.5 <1.0
Mean gradient (mm Hg) <25 25-40 >40
Peak jet velocity (m/s) <2.0 2-3 3-4 >4
Data from Baumgartner H, Hung J, Bermego J, et al: Echocardiographic assessment of valve stenosis: EAE/ASE recommendations for clinical
practice. J Am Soc Echocardiogr 2009;22:1-22.
Fig. 7.2 Medtronic bileaflet mechanical prosthetic valve. (Modified
from Medtronic, Inc.)
Fig. 7.3 Medtronic Hancock II bioprosthetic valve. (Modified from
Medtronic, Inc.)
in this patient population when compared to standard therapy. Since
the landmark trial in 2010, TAVI has emerged as an effective therapy
for severe symptomatic AS in patients across the entire spectrum of
surgical risk, from extreme risk to low risk.
public health problem. Less common causes of MS include mitral
annular calcification, radiation exposure, congenital, or mechanical
obstruction from an atrial myxoma, vegetation, or thrombus.
Patients being considered for AVR should undergo a thorough
individualized evaluation by a multidisciplinary heart valve team. The
patient’s life expectancy, surgical risk, comorbidities, frailty, anatomy,
quality of life, values, and preferences should all be considered before
making an informed shared decision on treatment strategy.
Pathophysiology
Rheumatic fever is the result of an abnormal immune response usually
occurring after 10 days to 3 weeks after untreated group A streptococcal pharyngitis. It typically affects children between the ages of 6 and 15
years. The diagnosis can be made based on clinical manifestations and
MITRAL STENOSIS
Definition and Etiology
Mitral stenosis (MS) is defined by the restriction of blood flow from
the left atrium (LA) to the left ventricle during diastole. RHD is by far
the most common cause of MS. In developed nations, rheumatic MS
has become less common with the decreasing incidence of rheumatic
fever. However, in developing nations, RHD remains a significant
the revised Jones criteria (Table 7.4).
In RHD, there is inflammatory process thought to be due to
cross-reactivity between streptococcal antigen and valve tissue. This
along with chronic turbulent flow through a deformed valve results
in thickening and calcification of the mitral leaflets, thickening and
shortening of the chordae tendineae, and fusion of the leaflet commissures (Fig. 7.5). This ultimately leads to a reduced orifice through
which blood can flow from the LA to the left ventricle during diastole.
CHAPTER 7 Valvular Heart Disease
ABC
AB
67
Fig. 7.4 Edwards SAPIEN transcatheter heart valve. (A) Valve is delivered retrograde from the femoral artery
and positioned at the level of the aortic annulus. (B) Balloon inflated, deploying the valve. (C) Deployed valve.
(From Cardiology Secrets, 5th ed, Elsevier, 2018.)
TABLE 7.4 Revised Jones Criteria
a
Major Criteria Minor Criteria
Carditis (pleuritic chest pain, friction rub, heart failure)
Polyarthritis
Chorea
Fever
Arthralgia
Previous rheumatic fever or known rheumatic heart disease
Erythema marginatum
Subcutaneous nodules
a
Rheumatic fever is diagnosed based on the presence of two major criteria or one major and two minor criteria after a recent documented group A
streptococcal infection.
Fig. 7.5 Commissural fusion in mitral stenosis. (A) Left atrial aspect. (B) Left ventricular aspect. (From Car-
diovascular Pathology, Fourth Ed, Elsevier, 2016.)
68 SECTION II Cardiovascular Disease
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The hemodynamic consequences of MS primarily affect the pulmo-
nary capillary bed, pulmonary artery, and right ventricle. In pure MS,
the left ventricle remains unaffected. With resistance to left atrial emptying during diastole, left atrial pressure (LAP) increases. This pressure
is reflected back to the capillary bed and pulmonary artery, which can
result in pulmonary edema and pulmonary hypertension. This can
lead to pressure overload of the right ventricle with subsequent right
ventricle hypertrophy (RVH), tricuspid regurgitation (TR), and eventual right ventricular (RV) failure.
Natural History and Clinical Presentation
In developed countries, rheumatic MS is usually a slow progressive disease with a prolonged asymptomatic period of up to several decades.
In developing countries, the disease course can be more rapid with
symptoms in young adults and children. Symptom onset occurs once
the mitral valve area is less than 1.5 cm2. Once symptom onset occurs,
the prognosis becomes worse. Mortality has been linked to New York
Heart Association (NYHA) functional class. The presence of atrial
fibrillation (AF) and pulmonary hypertension has also been established as a poor prognostic indicator.
Patients often present with dyspnea on exertion and decreased
exercise tolerance. This is a consequence of elevated LAP and pulmonary pressures. Additionally, with exertion, an increase in heart rate
leads to a decrease in diastolic filling time and increase in the diastolic
gradient across the mitral valve.
Elevated LAP leads to left atrial dilation and AF. This can often pre-
cipitate or exacerbate the symptoms of MS in two possible ways. First,
in AF, there is the loss of atrial contraction which further impedes diastolic flow across a stenotic mitral valve. Second, AF often leads to high
heart rates and decreases diastolic filling time. Also, with AF associated with MS, there is an increased thromboembolic risk. If the LA
becomes severely dilated, it can compress the recurrent laryngeal nerve
and cause hoarseness (Ortner syndrome) or coughing.
Increases in pulmonary pressures and vascular congestion can
lead to hemoptysis. As pulmonary hypertension progresses, it affects
the right heart and right-sided filling pressures, ultimately leading to
symptoms of right heart failure such as ascites and peripheral edema.
Symptoms can be provoked with any state causing an increase in
cardiac output or heart rate such as exertion, stress, illness, infection,
or arrhythmia. Symptoms may be unmasked in previously asymptomatic women with MS who become pregnant given the increase in heart
rate and cardiac output associated with pregnancy.
Physical Examination
Several components of the physical examination need to be carefully
assessed when evaluating patients with MS. The patient should be examined in a quiet room and positioned in the left lateral decubitus position
because certain characteristic findings of MS may be difficult to appreciate.
S1 is loud early on in the disease as elevated LAP leads to increased
excursion of the mitral leaflets. However, as the disease progresses and
the leaflets become calcified and rigid, S1 diminishes. The S2 is initially
normal but P2 can increase in intensity as pulmonary pressures rise.
Eventually a single S2 can result. S3 is typically not heard but S4 can be
heard due to right ventricular hypertrophy (RVH).
A diastolic opening snap (OS) can be heard due to the initial rapid
opening of the mitral leaflets followed by an abrupt halt due to fusion
of the leaflet tips. The interval between S2 and OS varies inversely with
the severity of MS. The earlier in diastole the OS occurs, the more
severe the MS as this is reflective of higher LAP.
The murmur appreciated in MS is a low-pitched diastolic rumble
best heard at the apex and at end expiration using the bell of the stethoscope. In mild MS, the murmur may be heard only in late diastole. As
MS progresses the murmur may be heard throughout diastole, and if
the MS is very severe the murmur may be very soft or absent due to
slow flow across the mitral valve.
Patients with symptomatic MS may have signs of heart failure
such as rales, jugular venous distension, hepatomegaly, and peripheral
edema. If there is significant pulmonary hypertension, a parasternal lift
or RV heave may be appreciable.
Diagnosis
ECG and chest radiograph can have nonspecific findings. ECG can
show left atrial enlargement, AF, or RVH. Chest radiograph may
demonstrate pulmonary vascular congestion, RV dilation, pulmonary
artery dilation, or left atrial enlargement (“double density” sign).
TTE is the diagnostic test for MS. TTE is also used to evaluate the
severity of MS, assess the effects of the MS on the cardiac chambers
and pulmonary pressures, assess for concomitant valvular disease, and
assess for suitability of valve anatomy for percutaneous mitral balloon
valvotomy (PMBV). On TTE, the mitral leaflets appear thickened and
deformed. In rheumatic MS, leaflet motion during diastole is restricted
and results in a characteristic “hockey stick” appearance. Doppler
interrogation can provide an estimation of mitral valve area and pulmonary artery pressure. The TTE can also assess for the other findings
associated with MS such as left atrial dilation, RVH or RV dilation, and
TR. With the findings on TTE and the patient’s symptoms, MS severity
can be staged (Table 7.5).
When there is a discrepancy between the TTE findings and clinical
findings, exercise stress echocardiography can be performed to evaluate the mitral valve gradients and pulmonary pressures during exercise. Alternatively, cardiac catheterization can be considered to obtain
direct measurements of the cardiac chambers and mitral gradients.
Treatment
There is a limited role for medical therapy in the treatment of MS. If
patients have symptoms of heart failure, diuretics can be used to alleviate symptoms. Slowing the heart rate with β-blockers or calcium-channel blockers will increase diastolic filling time and decrease mitral
gradients. Rate control is particularly important in AF. Anticoagulation
with a vitamin K antagonist is recommended in patients with MS and
AF, prior embolic event, or left atrial thrombus. Direct oral anticoagulants have not been approved for this indication.
The decision to proceed with an intervention of the mitral valve
depends on the severity of MS and the presence of symptoms, AF, and
pulmonary hypertension. Valve morphology, presence of concomitant
MR, presence of left atrial thrombus, and the patient’s surgical risk will
guide whether the patient undergoes a surgical mitral valve replacement
or PMBV. Contraindications for PMBV include the presence of left
atrial thrombus and more than moderate MR. TTE can be used to assess
the suitability for PMBV by assessing the mobility, thickening, and calcification of the mitral leaflets and the degree of subvalvular thickening.
Refer to Table 7.6 for a summary of the recommendations for mitral
valve intervention described in the 2014 AHA/ACC valve guidelines.
PULMONIC STENOSIS
Definition and Etiology
Pulmonic stenosis (PS) is defined by a restriction in leaflet motion
resulting in RV outflow obstruction and a pressure gradient between
the right ventricle and main pulmonary artery. The etiology of PS
is almost always congenital and usually occurs as an isolated lesion.
However, it can also be associated with other congenital conditions
such as tetralogy of Fallot, congenital rubella syndrome, and Noonan
syndrome.
CHAPTER 7 Valvular Heart Disease
TABLE 7.5 Stages of MS
Stage Definition Valve Anatomy Hemodynamic Consequences Symptoms
A At risk of MS Doming of mitral leaflets during diastole None None
B Progressive MS Rheumatic valve changes with commissural
fusion and diastolic doming of the mitral
leaflets
MVA >1.5 cm
C Asymptomatic severe MS Rheumatic valve changes with commissural
fusion and diastolic doming of the mitral
leaflets
MVA ≤1.5 cm2 (MVA <1.0 cm2 with very
severe MS)
D Symptomatic severe MS See Stage C See Stage C Decreased exercise
Modified from Nishimura R, Otto C, Bonow RO, et al: 2014 AHA/ACC guideline for the management of patients with valvular heart disease. J Am
Coll Cardiol 2014;63:e57-e185.
2
Mild to moderate LA enlargement
Normal pulmonary pressure at rest
Severe LA enlargement
Elevated pulmonary artery pressure
None
None
tolerance
Exertional dyspnea
TABLE 7.6 Summary of Recommendations for Mitral Valve Intervention in MS
Recommendation Class of Recommendation
PMBV is recommended for symptomatic patients with severe MS (MVA ≤1.5 cm2, stage D) and favorable
valve morphology in the absence of contraindications
MVR is indicated in severely symptomatic patients (NYHA class III/IV) with severe MS (MVA ≤1.5 cm2, stage
D) who are not high risk for surgery and who are not candidates for or failed previous PMBV
Concomitant MVR is indicated for patients with severe MS (MVA ≤1.5 cm2, stage C or D) undergoing other
cardiac surgery
PMBV is reasonable for asymptomatic patients with very severe MS (MVA ≤1.0 cm2, stage C) and favorable
valve morphology in the absence of contraindications
MVR is reasonable for severely symptomatic patients (NYHA class III/IV) with severe MS (MVA ≤1.5 cm2,
stage D), provided there are other operative indications
PMBV may be considered for asymptomatic patients with severe MS (MVA ≤1.5 cm2, stage C) and favorable
valve morphology who have new onset of AF in the absence of contraindications
PMBV may be considered for symptomatic patients with MVA >1.5 cm2 if there is evidence of hemodynami-
cally significant MS during exercise
PMBV may be considered for severely symptomatic patients (NYHA class III/IV) with severe MS (MVA ≤1.5
cm2, stage D) who have suboptimal valve anatomy and are not candidates for surgery or at high risk for
surgery
Concomitant MVR may be considered for patients with moderate MS (MVA 1.6 to 2.0 cm2) undergoing other
cardiac surgery
MVR and excision of the left atrial appendage may be considered for patients with severe MS (MVA ≤1.5
cm2, stages C and D) who have had recurrent embolic events while receiving adequate anticoagulation
Modified from Nishimura R, Otto C, Bonow RO, et al: 2014 AHA/ACC guideline for the management of patients with valvular heart disease. J Am
Coll Cardiol 2014;63:e57-e185.
I
I
I
IIa
IIa
IIb
IIb
IIb
IIb
IIb
69
Pathophysiology
In PS, the valve is typically trileaflet with thickening and fusion of the
commissures resulting in restricted leaflet opening during systole.
Post-stenotic dilation of the main pulmonary artery can occur due to
eccentric flow through the stenotic valve. Over time, RVH can occur
due to increased afterload.
Natural History and Clinical Presentation
Isolated PS is generally well tolerated and survival is comparable to
the general population. Patients with mild PS are asymptomatic and
may not be diagnosed with PS until adulthood. Moderate PS is usually
identified in childhood and patients are usually symptomatic due to
RV pressure overload. Decreasing right-sided cardiac output leads to
symptoms of dyspnea on exertion and fatigue. In more advanced disease, patients can have RV failure and cyanosis.
Physical Examination
On physical examination, patients with PS can have a parasternal lift
as a result of RVH. The jugular veins may demonstrate prominent a
waves. The murmur of PS is a systolic ejection murmur best heard at
the left upper sternal border radiating to the back with the duration
correlating with severity. A late peaking murmur indicates more severe
disease. A systolic ejection click may be heard in mild to moderate PS.
S2 can have wide splitting due to prolonged ejection time of the right
ventricle. Fixed splitting of S2 occurs in severe disease when the RV
output becomes fixed.
70 SECTION II Cardiovascular Disease
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Diagnosis
TTE can be used to diagnose PS, assess the severity of PS, and evaluate
the right ventricle. Using Doppler measurements, the gradients across a
stenotic pulmonic valve can be estimated. If TTE is inconclusive or for
patients with complex anatomy, cardiac magnetic resonance imaging
(CMR) can be considered as an alternative imaging modality to assess the
severity of valve disease and quantitatively measure RV size and function.
Treatment
Intervention is guided by the valve anatomy, gradients measured on
TTE, and the presence of symptoms. Percutaneous balloon valvotomy is recommended in asymptomatic patients with a peak gradient
of greater than 60 mm Hg or a mean gradient of 40 mm Hg, or in
symptomatic patients with a peak gradient of 50 mm Hg or a mean
gradient of 30 mm Hg. A surgical approach is usually recommended
for dysplastic valves, in the presence of severe pulmonic regurgitation,
or if there is another indication for surgery.
TRICUSPID STENOSIS
Definition and Etiology
In tricuspid stenosis (TS), there is restriction of blood flow between the
right atrium and right ventricle. The etiology of TS is most commonly
rheumatic and is generally associated with MS. Isolated TS is rare but
can be seen in congenital tricuspid valve atresia, right heart tumors,
carcinoid syndrome, and endocarditis.
Pathophysiology
TS causes flow obstruction at the level of the tricuspid valve resulting
in a diastolic pressure gradient between the right atrium and right ventricle. This leads to elevated right atrial pressure (RAP) and systemic
venous congestion. With exertion or tachycardia, diastolic filling time
decreases and the diastolic pressure gradient increases. With inspiration, the decrease in intrathoracic pressure results in increased venous
return which also increases the pressure gradient across the tricuspid
valve. Conversely, expiration leads to a decrease in the pressure gradient.
Natural History and Clinical Presentation
The natural history of patients with TS is variable. Most patients with
rheumatic TS have concomitant significant aortic and/or mitral valve
disease. Tricuspid valve atresia is managed with multiple surgeries
starting in the neonatal period into early childhood.
Patients present with signs and symptoms of systemic venous congestion including ascites, peripheral edema, and hepatomegaly. Patients
may report a fluttering sensation in the neck from prominent a waves.
Physical Examination
With an increase in RAP there is jugular venous distension. A prominent a wave can often be appreciated. A rise in jugular venous pressure
with inspiration (Kussmaul sign) may also be seen. Other signs of systemic venous congestion can be present including hepatomegaly, ascites, peripheral edema, and anasarca. The murmur of TS is described as
a low-frequency, diastolic murmur best heard at the left lower sternal
border. There may also be an opening snap. These sounds are difficult
to distinguish from the murmur and opening snap of MS. However,
with right-sided murmurs, the intensity of the TS murmur should
increase with inspiration (Carvallo sign).
Diagnosis
TS can be diagnosed using TTE. In rheumatic TS, as seen in MS, the
leaflets are restricted, thickened, and calcified. TTE is also used to
assess for concomitant valve disease and to estimate the right atrial size
and pressure. Using Doppler, the diastolic pressure gradients can be
measured across the tricuspid valve and the tricuspid valve area can be
estimated. A valve area of 1.0 cm2 or less is considered to be severe TS.
Treatment
There are limited data to guide treatment in TS. Options include
medical therapy such as diuretics to help with systemic venous congestion, surgical intervention, or percutaneous balloon valvotomy.
The decision for surgical versus percutaneous approach should be
individualized and based on valve anatomy, surgical risk, and operator experience. A surgical approach is typically reserved for symptomatic patients with severe TS or asymptomatic patients with severe TS
requiring cardiac surgery for another indication.
AORTIC REGURGITATION
Definition and Etiology
Aortic regurgitation (AR) is the result of inadequate coaptation of the
aortic valve leaflets during diastole leading to regurgitant flow of blood
from the aorta to the left ventricle. The ability of the left ventricle to
accommodate this additional volume is dependent on the chronicity
of the disease. Therefore, acute severe AR and chronic AR should be
considered as separate disease processes.
The two most common causes of acute severe AR in a native aortic
valve are endocarditis and aortic dissection. Endocarditis can lead to
leaflet destruction, leaflet perforation, or perivalvular abscess that can
rupture into the left ventricle. Aortic dissection can result in AR by
dilation of the sinuses, involvement of the commissures or leaflets, or
prolapse of the dissection flap across the aortic valve.
In developing countries, chronic AR is usually due to rheumatic
heart disease. In developed countries, aortic root dilation, calcific
degeneration, and bicuspid aortic valve are the most common causes.
However, many other disease processes can affect the aortic valve or
the ascending aorta and lead to chronic AR (Table 7.7).
Pathophysiology
In acute severe AR, a large regurgitant volume enters an unprepared
left ventricle which results in a decrease in effective stroke volume and
rapid increase in LV end-diastolic pressure with subsequent pulmonary edema, cardiogenic shock, and possible hemodynamic collapse.
In chronic AR, the left ventricle is able to make compensatory
changes to maintain cardiac output. The regurgitant flow from the
aorta into the left ventricle results in an increase in LV end-diastolic volume and wall stress. In response, there is eccentric hypertrophy, chamber dilation, and an increase in ventricular compliance.
Therefore, LV end-diastolic pressure can remain normal despite a
significant increase in LV volume. In addition, these compensatory
changes can lead to an increase in total stroke volume, which results
in an elevation in systolic pressure. During diastole, there is rapid
equalization of pressures between the aorta and left ventricle resulting
in a low diastolic pressure. This accounts for the wide pulse pressure
and several of the characteristic physical examination findings seen in
chronic AR.
Natural History and Clinical Presentation
Patients with acute severe AR often present with pulmonary edema
and cardiogenic shock. Other presenting symptoms will depend on the
etiology, which is usually aortic dissection or endocarditis.
In contrast, there is a prolonged asymptomatic period in chronic
AR. Even with severe AR, exercise tolerance can be preserved as an
increase in heart rate during exercise leads to shorter diastolic filling times, and thus less AR. However, with progressive LV dilation,
CHAPTER 7 Valvular Heart Disease
TABLE 7.7 Causes of Chronic Aortic Regurgitation
Mechanism Etiology
Congenital/leaflet abnormalities Bicuspid, unicuspid, or quadricuspid aortic valve
Ventricular septal defect
Acquired leaflet abnormalities Senile calcification
Infective endocarditis
Rheumatic disease
Radiation-induced valvulopathy
Toxin-induced valvulopathy: anorectic drugs, 5-hydroxytryptamine
Congenital/genetic aortic root abnormalities Annuloaortic ectasia
Connective tissue disease: Loeys Dietz, Ehlers-Danlos, Marfan syndrome, osteogenesis imperfecta
Acquired aortic root abnormalities Idiopathic aortic root dilation
Systemic hypertension
Autoimmune disease: systemic lupus erythematosus, ankylosing spondylitis, reactive arthritis
Aortitis: syphilis, Takayasu arteritis
Aortic dissection
Trauma
Modified from: Zoghbi W, Adams D, et al: Recommendations for noninvasive evaluation of native valvular regurgitation. JASE 2017;30:303-371.
71
patients can develop LV systolic dysfunction and symptoms of heart
failure.
Physical Examination
Patients with acute severe AR will have physical examination findings consistent with cardiogenic shock and pulmonary edema such as
hypotension, pallor, peripheral vasoconstriction, and rales. Wide pulse
pressures and the characteristic findings seen in chronic AR are typically not appreciated.
With regards to the heart sounds in acute severe AR, A2 may be
diminished, P2 is more prominent due to pulmonary hypertension,
and S3 can be heard. The murmurs heard in acute AR include an
early, low-pitched, diastolic murmur and a soft systolic murmur due
to increased flow across the aortic valve. The presence of both results
in a characteristic “to-and-fro” murmur. However, depending on the
diastolic gradient between the aorta and left ventricle, these murmurs
may be inaudible.
The wide pulse pressure seen in chronic AR can lead to several
physical findings (Table 7.8). The murmur of chronic AR is a blowing early diastolic murmur best heard at the left upper sternal border
with the patient sitting up, leaning forward, and at end-expiration. As
AR progresses, this murmur can become holodiastolic and harsher in
quality. In very severe AR, the murmur can become soft or even absent.
An Austin-Flint murmur, a mid to late diastolic rumble best heard
at the apex in severe AR and due to vibration of the anterior mitral leaflet as it is struck by the jet of AR, may also be appreciated. Additionally,
a short midsystolic ejection murmur radiating to the neck can be heard
as a result of increased stroke volume.
Diagnosis
In both acute and chronic AR, echocardiography can evaluate the presence, severity, and mechanism of AR, the effect of AR on the other
cardiac chambers, and the presence of concomitant valve disease. In
the case of acute severe AR with suspected aortic dissection or endocarditis, a transesophageal echocardiogram (TEE) should be considered
over TTE given its superior sensitivity and specificity for these diagnoses. Computed tomography (CT) imaging has similar sensitivity and
specificity for diagnosing aortic dissection. However, TEE also allows
for concomitant evaluation of the aortic valve structure, AR, and the
other cardiac structures.
In the assessment of chronic AR, when the TTE results are inconclusive or discrepant from clinical findings, alternative imaging modalities can be considered. TEE generally provides superior image quality
compared to TTE. CMR can accurately quantify the severity of AR as
well as chamber sizes and LV systolic function. Aortography and cardiac catheterization may also be considered to evaluate AR, aortic root,
and left-sided filling pressures. However, their role has diminished
because of the availability and accuracy of noninvasive imaging.
Treatment
In acute severe AR, emergent or urgent surgical intervention is usually
indicated in the setting of aortic dissection or infective endocarditis.
Prior to surgery, the mainstay of medical therapy is afterload reduction. This can be achieved with intravenous nitroprusside. Diuretics
and ionotropic agents may be helpful in the setting of cardiogenic
shock and pulmonary edema. Beta-blockers, while helpful for aortic dissection, can lead to further hemodynamic deterioration as the
increase in diastolic filling time leads to more AR. Vasopressors and
intra-aortic balloon pumps are contraindicated in this setting.
With chronic AR, there is a limited role for medical therapy.
Vasodilators such as hydralazine, angiotensin-converting enzyme
(ACE) inhibitors, and calcium-channel blockers can be used in patients
who are asymptomatic and hypertensive. There is conflicting evidence
for their use to delay surgery. AVR is recommended once a patient has
severe symptomatic AR or severe asymptomatic AR with a LV systolic
dysfunction (left ventricular ejection fraction (LVEF) of less than 50%)
or chamber dilation (LV end systolic diameter (LVESD) of greater
than 50 mm or LV end diastolic diameter (LVEDD) of greater than 65
mm). AVR is also indicated in patients with severe asymptomatic AR if
there is another indication for cardiac surgery.
The options for mechanical and biologic prostheses are similar to
those for surgical AVR for AS. However, a percutaneous approach is
not available.
MITRAL REGURGITATION
Definition and Etiology
Mitral regurgitation (MR) is defined by the inadequate coaptation of the
mitral leaflets during systole resulting in regurgitant flow from the left ventricle to the left atrium. Similar to AR, MR leads to LV volume overload
72 SECTION II Cardiovascular Disease
Anterior mitral annulus
Posterior annulus
Chordae tendineae
mitral leaflet
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TABLE 7.8 Signs of Chronic Aortic
Regurgitation
Name Description
Corrigan pulse Rapid upstroke and collapse of pulses; “water
Musset sign Head bob with each heartbeat
Traube sign Systolic and diastolic sounds heard over
Duroziez sign Systolic and diastolic bruit heard with com-
Quincke pulses Capillary pulsations
Mueller sign Pulsation of uvula
Becker sign Pulsation of retinal arteries and pupils
Hills sign Popliteal systolic cuff pressure exceed brachial
Mayne sign >15 mm Hg decrease in diastolic blood pres-
Rosenbach sign Pulsations of liver
Gerhard sign Pulsations of spleen
Lateral
commissure
Fig. 7.6 Mitral apparatus. (From Otto C: Textbook of Clinical Echocardi-
ography, 6th ed., Elsevier, 2018.)
and the ability of the left ventricle to compensate for this additional volume is dependent upon chronicity. Therefore, like AR, acute severe MR
and chronic MR should be considered as two distinct disease processes.
The mitral apparatus consists of the left atrial wall, mitral annulus,
anterior and posterior leaflets, chordae tendineae, papillary muscles,
and the LV myocardium underlying the papillary muscles (Fig. 7.6).
Disturbance to any component of the mitral apparatus can result in MR.
Acute MR can be caused by ischemic and nonischemic etiologies.
Papillary muscle rupture or displacement can be seen in the setting
of an acute myocardial infarction or ischemia. Nonischemic causes
include infective endocarditis, ruptured chordae tendineae, trauma,
RHD, and dynamic LV outflow obstruction.
L
Lateral
papillary m.
hammer pulses”
femoral arteries; “pistol shot pulse”
pression of femoral artery
pressure by >20 mm Hg
sure with arm elevation
Anterior mitral leaflet
C
Medial
commissure
M
Posterior
(3 scallops)
Medial
papillary m.
Given the complexity of the mitral apparatus, it is useful to categorize the causes of MR as primary or secondary (Table 7.9). Primary
MR is due to an intrinsic abnormality of the mitral leaflets. Secondary
MR is a result of distortion of the mitral annulus in the setting of
ventricular remodeling. Distinguishing between primary and secondary MR is important because the management and outcomes differ.
Alternatively, MR can be classified based on leaflet motion using the
Carpentier classification (Fig. 7.7).
Pathophysiology
The pathophysiology of MR and the differences in the pathophysiology between acute and chronic MR are illustrated in Fig. 7.8. In acute
severe MR, there is a sudden increase in preload and decrease in afterload. This leads to an increase in the total stroke volume (TSV) and
LVEF. However, the forward stroke volume (FSV) decreases resulting
in reduced cardiac output. Simultaneously, there is an acute rise in LAP
causing pulmonary edema. This ultimately leads to cardiogenic shock.
In chronic compensated MR, the progressive rise in LV preload
leads to increased wall stress. In response, there is eccentric hypertrophy of the left ventricle and an increase in the LV end diastolic volume. This not only increases LVEF and TSV, but it also allows for the
maintenance of a normal FSV. However, as MR progresses, LV systolic
dysfunction and dilation occur. In this setting, LVEF, TSV, and FSV all
decrease, resulting in chronic decompensated MR.
In chronic MR, the compliant left atrium is able to accommodate a
large regurgitant volume from the left ventricle. However, this eventually results in left atrial dilation and pulmonary hypertension.
Natural History and Clinical Presentation
Patients with acute severe MR are acutely ill and often in cardiogenic
shock. Along with hemodynamic instability, patients may have symptoms related to the etiology of MR. For example, in the setting of an
acute myocardial infarction with papillary muscle rupture, a patient
may present with chest pain along with ischemic ECG changes and elevated cardiac enzymes. Patients with infective endocarditis may have
fevers, positive blood cultures, vascular phenomena, immunologic
phenomena, or a predisposing condition such as intravenous drug use.
With chronic MR, the natural history and clinical presentation are
quite different because the left ventricle has time to remodel and compensate via the mechanisms noted above. Often times, patients have
a prolonged asymptomatic phase. Over time, as the left-sided filling
pressures increase, patients may develop fatigue or decreased exercise
tolerance. Eventually, patients can have signs and symptoms of congestive heart failure (CHF) such as dyspnea on exertion, orthopnea, paroxysmal nocturnal dyspnea, and/or peripheral edema. With left atrial
dilation, patients may develop AF.
Physical Examination
Patients with acute severe MR are often in pulmonary edema and
cardiogenic shock. Physical examination may be remarkable for pallor, cool extremities due to peripheral vasoconstriction, rales, jugular
venous distension, and diminished peripheral pulses. The murmur of
acute severe MR is usually soft, low-pitched, decrescendo, and early
systolic. However, in about half of the patients, no murmur may be
appreciated due to the low-pressure gradient between the left ventricle
and the left atrium. Therefore, the absence of a systolic murmur does
not necessarily rule out acute severe MR.
In chronic MR, S1 is diminished due to inadequate coaptation of
the mitral leaflets. S2 is widely split with a reduced forward stroke volume leading to an early A2 and pulmonary hypertension delaying P2.
An S3 can also be appreciated with the increased diastolic flow across
the mitral valve into a left ventricle. The murmur of chronic MR is
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