Download Common Types of Valvular Heart Disease

Common Types of
Valvular Heart Disease
Patients with valvular heart disease comprise a significant portion of many a clinician’s daily practice.
Join Dr. Trebichavsky and Dr. Kornbluth as they outline the pathophysiology, symptoms, clinical findings and
management associated with common types of this disease.
Josée Trebichavsky, LL.B, BCL, MD; and Murray Kornbluth, MD, FRCPC
Presented at McGill University’s 58th Annual Refresher Course for Family Physicians, Montreal,
Quebec, November 2007.
Aortic stenosis (AS)
AS is usually an idiopathic disease which results from
degeneration and calcification of the aortic cusps. In patients
< 65-years-of-age, the most common etiology is that of a
congenitally bicuspid valve.
Pathophysiology
Briefly, the pathophysiology of AS involves compensatory
hypertrophy of the left ventricle as the severity of AS worsens.
The left ventricular hypertrophy (LVH) serves to maintain a
constant and normal cardiac output. However, the compensatory hypertrophic process is eventually overcome by the
high left ventricular (LV) intracavitary pressures. This leads to
LV systolic dysfunction (LVSD) and heart failure (HF).
Mr. Stewart’s Case
Mr. Stewart is a 65-year-old male who presents with a
systolic ejection murmur. His ECHO reveals severe aortic
stenosis with an aortic valve area of 0.7 cm2 and a left
ventricular ejection fraction of 60%-65%. What
symptoms might he be experiencing?
For the correct answer, turn to page 28.
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Definition of severity
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Mrs. Huynh’s Case
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as by the mean gradient
dispthe left ventricle and the aorta
during systole. Generally speaking, an aortic valve area
< 1.0 cm2 with a mean gradient of at least 40 mmHg is defined
as severe stenosis. Moderate stenosis encompasses an aortic
valve area between 1.0 cm2 and 1.5 cm2 with mean gradients
usually ranging between 25 mmHg and 40 mmHg. Mildly
stenotic valves are those with a valve area between 1.6 cm2
and 2.0 cm2 with gradients < 25 mmHg.
Symptoms
The classic symptoms of AS are angina, syncope and dyspnea.
These symptoms carry significant prognostic importance.
Namely, once angina, syncope or HF develops, life expectancy is greatly reduced. Specifically, if the aortic valve is not
replaced, mortality associated with the development of angina
is approximately 50% within five years. There is a 50% mortality rate within three years after the development of syncope,
Mr. Godin’s Case
©
Mr. Godin is a 55-year-old male who presents with
significant dyspnea. On exam, you hear a blowing
decrescendo diastolic murmur at the left sternal border.
What it your diagnosis and how do you proceed?
To find out more, turn to page 28.
Mrs. Huynh is a 35-year-old female who, on her annual
physical examination, is found to have a low-pitched
diastolic rumble at the apex. On further questioning, she
admits to palpitations and low threshold dyspnea (New
York Heart Association [NYHA] Class 3-4). Her ECHO
reveals severe mitral stenosis with a mitral valve area of
0.7 cm2. What management options are available?
To find out more, turn to page 28.
Mr. Hadjis’ Case
Mr. Hadjis is a 45-year-old male who is asymptomatic. On
auscultation, you hear a holosystolic murmur at the left
ventricular apex. You also note a third heart sound. What
other findings would you expect on the physical exam?
For the correct answer, turn to page 28.
whereas the onset of dyspnea carries a 50% mortality rate
within two years of its onset.
Perspectives in Cardiology / October 2008 25
Valvular Heart Disease
Physical findings
Mitral stenosis (MS)
The hallmark sign of AS is a systolic ejection murmur that
radiates into the carotids. The murmur is usually best heard
in the second right intercostal space. Sometimes, it may be
heard best in the apical area and may be confused with mitral
regurgitation (MR) (Gallivardin’s phenomenon). As the severity of stenosis increases, the murmur peaks progressively later
in systole (Table 1). The intensity of the murmur is not a reliable indicator of the severity of the stenosis since the murmur
may become soft and sometimes even inaudible as the cardiac
output diminishes with progressive LVSD. The carotid
upstroke classically becomes diminished in amplitude and
delayed in time, so-called “parvus et tardus.” Another sign of
severe AS includes a soft or absent aortic component of the
second heart sound. The second heart sound also may become
paradoxically split due to a delay in LV ejection time. The apical impulse is sustained throughout most, if not all of systole
due to LVH.
MS is usually a sequela of rheumatic heart disease and primarily affects women. Less common causes include:
• congenitally malformed valves,
• idiopathic calcification and
• systemic lupus erythematosus.
Management
The perfectly asymptomatic patient with severe AS and normal LV systolic function may be followed every six months
for the development of symptoms or LVSD as assessed by
echocardiography. In some sedentary patients who are
“asymptomatic,” exercise stress testing may be useful to
establish the symptomatic state more objectively. The test can
be performed safely in these patients if great caution is used
in the presence of a physician. Here, exercise testing may provide additional information on which to base clinical decision-making.
The decision to replace the aortic valve in a patient with
severe AS is dependent on two critical factors:
1. The presence of symptoms
2. Development of LVSD in the asymptomatic patient
Since there is no proven medical therapy, aortic valve replacement with either a biological or a mechanical prosthetic valve
is generally recommended for the following patients:
1. The asymptomatic patient with LVSD
2. The symptomatic patient
3. The patient with moderate or severe stenosis
undergoing coronary artery bypass grafting surgery or
other valve surgery
26 Perspectives in Cardiology / October 2008
Pathophysiology
The symptoms of MS are related to the increased left atrial
pressure and the reduced cardiac output primarily caused by
impaired filling of the left ventricle. As left atrial pressure
progressively rises with increasing obstruction of LV filling,
pulmonary hypertension (HTN) develops, eventually compromising right ventricular systolic function. At this point,
symptoms of right-sided HF may appear.
Definition of severity
Severity of MS is determined by the mitral valve area and the
mean gradient between the left atrium and the left ventricle
during diastole as assessed by echocardiography. In general,
severe MS is defined as a mitral valve area below 1.0 cm2
with a mean gradient above 10 mmHg. Moderate stenosis is
defined as a mitral valve area between 1.0 cm2 and 1.5 cm2
with mean gradients between 5 mmHg and 10 mmHg and
mild stenosis shows a mitral valve area between 1.6 cm2 and
2.0 cm2 with mean gradients across the valve below 5 mmHg.
Symptoms
Patients with MS complain of dyspnea on exertion, orthopnea
and paroxysmal nocturnal dyspnea. Less frequent symptoms
include hemoptysis, hoarseness and symptoms of right-sided
HF. Often the patient remains asymptomatic until the development of atrial fibrillation (AF) when dyspnea or orthopnea
are noted as a consequence of a shortened diastolic filling
time.
Physical findings
The classic sign on physical examination of severe MS is the
diastolic rumble that follows an opening snap. The diastolic
rumble is low pitched and thus best heard with the bell of the
stethoscope placed on the apex when the patient is lying in the
left lateral decubitus position. The duration of the murmur
correlates with severity. At the end of diastole, the atrial kick
intensifies the rumble (pre-systolic accentuation). If the
Valvular Heart Disease
mitral valve is pliable and non-calcified, the first heart sound
is characteristically loud due to the force of ventricular
systole closing the valve. Valvular severity can be estimated
by assessing the time interval between the aortic component
of the second heart sound and the opening snap. As MS
becomes progressively more severe, the so-called A2-OS
interval shortens. Other findings of severe MS complicated
by pulmonary HTN include the presence of:
• a loud pulmonic component of the second heart sound,
• a right ventricular heave,
• elevated neck veins and
• peripheral edema.
Management
Medical therapy for symptoms associated with severe MS
includes diuretics, which effectively lower left atrial pressure,
thereby reducing symptoms. If AF develops, rate control with
digoxin, a ß-blocker or a calcium channel blocker is crucial
for ensuring adequate LV filling time. Anticoagulant therapy
is mandated since there is a high risk of embolism in patients
with chronic AF and MS.
Balloon valvuloplasty provides excellent mechanical relief
of severe MS that usually results in prolonged benefit. Strict
contraindications to balloon valvuloplasty include the presence of a left atrial or appendage clot or the presence of significant MR. As well, valvuloplasty is most effective in the
absence of significant valvular or subvalvular calcification
and thickening.
In cases where valvuloplasty is not feasible or appropriate,
mitral valve replacement (MVR) is highly effective in improving survival and reducing symptoms. MVR is generally
reserved for patients with severe MS who experience severe
symptoms (New York Heart Association [NYHA] Class 3 or
4) or those who show evidence of significant pulmonary
HTN.
Dr. Trebichavsky is a First-year Resident in
Internal Medicine, based at the Montreal
General Hospital site, MUHC, Montreal,
Quebec.
Dr. Kornbluth is the Director of Cardiology
and Cardiac Intensive Care Unit, Montreal
General Hospital site, MUHC, Montreal,
Quebec.
Chronic aortic regurgitation
(AR)
Chronic AR results from disease of either the aortic cusps or
the aortic root that distorts the leaflets thereby preventing
their coaptation. Common leaflet abnormalities include
bicuspid valves, as well as infective endocarditis and
rheumatic fever. Aortic root causes of AR include idiopathic
root dilatation and collagen vascular disease.
Pathophysiology
Chronic AR is a volume overload state akin to chronic MR.
LV enlargement due to excess volume produces a large total
stroke volume that, unlike MR, is entirely ejected forward.
Increased stroke volume causes an increase in pulse pressure,
which leads to systolic HTN. Common symptoms of chronic severe AR include:
• dyspnea,
• orthopnea,
• paroxysmal nocturnal dyspnea and
• angina.
Physical findings
A large total stroke volume in chronic AR increases pulse
pressure which leads to a myriad of clinical signs, such as de
Musset’s sign (rhythmic head bobbing) and Mueller’s sign
(systolic pulsation of the uvula). The typical diastolic murmur
is decrescendo and blowing, which is heard along the left sternal border if the etiology of the regurgitation relates to a
leaflet problem. The murmur is best heard at the right sternal
border when the etiology is that of a dilated aortic root.
Duration of the murmur correlates with the severity of the
regurgitation. The apical impulse is diffuse, displaced and sustained. A third and fourth heart sound may be detected.
Management
Medical therapy may offer symptomatic relief, but does not
alter the natural history of the disease. Again, diuretics and
vasodilators may help with symptoms. In general, the “55
rule” is useful in gauging the timing of surgery. Namely, the
asymptomatic patient with normal LV size and systolic function may be monitored every six months. Aortic valve replacement is indicated for the asymptomatic patient with a LV ejection fraction < 55% or LV enlargement as defined by a LV endsystolic dimension measuring > 55 mm. Finally, replacement
Perspectives in Cardiology / October 2008 27
Valvular Heart Disease
Mr. Stewart’s case cont’d...
Mr. Stewart has severe aortic stenosis. The classic
triad of symptoms includes:
• dyspnea,
• syncope and
• angina.
Each symptom carries prognostic relevance and
mandates surgical intervention even in the presence of
normal LV systolic function.
Mr. Godin’s case cont’d...
Mr. Godin has findings consistent with chronic aortic
regurgitation. Documentation of the valvular pathology and
LV function and size is required with echocardiography.
Because he is symptomatic, surgical intervention is
indicated.
Mrs. Huynh’s case cont’d...
Mrs. Huynh has severe mitral stenosis. Given the
presence of symptoms, relief of the obstruction to left
ventricular filling is required. Ideally, this is
accomplished by balloon valvuloplasty, assuming that
there are no contraindications and that the valve is
structurally amenable to this therapy. If valvuloplasty is
precluded, MVR is warranted. Medical therapy, in
anticipation of invasive intervention, consists of
maintenance of sinus rhythm and the use of diuretics.
Mr. Hadjis’ case cont’d...
Mr. Hadjis has findings consistent with chonic severe mitral
regurgitation. Other possible findings on physical exam
include a displaced apical impulse, a diastolic rumble
mimicking MS and signs of left ventricular heart failure.
of the valve is indicated for all patients with significant
symptoms.
Chronic MR
The most common causes of chronic MR include:
• mitral valve prolapse (MVP),
• chronic ischemia and
• degenerative disease.
28 Perspectives in Cardiology / October 2008
Pathophysiology
Chronic MR leads to volume overload of the left ventricle.
The left ventricle increases in size in order to maintain a
normal cardiac output in the context of regurgitation of
blood back into the left atrium. Progressive enlargement of
the left atrium with increased left atrial compliance protects
against high left atrial pressures. Progressive eccentric
hypertrophy of the left ventricle ensures a normal filling
pressure. LV ejection fraction is super normal due to optimal loading conditions.
Symptoms
Patients with chronic MR may eventually develop symptoms typical of left-sided HF which include:
• dyspnea on exertion,
• orthopnea and
• paroxysmal nocturnal dyspnea together with fatigue.
Physical findings
A high-pitched holosystolic apical murmur heard best at the
LV apex and radiating to the axilla is the classic physical
finding. MVP is associated with systolic clicks preceding
the murmur. Patients with MVP or papillary muscle dysfunction may exhibit a mid-to-late systolic murmur. A displaced apex points to the development of cardiac enlargement. Rapid filling of the left ventricle by the large volume
of blood stored in the left atrium causes a third heart sound.
A low-pitched diastolic rumble may be heard at the apex
and denotes the large volume filling the left ventricle in
early diastole. This mimics the diastolic rumble of MS
(pseudo MS). However, unlike true MS, a loud first heart
sound and an opening snap are absent.
Management
As in chronic AR, medical therapy has not been shown to
alter the natural history of the disease; however, diuretics
and vasodilators may afford symptomatic relief. Definitive
treatment is surgical. As such, mitral valve repair is always
preferable to MVR whenever feasible. A major advantage of
repair is post-surgical preservation of LV systolic function.
Mitral valve repair also obviates the need for anticoagulant
Valvular Heart Disease
Table 1
Ausculatory findings associated with common valve problems1
Lesion
Cardiac cycle
Quality
Location
Other sounds
Aortic stenosis
• Systolic
• Mid-peaking to
late-peaking
Harsh
Aortic area, left
sternal border, apex
• Soft S2
• S4
Mitral stenosis
• Diastolic
• Increases with
atrial contraction
if in sinus rhythm
Rumble
Apex
• Opening snap
• Loud S1
Aortic regurgitation
• Diastolic
• Early decrescendo
Blowing
Left sternal
border, aortic area
• S3 and/or S4
Mitral regurgitation
• Holosystolic
• Late systolic with
MVP, papillary
muscle dysfunction
Blowing
Apex, axilla
• Click(s) with
MVP
• Soft S1
• S3
MVP: Mitral valve prolapse
therapy in patients with a normal sinus rhythm. The timing
of surgical intervention and the decision to proceed with
surgery depends on the patient’s symptomatology and LV
systolic function and size.
The asymptomatic patient with an ejection fraction of
≥ 60% and a LV end-systolic diameter < 40 mm may be followed every six months. A decreasing ejection fraction, progressive LV dilatation or the onset of symptoms mandates
surgery. In the event that the mitral valve cannot be repaired,
replacement of the mitral valve with either a biological or
mechanical prosthesis is required.
predicated on the presence of significant symptoms and the
health of the left ventricle in general and not the degree of
severity of the valvulopathy in and of itself. Patients with
valvular heart disease comprise a significant portion of many
a clinician’s daily practice and familiarity with presenting
symptoms, clinical findings and management is crucial. PCard
Final thoughts
Valvular heart disease is an exciting and intellectually challenging field for the clinician in the broad scope of cardiac
pathologies. A good understanding of the pathophysiology of
the various valvular lesions helps the clinician in the overall
assessment of the patient. A careful history and physical
exam are essential and irreplaceable in diagnosing and
managing patients with various valvular pathologies.
Management of patients with valvular heart disease is
Reference
1. Curtin R, Griffin B: Valvular Heart Disease. ACP Medicine. Cardiovascular
Medicine: XI, June 2006.
Resources
1. Bonow R, Carabello BA, Chatterjee K, et al: ACC/AHA 2006 Guidelines for the
Management of Patients With Valvular Heart Disease. J Am Coll Cardiol 2006;
48(3):e1-148.
2. Lilly L (ed.), Pathophysiology of Heart Disease. Third Edition. Lippincott Williams
and Wilkins, Philadelphia, 2003.
Perspectives in Cardiology / October 2008 29