Aortic stenosis

1. ………………………………………………..

2.  1.rheumatic heart disease:
Is the most common cause resulting from
adhesions and fusions of the commissures
and cusps.
 2. congenitally abnormal aortic valve:
normal valve may be stenotic with
commissural fusion at birth but usually
not causing serious narrowing of the
aortic orifice during childhood.

3.  The abnormal architecture induces
turbulent flow which traumatizes the
leaflets and leads to fibrosis , increased
rigidity, calcification of leaflets and
narrowing of the aortic orifice in
adulthood.

4. 3.senile aortic stenosis:
Age related AS degeneration and
calcification of previously normal
valve in elderly , usually smokers,
daibetics, hypertension and
hyperlipidemic.

5.  4.SLE and severe familial
hypercholesterolemia occasionally cause
aortic stenosis.

6.  7% of total cases of CHD
 Increased pressure in the LF side of the
heart (LV hypertrophy)
 Assessment… murmur ,thrill ,high BP, high
HR.

8.  Murmur is loudest
 Loudness is
proportional to
severity
 LVH
 ……………

9.  Obstructed left ventricular outflow due to
aortic stenosis leads to increased left
ventricular pressure and compensatory
left ventricular hypertrophy.
 Cardiac output at rest is maintained
within normal limits in most patients with
severe AS, it often fails to rise normally
during exertion.

10.  late in the course of the disease , the
cardiac output and stroke volume decline
(due to LV dysfunction) resulting in
decline of pressure gradient across the
aortic valve and rise in pulmonary arterial
pressure.

11.  Ischemia in AS:
due to hypertrophy , heart required more
blood for oxygenation that may be not be
possible in sever AS resulting in myocardial
ischemia even in the absence of coronary
artery disease.

12.  High left ventricular pressure may compress
the coronary blood flow manifesting as
myocardial ischemia angina, and left
ventricular failure.
 This ischemia become more severe on
exercise.

13.  Severity of AS is determined by the valve
area and the pressure gradient across the
valve(usually by echo).
 Normal aortic valve size is 3-4 cm.
 Severe AS: critical obstruction to left
ventricular outflow is usually characterized
by a peak systolic pressure gradient
exceeding 50mmhg in the presence of a
normal cardiac output and aortic valve area
less than 0.8cm.

14.  Moderate AS: aortic valve area less than 1.0 -
1.5cm.
 Mild AS: 1.5-2.0 cm.

15.  Symptoms:
 1.long asymptomatic phase.
 2.symptomatic AS manifests as:
angina
exercise induced syncope.
exertional dysphea and ultimately
heart failure and sudden death.
 these symptoms appear when the aortic
orifice is reduced to one third of its normal
size.

16.  Syncope attacks are due to markedly
decreased cerebral perfusion that occurs
during exertion due to systemic
vasodilatation in the presence of reduced
cardiac output due to fixed obstruction.

17.  Angina occurs due to myocardial ischemia
which develops when left ventricular oxygen
demand exceeds supply .
 Decreased coronary blood flow which does
not fulfill the requirement of the
hypertrophied heart particularly after
exercise.
 Decreased coronary blood flow may be due
to compression of coronary arteries by the
hypertrophied myocardium.

18.  Exertional dyspnea orthopnea and PND are
late symptoms in AS and reflect pulmonary
venous hypertension.
 HEART FAILURE:
heart failure occurs due to both left
ventricular systolic and diastolic dysfunction.

19.  Gastrointestinal bleeding GI bleeding may
develop in patients with severe AS ,often
associated with vascular malformations with
malformations associated with severe AS

20.  INSPECTION OF PERCORDIUM:
 Apex beat is not displaced , visible on its
normal position.
 PALPATAION:
 Apex beat is not displaced because
hypertrophy (in contrast to dilatation) does
not produce cardiomegaly.
 Apex beat is heaving in character (forceful)
due to left ventricular hypertrophy(as result
of pressure overload).

21.  A systolic thrill may be felt in the aortic
area or suprasternal notch and is
transmitted along the carotid arteries.
 Right ventricular failure with
hepatomegaly , and edema precedes left
ventricular septum that encroaches the
right ventricular cavity causing
impairment of right ventricular filling

22.  HEART SOUNDS:
 S1 is normal .
 A prominent fourth heart sound.

23.  MURMUR:
 Mid systolic murmur present at aortic area.
 The murmur is usually rough in quality and
best heard in aortic area .
 It radiates to the carotid artery and also the
precordium to the apex.(it usually produces
confusion that patient has two lesions AS and
MR ; however remember that systolic
murmur at apex is murmur of MR that
pansystolic while murmur of AS is mid
systolic ).

24.  The murmur of AS is reduced in intensity
when standing due to reduced transvalvular
flow.
 Longer the murmur severe is the aortic
stenosis .
 However when the left ventricle fails the
stroke volume falls , the systolic murmur of
AS becomes softer, rarely it disappears
altogether.

25.  PULSE: carotid pulse is low volume and
slowly rising .
 Simultaneous palpation of the apex and
carotid artery reveals delay in carotid pulse
in severe AS.
 JVP: prominent due to reduced compliance
of right ventricular due to pulmonary
hypertension or hypertrophy of the
ventricular septum.

26.  CHESTCX RAY:
 May be normal .
 In critical AS the heart is usually normal in
size or slightly enlarged.
 Dilation of ascending aorta on PA view in
commonly seen.

27.  ECG:
 Left ventricular hypertrophy.
 Left ventricular pressure overload.
 Left atrial enlargement.

28.  ECHOCARDIOGRAPHY:
 This shows thickened .calcified and immobile
aortic valve cusp.
 Detects left ventricular hypertrophy , its
systolic and diastolic function.
 Demonstrates the pressure across the valve
and the valve area.
 Pressure more than 50mmhg or an aortic
area less than 0.8 cm2 indicates that the
aortic stenosis is severe enough to cause
patients symptoms.

29.  Medical treatment is not effective for aortic
stenosis.
 Patients who develops any of the three
symptoms( angina, syncope or heart
failure)is candidate for valve replacement.
 Surgery is not indicated for asymptomatic
patients except those with declining left
ventricular function, very severe left
ventricular hypertrophy and very high
pressure or reduced valve area.

30.  Treatment..
- Beta-blocker or ca channel blocker to
decreased hypertrophy
- Balloon valvoplasty

31.  Medical treatment is given to those
patients who are inoperable (usually
comorbids).
 Avoid physical activity.
 Carefully follow up of the patient because
the disease is progressive.
 Pressure increase by 4-8mmhg per year
while valve area decrease by 0.2-
0.3cm2m per year.

32.  In mild AS, repeat echo every 2 years.
 In asymptomatic patient severe AS echo
should be done every 6-12months.
 Angina may be treated with bete-blockers
but cautiously because they may lead to
shock or heart failure.
 ACE inhibitors in small does are indicated
in patients with symptomatic left
ventricular systolic dysfunction who are
not candidate for surgery.

33.  Valve replacement is indicated early and
in following conditions:
 All symptomatic patients including with
left ventricular dysfunction .
 Asymptomatic patient with decling left
ventricular function.
 Severe left ventricular hypertrophy.
 Severely reduced valve area.
 Patient of severe AS undergoing another
cardiovascular operation.

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