Aortic insufficiency (AI), also known
as aortic regurgitation (AR), is the leaking of the aortic
valve of the heart that causes blood to flow in the reverse direction during ventricular diastole, from
the aorta into the
left
ventricle. Aortic insufficiency can be due to abnormalities of either the
aortic valve or the aortic root (the beginning of the aorta)
Causes:
[A] Congenital:
·
Bicuspid valve or
·
Disproportionate cusps.
[B] Acquired:
·
Rheumatic heart disease.
·
Infective endocarditis.
·
Trauma.
·
Aortic dilatation (Aneurysm, dissection,
syphilis)
Clinical
features:
Symptoms:
1.
Mild to moderate AR:
·
Often asymptomatic.
·
Awareness of heart beat (palpitations)
2.
Severe AR:
·
Breathlessness.
·
Angina.
Signs:
1.
Pulse:
·
Large volume or ‘Collapsing pulse’.
·
Bounding peripheral pulses.
·
Capillary pulsation in nail
beds-Quincke’s sign.
·
Femoral bruit (Pistol shot)-Duroziez’s
sign.
·
Head nodding with pulse-de Musset’s
sign.
2.
Blood pressure:
·
High systolic pressure.
·
Low diastolic pressure.
·
High pulse pressure.
3.
Precordium (cardiac findings):
(a) Inspection:
·
Apex-beat visible.
·
Shifted downwards and outwards (if LVF).
(b) Palpation:
·
Thrusting (heaving) apex beat.
·
Early diastolic thrill.
(c) Auscultation:
·
First heart sound-normal.
·
Secondary heart sound-soft.
·
Early diastolic murmur (the murmur of
AR)
·
Systolic murmur (↑ed stroke volume over
aortic area)
·
Fourth heart sound.
4.
Other signs:
·
Displaced, heaving apex beat (volume
overload).
·
Presystolic impulse.
·
Fourth heart sound.
·
Pulmonary venous congestion
(Crepitations)
Investigations:
1.
ECG: Initially normal, later LVH and T
wave inversion.
2.
Chest X-ray:
·
Cardiac dilatation, may be aortic
dilatation
·
Features of left heart failure (LHF).
3.
Echocardiography:
·
Dilated left ventricle.
·
Hyperdynamic left ventricle.
·
Fluttering anterior mitral leaflet.
·
Doppler detects reflux.
4.
Cardiac catheterization:
·
Dilated left ventricle.
·
Aortic regurgitation.
·
Dilated aortic root.
Management:
Medical
treatment:
a)
Diuretics (if symptoms are mild or
patient is inoperable)
b)
Antibiotics prophylaxis against
endocarditis.
c)
Vasodilators (e.g. ACE-inhibitors): to
prevent progressive left ventricular dilatation.
d)
Treatment of underlying condition, e.g.
syphilis.
Surgical
treatment: Aortic valve replacement under
cardiopulmonary bypass. Surgery is also indicated in asymptomatic patients if
there is progressive radiological cardiolomegaly or echo evidence of
deteriorating left ventricle function. When aortic root dilatation is the cause
of aortic regurgitation (e.g. Marfan’s syndrome) aortic regurgitation (e.g.
Marfan’s syndrome) aortic root replacement may be necessary.
Reference:
1.
Davidson’s Principles and Practice of
Medicine, 21st edition.
2.
Wikipedia the free encyclopedia.
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