Download Aortic Stenosis

Aortic Stenosis
Causes
Valvular AS
- Congenital bicuspid valve
o Suspect if in younger patients
(40s-50s)
o Presence of ejection click
suggests bicuspid valve
- Calcific degenerative valve
o Suspect if in older patients (60s80s)
- Rheumatic heart disease
o Note: Isolated Aortic valve RHD is
uncommon – usually tgt with
mitral valve disease
- Others (rare): Type II Hyperlipidemia,
Radiation, SLE, Rheumatoid
Subvalvular
- Hypertrophic obstructive
cardiomyopathy
o Dynamic stenosis & LVOT
obstruction
o Due to genetic causes
- Discrete subaortic membrane
o Congenital malformation
Supravalvular
(Due to narrowing of ascending aorta or supravalvular
fibrous diaphragm causing obstruction)
- Williams Syndrome
o Elfin facies, Pointed chin, Small
and widely spaced teeth, Mental
retardation
Clinical Features
Usually asymptomatic until AS is
moderately-severe
Symptoms:
- Angina [Survival: 5 years]
o ↑ Myocardial demand
(LVH  Ischemia of hypertrophic
myocardium)
o ↓ Coronary Blood Flow
(Prolonged systolic ejection time 
↓ diastole & coronary perfusion
pressure)
- Syncope [Survival: 3 years]
o Exertional/exercise-induced
syncope
o Exercise  ↑ left ventricular
obstruction  ↓ cardiac output 
↓ Blood pressure  Syncope
- Dyspnea [Survival: 2 years]
o Indication of LV failure!
o Forward: Failure of LVH to
compensate/maintain EF  ↓
Ejection fraction  Dyspnea
o Backward: Pressure overload 
LVH  ↓ LV compliance  ↑ LV
diastolic pressure  Dyspnea
Associated features:
- Skin & mucosal bleeding
o Acquired Type 2A von Willebrand
syndrome secondary to severe AS
o Mechanism: High shear stress as
vWF passes through stenotic aortic
valve  Induce structural changes
in shape of vWF  Susceptible to
proteolysis by ADAMST13  Loss of
vWF
o a/w Heyde’s syndrome:
Gastrointestinal Angiodysplasia
o Normal hemostasis is restored
following aortic valve replacement
- Familial
hypercholesterolemia
Differentials:
- Aortic sclerosis
o No radiation to carotids
o No signs of severity (e.g. reverse
splitting of S2, S4)
- Pulmonary Stenosis
-
Microangiopathic Hemolytic
Anemia (MAHA)
Signs of Severity
Murmur characteristics:
- Late-peaking ESM
- Reverse Splitting of S2
o Mild: A2  P2
o Moderate: A2 & P2 (single S2)
o Severe: P2  A2
(delayed aortic valve closure)
- Soft/inaudible A2
o Due to poorly mobile stenotic
valve
- Presence of S4
o Due to left ventricular failure
Pulse/Apex beat:
- Pulsus parvus et tardus
o Slow-rising, small volume pulse
- Narrow pulse pressure
- Heaving apex beat
Complications:
- Cardiac failure
Staging of Valvular Heart
Disease
- Stage A: At Risk
o Patients with risk factors for
developing valvular heart
disease
- Stage B: Progressive
o Asymptomatic mild-tomoderate valvular heart
disease
- Stage C: Asymptomatic
Severe
o C1: Compensated LV/RV
function (e.g. LVEF >50%)
o C2: Decompensated LV/RV
function (e.g. LVEF<50%)
- Stage D: Symptomatic
Severe
Investigations
Echocardiography
(Imaging modality of choice!)
- Assess Morphology of aortic valve
o Confirm Diagnosis
o Determine Etiology: Bicuspid, calcific
degeneration, rheumatic
o If aortic valve morphology is normal,
likely to be supra/subvalvular AS
- Assess Severity
o Based on Valve Area & Trans-aortic
pressure gradient
Valve Area
Pressure
Gradient
Mild
>1.5cm2
<20mmHg
Mod
1.0-1.5cm2
20-40
Severe
<1.0cm2
>40mmHg
- Assess LV Systolic Function
o LVEF<50% in Severe AS  Indication
for surgery!
Electrocardiogram
- LV Hypertrophy with strain pattern
(indicating pressure overload)
- LA Enlargement, L Axis Deviation,
LBBB
Chest X-Ray
- Aortic valve calcification
(best seen on lateral view)
- Post-stenotic dilation of ascending
aorta
Management
Patients with severe valvular heart disease should be
evaluated by a multidisciplinary Heart Valve Team
whenever intervention is considered, comprising of
cardiologist, cardiac surgeon, radiologist (cardiac
imaging), anesthesiologist and nurses.
Non-Pharmacologic
Activity restriction
- Avoid vigorous physical exertion in
moderate & severe AS
Regular follow-up for development of
symptoms
Pharmacologic
No medical treatment to delay
progression of AS
Medical management of complications
(e.g. Heart failure)
Avoid certain medications:
- Negative inotropes (ACE-I, BetaBlockers)
- Venodilators (e.g. Nitrates)
- Diuretics
Surgical
Aortic Valve Replacement
- Indication for surgery:
o Severe aortic stenosis
o + 1 of the following:
 Symptomatic [D]
 Note: Survival rates drop drastically
with onset of symptoms! – hence
intervention is needed!!
Ejection Fraction <50% [C2]

 Undergoing other cardiac
surgery [C1,C2, D]
(e.g. CABG, Aortic root surgery, Mitral
valve repair)
[Class I Recommendation based on ACC/AHA 2014
guidelines]
Note: 3 indications in General:
- Symptomatic AS (invariably severe)
- Asymptomatic Severe AS with LVEF <50%
- Asymptomatic Mod-severe AS undergoing
cardiovascular operation
Transcatheter Aortic Valve Implantation
(TAVI)
- Percutaneous prosthetic valve insertion
under fluoroscopic & TEE guidance
- Indicated for patients who are
candidates for AVR but have prohibitive
surgical risk