Overall, most common cause → Calcification
(1) Calcification (normal ageing)
Most common cause in older patients > 65 years
(2) Bicuspid aortic valve
Most common cause in younger patients < 65 years
Normal aortic valve is tricuspid (the only bicuspid valve is mitral valve); bicuspid aortic valve may be stenotic due to cusp fusion.
(3) William’s syndrome (supravalvular stenosis)
A congenital fibrous diaphragm is present above the aortic valve.
(4) HOCM (subvalvular stenosis)
(5) Rheumatic heart disease
RHD may result in aortic valve stenosis due to cusp fusion.
Assessing the severity
Severity of AS is assessed by:
Pressure gradient across the valve
Normal valve area = 3 – 4
Normal valve gradient < 5 mmHg
Severity of aortic stenosis
Severity valve area ()
Mean gradient (mmHg)
1.5 - 3
1.0 – 1.5
25 - 50
The classic triad of AS is:
(1) Angina (exertional)
Angina occurs due to 3 reasons:
↑Oxygen demand due to LVH
↓Coronary perfusion due to stenosis and ↓C.O
In 50% of AS patients above the age of 35 years, angina occurs due to coexisting CAD.
(2) SOB (exertional)
SOB/orthopnea/PND occurs due to both:
Systolic failure (dilated ventricles due to high pressure - dilated cardiomyopathy)
Diastolic failure (LVH - Hypertrophic cardiomyopathy)
(C) Syncope (on exertion)
GENERAL PHYSICAL EXAMINATION
(1) CAROTID PULSE
“Low volume” and “slowly rising pulse” called slow rising pulse.
(2) PULSE PRESSURE
Narrow (because systolic pressure decreases due to ↓C.O
Vs. aortic regurgitation, in which pulse pressure becomes wide (due to increased cardiac out resulting in increased systolic pressure)
Prominent “a” wave – This is due to reduced compliance of right ventricle which is due to:
Hypertrophy of ventricular septum
“a” wave is produced by “atrial contraction” (late ventricular diastole).
PROMINENT “a” WAVE
“a” wave will be prominent whenever atrial pressure increases:
All these conditions causes: ↑RV pressure → ↑RA pressure → Prominent “a” wave
ABSENT “a” WAVE
(1) APEX BEAT
Site: Not displaced (The concentric hypertrophy, in contrast to, dilatation, does not produce cardiomegaly)
Character: Heaving (forceful – Due to LVH)
CONCENTRIC LVH (hypertrophic cardiomyopathy)
Eccentric LVH (dilated cardiomyopathy)
LV wall thickness
Normal or decreased
(but on the inside, so no cardiomegaly – Apex beat not displaced)
(Results in cardiomegaly – Displaced apex beat))
Type of heart failure
Increase in left ventricular volume (and pressure):
Chronic pressure overload
(2) SYSTOLIC THRILL
At aortic area
REASON: Calcified aortic valve is immobile → A2 is not audible; only P2 is audible → Soft S2
SEVERE AS: When S2 is not audible, it can be concluded that AS is severe.
Reverse splitting of S2:
REASON: Delayed closure of aortic valve due to AS → P2 occurs earlier than A2 → Reverse splitting of S2
Due to LVH
MURMUR (EJECTION – SYSTOLIC)
Carotid artery: The ejection systolic murmur of HOCM does not radiate to neck which helps in differentiating it from murmur of AS.
Apex: Murmur of MR at apex is “pansystolic” while that of AS is ejection-systolic.
Valsalva, standing, hand grip: Murmur decreases due to ↓transvalvular flow
Squatting, leg raise: Murmur increases due to ↑transvalvular flow
Longer the murmur, severe is aortic stenosis.
Intensity of murmur typically increases as the disease progresses.
However, in very severe aortic stenosis, cardiac output decreases; as a result, the murmur becomes “softer” or “disappears”. Therefore, intensity of murmur is not a good indicator of disease severity.
TTE → TEE → Cardiac catheterization
Normal (concentric hypertrophy – no cardiomegaly)
Echo can determine:
(4) Cardiac catherization
Cardiac catherization is indicated in three conditions:
Measure gradient: Rarely, cardiac catherization is indicated to measure gradient if echocardiography is unable to determine whether severe aortic stenosis is present or not.
Angina: Cardiac catherization is indicated when it is suspected that the angina of aortic stenosis may be due to coexisting CAD (50% of aortic stenosis patients older than 35 years of age have CAD).
AVR: Angiography should be done before AVR, so that CABG, if indicated, can be performed during the procedure of valve replacement.
Mild to moderate AS: If the patient is asymptomatic, and AS is not severe, just observe the patient is the general rule.
Severe AS: AVR is indicated
Medical treatment is not effective.
Development of any of the three symptoms is indication for AVR.
(A) MEDICAL TREATMENT
BETA BLOCKERS: Can be used for angina (but may cause hypotension)
ACE INHIBITORS, DIGOXIN, NITRATES: Just like HOCM, these drugs are relatively contraindicated.
Symptomatic systolic failure
(B) Surgical treatment
Symptomatic patients (any of the three symptoms)
Asymptomatic but severe AS (i.e; valvular gradient > 50 mmHg or valve area < 0.7)
Patients undergoing CABG or any other heart surgery
(II) BALOON VALVULOPLASTY
Definition: It is widening of stenotic aortic valve using a balloon catheter inside the valve.
INDICATION: Patients with “critical” aortic stenosis who are not fit for AVR.
NOTE: Baloon valvuloplasty is not routinely done because “calcified” aortic stenosis does not respond very well to balloon valvuloplasty.
TAGS: aortic stenosis murmur radiation causes signs symptoms listen murmur location aortic stenosis treatment