aortic stenosis Flashcards
what is the most common cause of AS in the us
Degenerative calcification of a normal trileaflet valve
what is degenerative calcification of aortic valve
reduces systolic opening of the valve
what is the most common congenital AS
Congenital bicuspid valve
what is congenital bicuspid valve
two open leaflets on PSSAX-AV view, one usually bigger than other
what is the most common cause of AS worldwide
Rheumatic aortic stenosis
rheumatic aortic stenosis occurs concurrently with
mitral stenosis
two types of rheumatic AS
unicuspid and quadricuspid
what are the primary findings of AS (3)
- Thickened leaflets
- Restricted leaflet motion
- Narrow aortic valve orifice
what are the secondary findings of AS (5)
- AI
- LVH (due to pressure overload)(increased LVEDP and Left atrial pressure)
- LAE (left atrial enlargement)
- Decreased LV systolic function
- Post-stenotic dilation of the ascending aorta
quantification of AS
- PPG (bernoulis)
- MPG
- Aortic Valve Area by Continuity Equation
- VTI LVOT/VTI AV. V1/V2 ratio
PPG equation
4(V2^2 - V1^2)
PPG norms
mild AS PPG < 36 mmHg
moderate PPG = 36-64 mmHg
severe AS PPG > 64 mmHg
How do we get MPG
trace doppler envelops, velocities are measured and gradients are calculated
gradients are added together and divided by TOTAL
MPG norms
mild AS < 20 mmHg
moderate = 20-40 mmHg
severe > 40 mmHg
How many measurements are required if theres Afib
5
downfalls of using pressure gradients (bernoulis)
- dependent on volume flow rate
2. stroke volume abnormalities can over/underestimate AS
AVA by continuity equation
AVA= 0.785 x LVOTd^2 x VTI LVOT/ VTI AV
AVA norms
normal = 2.5-4.5 cm
mild AS > 1.5 cm
moderate = 1-1.5 cm
severe < 1 cm
where is pedoff (nonimaging probe) used
apex, SSN, right sternal border
its needed to get the highest V2
when is debutamine used
in patients with significant LV systolic dysfunction, we use it to increase SV
V1 to V2 ratio that is close to 1
indicates no or very little stenosis
V1 to V2 ratio norms
mild > 0.5
moderate 0.25-0.5
severe <0.25
Aortic valve index (AVI) equation
AVI = AVA cm/ BSA (body surface area) m
AVI nors
mild > 0.85
moderate 0.6-0.85
severe <0.6
