Aortic Stenosis Flashcards
What are the three causes of Aortic Stenosis?
Congenital, Degenerative, Rheumatic
What are the three types of Congenital causes?
Subvalvular, Valvular due to Bicuspid AOV, Supravalvular
With Bicuspid AOV you also need to look at the suprasternal notch for….
Aortic Coarctation
The resistance that the ventricles must overcome while ejecting blood
Afterload
What worsens as AS progresses?
Concentric Left Ventricular Hypertrophy
What happens to the LV late in the course of AS?
LV systolic dysfunction occurs=LVE @ end-systole and reduced contractility
What 3 things determine Afterload?
Semi-Lunar Valve Stenosis
High Arterial Blood Pressure
Increased Viscosity of Blood
2 other conditions that can increase afterload?
Renal Artery Stenosis
Coarctation of Aorta
Force-Velocity Relationship
The load the myocardial fibers produce to eject, the greater the afterload the worst the cardiac performance.
Velocity
The rate at which the fibers shorten during systole.
AS main etiologies
Degenerative
Congenital
Rheumatic
Degenerative
AKA senile. Degenerative calcification most common cause
65-70 yrs of age
Congenital
Bicuspid Valve, Subaortic membrane, supravalvular coarctation
Unlikely to see Rheumatic Aortic disease without…….
Mitral Stenosis cause by Rheumatic fever as well
Raphe
Underdeveloped cusp, will have one larger leaflet and one smaller
Sigmoid Septum
Thickening before the AOV. Common in older population.
Uni-Cuspid
Opens with a doming motion, single orifice with teardrop appearance
Cross sectional area x TVI=
Stroke Volume
Color M-Mode is superior in assessing
width of the jet
Echo Features in Degenerative/ Rheumatic
Cusp appearance- thickened, dense fibrotic
Cusp motion- Decreased cusp motion/excursion
LV wall appearance- Concentric Hypertrophy
When are AS symptoms seen?
Often not until AS is moderate to severe
Symptoms of AS include:
DOE
Chest Pain
Possible exertional syncope
Heart Failure
Murmur Heard
Harsh Systolic Ejection murmur
Crescendo-Descrendo in shape
Heard at RT upper-sternal border
Sclerotic vs Stenotic
Sclerotic- cusps are calcified
Stenotic- flow is obstructed
Low CO state would tend to ________ Pk velocity, and ________ valve area
underestimate, overestimate
High CO state would tend to ________ Pk velocity and ________ valve area.
overestimate, underestimate
SV x VTI=
CSA
M-Mode of Bicuspid AOV
Eccentric Closure Line
_______ is superior to M-Mode in the diagnosis of Bicuspid AOV.
2-D
Malformation of leaflet and doming may be seen in ________
Early Systole
Diastolic Doming may be present if __________
AOV prolapse
Characteristic of Bicuspid AOV
Football or Cat Eye shape in Systole
Results and Complications of AS
LV pressure overload
Concentric LV Hypertrophy
What does a B-Bump finding on M-Mode indicate?
An Increase in LVEDP
Increased Risk For?
Infective Endocarditis
Embolic Events
Serious Arrythmia
Sudden Death
Importance of assessing LV size and fx?
Clinical Management
LV size at End Systole > 55 mm (indicates decomposition)
-timing of surgical event-
What helps define the orifice, locate the stenotic jet, and locate/ assess regurgitation?
Color Doppler
What is the preferred AVA method?
VTI Method
Use PLAX view in early-mid systole to determine
LVOT diameter
0.5-1.0 cm from cusp
Pitfalls of AVA calculations
Difficult to know where to take your PW Doppler sample in the LVOT.
What is considered mild on AS Grading Criteria for Pk Pr Gradient?
16-36 mmHg
What is considered moderate on AS Grading Criteria for Pk Pr Gradient?
36-64 mmHg
What is considered severe on AS Grading Criteria for Pk Pr Gradient?
> 64 mmHg
What is considered mild on AS Grading Criteria for Mean Pr Gradient?
< 30 mmHg
What is considered moderate on AS Grading Criteria for Mean Pr Gradient?
30-50 mmHg
What is considered severe on AS Grading Criteria for Mean Pr Gradient?
> 50 mmHg
What is the AS gradient criteria for peak jet velocity?
> 4 m/s
What is the normal valve area?
> 3-5 cm squared
What is considered mild on valve area?
> 1.5 cm squared
What is considered moderate on valve area?
1.1- 1.5 cm squared
What is considered mild on valve area?
> 1.0 cm squared
The AOV planimetry is taken when?
Early Systole
