Stenosis/Final Flashcards
What are the two types of information categories one must use to assess stenosis?
Hemodynamic information and anatomic information
What type of hemodynamic information do we use in assessing a stenosis?
Peak velocity, maximum pressure gradient, mean pressure gradient
What is the units for the peak velocity and what type of Doppler is used to obtain the peak velocity?
Meters per second, CW
How is the maximum pressure gradient obtained and what are the units?
Obtain the peak velocity and then plug it into Bernoulli’s equation.
mmHg
What is the equation for obtaining the maximum pressure gradient?
Maximum PG (mmHg) = 4(V)2
What is the mean pressure gradient?
The average of all velocities
What are the methods to assess valves with stenosis?
Continuity equation, pressure halftime, Decel time method, PISA
Bernoulli’s equation explains the relationship between what two factors?
Pressure and velocity
When is flow considered stenotic flow?
When it is greater than 2 m/s
What type of pressure gradient does the Bernoulli’s equation provide?
The peak instantaneous pressure gradient
How is the mean pressure gradient obtained?
By Planimetry of the Doppler signal
What is the murmur for aortic stenosis?
A systolic crescendo decrescendo
What is the peak velocity for aortic stenosis? What is the peak velocity for aortic sclerosis?
The peak velocity for aortic stenosis is >2.0 m/s. The peak velocity for aortic sclerosis is <2.0 m/s.
What is seen in M mode with a bicuspid aortic valve?
An eccentric closure line
When using PEDOFF in the right parasternal window the waveform for aortic Doppler flow will appear above or below the baseline?
Above the baseline
What information needs to be obtained in order to assess aortic stenosis?
Peak velocity, maximum pressure gradient, mean pressure gradient, and the aortic valve area
Doppler provides instantaneous pressure gradient the Cath Lab provides what type of pressure gradient?
Peak to Peak pressure gradient
What is the letter that represents flow? What equation represents flow? What happens if the area decreases?
Q
Flow = velocity x area
The velocity increases
What equation helps us obtain the aortic valve area? What is the equation to obtain the aortic valve area?
Continuity equation
AVA (cm2) = CSA (LVOT cm2) x VTI (LVOT)/VTI (AoV)
What is the continuity equation?
Q1= Q2 or,
V1(A1) = V2(A2) or,
V(LVOT) x A(LVOT) = V(AoV) x A(AoV)
What Doppler information can be used to find the aortic valve area? Looking for the two equations the information would be plugged into.
VTI or PW and CW Doppler
AVA = CSA(LVOT) x V(LVOT PW)/V(AoV CW) or
AVA = CSA (LVOT) x VTI (LVOT)/VTI (AoV)
What is the equation to obtain the cross-sectional area of a valve?
CSA (LVOT cm2) = .785 x LVOT diameter squared
What type of velocity is obtained to plug into the continuity equation?
Peak velocity
What is the shorthand equation for the aortic valve area utilizing the continuity equation?
A2= A1 x V1/V2
What is the equation for the velocity ratio in regard to aortic stenosis?
VR = V (Lvot)/V (Aov)
What are three conditions that can overestimate aortic stenosis values?
Anemia, aortic insufficiency, pregnancy
What are four conditions that can under estimate aortic stenosis values?
Low cardiac output, mitral regurgitation, dysrhythmias, poor Doppler angle
How can you discern the aortic stenosis jet from the mitral regurgitation jet?
The mitral regurgitation jet is wider than the aortic stenosis jet because the mitral regurgitation jet encompasses the I VCT through the I VRT.
What is the peak velocity for mild aortic stenosis? What is the peak velocity for severe aortic stenosis?
Mild is 2.6-2.9 m/s and severe is >/= 4.0 m/s
What is the mean gradient for mild aortic stenosis? What is the mean gradient for severe aortic stenosis?
Mild is <20 mmHg and severe is >/= 40 mmHg
What is the aortic valve area for mild aortic stenosis? What is the aortic valve area for severe aortic stenosis?
Mild is greater than 1.5 cm² and severe is less than 1.0 cm²
What is the indexed aortic valve area for mild aortic stenosis? What is the indexed aortic valve area for severe aortic stenosis?
Mild >0.85 cm²/m2 and severe <0.6 cm²/m2
What is the velocity ratio for mild aortic stenosis? What is the velocity ratio for severe aortic stenosis?
Mild >0.50 and severe <0.25
What does the echocardiographer perform in the case of aortic stenosis as required by Sentara protocol?
For aortic stenosis per sentara protocol, the echocardiographer would obtain the LVOT diameter, the LVOT VTI, the AOV VTI, and PEDOFF
What is the pressure prior to the stenosis and the pressure after the stenosis?
Increased pressure prior to the stenosis, decreased pressure after the stenosis
