echo exam Flashcards
(85 cards)
1
Q
Nyquist limit equation
A
1/2* PRF
2
Q
Axial resolution equation
A
1/2 * SPL
3
Q
Doppler equation
A
deltaF=Vcostheta2Ft/c
delta F = Fr - Ft
V is velocity of blood
2 is number of doppler shifts
c is speed of sound through soft tissue:1540m/s
4
Q
Relative speed of u/s in different media
A
bone>tendon>muscle>blood=liver>soft tissue>fat>lung>air
5
Q
Determinants of velocity
A
stiffness (up)
density (down)
6
Q
velocity determination (medium or source)
A
medium
7
Q
wavelength determined by..
A
source and medium
same with SPL
8
Q
strength and seconds determined by
A
source
frequency, amplitude, etc
9
Q
temp above which PZT is dead
A
curie temp
10
Q
acoustic impedance eqn
A
z = density * velocity
11
Q
matching layer thickness
A
1/4 * wavelength
12
Q
PZT thickness
A
1/2 * wavelength
13
Q
quality factor eqn
A
= Resonant frequency/bandwidth
14
Q
Backing material affects on SPL, BW, sensitivity, intensity, DF
A
dampens crystal decreases SPL => improves axial resolution increases BW => decreases QF decreases sensitivity decreases intensity decreases DF
15
Q
what determines resonant frequency in PULSE WAVE DOPPLER
A
RF = Velocity/2xThickness (both of the PZT crystal)
16
Q
equivalent of temporal resolution
A
frame rate ~PRF
17
Q
Functions of receiver
A
- Amplification (gain)
- Compensation (time gain compensation)
- Compression
- Demodulation
- Rejection
18
Q
power related to amplitude
A
proportional to amplitude squared
ie: doubling amplitude would increase power by 4 times
19
Q
intensity related to amplitude
A
proportional to amplitude squared
ie: doubling amplitude would increase power by 4 times
20
Q
synonyms for axial resolution
A
LARRD (longitudinal, axial, radial, range, depth)
21
Q
synonyms for lateral resolution
A
LATA (lateral, angular, transverse, azimuthal)
22
Q
what is duty factor
A
% of time probe is emitting pulses (CWD=100%)
23
Q
different types of myocardium with dobutamine stress
A
stunned, hibernating, ischemic, scar
24
Q
difference between stunned and hibernating myocardium (with dobutamine)
A
hibernating myocardium has biphasic response to dobutamine (salvageable and needs revascularization)
stunned keeps improving with dobutamine (newly reperfused myocardium)
25
Common frequencies of echo machines
TTE vs TEE
Echo machines operate between 2-10MHz
most common is 5-7MHz with TEE probes
TEE higher than TTE=> better spatial resolution
26
attenuation coefficient
and how it's used
1/2*frequency
| *path length gives you how much it attenuates over distance
27
spatial peak temporal average max limit for focused and unfocused beams
100mW/cm2 max for focused beams
1W/cm2 max for unfocused
28
near field length equation
radius of transducer squared/wavelength
29
Risk factors for SAM after MVR (8 things)
1. c sept dist <2.5cm
2. narrow lvot < 2cm
3. MA angle <120 degrees
4. AL/PL ratio<1.3 (measured with valve closed at beginning of systole)
5. basal sept hypertrophy >1.5cm
6. Anterior leaflet >2cm (measured end diastole open)
7. posterior leaflet >1.5cm (measured end diastole open)
8. EDD< 4.5cm
30
Predictors of failed MVR for ischemic MR (5 things)
1. annulus diameter>4cm
2. tethering height>10mm
3. tethering area>1.6cm2
4. PL angle> 45 degrees
5. LVEDd>6cm
31
with HOCM:
criteria mandating surgery
criteria with worse prognosis (2 things)
peak gradient > 50mmHg: surgical myectomy recommended
Wall thickness > 30mm and peak instantaneous gradient > 30mmHg associated with worse survival
32
LV noncompaction criteria
what is LV noncompaction
hypertrabeculated/poor function/dysrhythmias
Jenni criteria:
1. ratio of NC:C > 2:1 at end systole
2. Mid to apical inferior and lateral LV
3. color flow within recesses
33
Load independent measures of systolic function (4 things)
1. end systolic elastance
2. preload recruitable stroke work
3. strain rate
4. preload adjusted max power
34
Normal LV wall thickness (M/F)
what view?
6-9mm for women
6-10mm for men
(TG mid short axis)
35
Normal RV wall thickness
RVH > 5mm
36
Normal LVIDd and LVIDs
What view?
LVIDd greater than 5.4/5.5cm enlarged (peak of R wave)
LVIDs greater than 4.0cm is enlarged
ME 2 chamber
37
TV annular dilation
what view?
what axis does it dilate?
TV dilation is greater than 4.0cm at end diastole
ME 4 chamber
TV dilates in septal/lateral plane
38
MV annular dilation
what view?
what axis does it dilate?
MV dilation is greater than 4.0cm at end diastole
ME long axis
MV dilates in A/P plane
39
VAD map goals
60-85
40
E and Vp predict LAP
E/Vp > 2.5 indicates PCWP >15mmHg
41
Normal LV FS, FAC, EF
what views?
FS normal>25% (m mode of TG mid SAX)
FAC normal >35% (TG mid SAX)
LVEF normal >53%
42
LV dp/dt
how to calc?
normal values?
LV Dp/dt from 1-3m/s of MR jet (calc pressure gradients)
normal >1000mmHg/s
43
SWMA grading
```
grade 1 normal; radial shortening >30%
grade 2 mild hypokinesis; 10-30%
grade 3 severe hypokinesis <10%
grade 4 akinesia
grade 5 dyskinesis
```
44
modified bernoulli eqn
when to use?
if you used it, overestimate or underestimate degree of stenosis?
If V1>1.5m/s can’t use simplified Bernoulli (would overestimate degree of stenosis)
modified: delta P = 4[(V2)2 - (V1)2]
45
Katz plaque grading
which are associated with poor outcomes?
grade 1 < 2mm
grade 3: 3-5mm
grade 5 is anything mobile
grade 4 and 5 associated with adverse neurologic outcomes
46
Ebstein's valve criteria (index and true measure)
septal leaflet > 0.8cm/m2 from annulus or >20mm in adults
47
Wave properties determined by source, medium or both
time (sec) by source
strength by source
velocity by medium (stiffness same direction/density opposite direction)
length by both
48
what is Vp?
what does it measure?
How is it measured?
Normal?
Vp is propagation velocity of early mitral inflow measured with CFD over M mode; 4cm into LV
measurement of diastolic function
normal > 50cm/sec
49
LV mpi equation
what does it measure?
what's normal and abnormal?
LV myocardial performance index
Measures Systolic/diastolic fxn
=(IVRT+IVCT)/ET
<0.35 is normal
>0.5 abnormal (LOWER IS BETTER)
50
RV mpi equation
what does it measure?
what's normal and abnormal?
RV myocardial performance index
Measures Systolic/diastolic fxn
=(IVRT+IVCT)/ET
>0.55 is bad with TDI
>0.4 bad by CWD
51
Stages of hypoplastic left heart surgery
1. Norwood:
a. atrial septectomy
b. RVOT and PV attached to Neo-aorta along with small native aorta
c. ligate main PA
d. ligate PDA
e. either sano (RV to main PA) or BT shunt (R innominate to RPA)
2. bidirectional glen (ligate shunt and SVC to RPA)
3. Fontan (IVC to RPA) sometimes fenestration in IVC to RA
52
Difference between sano and BT shunt
Part of Norwood procedure for HLH (1st stage)
sano (RV to main PA)
BT shunt (R innominate to RPA)
53
Diastology with age
impaired relaxation: E/A decreases and e’ decreases
54
complications with TEE
GI perf incidence
Complication of TEE is 1 in 500
1 in 5000 for GI perf
55
prosthetic severe AS cutoffs (7 things)
1. AT>100ms
2. AT/ET>0.4
3. peak velocity>4m/s
4. mean gradient>35mmHg
5. CFD: tombstone:bad; triangle:good
6. dimensionless index<0.25
7. EOA<0.8cm2
56
percentage of normal prosthetic valves that have trace to mild regurg
10% have trace to mild regurg
57
prosthetic mitral stenosis (5 things)
1. peak transmitral velocity >2.5m/s
2. peak gradient of >10mmHg
3. VTI MV/VTI LVOT > 2.5
4. EOA < 1.0cm2
5. PHT > 200ms
*PHT of 220ms overestimates EOA (underestimates degree of stenosis) with prosthetic
58
Patient prostheses mismatch
aortic (including mild and severe)
mitral
aortic EOA/BSA mild< 0.85 cm2/m2
aortic EOA/BSA severe<0.65cm2/m2
mitral EOA/BSA < 1.2cm2/m2
59
when is clot risk highest for prosthetic valves
clot risk highest in first 6 months
60
Shone complex
hypoplastic left sided structures
supravalvular mitral ring and parachute mitral valve
61
Alagille syndrome
PS, TOF, VSDs, liver defects
62
RV systolic function measurements (6 things)
abnormal values
1. TAPSE<1.6-1.7cm
2. FAC <35 (4chamber)
3. EF<45%
4. RV Dp/dt<400
5. free wall strain more positive than -20
6. s’<10
63
Most common sites of intimal tear for dissections
70% near sinus of valsalva (1-3cm distal)
30% ligamentum arteriosum (aortic isthmus)
64
LVAD inflow and outflow velocities
inflow velocities >1.5m/s shows obstruction
outflow >2m/s shows obstruction
65
TEVAR endoleak classification
time: (primary before 30 days and secondary after)
```
location:
1 attachment site
2 branch
3 graft defect
4 leaks due to graft wall porosity
```
66
Severe PR (3 criteria)
PHT<100ms
VC>0.6cm
RF>40%
67
Lutembacher syndrome
MS and ASD
68
LV mass calculation measurements
end diastole: LVID, ILWT, IVST
69
Cardiac MRI
volumes compared to echo
best measure of valve severity
RVOL is best quantitative measure of valve regurg severity
CMR volumes are larger than echo derived volumes
70
Mitraclip criteria (9 things)
1. coaptation length >2mm
2. coaptation depth < 11mm
3. flail gap < 10mm
4. flail width < 15mm
5. no severe MAC or leaflet calcification
6. leaflet thickness < 5mm
7. LVEF > 20%
8. LVEDd < 60mm
9. MVA > 4cm2
71
TS severe criteria
TVA <1cm2
| mean gradient > 5mmHg
72
pseudo-AS criteria
why important?
Need 0.3cm2 or more increase in AVA with dobutamine stress to be considered pseudo-AS
DO NOT benefit from surgery
73
normal AVA
adult is 3-4cm2
74
3d LVOT measurement vs 2d
3D LVOT images are bigger than 2D (3 is bigger than 2)
75
Normal washing jets length in mitral position
what about medtronic-hall?
<2.5cm in length in mitral position
Medtronic hall 5-6cm
76
Crawford aneurysm classification general rule
number goes up, it moves more distal
except 5 is weird
77
frequency affect on rayleigh scattering
Rayleigh scattering increases with increasing frequency
COUNTERINTUITIVE
78
Impella measurement
AV annulus to inlet portion of device distance is 3.5-4cm
*5 cm with new 5.5 L flow impella (no pigtail)
79
oblique sinus
space around LAA
80
transverse sinus
space around aorta and PA
81
important Prosthetic valve measurements in aortic position
ross
stented bioprosthetic
stentless bioprosthetic
ross: PV annulus, aortic annulus, STJ proximal ascending aorta
stented bio prosthetic: AV annulus
stentless bioprosthetic: AV annulus, STJ, proximal ascending aorta
82
position of IABP
1-2 cm distal to left subclavian artery
83
grading paravalvular regur after TAVR
<10% circumference : mild
10-29%: moderate
>30%: severe
84
noonan syndrome
associated with PS
85
What E wave on MVI velocity consistent with severe MR
>1.2m/s
