TEE Flashcards
Normal Systolic LVID
Men: 32.4 +/- 3.7 mm
Women: 28.2 +/- 3.3 mm
Normal Diastolic LVID
Men: 50.2 +/- 4.1 mm
Women: 45 +/- 3.6 mm
Normal LVEDV
Men: 74 mL/m^2
Women: 61 mL/m^2
Normal LVESV
Men: 31 mL/m^2
Women: 24 mL/m^2
Relative Wall Thickness
(2 x PWT)/LVIDd
Concentric hypertrophy
RWT >0.42
Eccentric hypertrophy
RWT <0.42
Ejection Fraction
(EDV - ESV)/EDV
RV free wall thickness
End-diastole
<0.5 cm
RV dimensions
RVD1 (TV annulus): 2-2.8 cm
RVD2 (mid-ventricle): 2.7-3.3 cm
RVD3 (long axis): 7.1-7.9 cm
LA dimension
Men: 3-4 cm
Women: 2.7-3.8 cm
Volume: <34 mL/m^2
RA volume
Men: 25 +/- 7 mL/m^2
Women: 21 +/- 6 mL/m^2
Aortic Regurgitation
When to replace valve?
- Severe, symptomatic AR
- Asymptomatic patients with
- Dilated heart (EDD >70 mm)
- Decreased EF (<55%)
- Dilated aortic root (>50-55 mm)
Aortic Regurgitation
Pressure Half Time (PHT)
Mild: >500 ms
Moderate: 200-500 ms
Severe: <200 ms
Aortic Regurgitation
Deceleration Slope
Mild: <2 m/s
Moderate: 2-3 m/s
Severe: >3 m/s
Aortic Regurgitation
Descending Aorta Flow Reversal
Mild: Early brief
Moderate: Intermediate
Severe: Holodiastolic
Aortic Regurgitation
Vena Contracta width
Mild: <3 mm
Moderate: 3-6 mm
Severe: >6 mm
Aortic Regurgitation
AR Jet/LVOT width
Mild: <25%
Moderate: 25-64%
Severe: >64%
Aortic Regurgitation
Regurgitant Volume
Mild: <30 mL
Moderate: 30-59 mL
Severe: >59 mL
Aortic Regurgitation
Regurgitant Fraction
Mild: 20-30%
Moderate: 30-49%
Severe: >49%
Aortic Regurgitation
EROA
Mild: <0.1 cm^2
Moderate: 0.1-0.29 cm^2
Severe: >0.29 cm^2
Aortic Stenosis
Modified Gorlin Equation
AVA = CO / MG^(1/2) AVA = CO / PG
Aortic Stenosis
Peak Velocity
Aortic Sclerosis: = 2.5 m/s
Mild: 2.6-2.9 m/s
Moderate: 3-4 m/s
Severe: >4 m/s
Aortic Stenosis
Mean Gradient
Mild: <20 mmHg
Moderate: 20-40 mmHg
Severe: >40 mmHg
Aortic Stenosis
AVA
Mild: >1.5 cm^2
Moderate: 1-1.5 cm^2
Severe: <1 cm^2
Aortic Stenosis
Indexed AVA
Mild: >0.85 cm^2/m^2
Moderate: 0.6-0.85 cm^2/m^2
Severe: <0.6 cm^2/m^2
Aortic Stenosis Velocity Ratio (Dimensionless Index)
Mild: > 0.5
Moderate: 0.25-0.5
Severe: <0.25
LV Fractional Shortening
(LVEDd - LVESd) / LVEDd
Normal >25%
LV Fractional Area Change
(EDA - ESA) / EDA
Normal >40-45%
Ejection Fraction
(EDV - ESV) / EDV
Normal >55%
Simplified Bernoulli’s Equation
P = 4v^2
Dp/Dt
32/Dt
Normal >1200 mmHg/s
Abnormal <800 mmHg/s
Independent of afterload, dependent on preload
Velocity of Circumferential Shortening (VCF)
FS/LVET
Normal 1.09 +/- 0.3 circ/s
End Systolic Elastance
- Plot series of end-systolic points under various loading conditions
- Steeper slope = better systolic function
- Load independent
Preload-Recruitable Stroke Work
- Stroke work = area under pressure-volume loop
- Plot stroke work as function of end-diastolic volume
- Steeper slope = better systolic function
- Load independent
Preload Adjusted Max Power
=Stroke Work / (EDV)^2
=Stroke Work / (EDA)^(3/2)
-Load independent
Systolic Mitral Annular Velocity (Sm)
- S’ velocity lateral annulus
- Normal >8 cm/s
- Abnormal <5 cm/s
Strain Rate
= (v1-v2) / x
Dimensionless
Exempt from influence of translation
Load independent
Load Independent Measures of Systolic Function
- End-systolic elastance
- Preload recruitable stroke work
- Preload adjusted max power
- Strain rate
MAPSE
Normal 12 +/- 2 mm
Abnormal <8 mm
Myocardial Performance Index (MPI)
(ICT + IRT) / ET
Normal 0.39 +/- 0.05
Abnormal >0.5
Mitral valve annulus diameter
ME long axis view
Mid-diastole
29 +/- 4 mm
Mitral Regurgitation
Ajet/Aatria
Mild: <20%
Moderate: 20-40%
Severe: >40%
Mitral Regurgitation
Vena Contracta
Mild: <3 mm
Moderate: 3-6.9 mm
Severe: >7 mm
Mitral Regurgitation
MR Jet Area
Mild: <4 cm^3
Moderate: 4-10 cm^3
Severe: >10 cm^3
Mitral Regurgitation
Pulmonary Vein Flow
Mild: Normal
Moderate: Blunted S
Severe: S reversal
Mitral Regurgitation Regurgitant Fraction (RF)
RF = RV / SV(MV)
Mild: <30%
Moderate: 30-49%
Severe: >50%
Mitral Regurgitation Regurgitant Volume (RV)
RV = SV(MVinflow) - SV(LVOT) RV = EROA / VTI(MR) Mild: <30 cc Moderate: 30-59 cc Severe: >60 cc
Mitral Regurgitation
EROA
EROA = RV / VTI(MR) EROA(PISA) = Q(MRPisa) / V(MRpeak) Mild: < 0.2 cm^2 Moderate: 0.2-0.39 cm^2 Severe: >0.4 cm^2
Mitral Regurgitation
CWD Strength
Mild: Faint
Moderate: Moderate, partial
Severe: Very dense, holosystolic
Mitral Regurgitation
PISA Radius
If Valias = 40 and V(MRpeak) ~500 cm/s
Mild: <4 mm
Moderate: 4-10 mm
Severe: >10 mm
SAM Risk Factors
- LV EDD <45 mm
- Aortomitral angle <120
- C-sept distance <25 mm
- AL/PL <1.3 (valve closed)
- Basal septum >15 mm
- LVOT <2 cm
- AL length >2 cm (valve open)
- PL length >1.5 cm (valve open)
Mitral Stenosis
MVA by PHT
MVA = 220 / PHT
Mitral Stenosis
MVA by Deceleration Time
MVA = 759 / DT
Mitral Stenosis
Mean Gradient
Mild: <5 mmHg
Moderate: 5-10 mmHg
Severe: >10 mmHg
Mitral Stenosis
PHT
Normal: 40-70 ms
Mild: 70-150 ms
Moderate: 151-219 ms
Severe: >220 ms
Mitral Stenosis
MVA
Normal: >2.5 cm^2
Mild: 1.6-2.5 cm^2
Moderate: 1-1.5 cm^2
Severe: <1 cm^2
Mitral Stenosis
Peak PA Pressure
Normal: 20-30 mmHg
Mild: <30 mmHg
Moderate: 30-50 mmHg
Severe: >50 mmHg
Mitral Stenosis
PISA
MVA = {[23.14r^2 x (alpha/180)] * Valias} / Vpeak
Aortic Stenosis
Peak Gradient
Mild: 20-39 mmHg
Moderate: 40-69 mmHg
Severe: >70 mmHg
RV FAC
Normal >42-56%
Abnormal <35%
RV EF
Normal >51.5-64.5%
Abnormal <45%
TAPSE
Normal 21-27 mm
Abnormal <17 mm
RV Isovolumic Acceleration (IVA)
Normal 1.4 +/- 0.5 m/s^2
TV S’
Normal >9.8-16.4 cm/s
Abnormal <9.5 cm/s
RV dP/dT
15 mmHg/dT
Normal >400 mmHg/s
Very sensitive to loading conditions
Tricuspid Annulus
ESD 28 +/- 5 mm
EDD 31 +/- 5 mm
Tricuspid Regurgitation
Jet Area
Mild: <5 cm^2
Moderate: 5-10 cm^2
Severe: >10 cm^2
Tricuspid Regurgitation
VC Width
Mild: <0.3 cm
Moderate: 0.3-0.69 cm
Severe: >0.7 cm
Tricuspid Regurgitation
Hepatic Vein Flow
Mild: S dominant
Moderate: S blunting
Severe: S reversal
Tricuspid Regurgitation
EROA
Mild: <0.2 cm^2
Moderate: 0.2-0.39 cm^2
Severe: >0.4 cm^2
Tricuspid Regurgitation
Regurgitant Volume
Mild: <30 cc
Moderate: 30-44 cc
Severe: >45 cc
Tricuspid Stenosis
Tricuspid Valve Area
TVA = 190/PHT
Severe: < 1 cm^2
Tricuspid Stenosis
Mean Gradient
Mild: <2 mmHg
Moderate: 2-5 mmHg
Severe: >5 mmHg
Pulmonic Regurgitation
Severe PR
PI Jet Width/PA annulus 0.7
Deceleration time PI trace <260 ms
PHT PI jet <100 ms
Prominent flow reversal in main PA
Pulmonic Stenosis
Velocity
Mild: <3 m/s
Moderate: 3-4 m/s
Severe: >4 m/s
Pulmonic Stenosis
Peak Pressure Gradient
Mild: <36 mmHg
Moderate: 36-64 mmHg
Severe: >64 mmHg
RV MPI
MPI = (IVRT + IVCT) / ET
PW Normal: 0.26 +/- 0.085
PW Abnormal: >0.43
TDI Normal: 0.38 +/- 0.08
TDI Abnormal: >0.54
ASD
Ostium Secundum
- Most common ASD
- Defect in septum primum
- A/w MVP
ASD
Ostium Primum
- Endocardidal cushion defect
- A/w cleft AV, cleft septal TV leaflet, and cleft anterior MV leaflet
- A/w Trisomy 21
- Can be a/w restrictive or non-restrictive VSD
ASD
Sinus Venosus
- Located near SVC>IVC
- SVC sinus venosus a/w anomalous drainage of RUPV
- IVC sinus venosus a/w Scimitar Syndrome
ASD
Coronary Sinus
- Least common ASD
- A/w persistent L SVC
VSD Type 1 (Outlet, Supracristal)
- Defect just below PV
- Most likely to be a/w prolapse of RCC and resultant AR
- Least common VSD
VSD Type 2 (Membranous, subaortic, conoventricular, malalignment)
- Most common VSD (70%)
- Located near TV
- A/w LV septal aneurysms
- Can be a/w prolapse of RCC
- A/w TOF
VSD Type 3 (Inlet, endocardial cushion defect)
- A/w primum ASD
- A/w Trisomy 21
- A/w cleft AV leaflets, cleft septal TV leaflet, and cleft anterior MV leaflet
VSD Type 4 (muscular, trabecular)
-Located more inferior and posteriorly
Tetralogy of Fallot
- VSD (membranous)
- Overriding aorta
- Pulmonary obstruction
- RVH
- A/w R aortic arch (25%) and coronary artery abnormality
Ebstein’s Anomaly
- Large, sail-like anterior TV leaflet
- Apically displaced septal TV leaflet
- Atrialization of RV
- Dilated RV with severe volume overload 2/2 TR
- A/w ostium secundum ASD
- A/w WPW syndrome, atrial and ventricular arrhythmias
Diastology
Vp
Normal >45-50 cm/s
- Measure 4 cm into LV
- Dependent on preload
- E/Vp >2.5 predicts PCWP >15 in pts with EF <55%
Diastology
Grade 0
Normal
e’ >10 cm/s
Diastology
Grade 1
Impaired Relaxation
e’ <10 cm/s
E/e’ <8
E/A <0.8
DT >200 ms
ARdur-Adur <30 ms
Diastology
Grade 2
Pseudonormal
e’ <10 cm/s
E/e’ 9-12
E/A 0.8-1.5
DT 160-200 ms
ARdur-Adur >30 ms
Diastology
Grade 3
Restrictive
e’ <10 cm/s
E/e’ >13
E/A >2
DT <160 ms
ARdur-Adur >30 ms
Diastology
Predictors of Increased Filling pressures
E/E’ >15
IVRT/Te-e’ <2
E/Vp >2.5 predicts PCWP >15 (if EF <55%)
ARdur - Adur >30 ms
Diastology (Updated)
Normal
Mitral E/A ratio >0.8
Average E/e’ <10
Peak TR velocity <2.8
LA volume index <34
Diastology (Updated)
Grade 1
Mitral E/A ratio <0.8
Average E/e’ <10
Peak TR velocity <2.8
LA volume index normal or increased
Diastology (Updated)
Grade 2
Mitral E/A ratio >0.8 to <2
Average E/e’ 10-14
Peak TR velocity >2.8
LA volume index >34
Diastology (Updated)
Grade 3
Mitral E/A ratio >2
Average E/e’ >14
Peak TR velocity >2.8
LA volume index >34
Wavelength
Length of single cycle
(trough to trough, or peak to peak)
wavelength=velocity/F
Spatial Pulse Length
Length of entire pulse
SPL = Wavelength x # cycles in pulse
Axial (LARD) Resolution
Ability to discern 2 separate objects front to back
1/2 SPL
Smaller SPL = better axial resolution
Longitudinal, axial, radial, range, depth
Period
Amount of time needed to complete single cycle
time for trough to trough or peak to peak
Pulse Duration
Amount of time needed to complete entire pulse
PD = Period x # cycles in pulse
Pulse Repetition Period
Amount of time needed to go from beginning of 1 one pulse to beginning of next pulse
Pulse Duration + Listening Time
Pulse Repetition Frequency
1/Pulse Repetition Period
# pulses/second
Helps determine Nyquist limit
Proportional to frame rate
Temporal Resolution
Ability to accurately image moving structures at a particular instance in time
Increased PRF = better temporal resolution
Nyquist Limit
Maximum Doppler shift that can be measured without aliasing occurring
= 1/2 PRF
Frequency
# cycles/second 1/period F=v/wavelength
Power
Amount of work US beam can do (transducer output)
Intensity
Power/unit area
Determines bioeffects of US
Amplitude
Difference between average and max values of an acoustic variable
Higher amplitude = stronger sound pulse
Power & Intensity proportional to Amplitude^2
Lateral (LATA) Resolution
Ability to determine 2 separate objects side by side
Determined by beam width (narrower is better)
Lateral, angular, transverse, azimuthal
Elevational Resolution
Ability to determine 2 separate objects along y-axis
Determined by beam height
Gain/Amplification
Amplification of returning US signal
Post-processing function
Time (Depth) Gain Compensation
Compensates for attenuation that occurs with increasing depth
Changes gain in horizontal position
Lateral Gain Compensation
Changes gain in vertical position
Compensates for attenuation
Corrects enhancement artifact
Compression
Reduces the dynamic range of signals
High compression produces more highly contrasted image, less “shades of grey”
Dynamic Range
Range of signals that can be processed by the machine
Inverse of compression
# of “shades of grey”
Focus
Point where US beam is narrowest
Best lateral resolution
Doppler Equation
FR-FT = V cos(theta) 2 FT/C V = velocity of blood flow Theta = angle between flow and probe FR = reflected frequency FT = transmitted frequency C = speed of US in soft tissue (1540 m/s)
Range Ambiguity
Inability to discern specific location of Doppler shift
Seen with CWD
Mechanical Index
Ability of the US beam to produce cavitation (bursting of bubbles) of contrast material
MI = peak negative pressure / (frequency)^(1/2)
Depends on transmitted frequency and pressure of sound wave
Tissue Harmonics
Small amount of US converted into a harmonic frequency as sound propagates
Occurs at deeper depths
Occurs along main axis
Contrast Harmonics
Echo contrast material (microbubbles) expand and compress as it interacts with US, creating harmonic frequencies and lighting up cardiac chambers
Cavitation
Rupture of microbubbles causing a great deal of harmonic frequencies
Occurs with MI >1
Resonance
Uneven shrinking and compression of microbubbles (expansion>compression) creates new harmonic frequencies
Occurs with MI 0.1-1
Acoustic Impedance (Z)
Acoustic resistance to sound traveling through a medium
Z = P x V
P = density
V = velocity
Resonant Frequency (RF)
Most common frequency in a pulse
CWD: RF determined by electrical frequency of voltage
PWD: RF = V/2Thickness
Bandwidth (BW)
Difference between lowest and highest frequencies in a pulse
Shorter SPL = higher BW
5 Functions of US Receiver
- Amplification
- Compensation
- Compression
- Demodulation
- Rejection
Demodulation
Changes shape of electrical signal to make it recognizable by image screen
Rectification - turns all negative voltages positive
Smoothing - smoothes out signal
Rejection (Threshold, suppresion)
Very low amplitude signals are ignored as noise
Reverberation artifact
US ricochets between 2 reflectors creating multiple equally spaced reflections
Ringdown artifact, comet-tail effect
Refraction artifact
US beam is refracted by reflector, placing object to the side and deeper than true position
Side lobes (grating lobes)
US beams traveling along side axes reflect off of a reflector, but machine assumes it is traveling along main axis
Acoustic Shadowing
Very strong reflector doesn’t allow penetration of US
Mirror Image artifact
US beam reflects off mirror, before hitting true object. Mirror image will be deeper and to the side, and equidistant to mirror as true object
Focal Zone
Length of near field (Ln)
Ln = r^2/wavelength
Q Factor
Q Factor = RF/BW
Scattering
Random redirection of sound in many directions
Occurs when reflector is smaller than or equal to wavelength of US beam
Directed related to frequency
Snell’s Law
sin(theta[t])/sin(theta[i]) = v2/v1
Used for refraction
Duty Factor
Amount of time that US machine is producing sound
=PD/PRP x 100%
Propagation Speed Artifact
Structure placed at incorrect depth because TEE assumes sounds travels at exactly 1540 m/s
Enhancement Artifact
Occurs when US travels through medium with lower rate of attenuation than surrounding soft tissue
Objects brighter distal to weakly attenuating medium
Attenuation Coefficient
Frequency/2
Aortic Stenosis
Prosthetic valve severe stenosis cutoffs
EOA <0.8 cm^2 AT > 100 ms AT/ET >0.4 DVI <0.25 MG > 35 mmHg Peak Vel >4 m/s
Mitral Regurgitation
Predictors for failed MVr for ischemic MR
Type IIIb Carpentier motion Annulus diameter >4 cm LV diastolic diameter >6 cm Tethering (tenting) height >10 mm Tenting Area >1.6 cm^2 Posterior leaflet angle >45 degrees