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Advanced Critical Care Ultrasound Quantitative Assessment Resource 2019-08-15T16:57:09+00:00

Advanced Critical Care Ultrasound Quantitative Assessment Resource

Disclaimer

Quantitative measurements are generally de-emphasized for POCUS applications. When quantitative measures are used, we are more closely approximating diagnostic level echocardiographic standards and thorough training is generally required. This resource is meant to assist the advanced critical care ultrasound clinician by providing a summary of some core normal/abnormal values, equations and review basic techniques relevant to advanced critical care ultrasonography. It can also be used as a study resource for those preparing for the National Board of Echocardiography Special Competence in Critical Care Echocardiography exam. This resource is intended as an efficient reference and those seeking more in depth review are urged to use the references provided

Anatomic Assessments

Quantitative assessments of chamber size are rarely necessary in POCUS applications. However, chamber size assessment may be helpful in determining the chronicity of disease (typically dilation takes time to develop), which may be relevant at the point-of-care when assessing LV and LA dilation. Furthermore, because RV size is often assessed in comparison to the LV, it can be difficult to accurately assess in patients with LV dilation. Current guidelines recommend volumetric assessment using biplane disc summation method but this is cumbersome and necessary views are not always possible in critically ill patients. Measuring the LA antero-posterior dimension remains widely used and may be useful when trying to determine the chronicity of a disease process (e.g. MR, diastolic dysfunction). Measuring LV and LA dimensions can be done with M-mode or 2D, the latter being preferred due to ensure on axis measurements.

 How To Obtain / MeasurementNormal Range (mm)Caveats
LV Chamber DiameterPLAX, perpendicular to LV diameter at end-diastole at level of mitral leaflet tips38-58*Single dimension may not represent entire LV (dilation can occur in other planes)
RV Basal DiameterRV-focused view, maximal transverse diameter in basal 1/3rd of the RV at end-diastole25-41*• Single dimension may not represent entire RV (dilation can occur in other planes)
• Highly dependent on probe position/angle due to RV’s crescent shape
RV Mid DiameterRV-focused view, transverse diameter at the level of papillary muscles (middle 1/3rd of the RV) at end-diastole19-35*
LA AP DimensionPLAX measure antero-posterior distance perpendicular to the aortic root long axis (leading edge to leading edge)2.7-4.0Single dimension may not represent entire LA (dilation can occur in other planes)

*approximations, actual normal measures differ by sex

J Am Soc Echocardiogr. 2015;28:1-39

Quantitative RV wall thickness measurement can help in determining the chronicity of pulmonary hypertension for example in assessment of possible acute pulmonary embolism or RV failure.

 How To ObtainMeasurementNormal Range (mm)Caveats
RV Wall ThicknessSubcostal or PLAX, minimize depth and adjust focusAt end-diastole at the level of the tip of the anterior TV leaflet1-5• Single measure may not represent entire ventricle
• Borders may be difficult in cases of thickened pericardium

J Am Soc Echocardiogr. 2015;28:1-39

Hemodynamic Assessment

Experienced clinicians can accurately assess LV ejection fraction with qualitative assessment. In critically ill patients however, cardiac output may be a more useful clinical end point in guiding resuscitation and hemodynamic support. For children and patients at extremes of size, cardiac index should be used instead of cardiac output. EPSS is a variable traditionally used with M-mode imaging where higher values have been associated with decreased LV EF; EPSS should not be used in isolation when assessing LV systolic function.

 NormalMildly AbnormalModerately AbnormalSeverely Abnormal
LV EF (%)52-74*41-51*30-40<30
LV SV60-120m L*
Cardiac Output4-8 L/min
Cardiac Index2.5-4 L/min/m^2

*approximations, actual values differ by sex and age

J Am Soc Echocardiogr. 2015;28:1-39

 How To ObtainMeasurementTypical ValuesCaveats
LVOT DiameterPLAX view zoom-in on LVOTInner edge to inner edge diameter perpendicular to LVOT long axis at AV annulus (location of attachment of cusps to LVOT) at mid systole~2cm• Lack of consensus regarding measurement technique
• Small error in LVOT diameter can cause large effect on CO due to squaring of the radius
• Assumes LVOT to be circular whereas it is oval
LVOT VTIA5C view with PWD at LVOT or just apical to AV annulusMeasure VTI (negative direction) of systolic period~19cm• PWD gate must be located where LVOT diameter measured
• Assumes laminar flow through LVOT
EPSS*PLAXMeasure distance from tip of anterior mitral leaflet to interventricular septal wall at maximal opening during early systole<0.7-1cm• Single isolated surrogate measure, rather than a true measure of LV function
• Should not be used in isolation
• Confounded by LV dilation and left-sided valvular disease

* EPSS >7mm associated with LVEF≤30% in ED population ordered an echo with sensitivity 100% and specificity 52% (Am J Emerg Med. 2014 Jun;32(6):493-7)

LV Systolic Function Calculators

SV = π (LVOT radius)2 X LVOT VTI

LVOT Radius
LVOT VTI
SV

CO=HR X SV

HR
SV
CO

 CI=CO/BSA

CO
BSA
CI

BSA (Mosteller formula) =√[wt (kg) X ht (cm)/3600]

Weight (kg)
Height (cm)
BSA

RV contraction is complex and is typically assessed qualitatively and should be done with a variety of views including PLAX, PSAX at basal/aortic valve level, A4C, and subcostal views. TAPSE and RV S’ are single measures easily obtained which should not be used in isolation but can be used to support one’s qualitative assessment.

 How To ObtainMeasurementAbnormal ValuesCaveats
TAPSEApical view with proper alignment of M-mode through longitudinal axis of TV annulus excursionApical displacement of TV annulus during systole<1.7cm• Angle dependent
• Should not be used in isolation
RV S'A4C with TDI gate on the TV annulus or the middle of the basal segment of the RV free wallPeak velocity of during systole<9.5cm/s

J Am Soc Echocardiogr. 2015;28:1-39

IVC/RAP

Although commonly used for assessment of fluid responsiveness the IVC has very limited utility for this indication except in extreme cases and is regarded as generally useless as a marker of fluid responsiveness by most. It can however be used to estimate RA pressures in spontaneously breathing non-mechanically ventilated patients, if a CVC is not available to get the true value.

IVC How to ObtainCaveatsIVC SizeIVC Collapsibility with sniffRAP (mmHg)*
Subcostal long-axis view with patient supine, measure 1-2cm from IVC-RA junction (or at level of hepatic vein), at end-expiration• Movement of IVC during inspiration can cause off-axis imaging
• Lack of consensus on measurement technique
• Can be confused with aorta
<2.1cm<50%3
<2.1cm<50%8
>2.1cm>50%8
>2.1cm<50%15

*has not been validated in mechanically ventilated patients

J Am Soc Echocardiogr. 2015;28:1-39

Assessment of RVSP can be useful in patients with acute right heart failure, pulmonary hypertension and to monitor potentially harmful effects of mechanical ventilation (particularly in patients with severe lung injury). The simplified Bernoulli equation makes several assumptions including ignoring the blood’s viscous friction, flow acceleration and the initial blood velocity. RVSP is equal to PASP in the absence of obstruction or pressure gradient in the RVOT or PV.

 How to obtainMeasurementNormal valuesCaveats 
TR peak velocityAssess in all views where TR jet is visualized with colour doppler with CWDPeak velocity of TR jet from CWD envelope<35-40mm Hg•Not available in all patients

J Am Soc Echocardiogr. 2010;23:685-713

RVSP Calculator

RVSP = 4V2 + RAP

V
RAP
RVSP

Valvular Assessment

For many hemodynamically significant or catastrophic valvular lesions good quality 2D and colour doppler evaluation are often sufficient to make the diagnosis. Acute left-sided valvular disease (particularly acute AR and acute MR) can lead to hemodynamic collapse and further deterioration despite standard therapies for shock (i.e. vasopressors) and patients with such potential valvulopathy should be evaluated urgently. The mainstay of POCUS assessment of valvular disease is with 2D echocardiography and colour doppler. Two-dimensional echocardiography should assess for valvular prolapse, flail, perforations, restriction/stenosis/calcification and associated structural changes (chamber dilation). Colour doppler is used to evaluate valvular function as turbulent flow, regurgitation cannot be visualized without it. The following tables include some of the basic quantitative measures of valvular disease which may be used to add confidence for clinical presentations based on 2D and colour doppler. An important caution is that they are based on clinically stable patients with chronic valvular disease largely for surgical assessment and many variables may not be present or could be altered in critically ill patients with acute presentations. Expert consultation should be sought for comprehensive valvular evaluation and quantitative assessment.

Supportive 2D findings: calcifications, restricted valve movement, bicuspid valves

Supportive colour doppler findings: turbulent flow through AoV

 How To ObtainMeasurementThreshold for Severe Aortic StenosisLimitations/Caveats
Peak VelocityA5C with colour Doppler over LVOT/AoV and CWD through center of systolic jetMax velocity of systolic ejection jet (negative direction)≥4m/s• Requires adequate A5C view with parallel CWD alignment
• Dependent on flow
Mean GradientVTI of the systolic ejection jet (negative direction)≥40mm Hg
Dimensionless IndexAs described above
-using CWD for aortic valve peak velocity or VTI
-using PWD for LVOT peak velocity or VTI
DI =(LVOT VTI)/(Aortic Valve VTI)<0.25
Aortic Valve Area*AVA=(LVOT Area X LVOT VTI)/(Aortic valve VTI)

LVOT Area=πr^2
<1cm2Errors in LVOT diameter result in large errors in AVA due to squaring when obtaining LVOT area

*for atrial fibrillation or other arrhythmias average values for several measures (5-10) should be reported

J Am Soc Echocardiogr. 2009;22(1):1-23

J Am Soc Echocardiogr. 2017;30:372-92

DI Calculator

LVOT VTI
Aortic Valve VTI
DI

AVA Calculator

LVOT Area
LVOT VTI
Aortic Valve VTI
AVA

LVOT Area Calculator

Radius
LVOT Area

Supportive 2D findings: flail leaflet, wide coaptation defect, dilated LV (may not be present in acute AR)

Supportive colour Doppler findings: large central jet, large flow convergence

 How To ObtainMeasurementThreshold for Severe ARLimitations/Caveats
Jet Width to LVOT WidthPLAX, zoomed view with color dopplerWidth of regurgitant jet diameter as a ratio of LVOT diameter

(regurgitant jet diameter)/(LVOT diameter)
0.65May underestimate in eccentric jets
VCWPLAXMeasure narrowest width of jet at or just apical to the AoV>0.6cm• Cannot be used with multiple jets or bicuspid valves
• Alignment of regurgitant jet and US beam may influence colour jet width
Jet Deceleration, PHTBest alignment of AR jet, typically A5CObtain A5C view and put colour Doppler box over LVOT and AoV, place CWD through regurgitant jet in parallel alignment,
Trace angle of deceleration of AR jet
Steep, <200msAffected by LV filling pressures
Diastolic Flow Reversal in AortaSC longitudinal view of abdominal aortaPWD through proximal abdominal aortaProminent holodiastolic reversal• Qualitative
• Brief early diastolic reversal can be normal
• False positives (AV fistulae in upper limb)
• May not be holodiastolic in acute AR

J Am Soc Echocardiogr. 2017;30(4):303-371

Jet Width to LVOT Width Calculator

 

Regurgitant Jet Diameter
LVOT Diameter
Jet width to LVOT width

Supportive 2D findings: flail leaflet, ruptured papillary muscle/chordae tendinae, dilated LV and LA (may not be present in acute MR), MV perforation, eccentric jet

Supportive colour doppler findings: colour jet occupies large area of LA or travels to back wall of LA, large width between MV leaflets during systole

Acute MR: 2D findings are crucial as acute MR leads to rapidly developing hypotension and increased LA pressure which can cause typical echo findings of chronic MR to be underestimated (regurgitation jet by colour doppler and ventricular dilation).

***HR, SBP should be recorded at time of assessment as loading conditions have significant effect on gradients

 How To ObtainMeasurementThreshold for Severe MRLimitations/Caveats
Colour Flow Jet Area : LA AreaA4C zoomed of LA with colour box over MV and LATrace both areas

(regurgitant jet area)/(LA area)
>50%• May underestimate eccentric jets
• Affected by loading conditions (HR, SBP)
CWD JetA4C with colour box over MV and LA and CWD through MR jetQualitative assessment of MR CWD shapeTriangular• Qualitative
• Affected by loading conditions (HR, SBP)
• Lacks sensitivity
VCWPLAX zoomed with colour box over MV and LAMeasure narrowest width of jet at or just basal to MV≥0.7cm• Independent of loading conditions (benefit)
• Limited in presence of multiple jets and when MR is not holosystolic
Mitral InflowA4C with PWD aligned with direction of blood from LA to LV and PW gate at leaflet tipsPeak velocity of E wave (first positive wave of diastole in TTE)≥1.2m/s
*A wave dominant pattern excludes chronic severe MR
• Affected by diastolic function
• Limited in atrial fibrillation, mitral valve stenosis
• ECG strip may be needed
Pulmonary Vein Flow PatternA4C with PWD placed 1cm into pulmonary veinsQualitative assessment of negative Doppler flow in pulmonary veins during systolePresence of systolic flow reversal in ≥2 pulmonary veins• Requires high resolution at depth
• May be affected by eccentric jet thus requires visualization of systolic reversal in 2 pulmonary veins
• ECG tracing required

J Am Soc Echocardiogr. 2017;30(4):303-371

Color Flow Jet Area: LA Area Calculator

Regurgitant Jet Area
LA Area
Color flow jet area : LA jet area

Supportive 2D findings: flail leaflet, ruptured papillary muscle/chordae tendinae, dilated RA and RV (may be normal in acute severe TR), D-shaped septum during diastole (volume overload) but may be throughout cardiac cycle if concurrent RV pressure overload, dilated IVC

Supportive colour doppler findings: large regurgitant jet, regurgitant flow may go all the way to hepatic vein.

 How To ObtainMeasurementThreshold for Severe TRLimitations/Caveats
Color Flow Jet AreaBest alignment of TR jet, often A4C, colour box over the TV and RAQualitative assessment of relative size of jetLarge central jet, may be eccentricQualitative, may be overestimated with central jets or underestimate with eccentric jets
CWD JetBest alignment of TR jet, often A4C, colour box over TV and RA with CWD through center of TR jetQualitative assessment of density of CWD TR jetHighly dense (i.e. white) TR jetQualitative
VCVRV inflow or A4C, zoomed with colour box over TV and RAMeasure narrowest width of jet at or just basal to TV≥0.7cm• limited in cases of multiple jets
• independent of loading conditions (benefit)
Hepatic Vein FlowSubcostal long axis of IVC and hepatic vein, PWD in lumen of hepatic veinSemiquantitative assessment of flow reversal (positive deflection) during systole in hepatic veinSystolic flow reversal• limited in patients with Afib, AV dyssynchrony, paced rhythms
• ECG strip required

J Am Soc Echocardiogr. 2017;30(4):303-371

Pericardial Assessment

Remember false positives from epicardial fat which typically has some echogenicity/speckles, moves with the visceral pericardium and is classically located adjacent to the RV wall

Note: size of effusion does not necessarily correlate with tamponade physiology (chronicity plays a large role), loculated effusions may be difficult to visualize with TTE especially in post cardiac surgery patients (TEE may be indicated)

How To ObtainCaveatQualitative DescriptionPericardial Separation Distance
May be seen in multiple views, typically best in PLAX or S4C,
Measured by distance of echo free space between parietal and visceral pericardium at end-diastole
Size of pericardial effusion does not necessarily correlate to presence of tamponadeTrivialSeen only in systole
Small<10mm
Moderate10-20cm
Large>20cm
Very Large>25cm

J Am Soc Echocardiogr. 2013;26:965-1012

Always remember cardiac tamponade is a clinical diagnosis! Some findings may be attenuated, reversed or absent in patients on positive pressure ventilation. Typical signs of tamponade may not be present in patients with loculated/regional tamponade (most commonly post cardiac surgery patients). TEE may be necessary for accurate evaluation.

Supportive 2D findings: presence of pericardial effusion, dilated IVC, dilated hepatic veins, small LV cavity

Supportive doppler findings: reduced cardiac output along with the above 2D features

Feature Suggestive of Tamponade PhysiologyHow To ObtainMeasurementThreshold Consistent with Tamponade PhysiologyCaveats
IVC DilationSC long axis view of IVC +/- M modeMeasure diameter of IVC at end-inspiration and end-expiration>2.1cm with <50% collapse (if spontaneously breathing)Sensitive (seen in >90% of pts with tamponade) but not specific
RA Chamber CollapseA4C or S4CQualitatively or with M-mode, assess RA wall collapse during ventricular systole (start of R wave)RA collapse >1/3 of systolic phaseBrief indentation of RA wall can occur in patients without tamponade
RV Chamber CollapseAssess in multiple viewsQualitatively or with M-mode, assess RV free wall collapse during diastole (start of T wave)RV collapse >1/3 of diastolic phaseDifficult in tachycardic patients, may need to slow down speed or use M-mode
Inspiratory Septal Bulge/Bounce/D-ShapePSAX mid LV level
Or PLAX
Qualitative assessmentExaggerated septal bounce/bulge into LV especially during inspiration suggestive of ventricular interdependenceMultiple other causes: LBBB, RV paced rhythm, pulm HTN
TV Inflow Respiratory Variability†A4C with PWD at tip of TV leafletsMeasure the velocity of the TV first E wave after start of inspiration and expiration

(TV peak E wave vel expiration-TV peak E wave vel inspiration)/(TV peak E wave vel expiration)
>60% variability for peak tricuspid E inflow (calculated % will be a negative value)*Can also be seen in obstructive lung disease, respiratory distress with excessive inspiratory negative pressure generation, constrictive pericarditis, acute pulmonary hypertension/pulmonary embolism
MV Inflow Respiratory Variability†A4C with PWD at tip of MV leafletsMeasure the velocity of the MV first E wave after start of inspiration and expiration

(MV peak E wave vel expiration-MV peak E wave vel inspiration)/(MV peak E wave vel expiration)
>30% variability for peak mitral E inflow**
Hepatic Vein Diastolic FlowSC view of hepatic vein with PWD in hepatic vein lumenQualitative assessment of flow direction in hepatic vein during expirationHepatic vein flow blunting or reversal (away from the heart) during expiration• Hepatic vein can be difficult to visualize
• ECG tracing required

*some suggest threshold of 40% variability for TV inflow variability

**some suggest threshold of 25% for MR inflow variability

positive pressure ventilation can reverse, attenuate and even abolish the effect of respiratory variation in cardiac tamponade

J Am Soc Echocardiogr. 2013;26:965-1012

TV Inflow Respiratory Variability Calculator

TV peak E wave vel expiration
TV peak E wave vel inspiration
TV inflow respiratory variability

MV Inflow Respiratory Variability

 

MV peak E wave vel expiration
MV peak E wave vel inspiration
MV Inflow Respiratory Variability

Pleural Assessment

Qualitative assessments of pleural effusion size are usually sufficient for most clinical decision making, however quantitative estimate of size may help in evaluation of evolution over time or in determining when the effusion has been completely drained. The following table does not apply to small or loculated pleural effusions.

Patient Position and VentilationMeasurementPleural Effusion Size Estimation (mL)CaveatsReference
Sitting, spontaneously breathingMaximal distance between mid-height of diaphragm and visceral pleura at mid scapular line longitudinal axis at end-expirationDistance (mm) X 16Patients with effusions ≤30mm not includedInteract Cardiovasc Thorac Surg. 2010;10(2):204-207.
Supine, trunk elevated 15°, mechanically ventilatedMaximal distance between parietal and visceral pleura at end-expiration with transverse imaging plane at lung baseDistance (mm) X 20Patients with effusions <10mm not included
Variations in ventilator settings may affect measurements
Intensive Care Med. 2006;32(2):318-321.

Transcranial Doppler

A comprehensive transcranial doppler (TCD) assessment of multiple cerebral arteries can be technically challenging, time-consuming and outside the scope of even advanced POCUS practitioners. However isolated assessment of the middle cerebral artery through the transtemporal window is feasible, rapid and can provide valuable information at the point-of-care including midline shift, cerebral circulatory arrest, and vasospasm. It is imperative that the POCUS practitioner is aware of the applications and limitations of POCUS TCD.

Clinical QuestionHow To ObtainMeasurementThresholdLimitations/Caveats
VasospasmPlace phased-array probe with marker pointing anteriorly at the transtemporal window (typically just anterior and superior to the patient’s ear. Identify the sella turcica/sphenoid bone and tilt/slide superiorly to identify the thalami and the third ventricle. Insert a large colour box to identify the Circle of Willis and then the ipsilateral MCA. You can then decrease depth and colour box to focus on the ipsilateral MCA. Insert a PWD gate in the MCA while ensuring optimal on-axis Doppler interrogation.Trace the PWD envelope of one cardiac cycle; US machine will automatically calculate mean velocityMean Velocity
Normal: <80cm/s
Vasospasm:
Mild: >120cm/s
Moderate: >160cm/s
Severe >200cm/s
• Operator dependent
• Confounders include high/low hematocrit, hypotension/shock and other factors that may affect carotid artery flow (eg. stenosis)
• Analysis of MCA flows alone does not rule out presence of vasospasm in other arteries
ICPTrace the PWD envelope of one cardiac cycle and the US machine will automatically calculate mean velocity, peak systolic velocity, and end diastolic velocity. The TCD preset will also calculate pulsatility index (PI).

PI= (peak systolic velocity-end diastolic velocity)/(mean velocity)

estimated ICP=(10.93XPI)-1.28
Normal PI ~1.2 corresponding to ICP ~12mm Hg

PI ~2 corresponds to ICP ~ 20mm Hg
• As above
• PI correlates weakly with ICP but may be useful at extremes

CITATION: plan to include CHEST citation once it is published.

Surg Neurol 2004; 62:45–51.

Neurocrit Care 2012; 17:58–66.

Intensive Care Med 2003; 29:1088–1094.

Estimated ICP Calculator

Peak systolic velocity
End diastolic velocity
Mean velocity
Estimated ICP

Infrequent Findings

Assessment of diastolic dysfunction has limited applications at the point-of-care however there are associations with clinically relevant outcomes in critically ill patients. Diastolic dysfunction in conjunction with elevated LA pressures are important variables in patients with respiratory failure/pulmonary edema/ARDS, and those who fail to wean from mechanical ventilation. The 2016 guidelines simplified previous ones but unfortunately are cumbersome and frequently not possible to apply in critically ill patients. Greenstein and Mayo (2018) proposed a simplified approach to the assessment of diastolic dysfunction in critically ill patients using two variables listed below.

Diastolic Dysfunction Flowchart

In patients with normal LV EF, select all below that applies:

J Am Soc Echocardiogr. 2016;29:277-314

 How To ObtainMeasurementCaveats
Mitral E WaveA4C view with PWD gate between open mitral leaflet tips during diastolePeak velocity of early diastole wave (after T wave)Arrhythmias
Tachycardia
Age-dependent
Mitral A WavePeak velocity of late diastole wave (after P wave)
Septal or Lateral E'A4C view with TDI gate on septal or lateral side of mitral annulusPeak velocity in early diastole (negative direction)MV annular calcification
RWMA affecting sampled segments
TR VelocityA4C or PS with CWD, whichever obtains highest velocityPeak velocity during systole• Dependent on accurate RA pressure estimation
• TR jet may not be present in some patients
LA VolumeA2C and A4CVolume estimation by method of disks area length method, corrected for BSA• Requires adequate LA wall resolution, limited utility in POCUS
• Time-consuming

J Am Soc Echocardiogr. 2016;29:277-314

Rarely acute presentation with hemodynamic significance, if acute suspected assess for obstructing MV vegetation

Supportive 2D findings: restricted opening, commissural calcification/fusion, LA enlargement, elevated RVSP

Supportive colour doppler findings: narrow diameter of turbulent flow at MV

***HR, SBP should be recorded at time of assessment as loading conditions have significant effect on gradients

 How To ObtainMeasurementThreshold for Severe MSCaveats
MV Area by PlanimetryPSAX at MV leaflet tipsTrace MV orifice in mid-diastole<1cm2Requires high resolution
MV Area by PHTA4C with colour box over MV and LA and CWD through jetMeasure slope of transmitral flow during diastasis (between E and A waves)

220/PHT
Affected by diastolic function and other factors
Mean GradientTrace contour of diastolic mitral flow, US machine will calculate mean velocity and mean gradient>10mm HgAffected by loading conditions (HR, SBP)
RVSPA4C or PS colour box over TV and RA with CWD through jetPeak velocity during systole>50mm HgDependent on accurate RA pressure estimation

J Am Soc Echocardiogr. 2009;22(1):1-23

MV Area by PHT Calculator

PHT
MV area by PHT

Supportive 2D findings: TV leaflet thickening/calcification, restricted TV opening, diastolic “doming”, dilated RA, plethoric IVC

Supportive colour doppler findings: narrow diastolic inflow jet, turbulent flow during diastole

*all measures should be at end-inspiration, record HR during assessment

 How To ObtainMeasurementThreshold for Severe TSLimitations/Caveats
Mean Pressure GradientPS RV inflow or A4C with colour box over TV and RA and CWD through RV inflowTrace VTI of RV inflow envelope and machine will calculate mean velocity and mean gradient≥5mm HgAffected by HR, ideal at 70-80bpm

J Am Soc Echocardiogr. 2009;22(1):1-23

Pulmonic valve stenosis is usually congenital, and rare cause of acute illness.

 How To ObtainMeasurementThreshold for Severe PSLimitations/Caveat
Peak VelocityPSAX or SC with colour box over PV and CWD aligned with blood flow through PVMax velocity of systolic ejection jet (negative direction)>4m/sVisualization may be difficult
Can be affected by RV systolic function

J Am Soc Echocardiogr. 2009;22(1):1-23

PR Jet Width : Pulmonary Annulus Ratio Calculator

Regurgitant PR Jet Diameter
PV Annulus Diameter
PR Jet Width : Pulmonary Annulus Ratio

Acute acquired pulmonic regurgitation with hemodynamic significance is rare yet mild PR is common in normal healthy subjects.

 How To ObtainMeasurementThreshold for Severe PRLimitations/Caveats
PR Jet Width : Pulmonary Annulus RatioPSAX, zoomed colour box over PV and RVOT(regurgitation PR jet diameter) / (PV annulus diameter)>0.7Can be misleading in eccentric jets or central jets with entrainment
PR Jet Density and ContourBest alignment of PR jet, typically PSAX or SC with colour box over PV and RVOT, CWD through PR jetQualitative assessment of CWD PR jet envelope density and slopeDense jet with early termination of flow in diastoleQualitative

J Am Soc Echocardiogr. 2017;30(4):303-371

Pulmonary Annulus Ratio Calculator

Regurgitant PR Jet Diameter
PV Annulus Diameter
PR Jet Width : Pulmonary Annulus Ratio

Terminology

A2C- apical 2-chamber

A4C- apical 4-chamber

A5C- apical 5-chamber

AoV- aortic valve

BSA- body surface area

CWD- continuous wave doppler

EPSS- end-point septal separation

IVC- inferior vena cava

LV- left ventricle

LVOT- left ventricular outflow tract

ME4C- midedsophageal 4 chamber

MV- mitral valve

PLAX- parasternal long axis

POCUS- point of care ultrasound

PSAX- parasternal short axis

PWD- pulsed-wave doppler

RAP- right atrial pressure

RV- right ventricle

RVSP- right ventricular systolic pressure

S4C- subcostal 4-chamber

SC- subcostal

SVC- superior vena cava

TAPSE- tricuspid annular plane systolic excursion

TDI- tissue doppler imaging

VCW- vena contracta

VTI- velocity time integral