This document discusses the limitations and techniques for assessing right ventricular (RV) function using echocardiography. It is difficult to accurately evaluate RV volume, delineate borders, and image the entire RV using echocardiography due to its complex crescent shape. However, the document recommends using RV fractional area change, tricuspid annular plane systolic excursion, tissue Doppler S' velocity, and Tei index to quantitatively assess RV systolic function as they are reproducible methods. RV dimensions, wall thickness, and outflow tract size can also provide information on RV size and function. Assessment of RV diastolic function includes parameters like E/A ratio, E/E' ratio, and deceleration time.
4. Limitations of Echocardiography in The
Evaluations of RV Function
▶Difficulties in the estimation of RV volume
: crescentic shape of RV
:separation between RV inflow and outflow
: no uniform geometric assumption for measuringvolume
▶Difficulties in the delineation of endocardial border owing to
well developed trabeculation
▶Difficulties in the adequate image acquisition owing to the
location just behind the sternum
5. Limitations of Echocardiography in The
Evaluations of RV Function
▶ Difficult to standardize the evaluation method of RV function
: Variations in the direction or location of the RV are common
: Easily affected by preload, afterload, or LVfunction
▶Different complex contraction-relaxation mechanism among
the segments of the RV
▶Cannot image the entire RV in a single view
6. Function of the Right Ventricle
Why should we measure RV function?
▶ RV is not just a conduit of blood flow
: has its unique function
▶Prognostic significance in various clinicalsettings
▶Risk stratification or guide to optimal therapy
7. Function of theRight Ventricle
▶ Maintain adequate pulmonary artery perfusion pressure to
improve gas exchange
▶ Maintain low systemic venous pressure to prevent
congestion of tissues or organs
▶ Affect LV function
: limit LV preload in RV dysfunction
: Ventricular interdependence
▶ Prognostic significance in various clinical settings
8. 2D and M-mode: RV Area and FACin A4C
▶ Wellcorrelated withRV function measured by radionuclide
ventriculography or MRI
▶ Good predictor of prognosis
▶ Limitations: fail to measure FAC due to inadequate RV tracing
Referencerange Mild abnormal Moderate abnormal Severe abnormal
RV diastolic area(cm2) 11-28 29-32 33-37 ≥38
RV systolic area(cm2) 7.5-16 17-19 20-22 ≥23
RV FAC(%) 32-60 25-31 18-24 ≤17
9. RV WALL THICKNESS AND CHAMBER SIZE
RV INFERIOR
WALL
SUBCOSTAL
VIEW
N=<0.5cm
Measured at
peak r wave
10. 2D and M-mode: Thicknessof RV Free Wall
▶ Normal: less than 0.5 cm
▶ Measure at the level of TV chordae and at the peak of R wave of
ECG on subcostal view
▶ Well correlated with peak RV systolic pressure
15. 2D and M-mode: RVOT and PA Size
Referencerange Mild abnormal Moderate abnormal Severeabnormal
RVOT diameters, cm
Above aortic
valve(RVOT1)
2.5-2.9 3.0-3.2 3.3-3.5 ≥3.6
Above pulmonic
valve(RVOT1)
1.7-2.3 2.4-2.7 2.8-3.1 ≥3.2
PA Diameters, cm
Belowpulmonic valve
(PA1)
1.5-2.1 2.2-2.5 2.6-2.9 ≥3.0
16. 2D and M-mode: RV Size
▶ Normal RV is approximately 2/3 of the size of the LV
▶ RV Dilatation
: appears similar or larger than LV size
: shares the apex
17. Right ventricular function assessed by five methods –
1. TAPSE
2. FAC
3. TEI INDEX
4. S’ (Tissue doppler systolic signal velocity of TV lateral annulus)
5. Visual estimation of RV free wall and TV annular motion
18. 2D and M-mode: Fractional Area Change (FAC)
(End-diastolic area) – (end-systolic area)
x 100
(end-systolic area)
19. TricuspidAnnular Plane Systolic Excursion
▶ Degree of systolic excursion of TV lateralannulus onA4C
: 1.7-2.6 cm in normal
: Value less than 1.7 cm is considered as abnormal
▶ WellcorrelatedwithRVEF measuredby RVG
▶ Reproducible
▶ Strong predictor of prognosis in patients with CHF
22. TricuspidAnnular Plane Systolic Excursion
※ TAPSEand RVejection fraction
:TAPSE2cm=RVEF50%
:TAPSE1.7cm=RVEF45%
:TAPSE1cm=RVEF30%
:TAPSE0.5cm=RVEF20%
Eventfreesurvival according
to TAPSEin patientswith CHF
23. TISSUEDOPPLER IMAGING
• An apicalfour chamberviewis used
• Thepulsed Doppler samplevolumeisplaced in eitherthetricuspid annulusor themiddle of thebasal
segmentof theRVfree wall
• TheS´velocityisreadasthehighestsystolicvelocitywithout over-gaining theDoppler envelope
Normal >10cm/s
24. TISSUE DOPPLER (S´)
Advantages
• A simple,reproducible techniquewith good
discriminatory ability to detect normal
versusabnormal RV function
• Pulsed Doppler isavailableon allmodern
systems
• Maybe obtained and analyzed off-line
Disadvantages
• Lessreproducible for nonbasal segments
• Isangle dependent
• Limitednormativedatain allranges'and in
both sexes
• It assumes that the function of a single
segment represents the function of the entire
right ventricle
25. RVMPI (TEI INDEX)
• Ratiobetweenisovolumic timeandejectiontime
• RVindexof Myocardial Performance
• Global indexof both systolicand diastolic function of theright ventricle
IVRT +IVCT
ET
Normal <0.40 Normal <0.55
28. Advantages
• Thisapproach isfeasiblein alarge
majorityof subjects
• TheMPI is reproducible
• Itavoidsgeometric assumptionsand
limitations of thecomplexRV geometry
• Thepulsed TDI method allows for
measurementof MPI aswellasS´,E´,and A´all
fromasingle image
Disadvantages
• TheMPI isunreliablewhenRVETandTR time
aremeasuredwithdiffering R-R intervals,asin
atrial fibrillation
• Itisload dependent and unreliablewhen RA
pressuresare elevated
29. RV DIASTOLIC FUNCTION
• From the apical 4-chamber view,the Doppler beam should be aligned parallel to RV inflow
• Sample volume is placed at the tips of the tricuspid valve leaflets
• Measureatheld end-expiration and/or taketheaverageof ≥5consecutivebeats
• Measurementsare essentiallythe sameasthose used for the left side
30. RV DIASTOLIC FUNCTION
Variable Lower reference value Upper reference value
E (cm/s) 35 73
A (cm/s) 21 58
E/A ratio 0.8 <2.
Deceleration time (ms) 120 220
IVRT (ms) 23 73
E’ (cm/s) 8 20
A’(cm/s) 7 20
E’/A’ ratio 0.5 1.9
E/E’ 2 6
31. RECOMMENDATION
• Measurementof RVdiastolic function should be consideredin patientswithsuspectedRV impairment
asamarkerof earlyor subtleRVdysfunction,or in patientswithknownRV impairmentasamarkerfor
poor prognosis
• TranstricupsidE/A ratio,E/E’ratio, and RAsizehavebeen mostvalidatedarethepreferred measures
Grading of RVDiastolic Dysfunctionshould be done as follows:
E/A ratio <0.8suggestsimpaired relaxation
E/A ratio 0.8-<2.0with anE/E’ ratio >6or diastolic prominence in thehepaticveins suggest
pseudonormal filling
E/A ratio >2.with deceleration time<120mssuggestsrestrictivefilling
32. RIGHT ATRIAL ASSESSMENT
• Apical 4-chamber view
• Estimationof right atrialareaby planimetry
Themaximumlong distanceof theRAis from the
centerof thetricuspid annulusto the superiorRA
wall,parallelto theinteratrial septum
A mid RAminor distancveisdefined from the mid
levelof theRAfreewallto theinteratrial septum
perpendicularto thelong axis
RAareaistracedattheend of ventricular
systole,excluding theIVC, SVC,and RAA
Normal area<18cm²
33. RA PRESSURE DETERMINATION
• Measurementof theIVC should be obtained atend-expiration and justproximalto the junction of the
hepaticveinsthatlieapproximately0.5to 3.0cmproximalto theostiumof theright atrium
ToaccuratelyassessIVC collapse,the change
in diameterof theIVC witha sniffand also with
quiet respiration should be measured,
ensuringthatthe changein diameterdoes not
reflecta translationof theIVC into another
plane
34. Estimation of RA pressure from IVC
diameter
IVC SIZE BSA
NORMAL 17 mm <1.55 m2
20 mm 1.55-<1.71 m2
21 mm >1.71 m2
IVC COLLAPSE RAP
size Normal IVC >50% 05 mm hg
Normal IVC <50% 10 mmhg
Dilated IVC >50% 15 mmhg
Dilated IVC <50% 20 mmhg
36. HEMODYNAMIC ASSESSMENT
Systolic pulmonary artery pressure
• Estimated withTR jet velocity using simplified Bernoulli equation ( provided there is no RVOT
obstruction )
RVSP=4(V)2+RApressure
• Normal peak RVSP is 35 to 36 mmHg assuming RApressure of 3 to 5 mmHg
Note :MeasureTRjetvelocityfromvariousviewsto getthehighest velocity
39. HEMODYNAMIC ASSESSMENT
Mean Pulmonary Pressure
Can be measured :
• MAP =1/3(SPAP)+2/3(PADP)
• = 0.6.PASP+2.1
• =79-0.45.AT
• = 4(EARLYPR
VELOCITY)2+RAPRESSURE
40. EXCEPTION
If the transducer is not parallel to the flow to the TR jet ,peak velocity of the jet will be reduced
and underestimation of PASP
Incorrectly estimating mean RA pressure from the IVC can lead to under or overestimation of
pulmonary pressure
41. SUMMARY OF RECOMMENDATIONS
FOR THE ASSESSMENT OF RIGHT
VENTRICULAR SYSTOLIC FUNCTION
• Visualassessmentprovides qualitativeevaluationof RV function.
• Quantitative assessmentmeasures :
FAC,TAPSE,PulsedtissueDoppler S’andTeiindexarereliable , reproducible
methods.
• Combining more than one measure can reliably distinguish normal from abnormal.
• Strainand strain rate arenot routinely recommended.