ECHO ASSESMENT OF RV FUNCTION

DR. DEEPAK AGRAWALSIR GANGARAM HOSPITAL DELHI

RIGHT VENTRICULAR ANATOMY

Segmental Nomenclature of RV walls

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 measuring volume

▶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

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 LV function

▶Different complex contraction-relaxation mechanism among the segments of the RV

▶Cannot image the entire RV in a single view

Why should we measure RV function?

▶ RV is not just a conduit of blood flow

: has its unique function

▶Prognostic significance in various clinical settings

▶Risk stratification or guide to optimal therapy

Function of the Right Ventricle

▶ Conduit of blood flow ▶ 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

RV WALL THICKNESS AND CHAMBER SIZE

RV INFERIOR WALL

SUBCOSTAL VIEW

N=<0.5cmMeasured at peak r wave

2D and M-mode: Thickness of 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

RV DIMENTIONS

DIAMETERS ABOVE THE TRICUSPID VALVE ANNULUS

MID RV CAVITY

DISTANCE FROM THE TV ANNULUS TO RV APEX

RV DIMENTIONS

2D and M-mode: RV Dimension

Reference range Mild abnormal

Moderate abnormal

Severe abnormal

Basal RV diameter (RVD1) 2.0-2.8 2.9-3.3 3.4-3.8 ≥3.9

Mid-RV diameter (RVD2) 2.7-3.3 3.4-3.7 3.8-4.1 ≥4.2

Base–to-apex (RVD3) 7.1-7.9 8.0-8.5 8.6-9.1 ≥9.2

2D and M-mode: RVOT and PA Size

2D and M-mode: RVOT and PA Size

Reference range Mild abnormal

Moderate abnormal

Severe abnormal

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

Below pulmonic valve (PA1)

1.5-2.1 2.2-2.5 2.6-2.9 ≥3.0

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

2D and M-mode: Fractional Area Change (FAC)

(End-diastolic area) – (end-systolic area) x 100

(end-systolic area)

2D and M-mode: RV Area and FAC in A4C

▶ Well correlated with RV function measured by radionuclide

ventriculography or MRI

▶ Good predictor of prognosis

▶ Limitations: fail to measure FAC due to inadequate RV tracing

Reference range 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

Tricuspid Annular Plane Systolic Excursion

▶ Degree of systolic excursion of TV lateral annulus on A4C

: 1.5-2.0 cm in normal

: Value less than 1.5 cm is considered as abnormal

▶ Well correlated with RVEF measured by RVG

▶ Reproducible

▶ Strong predictor of prognosis in patients with CHF

REGIONAL ASSESSMENT OF RIGHT VENTRICLE : TAPSE

Tricuspid Annular Plane Systolic Excursion

※ TAPSE and RV ejection fraction : TAPSE 2cm = RVEF 50% : TAPSE 1.5cm = RVEF 40% : TAPSE 1cm = RVEF 30% : TAPSE 0.5cm = RVEF 20%

Event free survival according to TAPSE in patients with CHF

TISSUE DOPPLER IMAGING• An apical four chamber view is used• The pulsed Doppler sample volume is placed in either the tricuspid annulus or the

middle of the basal segment of the RV free wall• The S´ velocity is read as the highest systolic velocity without over-gaining the

Doppler envelope

Normal > 10 cm/s

TISSUE DOPPLER (S´)

Advantages Disadvantages • A simple, reproducible technique with

good discriminatory ability to detect normal versus abnormal RV function

• Pulsed Doppler is available on all modern systems

• Maybe obtained and analyzed off-line

• Less reproducible for nonbasal segments

• Is angle dependent• Limited normative data in all ranges'

and in both sexes• It assumes that the function of a

single segment represents the function of the entire right ventricle

RV IMP (TEI INDEX)

• RV index of Myocardial Performance• Global index of both systolic and diastolic function of the right ventricle

IVRT + IVCTET

Normal < 0.40 Normal < 0.55

If Heart rate > 100

Advantages Disadvantages • This approach is feasible in a large

majority of subjects• The MPI is reproducible• It avoids geometric assumptions and

limitations of the complex RV geometry

• The pulsed TDI method allows for measurement of MPI as well as S´, E´, and A´ all from a single image

• The MPI is unreliable when RV ET and TR time are measured with differing R-R intervals, as in atrial fibrillation

• It is load dependent and unreliable when RA pressures are elevated

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• Measure at held end-expiration and/or take the average of ≥ 5 consecutive beats• Measurements are essentially the same as those used for the left side

RV DIASTOLIC FUNCTION

Variable Lower reference value Upper reference valueE (cm/s) 35 73A (cm/s) 21 58E/A ratio 0.8 2.1Deceleration time (ms) 120 229IVRT (ms) 23 73E’ (cm/s) 8 20A’ (cm/s) 7 20E’/A’ ratio 0.5 1.9E/E’ 2 6

RECOMMENDATION• Measurement of RV diastolic function should be considered in patients with

suspected RV impairment as a marker of early or subtle RV dysfunction, or in patients with known RV impairment as a marker for poor prognosis

• Transtricupsid E/A ratio, E/E’ ratio, and RA size have been most validated are the preferred measures

Grading of RV Diastolic Dysfunction should be done as follows: E/A ratio < 0.8 suggests impaired relaxationE/A ratio 0.8-2.1 with an E/E’ ratio > 6 or diastolic prominence in the hepatic veins suggest pseudonormal fillingE/A ratio > 2.1 with deceleration time < 120 ms suggests restrictive filling

RIGHT ATRIAL ASSESSMENT• Apical 4-chamber view• Estimation of right atrial area by planimetry

The maximum long distance of the RAis from the center of the tricuspid annulus to the superior RA wall, parallel to the interatrial septumA mid RA minor distancve is defined from the mid level of the RA free wall to the interatrial septum perpendicular to the long axisRA area is traced at the end of ventricular systole, excluding the IVC, SVC, and RAA

Normal area < 18 cm²

RA PRESSURE DETERMINATION• Measurement of the IVC should be obtained at end-expiration and just proximal to

the junction of the hepatic veins that lie approximately 0.5 to 3.0 cm proximal to the ostium of the right atrium

To accurately assess IVC collapse, the change in diameter of the IVC with a sniff and also with quiet respiration should be measured, ensuring that the change in diameter does not reflect a translation of the IVC into another plane

RECOMMENDATIONS

For simplicity and uniformity of reporting, specific values of RA pressure , rather than ranges, should be used in the determination of SPAP

IVC diameter IVC collapsibility RA pressure≤ 2.1 cm > 50% with a sniff 3 mmHg > 2.1 cm < 50 % with a sniff 15 mmHg

In indeterminate cases in which IVC diameter and collapse do not fit this paradigm, an intermediate value of 8 mmHg may be used, preferably with use of secondary indices of RA pressures such as: RA dilatation, abnormal bowing of the IAS into the left atrium throughout the cardiac cycle

Advantages DisadvantagesIVC dimensions are usually obtainable from the subcostal window

IVC collapse does not accurately reflect RA pressure in ventilator-dependent patientsIt is less reliable for intermediate values of RA pressure

HEMODYNAMIC ASSESSMENT

Systolic pulmonary artery pressure• Estimated with TR jet velocity using simplified Bernoulli equation ( provided there is no

RVOT obstruction ) RVSP = 4(V)2+RA pressure

• Normal peak RVSP is 35 to 36 mmHg assuming RA pressure of 3 to 5 mmHg

Note : Measure TR jet velocity from various views to get the highest velocity

SYSTOLIC PULMONARY ARTERY PRESSURE

HEMODYNAMIC ASSESSMENT

Pulmonary artery diastolic pressure ( PADP ) • Estimated from velocity of end diastolic pulmonary regurgitant jet using PADP = 4(V)2+ RA pressure

HEMODYNAMIC ASSESSMENT

Mean Pulmonary Pressure Can be measured : • MAP = 1/3 (SPAP ) + 2/3 (PADP)

PULMONARY VASCULAR RESISTANCE

PVR = TRV max / RVOT TVI x 10 + 0.16

2.78 m/sec ÷ 11 cm x 10 + 0.16 = 2.68 Wood units Significant PHTN exists when PVR is > 3 Wood units

PVR

• The estimation of PVR is not adequately established to be recommended for routine use but may be considered in subjects in whom pulmonary systolic pressure may be exaggerated by high stroke volume or misleading low by reduced stroke volume

• The noninvasive estimation of PVR should not be used as a substitute for the invasive evaluation of PVR when this value is an important guide to therapy

RV STRAIN / STRAIN RATE

• Defined as percentage change in myocardial deformation • Strain rate is rate of deformation of myocartdium over time • Mainly for basal , mid and to a lesser degree apical segments of RV free

wall • Less load dependent and applicable across broad range of pathologies

CLINICAL AND PROGNOSTIC SIGNIFICANCE

• Conditions such as Acute PE cause increase in RV size prior to augmentation of pulmonary pressures

• Quantitative assessment can guide us more towards quality of life and adds information for functional outcome

SUMMARY OF RECOMMENDATIONS FOR THE ASSESSMENT OF RIGHT

VENTRICULAR SYSTOLIC FUNCTION

• Visual assessment provides qualitative evaluation of RV function.• Quantitative assessment measures :

FAC , TAPSE , Pulsed tissue Doppler S’ and Tei index are reliable , reproducible methods.• Combining more than one measure can reliably distinguish normal from

abnormal.• Strain and strain rate are not routinely recommended.

THANK YOU