ECHOCARDIOGRAPHIC PROTOCOL
The echocardiographic diagnosis of arrhythmogenic right ventricular cardiomyopathy
(ARVC) is possible only in the absence of other causes of dilatation of the right
ventricle such as:
1) other congenital heart disease (such as atrial septal defect, Ebstein’s anomaly)
2) right ventricular infarction
3) volume overload due to significant tricuspid regurgitation (TR)
4) pulmonary embolism
5) primary pulmonary hypertension
6) secondary pulmonary hypertension from causes such as mitral stenosis, COPD,
PE
Typically the echocardiogram is performed with the subject in the left lateral decubitus
position. At least three sinus beats of each view should be recorded during quiet
respiration or at end expiration. If the patient is in atrial fibrillation at least 5 beats
should be recorded. The images can be recorded on ½ inch videotape or digitally
captured and stored in a DICOM standard file. If a digital acquisition is planned prior
approval from the echo core lab should be obtained.
For each view, the gain and compression should be optimized so that the best
echocardiographic image of the endocardial borders is obtained. The selection of
harmonics or fundamental frequency should depend upon which yields the best
definition of structures. The depth should be selected that allows visualization of all of
the structures of interest. All images should have an ECG tracing and clear calibration
markings. If visualization of the RV is inadequate, an intravenous contras agent can be
administered to obtain better RV border delineation.
The RV shape is complex and its inflow, body and outflow portions cannot all be
visualized from one view. Thus imaging of the chamber is necessary from several
views. The echocardiographic examination should be performed according to a standard
procedure (TABLE I):
TABLE I
ECHOCARDIOGRAPHIC EXAMINATION: Methods
1) Parasternal long axis
2) Parasternal long axis to visualize the tricuspid valve (RV inflow view)
3) Parasternal short axis (multiple levels including the base of heart to visualize
RVOT)
4) Apical four-chamber
5) Apical two-chamber (separately of left ventricle and right ventricle)
6) Subcostal long axis
7) Subcostal short axis of RV inflow and outflow
1)
The first echocardiographic window that should be obtained is the parasternal
long axis. This imaging plane is recorded with the transducer in the third or
fourth intercostals space immediate to the left of the sternum. The transducer
should be angled so that aortic valve, mitral valve and left ventricle are in their
long axis. This view should be performed at a depth that allows visualization of
all structures and then at a lower depth focusing on the RV.
Structures of interest in this view include:
 Left ventricle – dimensions and wall motion
 Left atrium – size
 Mitral valve – structure and function
 Aortic valve – structure and function
 Right ventricle – dimension, morphology and wall motion
In this view, M-mode of the LV should be obtained at the highest sweep speed.
The line of interrogation should be at the leaflet tip and perpendicular to the long
axis of the LV. Color Doppler of the MV and AV should be obtained.
2)
The second view is the parasternal long axis of the RV which allows
visualization of the tricuspid valve (RV inflow view). This is obtained by
angling the transducer to the right from the parasternal long axis of the LV and
rotating the transducer slightly. The inferoposterior wall of the right ventricular
inflow tract under the tricuspid valve is the most important region to be
visualized, because it is a frequently affected region. To evaluate this region the
transducer should be angled toward the inferior vena cava or the liver. In ARVD
this region may appear as thinned and have diastolic bulging or wall motion
abnormalities (hypokinesis, akinesis or dyskinesis). In ARVD subjects the
inferoposterior wall motion is generally reduced as compared to healthy
subjects. In severe ARVD the only motion in this region is that of the leaflet
plane. Color Doppler of the TR jet should also be attempted.
3)
The parasternal short axis at the aortic valve level is obtained by angling the
probe 90° with respect to the parasternal long axis of the LV. This view provides
information about the outflow portion of the right ventricle. In many subjects the
ratio between the right ventricular outflow tract and the aorta (in systole) will be
enlarged. The outflow tract is one of the places where there are saccular
dilatations and wall motion abnormalities. The anterior wall, especially in its
apical portion, may be commonly affected by fibro-fatty replacement. Therefore,
it is important to view the anterior wall of the right ventricle from several short
axis views including mid-ventricle and apex. These are obtained by angling or
moving the probe more toward the apex while maintaining a tomographic cut of
the LV. These views are important for the analysis of the left ventricle and septal
configuration.
Color Doppler of pulmonic regurgitation and a peak velocity of the tricuspid
regurgitation jet by continuous wave Doppler should be obtained from the short
axis views of RV outflow and inflow respectively.
4)
The apical four-chamber view provides considerable information including the
relative sizes of the right and the left ventricle. The four-chamber view is
defined as a view which maximizes the LV long axis and the tricuspid and
mitral annular dimensions. In this view, the full excursion of the mitral and
tricuspid valves should be seen. From this view, the morphology and the motion
of the left ventricle and right ventricle are assessed. In order to permit
visualization of the trabecular pattern of the RV, an image should be obtained by
moving the transducer toward the midline and magnifying the RV. In the apical
four chamber view, color Doppler of mitral regurgitation and tricuspid
regurgitation should be recorded. Also pulse wave Doppler at the leaflet tips of
the mitral and tricuspid valves should be recorded at the fastest sweep speed in
order to assess diastolic function. Pulse wave Doppler or a pulmonary vein
should be recorded when feasible. Lastly, the continuous wave Doppler of the
tricuspid regurgitation jet should be recorded in order to calculate the peak RV
systolic pressure.
5)
Since the inferoposterior wall of the right ventricle is commonly involved in
ARVD, it is important to visualize this region from as many views as possible
the apical RV two-chamber view. Starting from the apical four-chamber, the
transducer is positioned over the RV apex and then angled and rotated to
visualize the inferoposterior wall of the RV and its apex. These walls are
assessed for wall motion and the myocardial trabecular pattern.
6)
The echocardiographic analysis continues with the study of the subcostal longaxis view. This view is obtained with the transducer moved to a subxyphoid
position and directed superiorly and leftward. The view is aligned so that the
orientation of the LV an RV are similar to that obtained in the apical four
chamber view. From this subcostal long-axis view one can obtain information
about the RV size and motion of its free wall and apex. The transducer is then
angled upward to visualize the shape and motion of the RVOT and to assess for
saccular dilatation and wall motion abnormalities.
7)
Finally the transducer is rotated into the subcostal short axis view. From this
projection both the inflow tract and the outflow tract of the right ventricle are
assessed. Again in this view key findings of ARVD include alteration of motion
such as diastolic bulging or wall motion abnormalities of the inflow tract and
enlargement, and saccular dilatation of the outflow tract.
The compilation of these views will allow for calculation of:



Cardiac chamber dimensions (including left ventricle, left atrium, right atrium and
right ventricle)
Right ventricular areas and volumes (RV volume will be calculated by the
previously validated biplane area-length method)
Right ventricular function
 Systolic: calculated by “descent of the base” method, endocardial area
change method and volume change
 Diastolic: E/A wave, deceleration time, dP/dt.





Right ventricular wall thickness
Severity of tricuspid valve regurgitation
Estimation of the right ventricular systolic pressure
Right ventricular regional function
Presence and location of RV aneurysms
Proposed Protocol for Echocardiographic Examination for Arrythmogenic Right
Ventricular Cardiomyopathy
Arrythmogenic Right Ventricular Cardiomyopathy (ARVC) is predominantly a disease
of the right ventricle1. An integral part of assessment for this disease entails
demonstration of right ventricular (RV) structural and functional abnormalities2.
Evaluation of the RV can present a formidable challenge, as its geometry is more
complex than that of the left ventricle. It has separate outflow and inflow portions and a
main body, which is crescentic and truncated. The right ventricular free wall also has a
variable trabecular pattern that further limits precise measurement of cavity size and
wall thickness. In addition, its retrosternal position can also add to the difficulty in
obtaining an optimal image of the RV.
In suggesting an echocardiographic protocol for ARVC, the study should represent a
thorough and systematic examination of both ventricles, particularly as the disease
process can be localised and involve the left ventricle3;4. The procedure must also be
reproducible and relevant in the context of a clinical setting. Therefore, the suggested
protocol concentrates on the sites of disease predilection, namely the RV apex, inflow
and outflow tracts- the so-called “triangle of dysplasia”5.
Right Ventricular Systolic Function
Quantitative evaluation of RV systolic function is difficult because of the limitations
imposed by RV chamber shape which lead to standard geometric formulas having only
limited applicability. However, quantitative calculation of RV volumes has been applied
in the context of ARVC 6. Three-dimensional reconstruction’s have been shown to be a
more accurate method of determining systolic function but at the present time its use is
restricted to the research setting, as it can be a time consuming procedure requiring
tedious endocardial border tracing and data analysis7. Measurement of tricuspid annular
motion has also been proposed as a method of estimating RV systolic function8. The use
of both M-mode and tissue Doppler has recently been applied in the assessment of
tricuspid annular motion in ARVC patients, suggesting a potential role in the early
diagnosis of the disease9. Further evaluation in larger series of ARVC patients will help
to confirm the utility of this technique. Therefore, at the present time, qualitative
evaluation of the RV using 2-D imaging from several different windows is suggested:
parasternal long and short axis, right ventricular inflow, apical four chamber, and
subcostal four-chamber views. The degree of RV dilatation can be described in relation
to the left ventricle (LV) with RV enlargement described as follows:
Mild: RV enlarged but a 2D area less than LV area
Moderate: RV area equals LV area
Severe: RV larger than LV area
Cardiac Chamber Size
Foale et al10 studied normal adult right ventricles to determine the reproducibility of
various tomographic planes and to obtain measurements of normal cavity sizes (Table
1). From this study the most easily obtained and reproducible measurements were
ascertained and are suggested as part of the standard examination. Because the inflow
tract (RVIT), ventricular body, and outflow tract (RVOT) are three distinct regions of
the right ventricle that are orientated in different axis, two measurements of each region
should be obtained from separate views: RVIT1 and RVIT3, RVOT1 and RVOT3,
and RVSAX (short-axis) and RVLAX (long-axis) (see Figures 1a-d for
echocardiographic views and protocol).
Cardiac Wall motion Abnormalities
As well as calculation of cardiac chamber sizes, subjective assessment of wall motion
abnormalities should form an integral part of the examination. Although quantitative
analysis of wall motion would enable an objective method of analysis, it is not a
technique that is widely available in clinical practice. A qualitative method has been
demonstrated to be viable and highly reproducible by Blomstrom et al11 and the
following recommendations for wall motion assessment are based on their protocol.
For the assessment of ventricular wall motion abnormalities (Table 2), the RV is
divided into seven segments (R1-7), the septum into five (S1-5), and the left ventricle
into eight (L1-8) (Figures 2a-e). In addition to the parasternal long axis view (2a) and
the apical short chamber view (2c), which have already been used in assessment of
cavity dimensions, the following planes are also utilised; parasternal short axis view at
the aortic root level (2b), parasternal short axis view at the mitral valve level (2d) and
parasternal short axis view at the papillary muscle level (2e).
Left Ventricular Assessment
All measurements are made following standard protocols12. ARVC is a progressive
disorder1 where the left ventricle may become involved. The disease usually affects
both the septum and LV free wall, either diffusely or, more often, regionally, with a
predilection for the posteroseptal and posterolateral areas4. Thus, assessment of the left
ventricle should involve search for disease extension.
Reference List
1. Richardson P, McKenna W, Bristow M, et al. Report of the 1995 World Health
Organization/International Society and Federation of Cardiology Task Force on the
Definition and Classification of cardiomyopathies [news] [see comments]. Circulation
1996; 93: 841-842.
2. McKenna WJ, Thiene G, Nava A, et al. Diagnosis of arrhythmogenic right ventricular
dysplasia/cardiomyopathy. Task Force of the Working Group Myocardial and Pericardial
Disease of the European Society of Cardiology and of the Scientific Council on
Cardiomyopathies of the International Society and Federation of Cardiology. Br.Heart J.
1994; 71: 215-218.
3. Pinamonti B, Sinagra G, Salvi A, et al. Left ventricular involvement in right ventricular dysplasia.
Am.Heart J. 1992; 123: 711-724.
4. Corrado D, Basso C, Thiene G, et al. Spectrum of clinicopathologic manifestations of
arrhythmogenic right ventricular cardiomyopathy/dysplasia: a multicenter study.
J.Am.Coll.Cardiol. 1997; 30: 1512-1520.
5. Marcus FI, Fontaine GH, Guiraudon G, et al. Right ventricular dysplasia: a report of 24 adult
cases. Circulation 1982; 65: 384-398.
6. Scognamiglio R, Fasoli G, Nava A, Miraglia G, Thiene G, Dalla-Volta S. Contribution of crosssectional echocardiography to the diagnosis of right ventricular dysplasia at the
asymptomatic stage. Eur.Heart J. 1989; 10: 538-542.
7. Jiang L, Siu SC, Handschumacher MD, et al. Three-dimensional echocardiography. In vivo
validation for right ventricular volume and function. Circulation 1994; 89: 2342-2350.
8. Hammarstrom E, Wranne B, Pinto FJ, Puryear J, Popp RL. Tricuspid annular motion.
J.Am.Soc.Echocardiogr. 1991; 4: 131-139.
9. Lindstrom L, Wilkenshoff UM, Larsson H, Wranne B. Echocardiographic assessment of
arrhythmogenic right ventricular cardiomyopathy. Heart 2001.Jul.;86.(1.):31.-8. 86: 3138.
10. Foale R, Nihoyannopoulos P, McKenna W, et al. Echocardiographic measurement of the normal
adult right ventricle [published errata appear in Br Heart J 1986 Sep;56(3):298298 and
1987 Apr;57(4):396]. Br.Heart J. 1986; 56: 33-44.
11. Blomstrom-Lundqvist C, Beckman-Suurkula M, Wallentin I, Jonsson R, Olsson SB. Ventricular
dimensions and wall motion assessed by echocardiography in patients with
arrhythmogenic right ventricular dysplasia. Eur.Heart J. 1988; 9: 1291-1302.
12. Schiller NB, Shah PM, Crawford M, et al. Recommendations for quantitation of the left ventricle
by two-dimensional echocardiography. American Society of Echocardiography
Committee on Standards, Subcommittee on Quantitation of Two-Dimensional
Echocardiograms. J.Am.Soc.Echocardiogr. 1989; 2: 358-367.
Figures 1a-d. Definitions of right ventricular echocardiographic cavity dimensions.
(From Foale et al, 1986)
Fig.1a Parasternal right ventricular inflow tract view.
With the transducer in the third or fourth intercostal space at the left sternal edge, the long axis of the left
heart is imaged with the interventricular septum and anterior aortic wall lying parallel to the chest wall. A shift in
transducer position to a point approximately midway between the parasternal edge and cardiac apex with medial and
downward tilt results in the ultrasound plane slipping across the sagittally orientated interventricular septum. Thus a
view of the right ventricular inflow tract and right ventricular body in the major axis is obtained (Fig. 1a).
The region of the right ventricular apex and the tricuspid valve annulus are used as the internal reference
points, so that the inflow part of the right ventricle from the tricuspid annulus to at least the proximal right ventricular
body is clearly defined. By scanning the ultrasound plane across the major axis of this region of the ventricle,
maximum dimensions are measured of the major axis of the right ventricular inflow tract (RVIT1), a measurement
taken within one third of the distance below the annulus towards the region of the right ventricular apex.
Fig.1b Apical four chamber view.
From an apical four-chamber view the ultrasound beam is orientated to obtain the maximum dimensions
of the right ventricular chamber (Fig. 1b). Measurements of the minor axis of the right ventricular inflow tract
(RVIT3) are taken within one third of the distance below the tricuspid valve annulus towards the right ventricular
apex.
Right ventricular body
From the apical four chamber view-The middle third of the right ventricle is identified as lying below the inflow
tract region (Fig. 1b). A measurement of the maximum dimension of this portion of the chamber, defined as the body,
is taken (RVSAX). From this view both the lateral free wall of the ventricle and the right side of the interventricular
septum lie parallel with the ultrasound beam; thus the endocardial echo, particularly that from the lateral wall, may on
occasion spread over 3-5 mm. In these cases the midpoint of this signal is taken as the point from which to measure
the distance between right ventricular septal surface and free wall. The major axis of the right ventricle (RV LAX) is
also measured from this view and is defined as the distance between the right ventricular apex to the mid-point of the
tricuspid valve annulus.
Fig.1c Parasternal long axis view of left heart.
M-mode echocardiography is used to measure the right ventricle anteriorly to the echoes which represent the
interventricular septum. The parasternal long axis view of the left ventricle obtained by cross sectional
echocardiography (Fig. 1c) identifies this M-mode dimension as the proximal region of the right ventricular outflow
tract (RVOT1). Measurement is made from the right side of the interventricular septum to the anterior right
ventricular free wall.
Fig 1d Right ventricular outflow tract view.
From the parasternal long axis view of the left heart the true long axis of the right ventricular outflow tract is
visualised by leftward and superior angulation of the transducer (Fig. 1d). With this manoeuvre the maximum
dimensions of the pulmonary annulus and proximal main pulmonary artery are kept in the same imaging plane.
Measurement of the right ventricular outflow tract from just beneath the pulmonary valve annulus is obtained
(RVOT3).
Figure 2: Definition of wall segments studied.
a- Parasternal long axis view of left heart. b- Parasternal short axis view at the aortic root level. cApical four chamber view .d- Parasternal short axis view at the mitral valve level. e- Parasternal
short axis view at the papillary muscle level. (From Blomstrom et al, 1988)
(R1= Anterior wall RVOT, R2= Anterior wall RVOT, R3= RV Anterior Free Wall, R4= RV
Anterior Free Wall, R5= RVInferior Wall, R6= Lateral Free Wall RV, R7= Lateral Free Wall RV
)
Not visualised
Normal
Mild hypokinesia
Severe hypokinesia
Akinesia
Dyskinesia
Isolated sacculations, bulging, outpouching
0
1
2
3
4
5
6
Table 2: Marking score
for wall motion
abnormality
Wall Motion Abnormality
Score
(From Foale et al,1985)