Download Pulmonary Arterial Hypertension: A Two

Arch Cardiovasc Imaging. 2016 May; 4(2):e41818.
doi: 10.5812/acvi.41818.
Published online 2016 May 29.
Review Article
Pulmonary Arterial Hypertension: A Two-Dimensional
Echocardiographic Approach from Screening to Prognosis
Samir Kanti Saha1,*
1
Department of Public Health and Clinical Medicine, Umea University, Sweden
*
Corresponding author: Samir Kanti Saha, Department of Public Health and Clinical Medicine, Umea University, Sweden. E-mail: [email protected]
Received 2016 March 31; Accepted 2016 April 30.
Abstract
An elevated pulmonary artery pressure (PAP) from any cause is associated with increased mortality, especially in cases of primary
pulmonary arterial hypertension (PAH). One of the many reasons behind a bad prognosis is the inherent difficulty in assessing right
ventricular (RV) function with reproducible methods. Intensive research involving the left heart has made it relatively easy to assess
left ventricular (LV) systolic and diastolic functions in many centers around the world. As for the RV, however, although increasing
attention has been focused on the right-sided heart in the recent times, neither global longitudinal strain nor right ventricular
ejection fraction (RVEF) has been studied well in relation to the outcome (unlike in the LV). Another issue is that the right heart
functions in a circuitry involving the right atrium (RA), the RV, and the pulmonary artery. Hence, all 3 components of this circuit
have important roles in unison to eject a cardiac output equivalent to the left-sided heart. In this review, we sought to discuss the
ways to quantity the function of the entire circuit using both standard and advanced echocardiographic imaging modalities. As
primary PAH is the classic form of pathology causing the RV to face an afterload with which it is not destined to cope, this review is
mainly based on the assessment of the right heart as a circuit in idiopathic primary PAH.
Keywords: Pulmonary Arterial Hypertension, Prognosis, Idiopathic
1. Context
Pulmonary hypertension (PH) is defined as an elevated
mean pulmonary artery pressure (PAPm) > 25 mmHg
at rest as estimated by right-heart catheterization (RHC).
There are broadly 4 classes of hemodynamically defined
PH, according to the very recent guideline published in
connection with the European Society of Cardiology meeting in London, United Kingdom, in 2015 (1). These are: 1)
pre-capillary PH, characterized by a PAPm > 25 mmHg and
a pulmonary artery wedge pressure (PAWP) < 15 mmHg
(This group has 4 clinical subclasses: a) PAH, b) PH due to
lung disease, c) chronic thromboembolic pulmonary hypertension (CTEPH), and d) PH with unclear and/or multifactorial mechanisms.); 2) post-capillary PH, characterized
by a PAPm > 25 mmHg and a PAWP > 15 mmHg; 3) isolated post-capillary PH, characterized by a diastolic pressure gradient < 7 mmHg and a pulmonary vascular resistance (PVR) < 3 Wood units; and 4) combined pre-and postcapillary states, characterized by a diastolic pressure gradient > 7 mmHg and a PVR > 3 Wood units. The last 2 classes
may have a common clinical scenario of left-heart disease and disease of unknown and/or multifactorial mechanisms (1). The last clinical classification proposed during
the world symposium on pulmonary hypertension in dana
point, California, in 2008 was updated in 2013 (2). Of the
basic 5 classes of PH (group 1: idiopathic, group 2: due to
left-heart disease, group 3: PH due to lung disease, group 4:
CTEPH, and group 5: miscellaneous), Group 1 now includes
under the subclasses of PAH about 12 different states, of
which idiopathic PAH has been classed as 1.1. The other
subclasses include portal hypertension, PAH due HIV infection, due to congenital heart disease, and due to drugs and
toxins.
This chapter deals primarily with Class 1.1 type of PAH
(IPAH), although the fundaments of imaging remain common to all classes of PH.
1.1. Physiology of the Pulmonary Circulation
The pulmonary circulation (a high volume, low pressure circuit) is characterized by an inflow pressure (PAP),
an outflow pressure (left atrial pressure), and a pulmonary
flow, which is almost equal to the systemic cardiac output. PVR, which estimates the functional state of the pulmonary circulation, is calculated through the transpulmonary gradient (PAPm-PAWP) divided by the cardiac output, usually via the catheterization of the right heart. The
procedure derives left atrial pressure either by balloonoccluded pressure or PAWP, while the cardiac output is
Copyright © 2016, Iranian Society of Echocardiography. This is an open-access article distributed under the terms of the Creative Commons Attribution-NonCommercial 4.0
International License (http://creativecommons.org/licenses/by-nc/4.0/) which permits copy and redistribute the material just in noncommercial usages, provided the
original work is properly cited.
Kanti Saha S
measured by thermodilution (3). Although RHC is considered the “gold standard” method for the estimation of
pressures with the RV pulmonary circuit, the overestimation or underestimation of pressures particularly PAWP is
not uncommon in situation where the 0 leveling at the
level of the catheterization table may overestimate PAP as
well as PAWP (4).
Once the diagnosis of PAH has been established by
RHC, the pathophysiological consequences rely on the
identification of the prognostic marker(s) using imaging
techniques, of which standard and advanced 2D echocardiographic techniques remain the modalities of the primary and universal choice. Since the RV and the RA are
components of the RV–pulmonary circulation circuit, the
most important victim of the elevated afterload resulting
from a dysfunctional pulmonary circulation is indeed the
RV even though RA remodeling eventually plays a part in
the progression of the disease, which is fatal. According to
REVEAL (Registry to evaluate early and long-term pah disease management) registry, the 3-year mortality rate can be
as high as 60% (5).
Echocardiographic assessment in suspected cases of
PAH should involve the RV, the RA, and the pulmonary
vasculature. The dysfunction of all 3 components of the
RA–RV–pulmonary vasculature circuitry has been linked to
death in PAH. Therefore, it is extremely important to study
the circuit in its entirety, as discussed below.
1.2.
Echocardiographic Assessment of the Right
Heart/Pulmonary Circuit in Idiopathic Pulmonary Arterial
Hypertension
1.2.1. Right Ventricle
The RV undergoes significant structural and functional
impairment as a result of the increased afterload due to an
elevated PAP (6). This adverse remodeling and maladaptation leads to decreased RV strain and inevitably to endstage heart failure and eventually to death (7, 8). It is, therefore, extremely important to study RV structural and functional parameters in any case with suspected PH of any
cause, especially IPAH. RV apical views should be acquired
as per the guidelines of the American Society of Echocardiography (9).
Because of the complex geometry of the RV, there are
multitudes of measures necessary to accurately quantify
RV systolic function. What can provide some telltale signs
of the underlying pathology is a careful visual assessment
of RV size with the measurement of the dimensions (any
value > 38 - 40 mm measured at end diastole is considered abnormal) from multiple planes, thickness (> 5 - 6
mm is considered abnormal; preferred view in that case
is the subcostal window), altered septal curvature in dias2
tole (volume overload, as in shunts), and altered septal curvature in diastole and systole (pressure overload). Thereafter, a combination of the following measures is often necessary to arrive at a conclusive decision vis-a-vis the functional status of the RV as regards the systolic function and
the degree of pressure overloading caused by the dysfunctional pulmonary vasculature.
1.3. Tricuspid Annular Plane Systolic Excursion
Tricuspid annular plane systolic excursion (TAPSE) is
one of the most common measures of RV systolic function obtained using M-mode echocardiography and is recommended by the American society of echocardiography’s
guideline for the routine evaluation of RV function. Although TAPSE measures the longitudinal motion of the RV,
it has a good correlation with global systolic markers such
as 2D RVEF, radionuclide-derived RVEF, and 2D-derived fractional area change (FAC [%]) (9). An excursion < 16 mm is
considered abnormal in the absence of previous thoracic
surgery for valvular, coronary, aortic, or congenital lesions
or in the absence of atrial fibrillation. In a mixed cohort of
IPAH and CTEPH, a TAPSE < 15 mm was one of the independent predictors of all-cause mortality in a 3-year follow-up
study (10). In a Swedish observational study (11) involving
a small cohort of cases from northern Sweden, however,
TAPSE had no correlation with RHC-obtained PVR. Fine et al.
(8) showed that TAPSE was inferior to RV strain in predicting cardiopulmonary and all-cause mortality. One of the
major limitations of TAPSE is that the value can be falsely elevated in a failing RV (10). Also, in severe tricuspid regurgitation, TAPSE could be falsely elevated because of volumedriven, hyperdynamic state perhaps providing a supraphysiological stroke output. The differential diagnosis of
lower TAPSE values, nevertheless, must include chronic LV
systolic failure (12) and heart failure with a preserved LV
systolic function (13), clinical states in which pulmonary
artery systolic pressure (PASP) is also elevated (clinical class
2 PH or hemodynamically defined post-capillary PH). Personal experience from this author suggests that TAPSE is
also probably unreliable in the transplanted heart to detect RV systolic dysfunction. This is probably because of
the fact that TAPSE measures longitudinal motion and does
not take into account the radial contribution for ejection,
unlike fractional area change (RVAC [%]), discussed below.
It should be mentioned here that in the background of an
elevated afterload, RV remodeling does take place in the
form of hypertrophy (and dilatation, eventually) whereby
radial fibers play an important role in ejection.
1.4. Right Ventricular Fraction Area Change
2D echocardiography-obtained RVFAC (%) is acquired
from RV-focused view (slight tilting of the probe to exclude
Arch Cardiovasc Imaging. 2016; 4(2):e41818.
Kanti Saha S
part of the lateral LV cavity in order that the RV apex as
well as its free wall is clearly viewed both during systole
and during diastole). Then RV inner area is traced during systole (RVAs) and during diastole (RVAd). RVFAC (%) is
then calculated by subtracting the areas divided by RVAd
and is expressed in percentages. RVFAC (%) provides an estimate of RV systolic function. A value < 35% is considered abnormal. In a group of patients with PAH, Sachdev
et al. (7) reported a mean RVFAC value = 27%. In the VALIENT ECHO study (14), an RVFAC < 35% was incrementally
associated with the cardiovascular composite outcome in
a group of multinational patients post myocardial infarction, once again indicating that primary LV dysfunction
must be ruled out in the clinical situations of an elevated
RV afterload. RVFAC (%) is perhaps superior to TAPSE for the
evaluation of RV systolic function, for reasons discussed
above.
1.5. Right Ventricular Index of Myocardial Performance
Also known as (RV) Tei index, the right ventricular index of myocardial performance (RIMP) provides an index
of the global systolic function. RIMP can be estimated using standard (conventional spectral) pulsed-wave Doppler
(global and volumetric or “blood pool” index), color tissue
Doppler imaging (TDI), or non-Doppler speckle-tracking
echocardiography (STE) (regional and mechanical index).
The spectral Doppler recordings of the tricuspid inflow
and the pulmonary artery flow (RV ejection) are utilized to
calculate RIMP. This “blood pool” method requires 2 consecutive cycles of the tricuspid inflow Doppler envelope
(E and A waves for each cycle). The advantage of the advanced imaging (pulsed-wave TDI/color TDI) is that it provides a superior temporal resolution with a high signal-tonoise ratio. For color TDI, however, a frame rate > 100 Hz
is recommended. Whichever method is used, RIMP is calculated through dividing the sum of the isovolumic contraction and relaxation times by the ejection time. Any
value > 0.40 - 0.50 is considered a depressed RV systolic
function. In a study involving 93 human subjects with
CTEPH (pre-capillary PH), Blanchard et al. (15) found that
not only pulsed-wave TDI-obtained RIMP correlated with
hemodynamically obtained PVR, but also the index was
abnormally high in the study subjects and decreased after pulmonary thromboendarterectomy. Interestingly, the
close correlation between the index and PVR persisted after
surgery, indicating the value of RIMP in PAH. One of the major strengths of RIMP is that it is independent of RV geometry, as the values are traditionally derived using the blood
pool pulsed-wave Doppler.
Arch Cardiovasc Imaging. 2016; 4(2):e41818.
1.6. Spectral Doppler-Derived Right Ventricular dp/dt Max
Ventricular dp/dt max stands for the rate of pressure
development during the phase of isovolumic contraction
and has been traditionally measured by cardiac catheterization. It has been long known that catheterizationobtained LV dp/dt correlates well with that obtained by
standard Doppler echocardiography, using the mitral regurgitation velocity envelope. LV contractility (dp/dt) can
be estimated by using the time interval between 1 and
3 m/sec on the mitral regurgitation velocity continuouswave spectrum. The rate of the Doppler-derived velocity increase is converted to a rate of pressure increase by using
the modified Bernoulli equation (4 × MV2 ). It means that
the difference in pressure is always 32 mmHg between the
spatial change of velocity during the interval of 1 m/s and
3 m/s. In the final calculation to derive dp/dt , 32 (mmHg)
is divided by the time it takes to increase regurgitant velocity from 1 m/s to 3 m/s. A faster time is in tandem with
a stronger contractility (16). In a similar manner, RV dp/dt
max is estimated using the tricuspid regurgitation velocity envelope. In a series of patients with PAH, the concept of dp/dt max has been used in which the investigators have found that not only an RV dp/dt < 410 mmHg/s
was a predictor of 3-year mortality, compared with the clinical markers of prognosis such as New York Heart Association class and 6-minute walk distance, RV dp/dt max had an
equivalent receiver operating characteristic accuracy and
an equally significant hazard ratio (10).
1.7. Tissue Doppler Imaging-Derived Tricuspid Lateral Annular
Systolic Velocity
Originally designed to quantify LV function, the modality has been applied successfully to quantify RV systolic
function. A typical velocity profile contains peak systole
and early and late diastolic waves, expressed in cm/s. In
the acquisition of a reliable velocity profile, care should be
taken to avoid angulation errors. This can be done by correctly aligning the Doppler cursor with the basal RV segment (17). In a healthy RV, the peak systolic velocity (S’)
should be > 10 cm/s, measured at the basal segment of the
RV. Although 1D-TDI is now out of fashion principally because of its angle-dependency and low signal-to-noise ratio, the S’ value should be reported in daily practice. Under normal conditions, the S’ wave should instantaneously
lead to the early diastolic velocity without any detectable
isovolumic relaxation period. If the isovolumic relaxation
is detected in a measureable manner, this should provide
indirect evidence of an elevated PASP. Therefore, in daily
practice, TDI is highly recommended. Tissue Doppler velocity has been very scarcely applied in PAH. In a series of human subjects with suspected PH undergoing RHC and TDI
3
Kanti Saha S
of the RV, the investigators found a decreased value of S’ in
subjects with a low RV stroke volume indexed to the body
surface area (RVSVi). RVSVi increased after an epoprostenol
injection, and so did TDI-obtained peak systolic velocity,
strain, and strain rate (18). The data indicate the clinical
value of S’ obtained by the TDI-based longitudinal velocity
estimation of the lateral tricuspid annulus.
was used while a pulmonary artery catheter was placed as
part of routine care (22), the authors found that a PAT <
107 ms indicated a relatively linear relationship that could
be described by the equation PAPm (mmHg) = 77 - (0.49
× PAT). The morphology of the pulsed-wave Doppler envelope is important. If the envelope has a mid-systolic notch,
it generally provides indirect evidence of an elevated PASP
(23).
1.8. Two-Dimensional Speckle-Tracking Echocardiography
2DSTE is an angle-dependent modality that uses a nonDoppler-based algorithm to quantify the strain by taking
advantage of the motion of the ultrasound beam-derived
“speckles” embedded in the myocardium. 2DSTE has now
practically replaced 1DTDI because of its far superior reproducibility and very nigh signal-to-noise ratio. According to the 2015 ASE’s recommendation on chamber quantification, the accumulated information (albeit heavily
weighted by a single vendor) denotes that a global longitudinal RV free wall strain rate > -20% (i.e., < 20% in absolute value) is probably abnormal (17). In the 1st ever study
to use 2DSTE along with TDI, the investigators showed that
not only were all STE and tissue Doppler echocardiography variables significantly lower in patients with PAH than
in healthy controls, the baseline echocardiographic variables improved significantly after vasodilator therapy. Additionally, the baseline echo variables also correlated with
6-minute walk distance. The Association was, nonetheless, weaker with tissue Doppler echocardiography than
with STE (19). Rajagopal et al. (20) cleverly utilized the
currently available LV-based STE software to compute RV
global longitudinal strain from multiple 2D views (similar
to LV global longitudinal strain, using triplane imaging).
Hopefully in the near future, new RV-dedicated software
will be available to reproduce RV global longitudinal strain
using the existing software dedicated for the LV (Figure 1).
1.9. Pulmonary Vasculature
1.9.1. Pulmonary Acceleration Time
The pulmonary artery acceleration time (PAT) should
be obtained by placing the pulsed-wave Doppler sample
volume 1 cm distal to the pulmonary valve leaflets in the
parasternal short-axis view at the aortic root level. PAT is
measured from the onset of ejection to peak ejection using
the calipers online. A normal PAT should exceed 100 ms.
In a study involving 29 subjects with combined IPAH and
PH (of other causes), PAT was non-linearly but inversely associated with RHC-obtained PASP and PAPm. The authors
demonstrated that a PAT cutoff = 90 mmHg had the best
sensitivity and specificity to detect a PASP > 38 mmHg (21).
In a group of 98 patients undergoing cardiac surgery,
where intraoperative transesophageal echocardiography
4
1.10. Estimation of Pulmonary Artery Systolic Pressure
PASP should be estimated routinely irrespective of the
referral reasons if there is a detectable tricuspid regurgitation. In PAH, suspicion of the diagnosis often starts
with the documentation of an elevated PASP. It is estimated
using the max tricuspid regurgitation velocity from all
3 views, namely RV inflow and the parasternal short-axis
and apical 4-chamber views. (The maximum transtricuspid gradient should be taken using the modified Bernoulli
equation.) This peak gradient is then added up with the estimated central venous (RA) pressure. RA pressure by standard echocardiography is estimated through the diameter
of the inferior vena cava (IVC) and its respiratory collapsibility. The American Society of Echocardiography (9) states
that simplicity and uniformity of reporting requires that
specific values of RA pressure, rather than ranges, be employed to determine PASP. In addition, an IVC diameter <
2.1 cm collapsing > 50% with a sniff denotes a normal RA
pressure = 3 mmHg (range = 0 - 5 mmHg), while an IVC diameter > 2.1 cm collapsing < 50% with a sniff indicates a
high RA pressure = 15 mmHg (range = 10 - 20 mmHg). In scenarios where the IVC diameter and collapse fail to fit this
paradigm, an intermediate value = 8 mmHg (range = 5 - 10
mmHg) may be drawn upon. This author suggests adding
> 20 mm (RA pressure) to the peak transtricuspid gradient if the hepatic veins are dilated with the systolic reversal of the flow by pulsed-wave Doppler in addition to IVC
dilatation and reduced respiratory responsiveness. A note
of caution though is that the numbers should match each
other generally in all cases. For example, it is expected that
the RA would be dilated in case the pressure is reaching 30
mmHg, except in acute pulmonary embolism. The correlation between RHC-obtained and echo-Doppler-obtained
PASP is usually very good, if estimated as per the guideline
(11, 24).
1.11. Estimation of Pulmonary Vascular Resistance
An elevated PVR is the hallmark of PAH. Using RHC, PVR
is estimated through dividing the transpulmonary pressure gradient (PAPm-PAWP) by the cardiac output. As the
usual practice is to screen suspected patients with PAH using echocardiography before RHC, investigators have used
Arch Cardiovasc Imaging. 2016; 4(2):e41818.
Kanti Saha S
Figure 1. Dedicated Software to Evaluate Right Ventricular Volume and Function
different ways of noninvasive estimations of PVR. One of
the most commonly cited formula was proposed by Abbas et al. (25). The formula states that PVR = TRV/VTI RVOT
× 10 + 0.16, where TRV is the tricuspid regurgitation velocity and VTI RVOT is the velocity time integral of the
RV outflow continuous wave envelope. One of the major
drawbacks of the equation is that it does not take into account the wedge pressure, which is essential to estimate
the transpulmonary gradient. However, using the equation, Ling and Marwick (26) showed how 4 different clinical
scenarios, as shown in the Table 1, could be resolved bedsides differentiating RV/pulmonary vascular dysfunction
due to different background diseases. The 4th scenario is
most probably due to intrinsic RV dysfunction.
Table 1. Four Possible Clinical Scenarios of Dysfunctional Right Ventricular and Pulmonary Vasculature
Scenarios
Description
1
Right ventricular dysfunction with an increased pulmonary
artery systolic pressure and pulmonary vascular resistance
(pulmonary arterial hypertension )
2
Preserved right ventricular systolic function with an increased
pulmonary artery systolic pressure and a normal pulmonary
vascular resistance (left ventricular disease)
3
Right ventricular dysfunction with a normal pulmonary artery
systolic pressure and an increased pulmonary vascular
resistance (low stroke output)
4
Right ventricular dysfunction with a normal pulmonary artery
systolic pressure and pulmonary vascular resistance (e.g.,
intrinsic right ventricular disease)
1.12. Right Atrium: A “Forgotten Chamber”
The RA has 3 principal functions: a reservoir function, during which the chamber receives blood from the
vena cavae during ventricular systole (closed tricuspid
valve); a passive conduit function during early diastole;
and a booster pump function during atrial contraction
during late diastole. Although generally not suitable for
the echocardiographic estimation of the biplane volume
(unlike in the left atrium), it is possible to quantify albeit
in a single plane the minimum/maximum volumes, conduit volume, active and passive emptying fraction, expansion index, and ejection fraction. This requires a timeconsuming process and it is dependent on an ECG signal
of high resolution with a distinct P wave. To circumvent
this time-consuming calculations, investigators have studied STE-obtained RA mechanics (reservoir strain) in PH due
to left-heart failure (12) as well as in IPAH (11). Both RA strain
and RA strain rate (Figures 2 and 3) have been used in the
Swedish cohort and have been shown to have a good association with both PVR (reservoir strain) and PASP (booster
strain) with the excellent reproducibility of the strain measures. More data are needed to adapt the STE of the RA in
PAH. One disadvantage with this is the fact that to date no
dedicated software algorithm has been available to study
RA mechanics. However, RA area (normal < 18 cm2 ) and
volume should be estimated as these have important diagnostic and prognostic values in PAH, regardless of etiology
(Table 2).
2. Conclusions
PAH is a devastating disease with very high mortality. Echocardiography plays a central role in the screen-
Arch Cardiovasc Imaging. 2016; 4(2):e41818.
5
Kanti Saha S
Figure 2. Right Atrial Strain (%) Imaging, Showing Three Mechanical Phases in a Normal Subject
Figure 3. Right Atrial Strain Rate Imaging, Showing Three Mechanical Phases in a Normal Subject
Table 2. Echocardiographic Markers That May Suggest Pulmonary Arterial Hypertension
Simple Echocardiographic Signs That May Indicate Referral For
Right-Heart Catheterization to Rule Out Idiopathic Pulmonary
Arterial Hypertension (After Ruling Out Left Ventricular Disease or
Shunts) in Patients With Unexplained Dyspnea
1
Peak tricuspid regurgitation velocity > 3.5 m/s, irrespective of the
inferior vena cava diameter with the alteration of the septal curvature
and an estimated pulmonary artery systolic pressure > 50 mm Hg
2
Dilated right ventricle (from any 2 levels) with fractional area change <
35%
3
Significant pulmonary regurgitation
4
Pulmonary artery acceleration time < 90 - 00 ms with mid-systolic
notching of the PA ejection envelope
5
E/E´ ratio (E´ = the average of septal and lateral E´) < 8 - 10
ing and follow-up as well as in assessing the prognosis and
risk stratification. Grapsa et al. (27) recently showed that
6
moderate-to-severe tricuspid regurgitation had the greatest odds of mortality 7 years upfront. No other RHC measures actually demonstrated such a high hazard ratio! On
the other hand, the study on the Stanford (USA) cohort by
Haddad et al. (28) showed that a “simple heart score” consisting of RV systolic dysfunction, enlarged RA, and systolic
blood pressure < 110 mmHg could be very useful for predicting the outcome in PAH. The authors also reported that
this score was almost similar to the NIH (Natational Institutes of Health) and REVEAL scores, indicating the validity
of the data obtained in the study.
As PVR is the ultimate hallmark of PAH, newer mathematical models should be constructed and use for example, RA reservoir strain because the Abbas formula (25)
does not take into account the PAWP. This is probably the
reason why the Abbas formula had a poor correlation with
the RH-obtained data in the Uppsala cohort (21).
Finally, the basics of the qualitative and quantitative asArch Cardiovasc Imaging. 2016; 4(2):e41818.
Kanti Saha S
sessment of the right-sided heart using the existing 2D and
standard echocardiography to accurately estimate PASP,
RA, RV remodeling, RV systolic function alone or in combination with TAPSE, FAC (%), and TDI-derived S’ are the key
elements that should be meticulously obtained, recorded,
and reported. The STE assessment of RA mechanics is optional at this stage but should be encouraged, even though
dedicated 2D-based right-sided software is not yet available. Despite 2 recently published wonderful studies using 3DSTE in PAH (29, 30) the modality is not available except for research purposes as of today. When more widely
available and normative data are published, 3DSTE should
be used as a complement to the long established 2D and
standard Doppler echocardiography. Modern-day echocardiography should also be used as a strong prognostic tool
(7, 8, 28) beyond the conventional use as a screening tool
in PAH. Only in very selective cases such as to study the delayed enhancement of the RV and the contrast enhancement of the pulmonary artery (angiography) could cardiac
magnetic resonance imaging be considered for diagnostic
and prognostic purposes (31). The ejection fraction of the
RV has not been studied or validated extensively. Whenever needed, such as before transplantation, RVEF could
be drawn upon via the uniplane Simpson method using
2D echocardiography or radionuclide methods. Isotopeindependent cardiac magnetic resonance and 3D echocardiography may also provide RVEF quite accurately as the
radionuclide method. Unpublished data have shown the
great potential of a 3D algorithm that can generate RVEF,
TAPSE, FAC (%), and RV global strain from a full volume data
set, showing an excellent correlation between 3D and cardiac magnetic resonance-obtained RVEF. Its value in PAH
has yet to be investigated.
References
1. Galie N, Humbert M, Vachiery JL, Gibbs S, Lang I, Torbicki A, et al. 2015
ESC/ERS Guidelines for the diagnosis and treatment of pulmonary
hypertension: The Joint Task Force for the Diagnosis and Treatment of Pulmonary Hypertension of the European Society of Cardiology (ESC) and the European Respiratory Society (ERS): Endorsed
by: Association for European Paediatric and Congenital Cardiology
(AEPC), International Society for Heart and Lung Transplantation
(ISHLT). Eur Respir J. 2015;46(4):903–75. doi: 10.1183/13993003.010322015. [PubMed: 26318161].
2. Simonneau G, Gatzoulis MA, Adatia I, Celermajer D, Denton C,
Ghofrani A, et al. Updated clinical classification of pulmonary
hypertension. J Am Coll Cardiol. 2013;62(25 Suppl):D34–41. doi:
10.1016/j.jacc.2013.10.029. [PubMed: 24355639].
3. Naeije R. Physiology of the pulmonary circulation and the right heart.
Curr Hypertens Rep. 2013;15(6):623–31. doi: 10.1007/s11906-013-0396-6.
[PubMed: 24097187].
4. Raina A, Benza RL. Ambulatory Hemodynamic Monitoring in the Management of Pulmonary Arterial Hypertension. Adv Pulm Hypertens.
2014;13(2):81.
5. Frost AE, Badesch DB, Miller DP, Benza RL, Meltzer LA, McGoon MD.
Evaluation of the predictive value of a clinical worsening definition
Arch Cardiovasc Imaging. 2016; 4(2):e41818.
6.
7.
8.
9.
10.
11.
12.
13.
14.
15.
16.
17.
using 2-year outcomes in patients with pulmonary arterial hypertension: a REVEAL Registry analysis. Chest. 2013;144(5):1521–9. doi:
10.1378/chest.12-3023. [PubMed: 23907471].
Calcutteea A, Lindqvist P, Soderberg S, Henein MY. Global and regional right ventricular dysfunction in pulmonary hypertension.
Echocardiography. 2014;31(2):164–71. doi: 10.1111/echo.12309. [PubMed:
23930912].
Sachdev A, Villarraga HR, Frantz RP, McGoon MD, Hsiao JF, Maalouf
JF, et al. Right ventricular strain for prediction of survival in patients
with pulmonary arterial hypertension. Chest. 2011;139(6):1299–309.
doi: 10.1378/chest.10-2015. [PubMed: 21148241].
Fine NM, Chen L, Bastiansen PM, Frantz RP, Pellikka PA, Oh JK,
et al. Outcome prediction by quantitative right ventricular function assessment in 575 subjects evaluated for pulmonary hypertension. Circ Cardiovasc Imaging. 2013;6(5):711–21. doi: 10.1161/CIRCIMAGING.113.000640. [PubMed: 23811750].
Rudski LG, Lai WW, Afilalo J, Hua L, Handschumacher MD, Chandrasekaran K, et al. Guidelines for the echocardiographic assessment
of the right heart in adults: a report from the American Society of
Echocardiography endorsed by the European Association of Echocardiography, a registered branch of the European Society of Cardiology, and the Canadian Society of Echocardiography. J Am Soc Echocardiogr. 2010;23(7):685–713. doi: 10.1016/j.echo.2010.05.010. [PubMed:
20620859] quiz 786-8.
Ameloot K, Palmers PJ, Vande Bruaene A, Gerits A, Budts W, Voigt JU,
et al. Clinical value of echocardiographic Doppler-derived right ventricular dp/dt in patients with pulmonary arterial hypertension. Eur
Heart J Cardiovasc Imaging. 2014;15(12):1411–9. doi: 10.1093/ehjci/jeu134.
[PubMed: 25201651].
Saha SK, Soderberg S, Lindqvist P. Association of Right Atrial Mechanics with Hemodynamics and Physical Capacity in Patients with Idiopathic Pulmonary Arterial Hypertension: Insight from a SingleCenter Cohort in Northern Sweden. Echocardiography. 2016;33(1):46–
56. doi: 10.1111/echo.12993. [PubMed: 26096217].
Padeletti M, Cameli M, Lisi M, Zaca V, Tsioulpas C, Bernazzali S,
et al. Right atrial speckle tracking analysis as a novel noninvasive
method for pulmonary hemodynamics assessment in patients with
chronic systolic heart failure. Echocardiography. 2011;28(6):658–64.
doi: 10.1111/j.1540-8175.2011.01413.x. [PubMed: 21676018].
Mohammed SF, Hussain I, AbouEzzeddine OF, Takahama H, Kwon
SH, Forfia P, et al. Right ventricular function in heart failure with
preserved ejection fraction: a community-based study. Circulation. 2014;130(25):2310–20. doi: 10.1161/CIRCULATIONAHA.113.008461.
[PubMed: 25391518].
Anavekar NS, Skali H, Bourgoun M, Ghali JK, Kober L, Maggioni AP,
et al. Usefulness of right ventricular fractional area change to predict death, heart failure, and stroke following myocardial infarction
(from the VALIANT ECHO Study). Am J Cardiol. 2008;101(5):607–12. doi:
10.1016/j.amjcard.2007.09.115. [PubMed: 18308007].
Blanchard DG, Malouf PJ, Gurudevan SV, Auger WR, Madani MM,
Thistlethwaite P, et al. Utility of right ventricular Tei index in the noninvasive evaluation of chronic thromboembolic pulmonary hypertension before and after pulmonary thromboendarterectomy. JACC
Cardiovasc Imaging. 2009;2(2):143–9. doi: 10.1016/j.jcmg.2008.10.012.
[PubMed: 19356547].
Chung N, Nishimura RA, Holmes DJ, Tajik AJ. Measurement of left ventricular dp/dt by simultaneous Doppler echocardiography and cardiac catheterization. J Am Soc Echocardiogr. 1992;5(2):147–52. [PubMed:
1571168].
Lang RM, Badano LP, Mor-Avi V, Afilalo J, Armstrong A, Ernande
L, et al. Recommendations for cardiac chamber quantification by
echocardiography in adults: an update from the American Society of Echocardiography and the European Association of Cardiovascular Imaging. J Am Soc Echocardiogr. 2015;28(1):1–39 e14. doi:
10.1016/j.echo.2014.10.003. [PubMed: 25559473].
7
Kanti Saha S
18. Urheim S, Cauduro S, Frantz R, McGoon M, Belohlavek M, Green T, et al.
Relation of tissue displacement and strain to invasively determined
right ventricular stroke volume. Am J Cardiol. 2005;96(8):1173–8. doi:
10.1016/j.amjcard.2005.06.049. [PubMed: 16214459].
19. Borges AC, Knebel F, Eddicks S, Panda A, Schattke S, Witt C, et
al. Right ventricular function assessed by two-dimensional strain
and tissue Doppler echocardiography in patients with pulmonary
arterial hypertension and effect of vasodilator therapy. Am J Cardiol. 2006;98(4):530–4. doi: 10.1016/j.amjcard.2006.02.060. [PubMed:
16893711].
20. Rajagopal S, Forsha DE, Risum N, Hornik CP, Poms AD, Fortin TA, et al.
Comprehensive assessment of right ventricular function in patients
with pulmonary hypertension with global longitudinal peak systolic
strain derived from multiple right ventricular views. J Am Soc Echocardiogr. 2014;27(6):657–665 e3. doi: 10.1016/j.echo.2014.02.001. [PubMed:
24656881].
21. Granstam SO, Bjorklund E, Wikstrom G, Roos MW. Use of echocardiographic pulmonary acceleration time and estimated vascular resistance for the evaluation of possible pulmonary hypertension.
Cardiovasc Ultrasound. 2013;11:7. doi: 10.1186/1476-7120-11-7. [PubMed:
23445525].
22. Cowie B, Kluger R, Rex S, Missant C. The relationship between
pulmonary artery acceleration time and mean pulmonary
artery pressure in patients undergoing cardiac surgery: An
observational study. Eur J Anaesthesiol.
2016;33(1):28–33. doi:
10.1097/EJA.0000000000000314. [PubMed: 26225501].
23. D’Alto M, Romeo E, Argiento P, Di Salvo G, Badagliacca R, Cirillo AP, et
al. Pulmonary arterial hypertension: the key role of echocardiography. Echocardiography. 2015;32 Suppl 1:S23–37. doi: 10.1111/echo.12283.
[PubMed: 25244441].
24. Lafitte S, Pillois X, Reant P, Picard F, Arsac F, Dijos M, et al. Estimation
of pulmonary pressures and diagnosis of pulmonary hypertension
by Doppler echocardiography: a retrospective comparison of routine echocardiography and invasive hemodynamics. J Am Soc Echocardiogr. 2013;26(5):457–63. doi: 10.1016/j.echo.2013.02.002. [PubMed:
8
23510536].
25. Abbas AE, Fortuin FD, Schiller NB, Appleton CP, Moreno CA, Lester
SJ. A simple method for noninvasive estimation of pulmonary vascular resistance. J Am Coll Cardiol. 2003;41(6):1021–7. doi: 10.1016/S07351097(02)02973-X. [PubMed: 12651052].
26. Ling LF, Marwick TH. Echocardiographic assessment of right ventricular function: how to account for tricuspid regurgitation and pulmonary hypertension. JACC Cardiovasc Imaging. 2012;5(7):747–53. doi:
10.1016/j.jcmg.2011.08.026. [PubMed: 22789943].
27. Grapsa J, Pereira Nunes MC, Tan TC, Cabrita IZ, Coulter T, Smith BC,
et al. Echocardiographic and Hemodynamic Predictors of Survival
in Precapillary Pulmonary Hypertension: Seven-Year Follow-Up. Circ
Cardiovasc Imaging. 2015;8(6) doi: 10.1161/CIRCIMAGING.114.002107.
[PubMed: 26063743].
28. Haddad F, Spruijt OA, Denault AY, Mercier O, Brunner N, Furman D, et
al. Right Heart Score for Predicting Outcome in Idiopathic, Familial,
or Drug- and Toxin-Associated Pulmonary Arterial Hypertension. JACC
Cardiovasc Imaging. 2015;8(6):627–38. doi: 10.1016/j.jcmg.2014.12.029.
[PubMed: 25981508].
29. Smith BC, Dobson G, Dawson D, Charalampopoulos A, Grapsa J, Nihoyannopoulos P. Three-dimensional speckle tracking of the right ventricle: toward optimal quantification of right ventricular dysfunction
in pulmonary hypertension. J Am Coll Cardiol. 2014;64(1):41–51. doi:
10.1016/j.jacc.2014.01.084. [PubMed: 24998127].
30. Ryo K, Goda A, Onishi T, Delgado-Montero A, Tayal B, Champion HC,
et al. Characterization of right ventricular remodeling in pulmonary
hypertension associated with patient outcomes by 3-dimensional
wall motion tracking echocardiography. Circ Cardiovasc Imaging.
2015;8(6) doi: 10.1161/CIRCIMAGING.114.003176. [PubMed: 26038432].
31. Marrone G, Mamone G, Luca A, Vitulo P, Bertani A, Pilato M, et
al. The role of 1.5T cardiac MRI in the diagnosis, prognosis and
management of pulmonary arterial hypertension. Int J Cardiovasc
Imaging. 2010;26(6):665–81. doi: 10.1007/s10554-010-9623-2. [PubMed:
20336377].
Arch Cardiovasc Imaging. 2016; 4(2):e41818.