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\begin{document}

\title{Comparison of Echocardiographic parameters with Cardiac Magnetic
Resonance Imaging in the Assessment of Right Ventricular Function}



\author[1]{Pradyumna Agasthi}%
\author[1]{Chieh-Ju  Chao, }%
\author[2]{Robert J. Siegel}%
\author[1]{Sai Harika  Pujari}%
\author[3]{Farouk Mookadam}%
\author[1]{Nithin Venepally }%
\author[1]{Panwen Wang}%
\author[1]{Hasan Ashraf}%
\author[1]{Francois Marcotte}%
\author[1]{Lisa Brown}%
\author[1]{Oksana Semkiv}%
\author[1]{Ayman Fath}%
\author[1]{Mohamed Allam}%
\author[1]{Clinton  Jokerst }%
\author[1]{Reza  Arsanjani}%
\affil[1]{Mayo Clinic Arizona}%
\affil[2]{Cedars Sinai Med Ctr}%
\affil[3]{Mayo Clinic}%


\vspace{-1em}



  
  \date{June 17, 2024}


\begingroup
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\selectlanguage{english}
\begin{abstract}
Introduction: The right ventricle (RV) strain measured by speckle
tracking (RVS) is a novel method of assessing RV function. We compared
RVS to RV fractional area change (FAC\%), tricuspid annular peak
systolic excursion (TAPSE) and Doppler tissue imaging-derived peak
systolic velocity (S') in the assessment of right ventricular (RV)
systolic function measured using cardiac magnetic resonance imaging
(MRI). Methods: We enrolled consecutive patients who underwent cardiac
MRI between Jan 2012- Dec 2017 and a transthoracic echocardiogram (TTE)
within 1 month of the MRI with no interval event. Baseline clinical
characteristics and MRI parameters were extracted from chart review.
Echocardiographic parameters were measured prospectively. TTE parameters
including RVS, TAPSE, S' and FAC\% were tested for accuracy to identify
impaired RV EF (EF \textless{}45\% \& \textless{}30\%) using receiver
operator curves. Results: The study cohort included 500 patients with
mean age 55 yr \selectlanguage{ngerman}± 18 and right ventricular systolic pressure 33.7 ± 13.6
mmHg. The area under ROC for RVS was 0.69 (95\% CI 0.63 -- 0.75) and
0.78 (95\% CI 0.70 -- 0.88) to predict RVEF \textless{}45\% \& RVEF
\textless{}30\% respectively. The RV FAC \% had second highest accuracy
of predicting RVEF among all the TTE parameters tested in study.
Conclusion: Right ventricular strain is the most accurate
echocardiographic method to detect impaired right ventricular systolic
function when using MRI as the gold standard.%
\end{abstract}\selectlanguage{ngerman}%



\sloppy


\textbf{Comparison of Echocardiographic parameters with Cardiac Magnetic
Resonance Imaging in the Assessment of Right Ventricular Function}

\textbf{Authors:}

Pradyumna Agasthi M.D \textsuperscript{a}; Chieh-Ju Chao,
M.D\textsuperscript{a}, Robert J. Siegel M.D\textsuperscript{b}, Sai
Harika Pujari M.B.B.S\textsuperscript{a}, Farouk Mookadam
M.B.B.Ch\textsuperscript{a} , Nithin R. Venepally M.B.B.S
\textsuperscript{a}, Panwen Wang PhD \textsuperscript{c}, Hasan Ashraf
M.D\textsuperscript{a}, Francois Marcotte M.D \textsuperscript{a}, Lisa
Brown R.D.C.S \textsuperscript{a}, Oksana I. Semkiv
R.D.C.S\textsuperscript{a}, Ayman R. Fath M.B.Ch.B \textsuperscript{a},
Mohamed N.A. Allam M.D \textsuperscript{a}, Clinton E. Jokerst
M.D\textsuperscript{d}, Reza Arsanjani M.D\textsuperscript{a}

a) Department of Cardiovascular Diseases, Mayo Clinic Arizona, Phoenix,
Arizona

b) Department of Cardiology, Cedars Sinai Medical Center, Los Angeles,
California

c) Department of Radiology, Mayo Clinic Arizona, Phoenix, Arizona

d) Department of Health Sciences Research, Mayo Clinic Arizona,
Scottsdale, Arizona

\textbf{Disclosure:} The authors report no financial relationships or
conflicts of interest regarding the content herein.

Corresponding Author:~ Pradyumna Agasthi M.D

Institutional Affiliation: Mayo Clinic Arizona

Address: 5777 East Mayo Boulevard,~\emph{Phoenix} , AZ 85054

Telephone:~~7864938374

Email: pradyumna\_agasthi@hotmail.com

\textbf{Structured Abstract:}

Introduction:

The right ventricle (RV) strain measured by speckle tracking (RVS) is a
novel method of assessing RV function. We compared RVS to RV fractional
area change (FAC\%), tricuspid annular peak systolic excursion (TAPSE)
and Doppler tissue imaging-derived peak systolic velocity (S') in the
assessment of right ventricular (RV) systolic function measured using
cardiac magnetic resonance imaging (MRI).

Methods:

We enrolled consecutive patients who underwent cardiac MRI between Jan
2012- Dec 2017 and a transthoracic echocardiogram (TTE) within 1 month
of the MRI with no interval event. Baseline clinical characteristics and
MRI parameters were extracted from chart review. Echocardiographic
parameters were measured prospectively. TTE parameters including RVS,
TAPSE, S' and FAC\% were tested for accuracy to identify impaired RV EF
(EF \textless{}45\% \& \textless{}30\%) using receiver operator curves.

Results:

The study cohort included 500 patients with mean age 55 yr \selectlanguage{ngerman}± 18 and
right ventricular systolic pressure 33.7 ± 13.6 mmHg. The area under ROC
for RVS was 0.69 (95\% CI 0.63 -- 0.75) and 0.78 (95\% CI 0.70 -- 0.88)
to predict RVEF \textless{}45\% \& RVEF \textless{}30\% respectively.
The RV FAC \% had second highest accuracy of predicting RVEF among all
the TTE parameters tested in study.

Conclusion:

Right ventricular strain is the most accurate echocardiographic method
to detect impaired right ventricular systolic function when using MRI as
the gold standard.

\textbf{Key Words:} 1) right ventricular function 2) Echocardiography 3)
Cardiac magnetic resonance imaging 4) Strain imaging

\textbf{Introduction:}

Right Ventricular (RV) function has significant prognostic importance
for a variety of heart diseases and their clinical outcomes. RV function
assessment is frequently conducted for staging and prognostic purposes,
especially in cardiac diseases with a right heart involvement. Of note,
RV dysfunction can affect the left ventricular (LV) Forward stroke
volume by restricting the preload of LV, as well as alter LV systolic
and diastolic function secondary to the interaction with the
interventricular septum and pericardium, and eventually lead to
biventricular failure . This is ascribed to the physiological function
of RV to maintain adequate pulmonary perfusion pressure and a low
systemic venous pressure.

Current clinical management has largely relied on non-invasive
modalities like echocardiography for RV function assessment.
Conventionally, one-dimensional echocardiography parameters such as
tricuspid annular peak systolic excursion (TAPSE), lateral tricuspid
annular systolic velocity (S') and two-dimensional (2D) parameters such
as RV functional area change (FAC) are being used. However, these
parameters are still subject to limitations due to the complex
anatomical structure and geometric shape of RV. The RV rendering volume
readings by echocardiography are susceptible to errors due to the
distinctive cavity geometry of the RV as opposed to the ellipsoid shape
of LV, and the change in longitudinal contraction pattern in diseased
states.

Cardiac magnetic resonance imaging (CMR) is considered as the gold
standard for RV function assessment. CMR provides accurate results in
quantifying heart function and structure and has become widely used for
different heart diseases. In RV assessment, RV volumes obtained by CMR
indicate a strong correlation with clinical assessment, and there is an
excellent accuracy and consistency of the volume measurements. Despite
the high accuracy and reproducibility, CMR has its constraints including
cost, availability, time-consuming, and skill-consuming as it requires
drawing endocardial contour manually, and also requires defining the
most basal short-axis slice and the endocardial border, which is
complicated by thin free wall and extensive trabeculations .

With the recent advance of speckle-tracking echocardiography, direct
measurement of myocardial deformation by strain becomes a great
alternative tool for RV function assessment . RV strain has been
reported as a technique with high accuracy and reproducibility and is
closely correlated with prognosis. However, only limited studies have
compared all these parameters with CMR. The purpose of this study is to
evaluate the accuracy of echocardiographic parameters in assessing RV
systolic function and specifically to compare standard echo parameters
to RV strain imaging and MRI to identify the best echo parameter(s) to
assess RV systolic function

\textbf{Methods:}

\textbf{Study individuals:}

We enrolled consecutive patients who underwent CMR between Jan 2012- Dec
2017 and a transthoracic echocardiogram (TTE) within 1 month of the CMR
with no interval clinical event. The study cohort included five hundred
subjects at Mayo Clinic Arizona. The following Doppler echocardiographic
parameters for assessment of RV systolic function: Tricuspid annular
peak systolic excursion (TAPSE), lateral tricuspid annular systolic
velocity (S'), lateral RV free wall peak systolic strain (S), and RV
fractional area change (RV FAC), and cardiac MRI (RVEF) were acquired in
all the subjects. Subdivisions in the patient group are based on RVEF
measured by CMR: RVEF \selectlanguage{english}[?] 45\% (n = 333, Group A), RVEF 30-45\% (n = 140,
Group B), and RVEF \selectlanguage{english}[?] 30\% (n = 27, Group C). All echocardiographic
parameters were reassessed by the investigators for the current study.

\textbf{Doppler echocardiography:}

Standard ultrasound scanners (Philips iE33; Philips Medical Systems,
Andover, MA, USA; GE Vivid E9, GE Healthcare, Milwaukee, WI, USA) with a
3.5 MHz transducer, including tissue Doppler imaging (TDI) was used for
transthoracic Doppler echocardiography and strain echocardiography was
conducted using a speckle tracking software. Both conventional M-mode
and 2D echocardiography were performed from the left parasternal and
apical window. Each measurement was taken carefully after examining
patients in both supine and left lateral positions. During the
end-systole and end-diastole, M-mode LV readings were acquired. LV EF
was calculated with LV volume measurements taken in biplane projection
from apical two-chamber and four-chamber views. Using the end-diastolic
values of septal and posterior wall thickness and LV cavity dimension,
LV mass was determined as per the cube formula. Bi-apical Simpson rule
was applied to compute LV volumes and the simplified Bernoulli equation
to calculate the tricuspid pressure gradient.

\textbf{Right Ventricular Dimensions:}

Two-dimensional echocardiography was used to derive RV area and length
measurements during end-systole and end-diastole from the apical
four-chamber view, and RV fractional area change was assessed. Final
figures were produced after an average of three cardiac cycles. Lateral
TAPSE was computed as the distance amid the tricuspid annulus greatest
apical long-axis movement and its basal, end-diastolic position taken at
the beginning of ECG QRS complex and was determined by M-mode
echocardiography. A 2-4 mm sampling gate and a 200 mm/s sweep were used
to attain pulsed-wave TDI of the peak systolic tricuspid annular motion
velocity at the lateral free wall (S', cm/s) in apical four-chamber view
.

\textbf{Speckle-tracking strain analysis:}

Speckle tracking strain echocardiography was used to determine RV
lateral free wall average peak systolic strain . RV strain was measured
using ECHOINSIGHT software (version 2.2.6.2230, Epsilon Imaging, Ann
Arbor, MI). Based on the 4-chamber apical view, three successive RV
cardiac cycles with a frame rate of 70-120/s were recorded. Right
ventricular endocardial border was manually traced in still end-systolic
frames, and the software performed automated tracking throughout the
cardiac cycle. The automated tracking was visually verified and manually
adjusted for adequate border delineation. Tissue velocities in the 2D
plane are displayed throughout the cardiac cycle, representing magnitude
and direction of motion. Finally, strain data was generated by analyzing
the speckle pattern along the endocardial border in reference to one
another. Longitudinal strain is defined as the percentage shortening of
a regional area of interest (ROI) relative to its original length and is
expressed as a negative value. The software further categorized the RV
myocardium into six sections: basal RV free wall, mid-RV free wall,
apical free wall, left basal septum, mid-left septum, and left apical
septum and calculated the regional wall strain with the same manner. RV
lateral free wall strain (average of the basal, mid, and apical free
wall) was used in our analysis. \textbf{Figure 1} demonstrated a
representative case of RV dimension measurement.

\textbf{Reproducibility:}

Reproducibility was assessed using 50 randomly chosen individuals from
all the three subgroups. The four echocardiographic parameters and RVEF
(assessed by MRI) were measured by two blinded observers (to both
echocardiography and MRI data), and inter-observer variability was
evaluated. The standard error of estimate of the mean percent signifies
measurement reproducibility.

\textbf{Cardiac magnetic resonance imaging:}

Periodic changes of the cardiac chambers and ventricular walls were
visualized and interpreted by an experienced observer blinded to
echocardiographic findings and clinical information. The imaging was
performed in the supine position on all subjects using a 1.5 T (Magnetom
Symphony) or a 3 T (Magnetom Trio, both from Siemens Medical Solutions,
Erlangen, Germany) whole-body clinical MRI system. All images were
tracked for end-systolic and end-diastolic endocardial contours.
Modified Simpson's rule was used to determine RV volumes. Three
electrodes positioned on the left anterior hemithorax and cardiac
synchronization was acquired. Commercially accessible (Argus version
4.01, Syngo MR B 13, Siemens Medical Solutions, Erlangen, Germany)
software accomplished an evaluation of images. A mid-ventricular axial
view, a cine breath-hold vertical long axis, and a cine breath-hold
horizontal long axis established cardiac short axis. During short
end-expiratory breath-holds, the ventricles were imaged in 8 mm
increments using adjacent short-axis slices from the base to apex while
the basal short-axis slice was placed beyond the mitral valve plane.
Long axis views verified the short-axis acquisitions for comprehensive
coverage of ventricles.

\textbf{Statistical analysis:}

Descriptive statistics were summarized as mean +- standard deviation or
number with percentage. Statistically relevant correlations between the
Doppler echocardiographic parameters and RVEF by CMR were achieved by
linear regression analysis. Receiver operating characteristics (ROC)
curves were obtained by analyzing the variables of echocardiography as
the sample factors and RVEF by CMR as the state variable. Shapiro-Wilk
test was made use to determine the normal distribution of data, whereas
an analysis of variance (ANOVA) was used to compare amongst the groups
of Doppler echocardiographic variables and other demographic variables.
As mentioned above, the standard error of estimate of the mean percent
signifies inter-observer variability. We used R 3.4.1 (Foundation for
Statistical Computing, Vienna, Austria) to run our analysis.

\textbf{Results:}

\emph{Patient Characteristics:}

When the three groups are compared, the patients did not differ
regarding age, body mass index, or height. A higher percentage of men
were present in patients with impaired RVEF. Hypertension was
predominant in the patients with normal RVEF, and diabetes mellitus was
more common in the patients with an impaired RVEF. As identified in
table 1, cardiovascular diagnoses varied among the groups, but
cardiomyopathy remained the most frequent diagnosis in all patients.

\emph{Echocardiographic Variables:}

\textbf{Table 2} shows the echocardiographic variables of the subgroups.
The right ventricular systolic pressure was 30.97 +/- 9.27, 36.72 +/-
14.50, and 48.12 +/- 13.92, respectively, in normal, moderately reduced,
and severely reduced EF patients (p\textless{}0.0001). Reproducibility
of inter-observer variabilities was calculated for all the four
variables, S', TAPSE, RV FAC, and lateral RV free wall strain. There was
a significant difference in the parameters assessed for RV systolic
function \textbf{(Table 2)} . There was a linear association with the
MRI reference parameter of RVEF with RVEF \textless{}45\% and RVEF
\textless{} 30\% for all the variables, with strain having the most
significant association \textbf{(Figure 2 and Figure 3} ). Other
parameters like LV mass index, LV end-diastolic mass, and LV
end-diastolic mass indices also significantly differed among the groups.
ROC curves with cutoffs of RVEF\textless{}45\%, and RVEF \selectlanguage{english}[?] 30\% are
shown in \textbf{Figure 4} estimating the accuracy of echocardiographic
parameters to predict RV function. The echocardiographic parameter that
most accurately assessed the RV systolic function was RV lateral free
wall strain and the area under the curve (AUC) for ROC was 0.69 (95\% CI
0.63 -- 0.75) and 0.78 (95\% CI 0.70 -- 0.88) in the groups B and C
respectively \textbf{(Table 3)} . RV FAC \% ranked second in the
accuracy of predicting RV systolic function among the TTE parameters in
both groups.

\emph{Reproducibility}

The standard error values of each parameter are 3.74\%
(r\textsuperscript{2}= 0.5605), 3.68\% (r\textsuperscript{2}=0.389),
4.09\% (r\textsuperscript{2}=0.619), 5.024\%
(r\textsuperscript{2}=0.889) and 2.24\% (r\textsuperscript{2}=0.922),
for S', TAPSE, RV FAC, lateral RV free wall strain and MRI derived RVEF
respectively.

\textbf{Discussion:}

In our study comprising 500 consecutive patients with a broad spectrum
of cardiovascular disorders, we evaluated the accuracy of commonly used
echocardiographic parameters, including peak systolic annular velocity
(s'), tricuspid annular plane systolic excursion (TAPSE), RV fractional
area change (RV FAC), as well as RV strain, compared to CMR RV ejection
fraction (RVEF) in assessing RV systolic function. To the best of our
knowledge, this is the largest study that contains a variety of patient
population and compares echocardiographic parameters with RVEF measured
by CMR . This is also the first study to demonstrate the superior
accuracy of RV free wall strain compared to other echocardiographic
parameters to distinguish RVEF \textless{} 45\% and RVEF
\textless{}30\%.

Similar to previous studies , we choose CMR measured RV ejection
fraction (RVEF) as our reference standard for RV systolic function
assessment. CMR enjoys the advantage of 3D volumetric information and
high spatial resolution to analyze the distinctive geometry of RV, which
is usually difficult to obtain by using 2D echocardiography
measurements. The accuracy and reproducibility of using CMR for
quantitative RV assessment have been demonstrated in multiple clinical
studies. As a functional parameter, RVEF reflects the contractility of
right heart myocardium, and can be affected by RV preload, afterload,
and other general variables including age, sex and body mass index. Age
and gender did not differ significantly between the groups in our study,
but the percentage of men was higher in Group B.

Among the four echocardiographic parameters, our results indicate that
RV strain and RV FAC are in general superior to TAPSE and S' in
accuracy, when compared with CMR RVEF by both spearman's correlation and
ROC curve analyses. Our results demonstrated a comparable or better
reproducibility of each parameter, compared to prior studies. This
finding suggests that two-dimensional parameters are superior two
one-dimensional parameters and implies the importance of using
two-dimensional or even three-dimensional tools for accurate RV function
assessment concerning its complex geometry.

\emph{RV peak systolic annular velocity (S')}

As a conventional RV function parameter, \textbf{S'} represents the
tricuspid annulus' longitudinal velocity at systole and is easy to
estimate, reliable and reproducible . Previous studies show that S'
might be the best predictor of RVEF, and may predict short-term outcome
of heart failure. S' was also questioned whether the displacement of the
myocardium or the regional velocities in a single segment can truly
represent the entire RV function. However, our observation indicates the
accuracy of S' in assessing RV systolic dysfunction maybe not as good as
suggested in prior studies . Using a cutoff of \textless{} 10 cm/s, the
accuracy (AUC) of S' in differentiating the severity of RV systolic
dysfunction were in the range of 0.58-0.65 in our study; which is
apparently lower than previously reported 0.7-0.8 range. Of note, the S'
threshold of RV systolic dysfunction varies considerably between studies
while the commonly accepted S' cutoff for RV dysfunction is \textless{}
10 cm/s . In addition, a study showed that S' detected best at a cut-off
value of 8.8 cm/sec in 10 patients with arrhythmogenic RV dysplasia and
low RVEF. Another study found that S' between lateral and septal
tricuspid annulus of 7 cm/s was the most accurate means to detect an
RVEF cut-off by MRI of 45\%. Overall, our data support that S' is more
accurate in cases with mild RV dysfunction as reported previously. The
S' cutoff used in prior studies ranged from 7 cm/s to 11 cm/s , which is
about 30 to 40\% variation between different studies. This implies a
single best cutoff threshold may not exist among different patient
cohorts.

\emph{Tricuspid annulus peak systolic excursion (TAPSE)}

TAPSE had similar performance as S' in our study and was slightly more
accurate than S' in patients with severe RV dysfunction
(AUC\textsubscript{TAPSE} 0.673 \textgreater{}
AUC\textsubscript{S'}0.652). TAPSE is also readily obtainable, and has
modest correlation with RVEF, 2D RV FAC and 2D RV EF although it
measures the longitudinal function. TAPSE is a simple and
straightforward measurement that doesn't require optimal image quality
and time-consuming image analysis. Similar to S', TAPSE assumes that the
basal and adjacent segment displacement in the four-chamber view
represents the entire RV function, which may not be valid in several
disease states and regional RV wall motion abnormalities. In other
words, TAPSE is comparatively load- and angle dependent, can subject to
cardiac translation and is the least user dependent parameter for RV
function assessment.

\emph{RV FAC}

In our study, the accuracy of RV FAC was comparable with RV free wall
strain in patients with mild and moderate RV dysfunction; the AUC range
was from 0.62 to 0.69. RV FAC was superior to the 1-dimensional
parameters, S' and TAPSE. As a well-established 2-dimensional parameter,
RV FAC has been validated in various studies and was shown to be an
independent indicator of sudden death, stroke, and heart failure. A
recent study indicated that RV FAC can accurately predict RVEF than
45\%, with an AUC of 0.89. Potential limitations of RV FAC include lack
of clear guidance in selecting the optimal view for measurements of a
3-dimensional object with complex geometric shape, and RV FAC neglects
contribution of RVOT to the overall RV function.

\emph{Speckle-tracking RV free wall strain}

RV lateral free wall strain had the best accuracy among the four
echocardiographic parameters. It consistently outperformed other
parameters in identifying different levels of RV systolic dysfunction
and was most accurate with severe RV systolic dysfunction. We identified
cutoff levels of lateral RV free wall strain of \textless{}23.5\% and
\textless{}20.5 \% that accurately detects for moderately and severely
reduced RV systolic function, respectively. Although the RV free wall
strain technically measures more of the longitudinal deformation of the
RV myocardium, it has been validated as a global function parameter in a
variety of diseases with promising results and predicting prognosis .
Compared to LV, base-to-apex shortening plays a more important role in
RV systolic function due to its distinct muscle fiber architecture. This
also partially explained the superiority of longitudinal RV strain in
assessing RV systolic function. In addition, speckle-tracking RV strain
also has the unique advantage of being angle-independent, and able to
measure the intrinsic myocardium deformation. An issue of using RV
strain is the different reference values generated by the software
package from different vendors; one should be cautious when comparing RV
strain data from different studies. The ease of performance for
sonographers comparing all four modalities in descending order are
TAPSE, S', FAC and RV strain. Theoretically, RV myocardial strain should
be superior to localized velocity measurements such as S'. Our study
demonstrates strain is superior to other echo parameters as compared
with Cardiac MRI as the standard.

In conclusion, conventional one-dimensional echocardiographic
parameters, such as S' and TAPSE, were well-validated and have the
advantage of simplicity, reproducibility and are less dependent on image
quality. However, either TAPSE or S' in our study were not as good as
reported in prior RV dysfunction studies. The 2-dimensional parameters,
RV FAC and RV free wall strain were superior in accuracy. The ease of
performance for sonographers comparing all four modalities in descending
order are TAPSE, S', FAC and RV strain.

Considering the availability, reproducibility, accuracy and the
correlation to prognosis, our results suggested that RV free wall strain
is the preferred choice for RV functional assessment among the four
echocardiographic parameters.

As a final comment, the AUC of all four parameters improved with
worsening RV dysfunction, which reflects the challenge in detecting mild
to moderate RV dysfunction in clinical practice. Despite the relatively
good AUC data, all the four echocardiographic parameters only had modest
correlations with CMR RVEF. This implied a substantial limitation on 1-
or 2-dimensional assessment of RV systolic function. In clinical
practice, these parameters can serve as surrogates of RV dysfunction
concerning their availability and relatively low costs. However, when
accurate assessment of RV systolic function is warranted, 3-dimensional
tools like cardiac MRI should be the preferred choice when it's
available.

\textbf{Study limitations:}

Our study aims to provide a general picture of RV dysfunction
assessments by different echocardiographic parameters in different
diseases, so a disease-specific analysis was not performed.
Statistically, the ROC analysis showing the accuracy gives a
satisfactory correlation. However, the inherent limitations of
measurement of variables exist. The study did not use three-dimensional
echocardiography, and the right ventricle's unique geometry makes it
difficult to obtain images using two-dimensional planes. RVEF is a
function of both longitudinal and concentric myocardial fibers, while
tricuspid annular systolic motion principally indicates the longitudinal
fibers' function only. The angle of interrogation and cardiac motion
influence the velocity measurement, especially from the apical
four-chamber view during long axis assessment limiting the accuracy of
S'. As mentioned above, RVEF measured by MRI can account for some
unknown extent of variability of data. Lack of 3D echocardiographic
assessment of RV function in our dataset remains a limitation in our
study. Prior studies have shown a good correlation 3D TTE with MRI for
the assessment of RV function. Good 3D assessment of RV function
requires excellent image quality, lack of arrhythmia and long breath
holds during image acquisition. It is prone to stich artifacts, needs
cumbersome software processing, has low frame rate and significant
inter-vendor variability, hampering routine use of 3D RV assessment in
contemporary practice.

\textbf{Conclusion:}

In conclusion, our study is the largest study to date to compare a
multiparameter echo-Doppler assessment of RV systolic function with RVEF
determined by cardiac MR for validation. Our results suggest the
superiority of lateral RV free wall strain to other conventional
echocardiographic parameters for detecting RV systolic dysfunction.
Lateral RV free wall strain of \textless{}23.5\% accurately detects
moderately reduced RVEF and lateral RV free wall strain \textless{}20.5
\% accurately detects severely reduced RV systolic function.

\textbf{Conflict of interest/Disclosures:} None of the authors have any
disclosures. Informed, written consent was obtained from all individuals
for whom information is included in this article. The authors have
conformed to institutional guidelines and those of the American
Physiological Society.

\textbf{Funding} :

This research did not receive any specific grant from funding agencies
in the public, commercial, or not-for-profit sectors.

\textbf{Table Legends:}

\textbf{Table 1:} Patient Characteristics.

\textbf{Table 2:} Baseline Echocardiographic and Cardiac Magnetic
Resonance Data

\textbf{Table 3:} Area under the Receiver Operating Curve
Characteristics of Echocardiographic parameters to predict right
ventricular ejection fraction measured using cardiac magnetic resonance
imaging.

\textbf{Figure Legends:}

\textbf{Figure 1:} A representative case of RV dimension measurements.
A) TAPSE B) RV peak myocardial contraction velocity (S'), C)
End-diastole and D) End-systole phases of RV fractional area change,
respectively, E) speckled tracking strain measurements of RV.

\textbf{Figure 2:} Spearman Correlation graphs in the study patients
with RVEF \textless{}45\%: Right ventricular (RV) ejection fraction
measured by cardiac magnetic resonance imaging (CMR) on vertical axis
and Doppler echocardiographic variables on horizontal axes. A) Lateral
tricuspid annular peak systolic velocity measured by tissue Doppler
imaging, S' B) Lateral RV free wall peak systolic strain (\%) C) RV
fractional long axis change (\%), RV FAC D) Tricuspid annular peak
systolic excursion, TAPSE (mm).

\textbf{Figure 3:} Spearman Correlation graphs in the study patients
with RVEF \textless{}30\%: Right ventricular (RV) ejection fraction
measured by cardiac magnetic resonance imaging (CMR) on vertical axis
and Doppler echocardiographic variables on horizontal axes. A) Lateral
tricuspid annular peak systolic velocity measured by tissue Doppler
imaging, S' B) Lateral RV free wall peak systolic strain (\%) C) RV
fractional long axis change (\%), RV FAC D) Tricuspid annular peak
systolic excursion, TAPSE (mm).

\textbf{Figure 4:} Receiver operating characteristic analysis curves for
the distinction by the echocardiographic parameters measured in the
study. A) Right ventricular ejection fraction (RVEF) \textless{} 45\% B)
RVEF \selectlanguage{english}[?] 30\%; RV FAC- RV Fractional long axis change, S'- Lateral
tricuspid annular peak systolic velocity, TAPSE- Tricuspid annular peak
systolic excursion.

CRediT author statement

Pradyumna Agasthi: Conceptualization, Methodology, Data Curation,
Investigation, Visualization, Writing-Original Draft, Writing-Review
\&Editing

Chieh-Ju Chao: Conceptualization, Data Curation, Writing-Original Draft,
Writing-Review \&Editing

Robert J. Siegel: Supervision, Conceptualization, Methodology,
Writing-Review \&Editing

Sai Harika Pujari: Data Curation, Visualization, Writing-Original Draft,
Writing-Review \&Editing

Farouk Mookadam: Supervision, Conceptualization, Methodology,
Writing-Review \&Editing

Nithin R. Venepally: Data Curation, Visualization, Writing-Review
\&Editing

Panwen Wang: Methodology, Investigation, Formal Analysis, Writing-Review
\&Editing

Hasan Ashraf: Conceptualization, Data Curation, Writing-Original Draft,
Writing-Review \&Editing

Francois Marcotte: Supervision, Conceptualization, Methodology,
Writing-Review \&Editing.

Lisa Brown: Data Curation, Visualization, Writing-Review \&Editing

Oksana Semkiv: Data Curation, Visualization, Writing-Review \&Editing

Ayman Fath: Data Curation, Visualization, Writing-Review \&Editing

Mohamed Allam: Data Curation, Visualization, Writing-Review \&Editing

Clinton E. Jokerst: Supervision, Conceptualization, Methodology,
Writing-Review \&Editing

Reza Arsanjani: Supervision, Project Administration, Conceptualization,
Methodology, Writing-Review \&Editing

\textbf{References:}

\textbf{Table 1:} Patient Characteristics.\selectlanguage{english}
\begin{longtable}[]{@{}lllll@{}}
\toprule
\begin{minipage}[b]{0.19\columnwidth}\raggedright\strut
\strut
\end{minipage} & \begin{minipage}[b]{0.19\columnwidth}\raggedright\strut
\textbf{Group A} \textbf{Right Ventricular ejection fraction [?] 45\%}
\textbf{(n=333)}\strut
\end{minipage} & \begin{minipage}[b]{0.19\columnwidth}\raggedright\strut
\textbf{Group B} \textbf{Right Ventricular ejection fraction
\textgreater{}30-45 \%} \textbf{(n=140)}\strut
\end{minipage} & \begin{minipage}[b]{0.19\columnwidth}\raggedright\strut
\textbf{Group C} \textbf{Right Ventricular ejection fraction [?] 30\%}
\textbf{(n=27)}\strut
\end{minipage} & \begin{minipage}[b]{0.19\columnwidth}\raggedright\strut
\textbf{P-value}\strut
\end{minipage}\tabularnewline
\midrule
\endhead
\begin{minipage}[t]{0.17\columnwidth}\raggedright\strut
\textbf{Age (years)}\strut
\end{minipage} & \begin{minipage}[t]{0.17\columnwidth}\raggedright\strut
56.02 \selectlanguage{ngerman}± 17.88\strut
\end{minipage} & \begin{minipage}[t]{0.17\columnwidth}\raggedright\strut
55.04 \selectlanguage{ngerman}± 18.59\strut
\end{minipage} & \begin{minipage}[t]{0.17\columnwidth}\raggedright\strut
54.61 \selectlanguage{ngerman}± 16.79\strut
\end{minipage} & \begin{minipage}[t]{0.17\columnwidth}\raggedright\strut
0.5404\strut
\end{minipage}\tabularnewline
\begin{minipage}[t]{0.17\columnwidth}\raggedright\strut
\textbf{Men n (\%)}\strut
\end{minipage} & \begin{minipage}[t]{0.17\columnwidth}\raggedright\strut
199 (59.76)\strut
\end{minipage} & \begin{minipage}[t]{0.17\columnwidth}\raggedright\strut
94 (67.14)\strut
\end{minipage} & \begin{minipage}[t]{0.17\columnwidth}\raggedright\strut
17 (62.96)\strut
\end{minipage} & \begin{minipage}[t]{0.17\columnwidth}\raggedright\strut
0.0370\strut
\end{minipage}\tabularnewline
\begin{minipage}[t]{0.17\columnwidth}\raggedright\strut
\textbf{Body mass index (kg/m\textsuperscript{2})}\strut
\end{minipage} & \begin{minipage}[t]{0.17\columnwidth}\raggedright\strut
27.26 \selectlanguage{ngerman}± 5.40\strut
\end{minipage} & \begin{minipage}[t]{0.17\columnwidth}\raggedright\strut
27.06 \selectlanguage{ngerman}± 4.52\strut
\end{minipage} & \begin{minipage}[t]{0.17\columnwidth}\raggedright\strut
27.34 \selectlanguage{ngerman}± 4.39\strut
\end{minipage} & \begin{minipage}[t]{0.17\columnwidth}\raggedright\strut
0.8323\strut
\end{minipage}\tabularnewline
\begin{minipage}[t]{0.17\columnwidth}\raggedright\strut
\textbf{Height (cm)}\strut
\end{minipage} & \begin{minipage}[t]{0.17\columnwidth}\raggedright\strut
172.22 \selectlanguage{ngerman}± 9.57\strut
\end{minipage} & \begin{minipage}[t]{0.17\columnwidth}\raggedright\strut
173.52 \selectlanguage{ngerman}± 9.11\strut
\end{minipage} & \begin{minipage}[t]{0.17\columnwidth}\raggedright\strut
176.05 \selectlanguage{ngerman}± 11.38\strut
\end{minipage} & \begin{minipage}[t]{0.17\columnwidth}\raggedright\strut
0.0274\strut
\end{minipage}\tabularnewline
\begin{minipage}[t]{0.17\columnwidth}\raggedright\strut
\textbf{Diabetes Mellitus n (\%)}\strut
\end{minipage} & \begin{minipage}[t]{0.17\columnwidth}\raggedright\strut
44 (13.21)\strut
\end{minipage} & \begin{minipage}[t]{0.17\columnwidth}\raggedright\strut
25 (17.86)\strut
\end{minipage} & \begin{minipage}[t]{0.17\columnwidth}\raggedright\strut
0 (0)\strut
\end{minipage} & \begin{minipage}[t]{0.17\columnwidth}\raggedright\strut
\textless{}0.0001\strut
\end{minipage}\tabularnewline
\begin{minipage}[t]{0.17\columnwidth}\raggedright\strut
\textbf{Hypertension n (\%)}\strut
\end{minipage} & \begin{minipage}[t]{0.17\columnwidth}\raggedright\strut
152 (45.65)\strut
\end{minipage} & \begin{minipage}[t]{0.17\columnwidth}\raggedright\strut
50 (35.71)\strut
\end{minipage} & \begin{minipage}[t]{0.17\columnwidth}\raggedright\strut
0 (0)\strut
\end{minipage} & \begin{minipage}[t]{0.17\columnwidth}\raggedright\strut
\textless{}0.0001\strut
\end{minipage}\tabularnewline
\begin{minipage}[t]{0.17\columnwidth}\raggedright\strut
\textbf{Sleep Apnea n (\%)}\strut
\end{minipage} & \begin{minipage}[t]{0.17\columnwidth}\raggedright\strut
65 (19.52)\strut
\end{minipage} & \begin{minipage}[t]{0.17\columnwidth}\raggedright\strut
29 (20.71)\strut
\end{minipage} & \begin{minipage}[t]{0.17\columnwidth}\raggedright\strut
0 (0)\strut
\end{minipage} & \begin{minipage}[t]{0.17\columnwidth}\raggedright\strut
\textless{}0.0001\strut
\end{minipage}\tabularnewline
\begin{minipage}[t]{0.17\columnwidth}\raggedright\strut
\textbf{Primary cardiovascular diagnosis:}\strut
\end{minipage} & \begin{minipage}[t]{0.17\columnwidth}\raggedright\strut
\textbf{Primary cardiovascular diagnosis:}\strut
\end{minipage} & \begin{minipage}[t]{0.17\columnwidth}\raggedright\strut
\textbf{Primary cardiovascular diagnosis:}\strut
\end{minipage} & \begin{minipage}[t]{0.17\columnwidth}\raggedright\strut
\textbf{Primary cardiovascular diagnosis:}\strut
\end{minipage} & \begin{minipage}[t]{0.17\columnwidth}\raggedright\strut
\textbf{Primary cardiovascular diagnosis:}\strut
\end{minipage}\tabularnewline
\begin{minipage}[t]{0.17\columnwidth}\raggedright\strut
\textbf{Normal n (\%)}\strut
\end{minipage} & \begin{minipage}[t]{0.17\columnwidth}\raggedright\strut
94 (28.23)\strut
\end{minipage} & \begin{minipage}[t]{0.17\columnwidth}\raggedright\strut
24 (17.14)\strut
\end{minipage} & \begin{minipage}[t]{0.17\columnwidth}\raggedright\strut
(0)\strut
\end{minipage} & \begin{minipage}[t]{0.17\columnwidth}\raggedright\strut
\textless{}0.0001\strut
\end{minipage}\tabularnewline
\begin{minipage}[t]{0.17\columnwidth}\raggedright\strut
\textbf{Coronary artery disease n (\%)}\strut
\end{minipage} & \begin{minipage}[t]{0.17\columnwidth}\raggedright\strut
43 (12.91)\strut
\end{minipage} & \begin{minipage}[t]{0.17\columnwidth}\raggedright\strut
18 (12.86)\strut
\end{minipage} & \begin{minipage}[t]{0.17\columnwidth}\raggedright\strut
6 (22.22)\strut
\end{minipage} & \begin{minipage}[t]{0.17\columnwidth}\raggedright\strut
\textless{}0.0001\strut
\end{minipage}\tabularnewline
\begin{minipage}[t]{0.17\columnwidth}\raggedright\strut
\textbf{Cardiomyopathy n (\%)}\strut
\end{minipage} & \begin{minipage}[t]{0.17\columnwidth}\raggedright\strut
142 (42.64)\strut
\end{minipage} & \begin{minipage}[t]{0.17\columnwidth}\raggedright\strut
66 (47.14)\strut
\end{minipage} & \begin{minipage}[t]{0.17\columnwidth}\raggedright\strut
24 (88.89)\strut
\end{minipage} & \begin{minipage}[t]{0.17\columnwidth}\raggedright\strut
\textless{}0.0001\strut
\end{minipage}\tabularnewline
\begin{minipage}[t]{0.17\columnwidth}\raggedright\strut
\textbf{Valvular heart disease n (\%)}\strut
\end{minipage} & \begin{minipage}[t]{0.17\columnwidth}\raggedright\strut
39 (11.71)\strut
\end{minipage} & \begin{minipage}[t]{0.17\columnwidth}\raggedright\strut
16 (11.43)\strut
\end{minipage} & \begin{minipage}[t]{0.17\columnwidth}\raggedright\strut
4 (14.81)\strut
\end{minipage} & \begin{minipage}[t]{0.17\columnwidth}\raggedright\strut
\textless{}0.0001\strut
\end{minipage}\tabularnewline
\begin{minipage}[t]{0.17\columnwidth}\raggedright\strut
\textbf{Tetralogy of Fallot n (\%)}\strut
\end{minipage} & \begin{minipage}[t]{0.17\columnwidth}\raggedright\strut
3 (0.9)\strut
\end{minipage} & \begin{minipage}[t]{0.17\columnwidth}\raggedright\strut
4 (2.86)\strut
\end{minipage} & \begin{minipage}[t]{0.17\columnwidth}\raggedright\strut
1 (3.7)\strut
\end{minipage} & \begin{minipage}[t]{0.17\columnwidth}\raggedright\strut
\textless{}0.0001\strut
\end{minipage}\tabularnewline
\begin{minipage}[t]{0.17\columnwidth}\raggedright\strut
\textbf{Transposition of great arteries n (\%)}\strut
\end{minipage} & \begin{minipage}[t]{0.17\columnwidth}\raggedright\strut
0 (0)\strut
\end{minipage} & \begin{minipage}[t]{0.17\columnwidth}\raggedright\strut
1 (0.71)\strut
\end{minipage} & \begin{minipage}[t]{0.17\columnwidth}\raggedright\strut
0 (0)\strut
\end{minipage} & \begin{minipage}[t]{0.17\columnwidth}\raggedright\strut
\textless{}0.0001\strut
\end{minipage}\tabularnewline
\begin{minipage}[t]{0.17\columnwidth}\raggedright\strut
\textbf{Other congenital heart disease n (\%)}\strut
\end{minipage} & \begin{minipage}[t]{0.17\columnwidth}\raggedright\strut
11 (3.3)\strut
\end{minipage} & \begin{minipage}[t]{0.17\columnwidth}\raggedright\strut
9 (6.43)\strut
\end{minipage} & \begin{minipage}[t]{0.17\columnwidth}\raggedright\strut
1 (3.7)\strut
\end{minipage} & \begin{minipage}[t]{0.17\columnwidth}\raggedright\strut
\textless{}0.0001\strut
\end{minipage}\tabularnewline
\begin{minipage}[t]{0.17\columnwidth}\raggedright\strut
\textbf{Other n (\%)}\strut
\end{minipage} & \begin{minipage}[t]{0.17\columnwidth}\raggedright\strut
37 (11.11)\strut
\end{minipage} & \begin{minipage}[t]{0.17\columnwidth}\raggedright\strut
22 (15.71)\strut
\end{minipage} & \begin{minipage}[t]{0.17\columnwidth}\raggedright\strut
3 (11.11)\strut
\end{minipage} & \begin{minipage}[t]{0.17\columnwidth}\raggedright\strut
\textless{}0.0001\strut
\end{minipage}\tabularnewline
\begin{minipage}[t]{0.17\columnwidth}\raggedright\strut
\textbf{Pulmonary hypertension n (\%)}\strut
\end{minipage} & \begin{minipage}[t]{0.17\columnwidth}\raggedright\strut
4 (1.2)\strut
\end{minipage} & \begin{minipage}[t]{0.17\columnwidth}\raggedright\strut
9 (6.43)\strut
\end{minipage} & \begin{minipage}[t]{0.17\columnwidth}\raggedright\strut
1 (3.7)\strut
\end{minipage} & \begin{minipage}[t]{0.17\columnwidth}\raggedright\strut
\textless{}0.0001\strut
\end{minipage}\tabularnewline
\bottomrule
\end{longtable}

\textbf{Table 2:} Baseline Echocardiographic and Cardiac Magnetic
Resonance Data\selectlanguage{english}
\begin{longtable}[]{@{}lllll@{}}
\toprule
\begin{minipage}[b]{0.19\columnwidth}\raggedright\strut
\strut
\end{minipage} & \begin{minipage}[b]{0.19\columnwidth}\raggedright\strut
\textbf{Group A} \textbf{Right Ventricular ejection fraction [?] 45\%}
\textbf{(n=333)}\strut
\end{minipage} & \begin{minipage}[b]{0.19\columnwidth}\raggedright\strut
\textbf{Group B} \textbf{Right Ventricular ejection fraction
\textgreater{}30-45 \%} \textbf{(n=140)}\strut
\end{minipage} & \begin{minipage}[b]{0.19\columnwidth}\raggedright\strut
\textbf{Group C} \textbf{Right Ventricular ejection fraction [?] 30\%}
\textbf{(n=27)}\strut
\end{minipage} & \begin{minipage}[b]{0.19\columnwidth}\raggedright\strut
\textbf{P-value}\strut
\end{minipage}\tabularnewline
\midrule
\endhead
\begin{minipage}[t]{0.17\columnwidth}\raggedright\strut
\textbf{Doppler echocardiographic data}\strut
\end{minipage} & \begin{minipage}[t]{0.17\columnwidth}\raggedright\strut
\textbf{Doppler echocardiographic data}\strut
\end{minipage} & \begin{minipage}[t]{0.17\columnwidth}\raggedright\strut
\textbf{Doppler echocardiographic data}\strut
\end{minipage} & \begin{minipage}[t]{0.17\columnwidth}\raggedright\strut
\textbf{Doppler echocardiographic data}\strut
\end{minipage} & \begin{minipage}[t]{0.17\columnwidth}\raggedright\strut
\textbf{Doppler echocardiographic data}\strut
\end{minipage}\tabularnewline
\begin{minipage}[t]{0.17\columnwidth}\raggedright\strut
\textbf{LV mass index (g,m2)}\strut
\end{minipage} & \begin{minipage}[t]{0.17\columnwidth}\raggedright\strut
102.45 \selectlanguage{ngerman}± 34.71\strut
\end{minipage} & \begin{minipage}[t]{0.17\columnwidth}\raggedright\strut
114.25 \selectlanguage{ngerman}± 45.98\strut
\end{minipage} & \begin{minipage}[t]{0.17\columnwidth}\raggedright\strut
129.54 \selectlanguage{ngerman}± 42.04\strut
\end{minipage} & \begin{minipage}[t]{0.17\columnwidth}\raggedright\strut
\textless{}0.0001\strut
\end{minipage}\tabularnewline
\begin{minipage}[t]{0.17\columnwidth}\raggedright\strut
\textbf{Left atrial volume index (ml/m\textsuperscript{2})}\strut
\end{minipage} & \begin{minipage}[t]{0.17\columnwidth}\raggedright\strut
33.66 \selectlanguage{ngerman}± 12.50\strut
\end{minipage} & \begin{minipage}[t]{0.17\columnwidth}\raggedright\strut
36.86 \selectlanguage{ngerman}± 13.84\strut
\end{minipage} & \begin{minipage}[t]{0.17\columnwidth}\raggedright\strut
45.17 \selectlanguage{ngerman}± 20.54\strut
\end{minipage} & \begin{minipage}[t]{0.17\columnwidth}\raggedright\strut
\textless{}0.0001\strut
\end{minipage}\tabularnewline
\begin{minipage}[t]{0.17\columnwidth}\raggedright\strut
\textbf{E (cm/sec)}\strut
\end{minipage} & \begin{minipage}[t]{0.17\columnwidth}\raggedright\strut
0.79 \selectlanguage{ngerman}± 0.24\strut
\end{minipage} & \begin{minipage}[t]{0.17\columnwidth}\raggedright\strut
0.79 \selectlanguage{ngerman}± 0.3\strut
\end{minipage} & \begin{minipage}[t]{0.17\columnwidth}\raggedright\strut
0.81 \selectlanguage{ngerman}± 0.25\strut
\end{minipage} & \begin{minipage}[t]{0.17\columnwidth}\raggedright\strut
0.8041\strut
\end{minipage}\tabularnewline
\begin{minipage}[t]{0.17\columnwidth}\raggedright\strut
\textbf{e'\_medial\_annulus (cm/sec)}\strut
\end{minipage} & \begin{minipage}[t]{0.17\columnwidth}\raggedright\strut
0.07 \selectlanguage{ngerman}± 0.03\strut
\end{minipage} & \begin{minipage}[t]{0.17\columnwidth}\raggedright\strut
0.07 \selectlanguage{ngerman}± 0.03\strut
\end{minipage} & \begin{minipage}[t]{0.17\columnwidth}\raggedright\strut
0.05 \selectlanguage{ngerman}± 0.03\strut
\end{minipage} & \begin{minipage}[t]{0.17\columnwidth}\raggedright\strut
0.1591\strut
\end{minipage}\tabularnewline
\begin{minipage}[t]{0.19\columnwidth}\raggedright\strut
\textbf{e'\_lateral\_annulus} \textbf{(cm/sec)}\strut
\end{minipage} & \begin{minipage}[t]{0.19\columnwidth}\raggedright\strut
0.19 \selectlanguage{ngerman}± 1.34\strut
\end{minipage} & \begin{minipage}[t]{0.19\columnwidth}\raggedright\strut
0.09 \selectlanguage{ngerman}± 0.04\strut
\end{minipage} & \begin{minipage}[t]{0.19\columnwidth}\raggedright\strut
0.07 \selectlanguage{ngerman}± 0.03\strut
\end{minipage} & \begin{minipage}[t]{0.19\columnwidth}\raggedright\strut
0.3427\strut
\end{minipage}\tabularnewline
\begin{minipage}[t]{0.17\columnwidth}\raggedright\strut
\textbf{E/e'\_medial}\strut
\end{minipage} & \begin{minipage}[t]{0.17\columnwidth}\raggedright\strut
13.65 \selectlanguage{ngerman}±7.79\strut
\end{minipage} & \begin{minipage}[t]{0.17\columnwidth}\raggedright\strut
13.22 \selectlanguage{ngerman}± 7.14\strut
\end{minipage} & \begin{minipage}[t]{0.17\columnwidth}\raggedright\strut
19.06 \selectlanguage{ngerman}± 10.15\strut
\end{minipage} & \begin{minipage}[t]{0.17\columnwidth}\raggedright\strut
0.1514\strut
\end{minipage}\tabularnewline
\begin{minipage}[t]{0.17\columnwidth}\raggedright\strut
\textbf{E/e'\_lateral}\strut
\end{minipage} & \begin{minipage}[t]{0.17\columnwidth}\raggedright\strut
10.97 \selectlanguage{ngerman}± 6.29\strut
\end{minipage} & \begin{minipage}[t]{0.17\columnwidth}\raggedright\strut
11.12 \selectlanguage{ngerman}± 6.68\strut
\end{minipage} & \begin{minipage}[t]{0.17\columnwidth}\raggedright\strut
12.47 \selectlanguage{ngerman}± 6.69\strut
\end{minipage} & \begin{minipage}[t]{0.17\columnwidth}\raggedright\strut
0.4245\strut
\end{minipage}\tabularnewline
\begin{minipage}[t]{0.17\columnwidth}\raggedright\strut
\textbf{Right ventricular systolic pressure (mmHg)}\strut
\end{minipage} & \begin{minipage}[t]{0.17\columnwidth}\raggedright\strut
30.97 \selectlanguage{ngerman}± 9.27\strut
\end{minipage} & \begin{minipage}[t]{0.17\columnwidth}\raggedright\strut
36.72 \selectlanguage{ngerman}± 14.50\strut
\end{minipage} & \begin{minipage}[t]{0.17\columnwidth}\raggedright\strut
48.12 \selectlanguage{ngerman}± 13.92\strut
\end{minipage} & \begin{minipage}[t]{0.17\columnwidth}\raggedright\strut
\textless{}0.0001\strut
\end{minipage}\tabularnewline
\begin{minipage}[t]{0.17\columnwidth}\raggedright\strut
\textbf{Left ventricular ejection fraction (\%)}\strut
\end{minipage} & \begin{minipage}[t]{0.17\columnwidth}\raggedright\strut
60.19 \selectlanguage{ngerman}± 12.65\strut
\end{minipage} & \begin{minipage}[t]{0.17\columnwidth}\raggedright\strut
50.20 \selectlanguage{ngerman}± 16.13\strut
\end{minipage} & \begin{minipage}[t]{0.17\columnwidth}\raggedright\strut
28.44 \selectlanguage{ngerman}± 15.29\strut
\end{minipage} & \begin{minipage}[t]{0.17\columnwidth}\raggedright\strut
\textless{}0.0001\strut
\end{minipage}\tabularnewline
\begin{minipage}[t]{0.17\columnwidth}\raggedright\strut
\textbf{Left ventricular end diastolic diameter (mm)}\strut
\end{minipage} & \begin{minipage}[t]{0.17\columnwidth}\raggedright\strut
46.50 \selectlanguage{ngerman}± 7.22\strut
\end{minipage} & \begin{minipage}[t]{0.17\columnwidth}\raggedright\strut
50.21 \selectlanguage{ngerman}± 8.05\strut
\end{minipage} & \begin{minipage}[t]{0.17\columnwidth}\raggedright\strut
59.81 \selectlanguage{ngerman}± 11.08\strut
\end{minipage} & \begin{minipage}[t]{0.17\columnwidth}\raggedright\strut
\textless{}0.0001\strut
\end{minipage}\tabularnewline
\begin{minipage}[t]{0.17\columnwidth}\raggedright\strut
\textbf{Left ventricular end systolic diameter (mm)}\strut
\end{minipage} & \begin{minipage}[t]{0.17\columnwidth}\raggedright\strut
30.09 \selectlanguage{ngerman}± 8.22\strut
\end{minipage} & \begin{minipage}[t]{0.17\columnwidth}\raggedright\strut
36.57 \selectlanguage{ngerman}± 12.78\strut
\end{minipage} & \begin{minipage}[t]{0.17\columnwidth}\raggedright\strut
49.26 \selectlanguage{ngerman}± 13.92\strut
\end{minipage} & \begin{minipage}[t]{0.17\columnwidth}\raggedright\strut
\textless{}0.0001\strut
\end{minipage}\tabularnewline
\begin{minipage}[t]{0.17\columnwidth}\raggedright\strut
\textbf{Right ventricular fractional area change (FAC) (\%)}\strut
\end{minipage} & \begin{minipage}[t]{0.17\columnwidth}\raggedright\strut
41.71 \selectlanguage{ngerman}± 8.70\strut
\end{minipage} & \begin{minipage}[t]{0.17\columnwidth}\raggedright\strut
38.67 \selectlanguage{ngerman}± 9.63\strut
\end{minipage} & \begin{minipage}[t]{0.17\columnwidth}\raggedright\strut
32.89 \selectlanguage{ngerman}± 12.23\strut
\end{minipage} & \begin{minipage}[t]{0.17\columnwidth}\raggedright\strut
\textless{}0.0001\strut
\end{minipage}\tabularnewline
\begin{minipage}[t]{0.17\columnwidth}\raggedright\strut
\textbf{Lateral free wall peak systolic strain, S (\%)}\strut
\end{minipage} & \begin{minipage}[t]{0.17\columnwidth}\raggedright\strut
-26.12 \selectlanguage{ngerman}± 16.10\strut
\end{minipage} & \begin{minipage}[t]{0.17\columnwidth}\raggedright\strut
-26.22 \selectlanguage{ngerman}± 29.04\strut
\end{minipage} & \begin{minipage}[t]{0.17\columnwidth}\raggedright\strut
-18.30 \selectlanguage{ngerman}± 6.52\strut
\end{minipage} & \begin{minipage}[t]{0.17\columnwidth}\raggedright\strut
0.2142\strut
\end{minipage}\tabularnewline
\begin{minipage}[t]{0.17\columnwidth}\raggedright\strut
\textbf{Lateral tricuspid annular systolic velocity, S' (cm/sec)}\strut
\end{minipage} & \begin{minipage}[t]{0.17\columnwidth}\raggedright\strut
10.72 \selectlanguage{ngerman}± 30.17\strut
\end{minipage} & \begin{minipage}[t]{0.17\columnwidth}\raggedright\strut
8.48 \selectlanguage{ngerman}± 2.48\strut
\end{minipage} & \begin{minipage}[t]{0.17\columnwidth}\raggedright\strut
7.70 \selectlanguage{ngerman}± 2.67\strut
\end{minipage} & \begin{minipage}[t]{0.17\columnwidth}\raggedright\strut
0.3181\strut
\end{minipage}\tabularnewline
\begin{minipage}[t]{0.17\columnwidth}\raggedright\strut
\textbf{Tricuspid annular plane systolic excursion, TAPSE (mm)}\strut
\end{minipage} & \begin{minipage}[t]{0.17\columnwidth}\raggedright\strut
20.84 \selectlanguage{ngerman}± 5.49\strut
\end{minipage} & \begin{minipage}[t]{0.17\columnwidth}\raggedright\strut
19.93 \selectlanguage{ngerman}± 6.21\strut
\end{minipage} & \begin{minipage}[t]{0.17\columnwidth}\raggedright\strut
16.11 \selectlanguage{ngerman}± 8.65\strut
\end{minipage} & \begin{minipage}[t]{0.17\columnwidth}\raggedright\strut
0.0003\strut
\end{minipage}\tabularnewline
\begin{minipage}[t]{0.17\columnwidth}\raggedright\strut
\textbf{Cardiac MRI data}\strut
\end{minipage} & \begin{minipage}[t]{0.17\columnwidth}\raggedright\strut
\textbf{Cardiac MRI data}\strut
\end{minipage} & \begin{minipage}[t]{0.17\columnwidth}\raggedright\strut
\textbf{Cardiac MRI data}\strut
\end{minipage} & \begin{minipage}[t]{0.17\columnwidth}\raggedright\strut
\textbf{Cardiac MRI data}\strut
\end{minipage} & \begin{minipage}[t]{0.17\columnwidth}\raggedright\strut
\textbf{Cardiac MRI data}\strut
\end{minipage}\tabularnewline
\begin{minipage}[t]{0.17\columnwidth}\raggedright\strut
\textbf{Left ventricular end diastolic mass (g)}\strut
\end{minipage} & \begin{minipage}[t]{0.17\columnwidth}\raggedright\strut
132.45 \selectlanguage{ngerman}±53.19\strut
\end{minipage} & \begin{minipage}[t]{0.17\columnwidth}\raggedright\strut
137.99 \selectlanguage{ngerman}± 56.97\strut
\end{minipage} & \begin{minipage}[t]{0.17\columnwidth}\raggedright\strut
167.66 \selectlanguage{ngerman}± 56.46\strut
\end{minipage} & \begin{minipage}[t]{0.17\columnwidth}\raggedright\strut
0.0087\strut
\end{minipage}\tabularnewline
\begin{minipage}[t]{0.17\columnwidth}\raggedright\strut
\textbf{Left ventricular end diastolic mass indices
(g/m\textsuperscript{2})}\strut
\end{minipage} & \begin{minipage}[t]{0.17\columnwidth}\raggedright\strut
69.73 \selectlanguage{ngerman}± 26.80\strut
\end{minipage} & \begin{minipage}[t]{0.17\columnwidth}\raggedright\strut
70.81 \selectlanguage{ngerman}± 26.97\strut
\end{minipage} & \begin{minipage}[t]{0.17\columnwidth}\raggedright\strut
84.12 \selectlanguage{ngerman}± 24.61\strut
\end{minipage} & \begin{minipage}[t]{0.17\columnwidth}\raggedright\strut
0.0771\strut
\end{minipage}\tabularnewline
\begin{minipage}[t]{0.17\columnwidth}\raggedright\strut
\textbf{Right ventricular end diastolic volume (ml)}\strut
\end{minipage} & \begin{minipage}[t]{0.17\columnwidth}\raggedright\strut
144.63 \selectlanguage{ngerman}± 42.54\strut
\end{minipage} & \begin{minipage}[t]{0.17\columnwidth}\raggedright\strut
161.60 \selectlanguage{ngerman}± 52.55\strut
\end{minipage} & \begin{minipage}[t]{0.17\columnwidth}\raggedright\strut
227.24 \selectlanguage{ngerman}± 85.81\strut
\end{minipage} & \begin{minipage}[t]{0.17\columnwidth}\raggedright\strut
\textless{}0.0001\strut
\end{minipage}\tabularnewline
\begin{minipage}[t]{0.17\columnwidth}\raggedright\strut
\textbf{Indexed Right ventricular end diastolic volume (ml)}\strut
\end{minipage} & \begin{minipage}[t]{0.17\columnwidth}\raggedright\strut
104.15 \selectlanguage{ngerman}± 529.43\strut
\end{minipage} & \begin{minipage}[t]{0.17\columnwidth}\raggedright\strut
84.04 \selectlanguage{ngerman}± 25.88\strut
\end{minipage} & \begin{minipage}[t]{0.17\columnwidth}\raggedright\strut
116.82 \selectlanguage{ngerman}± 39.26\strut
\end{minipage} & \begin{minipage}[t]{0.17\columnwidth}\raggedright\strut
0.8348\strut
\end{minipage}\tabularnewline
\begin{minipage}[t]{0.17\columnwidth}\raggedright\strut
\textbf{Right ventricular end systolic volume (ml)}\strut
\end{minipage} & \begin{minipage}[t]{0.17\columnwidth}\raggedright\strut
59.45 \selectlanguage{ngerman}± 22.90\strut
\end{minipage} & \begin{minipage}[t]{0.17\columnwidth}\raggedright\strut
93.70 \selectlanguage{ngerman}± 32.06\strut
\end{minipage} & \begin{minipage}[t]{0.17\columnwidth}\raggedright\strut
175.85 \selectlanguage{ngerman}± 73.64\strut
\end{minipage} & \begin{minipage}[t]{0.17\columnwidth}\raggedright\strut
\textless{}0.0001\strut
\end{minipage}\tabularnewline
\begin{minipage}[t]{0.17\columnwidth}\raggedright\strut
\textbf{Indexed Right ventricular end systolic volume (ml)}\strut
\end{minipage} & \begin{minipage}[t]{0.17\columnwidth}\raggedright\strut
30.77 \selectlanguage{ngerman}± 11.51\strut
\end{minipage} & \begin{minipage}[t]{0.17\columnwidth}\raggedright\strut
48.22 \selectlanguage{ngerman}± 16.90\strut
\end{minipage} & \begin{minipage}[t]{0.17\columnwidth}\raggedright\strut
90.82 \selectlanguage{ngerman}± 34.25\strut
\end{minipage} & \begin{minipage}[t]{0.17\columnwidth}\raggedright\strut
\textless{}0.0001\strut
\end{minipage}\tabularnewline
\begin{minipage}[t]{0.17\columnwidth}\raggedright\strut
\textbf{Right ventricular stroke volume (ml)}\strut
\end{minipage} & \begin{minipage}[t]{0.17\columnwidth}\raggedright\strut
85.13 \selectlanguage{ngerman}± 23.57\strut
\end{minipage} & \begin{minipage}[t]{0.17\columnwidth}\raggedright\strut
69.56 \selectlanguage{ngerman}± 23.53\strut
\end{minipage} & \begin{minipage}[t]{0.17\columnwidth}\raggedright\strut
51.47 \selectlanguage{ngerman}± 19.65\strut
\end{minipage} & \begin{minipage}[t]{0.17\columnwidth}\raggedright\strut
\textless{}0.0001\strut
\end{minipage}\tabularnewline
\begin{minipage}[t]{0.17\columnwidth}\raggedright\strut
\textbf{Indexed Right ventricular stroke volume (ml)}\strut
\end{minipage} & \begin{minipage}[t]{0.17\columnwidth}\raggedright\strut
43.72 \selectlanguage{ngerman}± 11.17\strut
\end{minipage} & \begin{minipage}[t]{0.17\columnwidth}\raggedright\strut
35.92 \selectlanguage{ngerman}± 11.01\strut
\end{minipage} & \begin{minipage}[t]{0.17\columnwidth}\raggedright\strut
25.38 \selectlanguage{ngerman}± 8.97\strut
\end{minipage} & \begin{minipage}[t]{0.17\columnwidth}\raggedright\strut
\textless{}0.0001\strut
\end{minipage}\tabularnewline
\begin{minipage}[t]{0.17\columnwidth}\raggedright\strut
\textbf{Right ventricular ejection fraction (\%)}\strut
\end{minipage} & \begin{minipage}[t]{0.17\columnwidth}\raggedright\strut
59.36 \selectlanguage{ngerman}± 6.79\strut
\end{minipage} & \begin{minipage}[t]{0.17\columnwidth}\raggedright\strut
42.79 \selectlanguage{ngerman}± 5.21\strut
\end{minipage} & \begin{minipage}[t]{0.17\columnwidth}\raggedright\strut
23.45 \selectlanguage{ngerman}± 6.27\strut
\end{minipage} & \begin{minipage}[t]{0.17\columnwidth}\raggedright\strut
\textless{}0.0001\strut
\end{minipage}\tabularnewline
\bottomrule
\end{longtable}

\textbf{Table 3:} Area under the Receiver Operating Curve
Characteristics of Echocardiographic parameters to predict right
ventricular ejection fraction measured using cardiac magnetic resonance
imaging.\selectlanguage{english}
\begin{longtable}[]{@{}lllll@{}}
\toprule
& \textbf{AUC} & \textbf{AUC (95\% CI)} & \textbf{Sensitivity} &
\textbf{Specificity}\tabularnewline
\midrule
\endhead
\textbf{Group B (Right Ventricular Ejection Fraction \textless{}45\%)} &
\textbf{Group B (Right Ventricular Ejection Fraction \textless{}45\%)} &
\textbf{Group B (Right Ventricular Ejection Fraction \textless{}45\%)} &
\textbf{Group B (Right Ventricular Ejection Fraction \textless{}45\%)} &
\textbf{Group B (Right Ventricular Ejection Fraction
\textless{}45\%)}\tabularnewline
\textbf{Strain (RV free wall) (\%)} & 0.6866 & 0.627-0.7463 & 0.6809 &
0.6275\tabularnewline
\textbf{S' (cm/sec)} & 0.5909 & 0.5264-0.6553 & 0.7613 &
0.4314\tabularnewline
\textbf{FAC (\%)} & 0.6658 & 0.605-0.7265 & 0.6734 &
0.598\tabularnewline
\textbf{TAPSE (mm)} & 0.5819 & 0.5144-0.6495 & 0.8241 &
0.3627\tabularnewline
\textbf{Group C (Right Ventricular Ejection Fraction \textless{} 30\%)}
& \textbf{Group C (Right Ventricular Ejection Fraction \textless{}
30\%)} & \textbf{Group C (Right Ventricular Ejection Fraction
\textless{} 30\%)} & \textbf{Group C (Right Ventricular Ejection
Fraction \textless{} 30\%)} & \textbf{Group C (Right Ventricular
Ejection Fraction \textless{} 30\%)}\tabularnewline
\textbf{Strain (RV free wall) (\%)} & 0.7795 & 0.6795-0.8795 & 0.7886 &
0.7407\tabularnewline
\textbf{S' (cm/sec)} & 0.6525 & 0.5369-0.7681 & 0.7886 &
0.7407\tabularnewline
\textbf{FAC (\%)} & 0.6942 & 0.5918-0.7966 & 0.4651 &
0.8519\tabularnewline
\textbf{TAPSE (mm)} & 0.6732 & 0.5508-0.7956 & 0.6469 &
0.7037\tabularnewline
\bottomrule
\end{longtable}\selectlanguage{english}
\begin{figure}[H]
\begin{center}
\includegraphics[width=0.70\columnwidth]{figures/Figure-1/Figure-1}

\end{center}
\end{figure}\selectlanguage{english}
\begin{figure}[H]
\begin{center}
\includegraphics[width=0.70\columnwidth]{figures/Figure-2/Figure-2}

\end{center}
\end{figure}\selectlanguage{english}
\begin{figure}[H]
\begin{center}
\includegraphics[width=0.70\columnwidth]{figures/Figure-3/Figure-3}

\end{center}
\end{figure}\selectlanguage{english}
\begin{figure}[H]
\begin{center}
\includegraphics[width=0.70\columnwidth]{figures/Figure-4/Figure-4}

\end{center}
\end{figure}

\selectlanguage{english}
\FloatBarrier
\end{document}

