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\begin{document}

\title{Left Atrial Function by Two-Dimensional Speckle Tracking
Echocardiography in Patients with Severe Rheumatic Mitral Stenosis and
Pulmonary Hypertension}



\author[1]{VIMAL MEHTA}%
\author[1]{Dhanjibhai Chaudhari}%
\author[1]{Pratishtha Mehra}%
\author[1]{Sudhanshu Mahajan}%
\author[1]{Jamal Yusuf}%
\author[1]{Safal Safal}%
\author[1]{Sanjeev Kathuria}%
\author[1]{Saibal Mukhopadhyay}%
\affil[1]{GB Pant Hospital}%


\vspace{-1em}



  
  \date{May 28, 2024}


\begingroup
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\selectlanguage{english}
\begin{abstract}
Aim: The aim of this study was to assess the left atrial (LA) function
in severe rheumatic mitral stenosis (MS) patients using two-dimensional
speckle tracking echocardiography (STE) and its correlation with
clinical symptoms and echocardiography parameters. Methods: A total of
120 subjects (80 patients with isolated severe MS {[}mitral valve area
(MVA) [?]1.5 cm2{]} in sinus rhythm and 40 healthy controls) underwent
comprehensive echocardiography including STE for assessment of LA strain
{[}reservoir strain (LASr), conduit strain (LAScd) and contractile
strain (LASct){]}. Results: The mean MVA in cases was 0.93 \selectlanguage{ngerman}± 0.21 cm2.
The mean values of LASr (14.73 ± 8.59\%), LAScd (-7.61 ± 4.47\%) and
LASct (-7.16 ± 5.15\%) among cases were significantly less (p\textless{}
0.001) when compared to controls where the values were 44.11 ± 10.44\%,
-32.45 ± 7.63\%, -11.85 ± 6.77\% respectively. Thus the compensatory LA
contractile function was also compromised. The New York Heart
Association (NYHA) class III, II and I dyspnea was present in 37
(46.25\%), 38 (47.5\%) and 5 (6.25\%) subjects respectively. All the
three LA strain parameters showed a trend towards decline with increase
in severity of MS, increase in LA size, increase in mean and peak
diastolic transmitral gradients and with higher NYHA functional class.
Conclusion: Left atrial dysfunction is common in severe rheumatic MS as
suggested by severely reduced LA reservoir, conduit and contractile
strain. Early and timely intervention in these patients irrespective of
NYHA functional class is advocated as it may likely improve the LA
function and avoid clinical deterioration.%
\end{abstract}\selectlanguage{ngerman}%



\sloppy


\textbf{Introduction}

Rheumatic heart disease (RHD) is endemic in developing countries, where
it remains the second most common cause of cardiovascular morbidity and
mortality after atherosclerotic cardiovascular disease Mitral valve is
the most commonly involved valve being afflicted in 60.2\% patients,
with mitral stenosis (MS) being the most common valve lesion in chronic
RHD. MS causes obstruction to left ventricular (LV) diastolic filling,
leading to morphological and functional changes in left atrium (LA) as a
result of LA pressure overload. The elevated LA pressure is transmitted
back to pulmonary circulation resulting in exertional dyspnea and
ultimately leads to development of post-capillary pulmonary
hypertension. LA compliance is an important determinant of LA pressure
as different LA pressures are recorded in different subjects despite
similar mitral valve areas (MVA).\textsuperscript{4} Chronic LA pressure
overload leads to atrial muscle bundle disorganization and fibrosis
resulting in both atrial stiffness and atrial reservoir
dysfunction.\textsuperscript{5} The left atrial dysfunction may be
detected and quantified by deformation imaging i.e. speckle tracking
echocardiography (STE). STE is a reliable and effective tool for
evaluating LA function.

LA dysfunction has been reported in patients with rheumatic
MS.\textsuperscript{10} However most studies have either assessed global
LA strain, reservoir or conduit strain values with contractile strain
being reported only in mild to moderate MS.\textsuperscript{10,11} Only
very limited data is available regarding all three strain parameters in
patients with severe MS. In the present study we assessed LA function
(reservoir, conduit strain and contractile strain) by two-dimensional
speckle tracking echocardiography and its correlation with clinical
symptoms and echocardiography parameters in patients with isolated
severe MS with pulmonary hypertension and healthy controls.

\textbf{Material and methods}

This study was a comparative cross-sectional study conducted at a
tertiary care hospital in North India in which 120 subjects including 80
patients with isolated severe MS (MVA [?]1.5 cm\textsuperscript{2}) with
pulmonary hypertension between 18-40 years of age who were in sinus
rhythm and 40 age matched healthy controls were enrolled from cardiology
outpatient department. Patients with moderate to severe mitral
regurgitation or other significant valve involvement and co-morbidities
like hypertension, diabetes mellitus, coronary artery disease, overt LV
systolic dysfunction were excluded. Philips EpiQ 7C echocardiography
system with 2.4 MHz transducer was used for recording echocardiographic
images. The study was carried out after prior approval from the
institutional ethical committee and written informed consent was
obtained from all the participants.

For all subjects, standard two-dimensional (2D), M-mode and Doppler
echocardiograms were obtained according to the American Society of
Echocardiography guidelines.\textsuperscript{11} Baseline measurements
included were LA dimension, LV internal dimension in diastole
(LVID\textsubscript{d}) and in systole (LVID\textsubscript{s}) and LV
ejection fraction (LVEF). MVA [?]1.5 cm\textsuperscript{2} (by planimetry)
was considered to define severe MS and MVA \textless{}1.0
cm\textsuperscript{2} defined very severe MS.\textsuperscript{13} Peak
diastolic gradient (PG) and mean diastolic gradient (MG) across the
mitral valve was calculated by continuous wave (CW) Doppler tracing.
Apical four chamber (A4C) and apical two chamber (A2C) views were
recorded in all the patients. Right ventricle systolic pressure (RVSP)
was measured from tricuspid regurgitation jet velocity by CW Doppler
after ruling out primary involvement of tricuspid and pulmonary
valve.\textsuperscript{14} Three consecutive cardiac cycles were
recorded and averaged.

Pulmonary hypertension (PH) was graded based on peak RVSP as mild 36-45
mm Hg, moderate 46-60 mm Hg and severe if \textgreater{}60 mm
Hg.\textsuperscript{15} Patients were classified according to the New
York Heart Association (NYHA) functional classification. Patients in
NYHA class IV were not included because all the patients recruited were
from OPD visits and were ambulatory.

\emph{Left atrial two dimensional speckle tracking echocardiography}

LA images were analyzed offline via QLAB 13 Philips software for speckle
tracking as depicted in Figure 1. LA deformation is a cyclical process,
which can be sub-divided into three phases: a) Reservoir phase: starts
at the end of ventricular diastole (mitral valve closure) and continues
until mitral valve opening. It encompasses the time of LV isovolumic
contraction, ejection and isovolumic relaxation, b) Conduit phase:
occurs from the time of mitral valve opening through diastasis until the
onset of LA contraction, c) Contraction phase: occurs from the onset of
LA contraction until the end of ventricular diastole (mitral valve
closure). For offline analysis of LA function, cardiac cycle was gated
with ECG and kept from end-diastole to end-diastole with zero reference
point taken as peak of R wave.\textsuperscript{16} After selection of
appropriate image and ECG gating of cardiac cycle, software
automatically traces the endocardial border of LA while manual
adjustments are done to exclude pulmonary veins and LA appendage.

\textbf{Statistical analysis}

Epi Info version 7.1.1 software was used for the analysis of the data.
Continuous data were presented as mean with standard deviation and
compared by t-test. Continuous data of more than two groups were
compared by ANOVA test. Categorical data were presented as frequency and
percentage and compared using a chi-square test. P value \textless{}0.05
was considered as significant. To investigate for inter-observer
variability for LA strain, analysis of 10 random subjects was done by
two independent investigators who were blinded to the clinical data. For
intra-observer variability, repeat offline LA strain estimation was done
at 5 \selectlanguage{ngerman}± 2 days later in 10 randomly selected patients. The interclass
correlation coefficients (ICCs) were calculated with point estimates and
95\% confidence intervals (CIs) being reported.

\textbf{Results}

We enrolled 120 subjects including 80 cases and 40 controls in our
study. There were 57 females and 23 males amongst cases while among
control population there were 15 females and 25 males. Table 1 shows the
baseline characteristics and various echocardiographic parameters among
study subjects. The mean LA size among cases was 4.67 ± 0.65 cm and mean
MVA was 0.93 ± 0.21 cm\textsuperscript{2}. Severe MS (MVA 1-1.5
cm\textsuperscript{2}) was seen in 44 (55\%) subjects while very severe
MS (MVA \textless{}1 cm\textsuperscript{2}) was seen in 36 (45\%)
subjects. The mean RVSP in cases was 60.01 ± 19.88 mm Hg suggesting
moderate to severe pulmonary hypertension. All three STE derived LA
strain {[}reservoir strain (LAS\textsubscript{r}), conduit strain
(LAS\textsubscript{cd}) and contractile strain
(LAS\textsubscript{ct}){]} parameters were significantly reduced among
cases (p \textless{}0.001) with mean values of
LAS\textsubscript{r}(14.73 ± 8.59\%), LAS\textsubscript{cd} (-7.61 ±
4.47\%) and LAS\textsubscript{ct} (-7.16 ± 5.15\%) when compared to
controls where the mean values were 44.11 ± 10.44\%, -32.45 ± 7.63\%,
-11.85 ± 6.77\% respectively. The interclass correlation coefficient for
LA strain measurement was 0.95 (95\% CI: 0.84-0.98) for inter-observer
agreement and 0.97 (95\% CI: 0.94-0.99) for intra-observer agreement,
indicating good inter-observer and intra-observer correlations.

The NYHA class III dyspnea was present in 37 (46.25\%) subjects, while
thirty-eight (47.5\%) subjects had NYHA class II dyspnea followed by 5
(6.25\%) subjects who had NYHA class I dyspnea. The descriptive
statistics associated with patients in different NYHA classes were
analyzed both between the groups and within group by ANOVA (Table 2).
There was no significant correlation between any echocardiography
derived parameters as well as LA strain parameters between various NYHA
classes except for MVA which was significantly lower in NYHA class III
(0.87 ± 0.21 cm\textsuperscript{2}) when compared to NYHA class II (0.97
± 0.2 cm\textsuperscript{2}) and I (1.18 ± 0.23 cm\textsuperscript{2})
{[}p= 0.004 between all groups{]} and RVSP which was significantly
higher in NYHA class III (66.32 ± 19.74 mmHg) when compared to class II
(55.03 ± 18.47) {[}p= 0.01 between NYHA class II and III{]}. All the
three mean LA strain values (reservoir, conduit, contractile strain)
were numerically lower in NYHA class III when compared to NYHA class I
patients but did not reach statistically significant difference.

We divided cases into groups based on increasing mean diastolic
transmitral gradient (four groups), increasing peak diastolic
transmitral gradient (three groups), increasing left atrial size (four
groups), increasing severity of pulmonary hypertension (four groups) and
decreasing mitral valve area (two groups) to study their correlation
with LA strain (Table 3). The numerical value of all three STE derived
LA strain parameters showed a trend towards decline with decrease in
MVA, increase in LA size and increase in severity of PH, increase in MG
and PG. But none of the above correlations achieved statistical
significance (Table 4).

\textbf{Discussion}

The main finding of our study is a significant decrease in all three
left atrial strain parameters i.e. reservoir, conduit and contractile
strain suggestive of severe LA dysfunction in patients with severe
rheumatic MS when compared to healthy controls. It has been shown in a
previous study by Mahfouz et al\textsuperscript{17} on 75 patients that
the conduit and reservoir function are affected in mild MS while LA
contractile strain is well preserved. The increased LA contractile
function appears as a compensatory mechanism to counterbalance reduced
LA reservoir and conduit function in mild MS as LV filling predominantly
occurs in LA contractile phase in MS in contrast to normal filling
pattern where LA filling predominantly occurs in the early conduit
phase.\textsuperscript{18} However characterizing the various components
of LA function in MS and in other disease states requires complex
methodology.\textsuperscript{19} The speckle tracking echocardiography
provides an opportunity to quantitatively characterize various
components of LA function non-invasively. Therefore, our study
population which comprised of patients with severe MS (n = 44) and very
severe MS (n = 36) could explain the reduction in all three LA strain
parameters suggesting advanced degree of LA dysfunction. Our study shows
that in severe MS, LA contractile function is also compromised in
addition to reservoir and conduit function. Another study by Demirkol et
al on 52 asymptomatic MS patients also showed that LA reservoir and
conduit strain was significantly reduced but the contractile strain was
increased in MS patients when compared to control population. This could
similarly be explained by difference in the characteristics of study
population as in their study cohort\textsuperscript{10}, MS patients had
mean MVA by planimetry of 1.38 ± 0.36 cm\textsuperscript{2} with mean
diastolic transmitral gradient of 7.9 ± 2.8 mm Hg in contrast to our
study where MS was more severe as mean MVA was 0.93 ± 0.21
cm\textsuperscript{2} and mean transmitral gradient was 12.33 ± 4.16 mm
Hg which could have compromised the contractile function.

93.75\%) subjects in our study were in NYHA functional class II and III.
There was a non-significant trend of higher mean LA size, peak and mean
diastolic transmitral gradients and RVSP with increasing NYHA functional
class while mean MVA was significantly less in NYHA class III group when
compared to class II and I group (p= 0.004 between all groups). There
was trend towards stepwise decrease in LA reservoir, conduit and
contractile strain with deteriorating NYHA functional class, however
this did not reach statistical significance. Our results were different
from a study by Chien et al\textsuperscript{20} on 69 MS patients which
showed positive correlation between atrial deformation and NYHA
functional class. In their study cohort, the mean MVA by planimetry was
1.41 ± 0.50 cm\textsuperscript{2} in contrast to our study where mean
MVA was 0.93 ± 0.21 cm\textsuperscript{2} and all patients had severe MS
and none with mild/moderate MS. Hence, LA strain parameters were
markedly decreased in our study population of severe MS patients
(suggesting LA dysfunction) making further numerical fall with
deteriorating NYHA functional class inconsequential. Secondly, in their
study\textsuperscript{20}, atrial fibrillation (AF) patients constituted
57\% of the study population, hence LA contractile strain was not
reported. Their results of atrial deformation are based upon LA
reservoir strain in addition to reservoir and conduit strain rate. In
our study, we excluded AF patients and we systematically evaluated and
analyzed all three LA strain parameters in our study cohort.

Mitral stenosis results in obstruction to LV filling resulting in LA
pressure overload which leads to alteration in LA geometry and function
with progressive interstitial fibrosis, dilatation and remodeling of LA,
ultimately culminating in LA dysfunction.\textsuperscript{5} However, LA
remodeling is at least partially reversible and mitral valve
intervention in the form of balloon mitral valvotomy/surgery can relieve
LA pressure overload, thereby reducing LA size and improving LA function
leading to reverse remodeling.\textsuperscript{22}

Our study has important clinical implication in that the patients with
severe MS regardless of severity of NYHA functional class develop severe
LA dysfunction which worsens with further decline in MVA. Therefore
patients with severe MS should be subjected to early and timely BMV so
as to improve their LA function.\textsuperscript{11,22} We also believe
that intervention may have an impact on preventing these patients to
develop atrial fibrillation (AF), RV dysfunction and improving their
prognosis. In the study by Ancona et al\textsuperscript{23} the degree
of reduced LA systolic strain in patients with rheumatic MS correlated
not only with worse cardiovascular outcomes during 3-year follow-up but
also was the most powerful predictor of new onset AF at 4-year
follow-up. In our study population of severe mitral stenosis and
pulmonary hypertension, marked LA dysfunction was present. The high RVSP
also likely contributed to LA dysfunction as higher pulmonary artery
pressures have been reported to have strong negative correlation with LA
compliance.\textsuperscript{4} Vriz et al\textsuperscript{24} showed
that reduced LA reservoir strain can predict development of RV
impairment and AF in patients with severe MS better than transmitral
gradients.

Finally, many factors could have contributed to this LA dysfunction
including chronic LA pressure overload, LA fibrosis, adverse remodeling
of LA, involvement of mitral apparatus in the rheumatic process, LV and
RV dysfunction. In fact our group has recently shown that decrease in
deformation of basal segments of LV is more compared to mid and apical
LV segments suggesting rheumatic endocarditis and scarring extend from
the mitral annulus to the surrounding basal LV myocardial
segments.\textsuperscript{25}

\textbf{Limitations}

The major limitation of our study is that we included only isolated
severe MS patients and hence our results are not applicable to patients
with multi-valvular disease or other valve disease. This was done so as
to have a uniform study population as including subjects with
regurgitant lesions would have resulted in volume overload of the left
atrium thereby affecting the results. Secondly our results are not
applicable to patients in AF as they were excluded. This was because the
speckle tracking echocardiography is ideally for patients with regular
heart rhythms~as strain values are directly influenced by the length of
diastole. Thirdly, image quality and different vendor machines as well
different versions of software of the same vendor may affect the
results. However, the same equipment and software were used to assess
all study subjects thereby avoiding any inconsistency in measurements.
Fourthly invasive cardiac catheterization was not done in our study.
This was because two-dimensional echocardiography is standard technique
to evaluate patients with rheumatic MS. Lastly we did not study the
effect of BMV on LA strain parameters which requires further
investigation.

\textbf{Conclusion}

The present study shows that marked left atrial dysfunction is seen in
severe rheumatic MS irrespective of NYHA functional class as suggested
by severely reduced left atrial reservoir, conduit and contractile
strain. LA function deteriorated further non-significantly with
increasing severity of MS (decreasing mitral valve area), increase in
left atrial size and increase in mean and peak transmitral gradient.
Hence, our study results suggests that early and timely intervention in
severe MS patients irrespective of NYHA functional class should be done
as it may likely improve the LA function and avoid clinical
deterioration. Further BMV may retard the development of AF and RV
dysfunction. This hypothesis however requires further study.

\textbf{Conflicts of Interest} : All the authors declare that they have
no conflicts of interest with respect to the present submission.

\textbf{Author contributions}

Vimal Mehta: Conceptualization, Data collection, Investigation,
Methodology, Formal analysis, Supervision, Writing- Review \& Editing-
Original \& Final Draft, Approval of final manuscript. Dhanjibhai
Chaudhari: Data collection, Formal analysis, Approval of final
manuscript. Pratishtha Mehra: Conceptualization, Data collection,
Investigation, Methodology, Formal analysis, Writing- Review \& Editing,
Resources, Approval of final manuscript. Sudhanshu Mahajan: Data
analysis, Writing- Review \& Editing- Original \& Final Draft, Approval
of final manuscript. Jamal Yusuf: Validation, Review \& Editing,
Approval of final manuscript. Safal: Critical intellectual inputs,
Review \& Editing, Approval of final manuscript. Sanjeev Kathuria:
Validation, Review \& Editing, Approval of final manuscript. Saibal
Mukhopadhyay: Methodology, Resources, Approval of final manuscript.

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\textbf{Table 1: Baseline characteristics and echocardiographic
parameters among subjects}\selectlanguage{english}
\begin{longtable}[]{@{}llll@{}}
\toprule
\begin{minipage}[b]{0.22\columnwidth}\raggedright\strut
\strut
\end{minipage} & \begin{minipage}[b]{0.22\columnwidth}\raggedright\strut
Cases (n= 80)\strut
\end{minipage} & \begin{minipage}[b]{0.22\columnwidth}\raggedright\strut
Controls (n=40)\strut
\end{minipage} & \begin{minipage}[b]{0.22\columnwidth}\raggedright\strut
P value\strut
\end{minipage}\tabularnewline
\midrule
\endhead
\begin{minipage}[t]{0.22\columnwidth}\raggedright\strut
Age (years)\strut
\end{minipage} & \begin{minipage}[t]{0.22\columnwidth}\raggedright\strut
30.4 \selectlanguage{ngerman}± 6.7\strut
\end{minipage} & \begin{minipage}[t]{0.22\columnwidth}\raggedright\strut
29.5 \selectlanguage{ngerman}± 5.9\strut
\end{minipage} & \begin{minipage}[t]{0.22\columnwidth}\raggedright\strut
0.46\strut
\end{minipage}\tabularnewline
\begin{minipage}[t]{0.22\columnwidth}\raggedright\strut
LA size (cm)\strut
\end{minipage} & \begin{minipage}[t]{0.22\columnwidth}\raggedright\strut
4.67 \selectlanguage{ngerman}± 0.65\strut
\end{minipage} & \begin{minipage}[t]{0.22\columnwidth}\raggedright\strut
2.79 \selectlanguage{ngerman}± 0.41\strut
\end{minipage} & \begin{minipage}[t]{0.22\columnwidth}\raggedright\strut
\textless{}0.001\strut
\end{minipage}\tabularnewline
\begin{minipage}[t]{0.22\columnwidth}\raggedright\strut
LVID\textsubscript{d} (cm)\strut
\end{minipage} & \begin{minipage}[t]{0.22\columnwidth}\raggedright\strut
4.40 \selectlanguage{ngerman}± 0.40\strut
\end{minipage} & \begin{minipage}[t]{0.22\columnwidth}\raggedright\strut
4.5 \selectlanguage{ngerman}± 0.21\strut
\end{minipage} & \begin{minipage}[t]{0.22\columnwidth}\raggedright\strut
0.09\strut
\end{minipage}\tabularnewline
\begin{minipage}[t]{0.22\columnwidth}\raggedright\strut
LVID\textsubscript{s} (cm)\strut
\end{minipage} & \begin{minipage}[t]{0.22\columnwidth}\raggedright\strut
2.79 \selectlanguage{ngerman}± 0.33\strut
\end{minipage} & \begin{minipage}[t]{0.22\columnwidth}\raggedright\strut
2.68 \selectlanguage{ngerman}± 0.18\strut
\end{minipage} & \begin{minipage}[t]{0.22\columnwidth}\raggedright\strut
0.06\strut
\end{minipage}\tabularnewline
\begin{minipage}[t]{0.22\columnwidth}\raggedright\strut
LVEF (\%)\strut
\end{minipage} & \begin{minipage}[t]{0.22\columnwidth}\raggedright\strut
59.85 \selectlanguage{ngerman}± 3.55\strut
\end{minipage} & \begin{minipage}[t]{0.22\columnwidth}\raggedright\strut
60.45 \selectlanguage{ngerman}± 1.89\strut
\end{minipage} & \begin{minipage}[t]{0.22\columnwidth}\raggedright\strut
0.23\strut
\end{minipage}\tabularnewline
\begin{minipage}[t]{0.22\columnwidth}\raggedright\strut
MVA (cm\textsuperscript{2})\strut
\end{minipage} & \begin{minipage}[t]{0.22\columnwidth}\raggedright\strut
0.93 \selectlanguage{ngerman}± 0.21\strut
\end{minipage} & \begin{minipage}[t]{0.22\columnwidth}\raggedright\strut
5.17 \selectlanguage{ngerman}± 0.53\strut
\end{minipage} & \begin{minipage}[t]{0.22\columnwidth}\raggedright\strut
\textless{}0.0001\strut
\end{minipage}\tabularnewline
\begin{minipage}[t]{0.22\columnwidth}\raggedright\strut
PG (mm Hg)\strut
\end{minipage} & \begin{minipage}[t]{0.22\columnwidth}\raggedright\strut
19.33 \selectlanguage{ngerman}± 5.82\strut
\end{minipage} & \begin{minipage}[t]{0.22\columnwidth}\raggedright\strut
-\strut
\end{minipage} & \begin{minipage}[t]{0.22\columnwidth}\raggedright\strut
-\strut
\end{minipage}\tabularnewline
\begin{minipage}[t]{0.22\columnwidth}\raggedright\strut
MG (mm Hg)\strut
\end{minipage} & \begin{minipage}[t]{0.22\columnwidth}\raggedright\strut
12.33 \selectlanguage{ngerman}± 4.16\strut
\end{minipage} & \begin{minipage}[t]{0.22\columnwidth}\raggedright\strut
-\strut
\end{minipage} & \begin{minipage}[t]{0.22\columnwidth}\raggedright\strut
-\strut
\end{minipage}\tabularnewline
\begin{minipage}[t]{0.22\columnwidth}\raggedright\strut
RVSP (mm Hg)\strut
\end{minipage} & \begin{minipage}[t]{0.22\columnwidth}\raggedright\strut
60.01 \selectlanguage{ngerman}± 19.88\strut
\end{minipage} & \begin{minipage}[t]{0.22\columnwidth}\raggedright\strut
-\strut
\end{minipage} & \begin{minipage}[t]{0.22\columnwidth}\raggedright\strut
-\strut
\end{minipage}\tabularnewline
\begin{minipage}[t]{0.24\columnwidth}\raggedright\strut
LAS\textsubscript{r} (positive value, \%)\strut
\end{minipage} & \begin{minipage}[t]{0.24\columnwidth}\raggedright\strut
14.73 \selectlanguage{ngerman}± 8.59\strut
\end{minipage} & \begin{minipage}[t]{0.24\columnwidth}\raggedright\strut
44.11 \selectlanguage{ngerman}± 10.44\strut
\end{minipage} & \begin{minipage}[t]{0.24\columnwidth}\raggedright\strut
\textless{}0.001\strut
\end{minipage}\tabularnewline
\begin{minipage}[t]{0.24\columnwidth}\raggedright\strut
LAS\textsubscript{cd} (negative value, \%)\strut
\end{minipage} & \begin{minipage}[t]{0.24\columnwidth}\raggedright\strut
-7.61 \selectlanguage{ngerman}± 4.47\strut
\end{minipage} & \begin{minipage}[t]{0.24\columnwidth}\raggedright\strut
-32.45 \selectlanguage{ngerman}± 7.63\strut
\end{minipage} & \begin{minipage}[t]{0.24\columnwidth}\raggedright\strut
\textless{}0.001\strut
\end{minipage}\tabularnewline
\begin{minipage}[t]{0.24\columnwidth}\raggedright\strut
LAS\textsubscript{ct} (negative value, \%)\strut
\end{minipage} & \begin{minipage}[t]{0.24\columnwidth}\raggedright\strut
-7.16 \selectlanguage{ngerman}± 5.15\strut
\end{minipage} & \begin{minipage}[t]{0.24\columnwidth}\raggedright\strut
-11.85 \selectlanguage{ngerman}± 6.77\strut
\end{minipage} & \begin{minipage}[t]{0.24\columnwidth}\raggedright\strut
\textless{}0.001\strut
\end{minipage}\tabularnewline
\bottomrule
\end{longtable}

LA- left atrium; LVEF- left ventricular ejection fraction; LVIDd- left
ventricle internal dimension in diastole; LVIDs- left ventricle internal
dimension in systole; LAS\textsubscript{r}- left atrium reservoir
strain; LAS\textsubscript{cd}- left atrium conduit strain;
LAS\textsubscript{ct}- left atrium contractile strain; MG- mean
diastolic transmitral gradient; MVA- mitral valve area; PG- peak
diastolic transmitral gradient; RVSP- right ventricle systolic pressure

\textbf{Table 2: Distribution and statistical comparison of
echocardiography parameters among patients grouped according to various
NYHA classes}\selectlanguage{english}
\begin{longtable}[]{@{}llllllll@{}}
\toprule
\begin{minipage}[b]{0.10\columnwidth}\raggedright\strut
Echocardiography parameters\strut
\end{minipage} & \begin{minipage}[b]{0.10\columnwidth}\raggedright\strut
NYHA class\strut
\end{minipage} & \begin{minipage}[b]{0.10\columnwidth}\raggedright\strut
NYHA class\strut
\end{minipage} & \begin{minipage}[b]{0.10\columnwidth}\raggedright\strut
NYHA class\strut
\end{minipage} & \begin{minipage}[b]{0.10\columnwidth}\raggedright\strut
P value between various NYHA classes\strut
\end{minipage} & \begin{minipage}[b]{0.10\columnwidth}\raggedright\strut
P value between various NYHA classes\strut
\end{minipage} & \begin{minipage}[b]{0.10\columnwidth}\raggedright\strut
P value between various NYHA classes\strut
\end{minipage} & \begin{minipage}[b]{0.10\columnwidth}\raggedright\strut
P value between various NYHA classes\strut
\end{minipage}\tabularnewline
\midrule
\endhead
\begin{minipage}[t]{0.12\columnwidth}\raggedright\strut
\strut
\end{minipage} & \begin{minipage}[t]{0.12\columnwidth}\raggedright\strut
I (Mean \selectlanguage{ngerman}± SD, n= 5)\strut
\end{minipage} & \begin{minipage}[t]{0.12\columnwidth}\raggedright\strut
II (Mean \selectlanguage{ngerman}± SD, n= 38)\strut
\end{minipage} & \begin{minipage}[t]{0.12\columnwidth}\raggedright\strut
III (Mean \selectlanguage{ngerman}± SD, n= 37)\strut
\end{minipage} & \begin{minipage}[t]{0.12\columnwidth}\raggedright\strut
I and II\strut
\end{minipage} & \begin{minipage}[t]{0.12\columnwidth}\raggedright\strut
II and III\strut
\end{minipage} & \begin{minipage}[t]{0.12\columnwidth}\raggedright\strut
III and I\strut
\end{minipage} & \begin{minipage}[t]{0.12\columnwidth}\raggedright\strut
Among three groups\strut
\end{minipage}\tabularnewline
\begin{minipage}[t]{0.10\columnwidth}\raggedright\strut
LA size (cm)\strut
\end{minipage} & \begin{minipage}[t]{0.10\columnwidth}\raggedright\strut
4.54 \selectlanguage{ngerman}± 0.97\strut
\end{minipage} & \begin{minipage}[t]{0.10\columnwidth}\raggedright\strut
4.56 \selectlanguage{ngerman}± 0.57\strut
\end{minipage} & \begin{minipage}[t]{0.10\columnwidth}\raggedright\strut
4.81 \selectlanguage{ngerman}± 0.68\strut
\end{minipage} & \begin{minipage}[t]{0.10\columnwidth}\raggedright\strut
0.95\strut
\end{minipage} & \begin{minipage}[t]{0.10\columnwidth}\raggedright\strut
0.10\strut
\end{minipage} & \begin{minipage}[t]{0.10\columnwidth}\raggedright\strut
0.39\strut
\end{minipage} & \begin{minipage}[t]{0.10\columnwidth}\raggedright\strut
0.24\strut
\end{minipage}\tabularnewline
\begin{minipage}[t]{0.10\columnwidth}\raggedright\strut
LVID\textsubscript{d} (cm)\strut
\end{minipage} & \begin{minipage}[t]{0.10\columnwidth}\raggedright\strut
4.28 \selectlanguage{ngerman}± 0.3\strut
\end{minipage} & \begin{minipage}[t]{0.10\columnwidth}\raggedright\strut
4.34 \selectlanguage{ngerman}± 0.38\strut
\end{minipage} & \begin{minipage}[t]{0.10\columnwidth}\raggedright\strut
4.48 \selectlanguage{ngerman}± 0.43\strut
\end{minipage} & \begin{minipage}[t]{0.10\columnwidth}\raggedright\strut
0.75\strut
\end{minipage} & \begin{minipage}[t]{0.10\columnwidth}\raggedright\strut
0.13\strut
\end{minipage} & \begin{minipage}[t]{0.10\columnwidth}\raggedright\strut
0.29\strut
\end{minipage} & \begin{minipage}[t]{0.10\columnwidth}\raggedright\strut
0.25\strut
\end{minipage}\tabularnewline
\begin{minipage}[t]{0.10\columnwidth}\raggedright\strut
LVID\textsubscript{s} (cm)\strut
\end{minipage} & \begin{minipage}[t]{0.10\columnwidth}\raggedright\strut
2.68 \selectlanguage{ngerman}± 0.33\strut
\end{minipage} & \begin{minipage}[t]{0.10\columnwidth}\raggedright\strut
2.77 \selectlanguage{ngerman}± 0.32\strut
\end{minipage} & \begin{minipage}[t]{0.10\columnwidth}\raggedright\strut
2.83 \selectlanguage{ngerman}± 0.36\strut
\end{minipage} & \begin{minipage}[t]{0.10\columnwidth}\raggedright\strut
0.57\strut
\end{minipage} & \begin{minipage}[t]{0.10\columnwidth}\raggedright\strut
0.47\strut
\end{minipage} & \begin{minipage}[t]{0.10\columnwidth}\raggedright\strut
0.36\strut
\end{minipage} & \begin{minipage}[t]{0.10\columnwidth}\raggedright\strut
0.58\strut
\end{minipage}\tabularnewline
\begin{minipage}[t]{0.10\columnwidth}\raggedright\strut
LVEF (\%)\strut
\end{minipage} & \begin{minipage}[t]{0.10\columnwidth}\raggedright\strut
58.80 \selectlanguage{ngerman}± 2.86\strut
\end{minipage} & \begin{minipage}[t]{0.10\columnwidth}\raggedright\strut
59.87 \selectlanguage{ngerman}± 3.05\strut
\end{minipage} & \begin{minipage}[t]{0.10\columnwidth}\raggedright\strut
59.97 \selectlanguage{ngerman}± 4.12\strut
\end{minipage} & \begin{minipage}[t]{0.10\columnwidth}\raggedright\strut
0.53\strut
\end{minipage} & \begin{minipage}[t]{0.10\columnwidth}\raggedright\strut
0.9\strut
\end{minipage} & \begin{minipage}[t]{0.10\columnwidth}\raggedright\strut
0.49\strut
\end{minipage} & \begin{minipage}[t]{0.10\columnwidth}\raggedright\strut
0.79\strut
\end{minipage}\tabularnewline
\begin{minipage}[t]{0.10\columnwidth}\raggedright\strut
MVA (cm\textsuperscript{2})\strut
\end{minipage} & \begin{minipage}[t]{0.10\columnwidth}\raggedright\strut
1.18 \selectlanguage{ngerman}± 0.23\strut
\end{minipage} & \begin{minipage}[t]{0.10\columnwidth}\raggedright\strut
0.97 \selectlanguage{ngerman}± 0.2\strut
\end{minipage} & \begin{minipage}[t]{0.10\columnwidth}\raggedright\strut
0.87 \selectlanguage{ngerman}± 0.21\strut
\end{minipage} & \begin{minipage}[t]{0.10\columnwidth}\raggedright\strut
0.03\strut
\end{minipage} & \begin{minipage}[t]{0.10\columnwidth}\raggedright\strut
0.03\strut
\end{minipage} & \begin{minipage}[t]{0.10\columnwidth}\raggedright\strut
0.002\strut
\end{minipage} & \begin{minipage}[t]{0.10\columnwidth}\raggedright\strut
0.004\strut
\end{minipage}\tabularnewline
\begin{minipage}[t]{0.10\columnwidth}\raggedright\strut
PG (mm Hg)\strut
\end{minipage} & \begin{minipage}[t]{0.10\columnwidth}\raggedright\strut
17.40 \selectlanguage{ngerman}± 7.02\strut
\end{minipage} & \begin{minipage}[t]{0.10\columnwidth}\raggedright\strut
18.26 \selectlanguage{ngerman}± 5.20\strut
\end{minipage} & \begin{minipage}[t]{0.10\columnwidth}\raggedright\strut
20.68 \selectlanguage{ngerman}± 6.13\strut
\end{minipage} & \begin{minipage}[t]{0.10\columnwidth}\raggedright\strut
0.75\strut
\end{minipage} & \begin{minipage}[t]{0.10\columnwidth}\raggedright\strut
0.07\strut
\end{minipage} & \begin{minipage}[t]{0.10\columnwidth}\raggedright\strut
0.24\strut
\end{minipage} & \begin{minipage}[t]{0.10\columnwidth}\raggedright\strut
0.15\strut
\end{minipage}\tabularnewline
\begin{minipage}[t]{0.10\columnwidth}\raggedright\strut
MG (mm Hg)\strut
\end{minipage} & \begin{minipage}[t]{0.10\columnwidth}\raggedright\strut
11.40 \selectlanguage{ngerman}± 5.37\strut
\end{minipage} & \begin{minipage}[t]{0.10\columnwidth}\raggedright\strut
11.47 \selectlanguage{ngerman}± 3.55\strut
\end{minipage} & \begin{minipage}[t]{0.10\columnwidth}\raggedright\strut
13.32 \selectlanguage{ngerman}± 4.46\strut
\end{minipage} & \begin{minipage}[t]{0.10\columnwidth}\raggedright\strut
0.97\strut
\end{minipage} & \begin{minipage}[t]{0.10\columnwidth}\raggedright\strut
0.055\strut
\end{minipage} & \begin{minipage}[t]{0.10\columnwidth}\raggedright\strut
0.33\strut
\end{minipage} & \begin{minipage}[t]{0.10\columnwidth}\raggedright\strut
0.14\strut
\end{minipage}\tabularnewline
\begin{minipage}[t]{0.10\columnwidth}\raggedright\strut
RVSP (mm Hg)\strut
\end{minipage} & \begin{minipage}[t]{0.10\columnwidth}\raggedright\strut
51.20 \selectlanguage{ngerman}± 21.03\strut
\end{minipage} & \begin{minipage}[t]{0.10\columnwidth}\raggedright\strut
55.03 \selectlanguage{ngerman}± 18.47\strut
\end{minipage} & \begin{minipage}[t]{0.10\columnwidth}\raggedright\strut
66.32 \selectlanguage{ngerman}± 19.74\strut
\end{minipage} & \begin{minipage}[t]{0.10\columnwidth}\raggedright\strut
0.67\strut
\end{minipage} & \begin{minipage}[t]{0.10\columnwidth}\raggedright\strut
0.01\strut
\end{minipage} & \begin{minipage}[t]{0.10\columnwidth}\raggedright\strut
0.10\strut
\end{minipage} & \begin{minipage}[t]{0.10\columnwidth}\raggedright\strut
0.02\strut
\end{minipage}\tabularnewline
\begin{minipage}[t]{0.10\columnwidth}\raggedright\strut
LAS\textsubscript{r} (\%)\strut
\end{minipage} & \begin{minipage}[t]{0.10\columnwidth}\raggedright\strut
14.75 \selectlanguage{ngerman}± 8.98\strut
\end{minipage} & \begin{minipage}[t]{0.10\columnwidth}\raggedright\strut
16.53 \selectlanguage{ngerman}± 10.38\strut
\end{minipage} & \begin{minipage}[t]{0.10\columnwidth}\raggedright\strut
12.89 \selectlanguage{ngerman}± 5.95\strut
\end{minipage} & \begin{minipage}[t]{0.10\columnwidth}\raggedright\strut
0.66\strut
\end{minipage} & \begin{minipage}[t]{0.10\columnwidth}\raggedright\strut
0.06\strut
\end{minipage} & \begin{minipage}[t]{0.10\columnwidth}\raggedright\strut
0.65\strut
\end{minipage} & \begin{minipage}[t]{0.10\columnwidth}\raggedright\strut
0.19\strut
\end{minipage}\tabularnewline
\begin{minipage}[t]{0.10\columnwidth}\raggedright\strut
LAS\textsubscript{cd} (\%)\strut
\end{minipage} & \begin{minipage}[t]{0.10\columnwidth}\raggedright\strut
-7.55 \selectlanguage{ngerman}± 5.61\strut
\end{minipage} & \begin{minipage}[t]{0.10\columnwidth}\raggedright\strut
-8.61 \selectlanguage{ngerman}± 5.02\strut
\end{minipage} & \begin{minipage}[t]{0.10\columnwidth}\raggedright\strut
-6.58 \selectlanguage{ngerman}± 3.52\strut
\end{minipage} & \begin{minipage}[t]{0.10\columnwidth}\raggedright\strut
0.61\strut
\end{minipage} & \begin{minipage}[t]{0.10\columnwidth}\raggedright\strut
0.05\strut
\end{minipage} & \begin{minipage}[t]{0.10\columnwidth}\raggedright\strut
0.65\strut
\end{minipage} & \begin{minipage}[t]{0.10\columnwidth}\raggedright\strut
0.15\strut
\end{minipage}\tabularnewline
\begin{minipage}[t]{0.10\columnwidth}\raggedright\strut
LAS\textsubscript{ct} (\%)\strut
\end{minipage} & \begin{minipage}[t]{0.10\columnwidth}\raggedright\strut
-7.19 \selectlanguage{ngerman}± 6.86\strut
\end{minipage} & \begin{minipage}[t]{0.10\columnwidth}\raggedright\strut
-7.87 \selectlanguage{ngerman}± 6.2\strut
\end{minipage} & \begin{minipage}[t]{0.10\columnwidth}\raggedright\strut
-6.40 \selectlanguage{ngerman}± 3.54\strut
\end{minipage} & \begin{minipage}[t]{0.10\columnwidth}\raggedright\strut
0.78\strut
\end{minipage} & \begin{minipage}[t]{0.10\columnwidth}\raggedright\strut
0.22\strut
\end{minipage} & \begin{minipage}[t]{0.10\columnwidth}\raggedright\strut
0.75\strut
\end{minipage} & \begin{minipage}[t]{0.10\columnwidth}\raggedright\strut
0.48\strut
\end{minipage}\tabularnewline
\bottomrule
\end{longtable}

LA- left atrium; LVEF- left ventricular ejection fraction; LVIDd- left
ventricle internal dimension in diastole; LVIDs- left ventricle internal
dimension in systole; LAS\textsubscript{r}- left atrium reservoir
strain; LAS\textsubscript{cd}- left atrium conduit strain;
LAS\textsubscript{ct}- left atrium contractile strain; MG- mean
diastolic transmitral gradient; MVA- mitral valve area; PG- peak
diastolic transmitral gradient; RVSP- right ventricle systolic pressure

\textbf{Table 3. Comparison between left atrial strain parameters with
various groups based on mean and peak diastolic transmitral gradient,
left atrium size, severity of pulmonary hypertension and mitral valve
area}\selectlanguage{english}
\begin{longtable}[]{@{}llll@{}}
\toprule
Echocardiography parameters & LA strain values & LA strain values & LA
strain values\tabularnewline
\midrule
\endhead
& \textbf{LAS\textsubscript{r} (\%)} & \textbf{LAS\textsubscript{cd}
(\%)} & \textbf{LAS\textsubscript{ct} (\%)}\tabularnewline
Mean diastolic transmitral gradient (mm Hg) & Mean diastolic transmitral
gradient (mm Hg) & Mean diastolic transmitral gradient (mm Hg) & Mean
diastolic transmitral gradient (mm Hg)\tabularnewline
\textless{}10 (Group I) n= 26 & 15.06 \selectlanguage{ngerman}± 7.74 & -8.54 \selectlanguage{ngerman}± 4.05 & -6.77 \selectlanguage{ngerman}±
5.12\tabularnewline
10-15 (Group II) n= 32 & 15.77 \selectlanguage{ngerman}± 7.38 & -7.90 \selectlanguage{ngerman}± 4.14 & -7.73 \selectlanguage{ngerman}±
4.32\tabularnewline
15-20 (Group III) n= 15 & 13.83 \selectlanguage{ngerman}± 12.32 & -6.68 \selectlanguage{ngerman}± 5.76 & -7.15 \selectlanguage{ngerman}±
7.18\tabularnewline
\textgreater{}20 (Group IV) n= 7 & 10.77 \selectlanguage{ngerman}± 7.69 & -4.80 \selectlanguage{ngerman}± 3.63 & -5.87 \selectlanguage{ngerman}±
4.43\tabularnewline
Peak diastolic transmitral gradient (mm Hg) & Peak diastolic transmitral
gradient (mm Hg) & Peak diastolic transmitral gradient (mm Hg) & Peak
diastolic transmitral gradient (mm Hg)\tabularnewline
10-20 (Group I) n= 50 & 15.20 \selectlanguage{ngerman}± 7.89 & -8.12 \selectlanguage{ngerman}± 4.26 & -7.13 \selectlanguage{ngerman}±
4.96\tabularnewline
20-30 (Group II) n= 25 & 14.09 \selectlanguage{ngerman}± 10.13 & -6.91 \selectlanguage{ngerman}± 4.90 & -7.17 \selectlanguage{ngerman}±
5.82\tabularnewline
\textgreater{}30(Group III) n= 5 & 13.17 \selectlanguage{ngerman}± 8.42 & -5.91 \selectlanguage{ngerman}± 4.27 & -7.26 \selectlanguage{ngerman}±
4.50\tabularnewline
Left atrium size (cm) & Left atrium size (cm) & Left atrium size (cm) &
Left atrium size (cm)\tabularnewline
\textless{}4 (Group I) n= 11 & 14.35 \selectlanguage{ngerman}± 7.15 & -9.38 \selectlanguage{ngerman}± 4.59 & -5.34 \selectlanguage{ngerman}±
3.76\tabularnewline
4-5 (Group II) n= 44 & 15.41 \selectlanguage{ngerman}± 8.17 & -7.70 \selectlanguage{ngerman}± 4.22 & -7.75 \selectlanguage{ngerman}±
4.94\tabularnewline
5-6 (Group III) n= 20 & 15.10 \selectlanguage{ngerman}± 10.70 & -7.31 \selectlanguage{ngerman}± 5.08 & -7.56 \selectlanguage{ngerman}±
6.45\tabularnewline
\textgreater{}6 (Group IV) n= 5 & 8.11 \selectlanguage{ngerman}± 2.59 & -4.02 \selectlanguage{ngerman}± 1.70 & -4.08 \selectlanguage{ngerman}±
2.01\tabularnewline
Severity of pulmonary hypertension & Severity of pulmonary hypertension
& Severity of pulmonary hypertension & Severity of pulmonary
hypertension\tabularnewline
No (Group I) n= 6 & 19.71 \selectlanguage{ngerman}±11.67 & -9.08 \selectlanguage{ngerman}± 5.06 & -10.63 \selectlanguage{ngerman}±
8.03\tabularnewline
Mild (Group II) n= 18 & 15.22 \selectlanguage{ngerman}± 6.67 & -8.67 \selectlanguage{ngerman}± 4.44 & -6.54 \selectlanguage{ngerman}±
3.16\tabularnewline
Moderate (Group III) n= 19 & 15.37 \selectlanguage{ngerman}± 10.71 & -8.01 \selectlanguage{ngerman}± 5.18 & -7.28 \selectlanguage{ngerman}±
6.24\tabularnewline
Severe (Group IV) n= 37 & 13.36 \selectlanguage{ngerman}± 7.64 & -6.64 \selectlanguage{ngerman}± 3.95 & -6.84 \selectlanguage{ngerman}±
4.76\tabularnewline
Mitral valve area & Mitral valve area & Mitral valve area & Mitral valve
area\tabularnewline
\textless{}1 cm\textsuperscript{2} (Group I) n= 44 & 15.60 \selectlanguage{ngerman}± 9.90 &
-7.87 \selectlanguage{ngerman}± 5.07 & -7.80 \selectlanguage{ngerman}± 5.62\tabularnewline
1-1.5 cm\textsuperscript{2} (Group II) n= 36 & 13.67 \selectlanguage{ngerman}± 6.63 & -7.28 \selectlanguage{ngerman}±
3.65 & -6.34 \selectlanguage{ngerman}± 4.47\tabularnewline
\bottomrule
\end{longtable}\selectlanguage{ngerman}

LAS\textsubscript{r}- left atrium reservoir strain;
LAS\textsubscript{cd}- left atrium conduit strain;
LAS\textsubscript{ct}- left atrium contractile strain

\textbf{Table 4. Statistical intergroup significance between left atrial
strain parameters with various groups based on mean and peak diastolic
transmitral gradient, left atrium size, severity of pulmonary
hypertension and mitral valve area}\selectlanguage{english}
\begin{longtable}[]{@{}llllllllllll@{}}
\toprule
Left atrium strain parameters & Left atrium strain parameters & P value
between four groups based on left atrium size & P value between four
groups based on left atrium size & P value between four groups based on
left atrium size & P value between four groups based on left atrium size
& P value between four groups based on left atrium size & P value
between four groups based on left atrium size & P value between four
groups based on left atrium size & P value between four groups based on
left atrium size & P value between four groups based on left atrium size
& P value between four groups based on left atrium size\tabularnewline
\midrule
\endhead
& & \textbf{I and II} & \textbf{I and II} & \textbf{II and III} &
\textbf{II and III} & \textbf{III and IV} & \textbf{III and IV} &
\textbf{IV and I} & \textbf{IV and I} & \textbf{Among all groups} &
\textbf{Among all groups}\tabularnewline
LAS\textsubscript{r} & LAS\textsubscript{r} & 0.715 & 0.715 & 0.896 &
0.896 & 0.107 & 0.107 & 0.181 & 0.181 & 0.352 & 0.352\tabularnewline
LAS\textsubscript{cd} & LAS\textsubscript{cd} & 0.261 & 0.261 & 0.743 &
0.743 & 0.14 & 0.14 & 0.027 & 0.027 & 0.167 & 0.167\tabularnewline
LAS\textsubscript{ct} & LAS\textsubscript{ct} & 0.168 & 0.168 & 0.9 &
0.9 & 0.177 & 0.177 & 0.65 & 0.65 & 0.282 & 0.282\tabularnewline
P value between four groups based on mean diastolic transmitral gradient
& P value between four groups based on mean diastolic transmitral
gradient & P value between four groups based on mean diastolic
transmitral gradient & P value between four groups based on mean
diastolic transmitral gradient & P value between four groups based on
mean diastolic transmitral gradient & P value between four groups based
on mean diastolic transmitral gradient & P value between four groups
based on mean diastolic transmitral gradient & P value between four
groups based on mean diastolic transmitral gradient & P value between
four groups based on mean diastolic transmitral gradient & P value
between four groups based on mean diastolic transmitral gradient & P
value between four groups based on mean diastolic transmitral gradient &
P value between four groups based on mean diastolic transmitral
gradient\tabularnewline
LAS\textsubscript{r} & LAS\textsubscript{r} & 0.758 & 0.758 & 0.477 &
0.477 & 0.441 & 0.441 & 0.247 & 0.247 & 0.549 & 0.549\tabularnewline
LAS\textsubscript{cd} & LAS\textsubscript{cd} & 0.592 & 0.592 & 0.38 &
0.38 & 0.358 & 0.358 & 0.052 & 0.052 & 0.201 & 0.201\tabularnewline
LAS\textsubscript{ct} & LAS\textsubscript{ct} & 0.481 & 0.481 & 0.717 &
0.717 & 0.595 & 0.595 & 0.689 & 0.689 & 0.808 & 0.808\tabularnewline
P value between four groups based on severity of pulmonary hypertension
& P value between four groups based on severity of pulmonary
hypertension & P value between four groups based on severity of
pulmonary hypertension & P value between four groups based on severity
of pulmonary hypertension & P value between four groups based on
severity of pulmonary hypertension & P value between four groups based
on severity of pulmonary hypertension & P value between four groups
based on severity of pulmonary hypertension & P value between four
groups based on severity of pulmonary hypertension & P value between
four groups based on severity of pulmonary hypertension & P value
between four groups based on severity of pulmonary hypertension & P
value between four groups based on severity of pulmonary hypertension &
P value between four groups based on severity of pulmonary
hypertension\tabularnewline
LAS\textsubscript{r} & LAS\textsubscript{r} & 0.271 & 0.271 & 0.957 &
0.957 & 0.409 & 0.409 & 0.097 & 0.097 & 0.38 & 0.38\tabularnewline
LAS\textsubscript{cd} & LAS\textsubscript{cd} & 0.847 & 0.847 & 0.651 &
0.651 & 0.281 & 0.281 & 0.218 & 0.218 & 0.32 & 0.32\tabularnewline
LAS\textsubscript{ct} & LAS\textsubscript{ct} & 0.096 & 0.096 & 0.666 &
0.666 & 0.766 & 0.766 & 0.099 & 0.099 & 0.37 & 0.37\tabularnewline
P value between three groups based on peak diastolic transmitral
gradient & P value between three groups based on peak diastolic
transmitral gradient & P value between three groups based on peak
diastolic transmitral gradient & P value between three groups based on
peak diastolic transmitral gradient & P value between three groups based
on peak diastolic transmitral gradient & P value between three groups
based on peak diastolic transmitral gradient & P value between three
groups based on peak diastolic transmitral gradient & P value between
three groups based on peak diastolic transmitral gradient & P value
between three groups based on peak diastolic transmitral gradient & P
value between three groups based on peak diastolic transmitral gradient
& P value between three groups based on peak diastolic transmitral
gradient & P value between three groups based on peak diastolic
transmitral gradient\tabularnewline
LAS\textsubscript{r} & LAS\textsubscript{r} & 0.603 & 0.603 & 0.828 &
0.828 & 0.618 & 0.618 & - & - & 0.801 & 0.801\tabularnewline
LAS\textsubscript{cd} & LAS\textsubscript{cd} & 0.272 & 0.272 & 0.651 &
0.651 & 0.296 & 0.296 & - & - & 0.376 & 0.376\tabularnewline
LAS\textsubscript{ct} & LAS\textsubscript{ct} & 0.982 & 0.982 & 0.972 &
0.972 & 0.961 & 0.961 & - & - & 0.999 & 0.999\tabularnewline
P value between two groups based on mitral valve area & P value between
two groups based on mitral valve area & P value between two groups based
on mitral valve area & P value between two groups based on mitral valve
area & P value between two groups based on mitral valve area & P value
between two groups based on mitral valve area & P value between two
groups based on mitral valve area & P value between two groups based on
mitral valve area & P value between two groups based on mitral valve
area & P value between two groups based on mitral valve area & P value
between two groups based on mitral valve area & P value between two
groups based on mitral valve area\tabularnewline
LAS\textsubscript{r} & LAS\textsubscript{r} & 0.322 & 0.322 & - & - & -
& - & - & - & - & -\tabularnewline
LAS\textsubscript{cd} & LAS\textsubscript{cd} & 0.562 & 0.562 & - & - &
- & - & - & - & - & -\tabularnewline
LAS\textsubscript{ct} & LAS\textsubscript{ct} & 0.209 & 0.209 & - & - &
- & - & - & - & - & -\tabularnewline
\bottomrule
\end{longtable}

LAS\textsubscript{r}- left atrium reservoir strain;
LAS\textsubscript{cd}- left atrium conduit strain;
LAS\textsubscript{ct}- left atrium contractile strain

\textbf{Figure Legend}

\textbf{Figure 1:} Left atrial two dimensional speckle tracking
echocardiography strain (reservoir, conduit and contractile strain)
values in end-diastole, (A) healthy control and (B) patient with severe
mitral stenosis. LASr- left atrium reservoir strain; LAScd- left atrium
conduit strain; LASct- left atrium contractile strain

\textbf{Table Legends}

Table 1: Baseline characteristics and echocardiographic parameters among
subjects

Table 2: Distribution and statistical comparison of echocardiography
parameters among patients grouped according to various NYHA classes

Table 3. Comparison between left atrial strain parameters with various
groups based on mean and peak diastolic transmitral gradient, left
atrium size, severity of pulmonary hypertension and mitral valve area

Table 4. Statistical intergroup significance between left atrial strain
parameters with various groups based on mean and peak diastolic
transmitral gradient, left atrium size, severity of pulmonary
hypertension and mitral valve area\selectlanguage{english}
\begin{figure}[H]
\begin{center}
\includegraphics[width=0.70\columnwidth]{figures/Figure-1/Figure-1}

\end{center}
\end{figure}

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

