\documentclass[10pt]{article}

\usepackage{fullpage}
\usepackage{setspace}
\usepackage{parskip}
\usepackage{titlesec}
\usepackage[section]{placeins}
\usepackage{xcolor}
\usepackage{breakcites}
\usepackage{lineno}
\usepackage{hyphenat}





\PassOptionsToPackage{hyphens}{url}
\usepackage[colorlinks = true,
            linkcolor = blue,
            urlcolor  = blue,
            citecolor = blue,
            anchorcolor = blue]{hyperref}
\usepackage{etoolbox}
\makeatletter
\patchcmd\@combinedblfloats{\box\@outputbox}{\unvbox\@outputbox}{}{%
  \errmessage{\noexpand\@combinedblfloats could not be patched}%
}%
\makeatother


\usepackage{natbib}




\renewenvironment{abstract}
  {{\bfseries\noindent{\abstractname}\par\nobreak}\footnotesize}
  {\bigskip}

\titlespacing{\section}{0pt}{*3}{*1}
\titlespacing{\subsection}{0pt}{*2}{*0.5}
\titlespacing{\subsubsection}{0pt}{*1.5}{0pt}


\usepackage{authblk}


\usepackage{graphicx}
\usepackage[space]{grffile}
\usepackage{latexsym}
\usepackage{textcomp}
\usepackage{longtable}
\usepackage{tabulary}
\usepackage{booktabs,array,multirow}
\usepackage{amsfonts,amsmath,amssymb}
\providecommand\citet{\cite}
\providecommand\citep{\cite}
\providecommand\citealt{\cite}
% You can conditionalize code for latexml or normal latex using this.
\newif\iflatexml\latexmlfalse
\providecommand{\tightlist}{\setlength{\itemsep}{0pt}\setlength{\parskip}{0pt}}%

\AtBeginDocument{\DeclareGraphicsExtensions{.pdf,.PDF,.eps,.EPS,.png,.PNG,.tif,.TIF,.jpg,.JPG,.jpeg,.JPEG}}

\usepackage[utf8]{inputenc}
\usepackage[T2A]{fontenc}
\usepackage[polish,ngerman,english]{babel}



\usepackage{float}








\begin{document}

\title{ESOPHAGEAL SIGNALS AS REFERENCE GUIDE FOR ABLATIONS IN CONGENITAL HEART
DISEASES}



\author[1]{İlker Ertugrul}%
\author[1]{Yasemin Donmez}%
\author[1]{Hikmet Yorgun}%
\author[2]{Kudret Aytemir}%
\author[1]{Tevfik Karagöz}%
\affil[1]{Hacettepe University Faculty of Medicine}%
\affil[2]{Hacettepe University Medical Faculty}%


\vspace{-1em}



  
  \date{May 30, 2024}


\begingroup
\let\center\flushleft
\let\endcenter\endflushleft
\maketitle
\endgroup





\selectlanguage{english}
\begin{abstract}
The quadripolar catheters used for the transesophageal
electrophysiological study is an alternative in such cases due to
limitations of vascular access and size of the pediatric patients,
additional catheter for intracardiac electrograms cannot be placed in
atria stable position.To aim of this article is to report the
effectiveness of transesophageal electrode as a reference catheter in
patients with limited vascular access and complex congenital heart
disease during ablation procedures. Transesophageal catheters can be
used as an alternative to the reference catheter in the
electrophysiology laboratory for provoking or terminating arrhythmias,
understanding mechanism of arrhythmias or as an aid in mapping%
\end{abstract}%



\sloppy


\textbf{Figure legends:}

\textbf{Figure 1} . Catheter positions and ablation point of patient,
esophageal catheter and its relation with atria is seen on fluoroscopic
images.

\textbf{Figure 2} . a) Ablation of left posteroseptal accessory pathway
in ccTGA patient, reference esophageal catheter is red. Esophageal
signals can be seen on the right side. b) Mapping with Advisor TM, HD
grid mapping catheter on electro anatomical anatomy of right atria,
arrow indicates signals received from posteriorly located esophageal
catheter displayed green.

\textbf{Figure 3} . Arrows pointing esophageal signals during mapping of
atrial tachycardia.

\textbf{Table legends:}

\textbf{Table 1} . Demographic and clinical features of the patients

\textbf{Table 2} . Mechanism and management of the arrhythmias of the
patients

\textbf{ESOPHAGEAL SIGNALS AS REFERENCE GUIDE FOR ABLATIONS IN
CONGENITAL HEART DISEASES}

Despite technological advances in the field of catheter ablation and
mapping system, there can be some limitations and challenges especially
in congenital heart disease due to complexity of anatomy. In complex
cardiac anatomy such as heterotaxia syndromes, chambers of heart, great
vessels and structures such as coronary sinus may pose problems as they
are not located where they used to be {[}1{]}. Vascular access is
another challenge beside this complex anatomy, and arrhythmia
mechanisms. During electrophysiological studies and ablation procedures
reference signal keeps its importance in respect to recent developments
of technology of mapping systems. A stable reference signal is mandatory
in all cases. In such cases due to limitations of vascular access and
size of the pediatric patients, additional catheter for intracardiac
electrograms cannot be placed in atria stable position. Due to stability
and gaining both atrium and ventricular signals, coronary sinus is the
most convenient place for reference catheters. The quadripolar catheters
used for the transesophageal electrophysiological study is an
alternative in such cases. Since the esophagus is in an anatomical
position close to the left atrium, signals acquired from esophagus have
both atrial and ventricular signals. In addition to acquiring stable
signals from atria and ventricle, it can also be used to stimulate the
atria {[}2, 3{]}.

To aim of this article is to report the effectiveness of transesophageal
electrode as a reference catheter in patients with limited vascular
access and complex congenital heart disease during ablation procedures.

\textbf{Case 1}

A 25-year-old girl with left atrial isomerism, mitral atresia, moderate
regurgitation of tricuspid valve, non-restrictive ventricular septal
defect, non-restrictive atrial septal defect, severe subpulmonary
stenosis with a systolic gradient of 60 mmHg and both great arteries
were arising from right ventricle presented with high ventricular
responded atrial tachycardia. Echocardiography showed no intracardiac
thrombus, signs of systolic dysfunction or heart failure. Conversion to
sinus rhythm could not be achieved with cardioversion. She underwent
ablation procedure after one month of palpitation symptoms. CARTO 3
systems (Biosense Webster, Inc., Diamond Bar, CA, USA) is used for the
three-dimensional mapping with Thermocool Smarttouch SF catheter.
Reference catheter could not be inserted due to absence of hepatic
portion of IVC. Ablation catheter inserted through right subclavian vein
with a The Agilis NxT Steerable Introducer. A quadripolar catheter
(Esolo FIAB, Italy) was inserted into esophagus as a reference catheter
(figure 1). The tachycardia cycle length was measured as 280 ms with 2:1
AV conduction. The activation and propagation mapping revealed that the
early-meets-late line was in the cavotricuspid isthmus region. In the
voltage mapping, a widespread and patchy-style scar area was detected in
the both atria. Cavotricuspid isthmus ablation was performed and sinus
rhythm was achieved. There was no complication related to procedure.

\textbf{Case 2}

A 11-year-old boy with Ebstein anomaly, who underwent tricuspid valve
replacement using a 27 mm St Jude prothesis when he was nine, underwent
ablation due to drug resistant atrial flutter. ECG revealed an atrial
rate of 250 ms and 4:1 AV conduction. Echocardiography revealed no
paravalvular regurgitation from prosthetic valve, thrombosis nor
increase in transvalvular mean doppler gradient of the prosthetic valve,
with a normal ventricular systolic function. He had history of several
CV under medical treatment of amiodarone and propranolol. Since
decapolar reference catheter could not be inserted into the coronary
sinus, a quadripolar catheter (Esolo FIAB, Italy) was inserted into
esophagus as a reference catheter. The EnSite NavX Precision system
(St. Jude Medical St. Paul, MN, USA) is used as three dimensional
mapping system and Tacticath \textsuperscript{TM} Quartz Contact Force
(St. Jude Medical St. Paul, MN, USA) for mapping and ablation procedure.
Widespread scar areas were detected in the posterolateral region of
right atrium. The patient had three distinctive type of tachycardia with
different cycle lengths, two reentries detected involving scar areas in
right atrium posterior and superior region. Ablation lines were applied
on that region in low voltage scar areas forming isthmuses for the
reentries. Since ablation of myocardium under mechanical valve could not
be performed due to loss of contact of catheter. CTI dependent flutter
could not be accomplished even though ablation line extended beyond
mechanical valve. Even though, CTI ablation could not be accomplished,
sinus rhythm achieved under medical treatment of flecainide and
propranolol and remained for two years after ablation procedure.

\textbf{Case 3}

A 15-year-old boy with a history of Rastelli procedure using a Hancock
valve conduit for congenitally corrected transposition of great
arteries, ventricular septal defect and pulmonary atresia underwent
ablation for the complaint of palpitations for the last 6 months. The
EnSite NavX Precision system (St. Jude Medical St. Paul, MN, USA) is
used as three dimensional mapping system and
Tacticath\textsuperscript{TM} Quartz Contact Force (St. Jude Medical St.
Paul, MN, USA) with Agilis NxT Steerable Introducer for mapping and
ablation procedure. Selective coronary angiography was performed as
catheter could not be positioned into the coronary sinus despite
multiple attempts which revealed that coronary veins were opened
separately without confluence of the coronary sinus. The Duodecapolar
Steerable catheter (Medtronic, USA) was placed in the right atrium.
Since the stable atrium potential could not be obtained, the
transesophageal electrode (Esolo FIAB, Italy) was advanced into the
esophagus towards the left atrium neighborhood via the nasal route. The
tachycardia with 1:1 VA relationship was induced by single extra
stimulus and catheter manipulation in the patient. Tachycardia was
interrupted with entrainment mapping, and tachycardia was terminated by
administration of adenosine. Activation and voltage mapping were
performed during tachycardia in order to evaluate the scar areas in the
atrium (figure 2a). Diagnostic maneuvers revealed AVRT with earliest
atrial activity during tachycardia localized left posteroseptal region.
Catheter was advanced into left atrium via patent foramen ovale, and
then early atrial activity of the left atrium was mapped during
tachycardia, -35 ms atrial activation was obtained in the left posterior
region. Ablation was performed successfully without any complications.

\textbf{Case 4}

A 2-month-old girl with 6 kg of body weight was referred to our clinic
with the diagnosis of tachycardia-induced cardiomyopathy.
Electrocardiogram revealed long RP tachycardia with deep inverted P
waves inferior leads. Echocardiography revealed a global dilatation of
left ventricle (left ventricle end diastolic dimension of 36 mm, z score
+4,3) with severe dysfunction of left ventricle (ejection fraction of
37\%). A quadripolar catheter (Esolo FIAB, Italy) was inserted into
esophagus as a reference catheter. Right atrial anatomy was mapped with
Marinr \textsuperscript{TM} CS Steerable Decapolar catheter (Medtronic,
Inc., Minneapolis, MN, USA). During the procedure, long RP tachycardia
was observed in the patient with negative P waves in the inferior leads.
Pacing maneuvers revealed tachycardia mechanism as atypical AVNRT. Upon
this, the activation mapping was obtained from earliest atrial
activations during tachycardia, and ablation was performed in the
posterior region of the right atrium near the entry of the coronary
sinus with power of 30 W and 50\textsuperscript{o}C temperature for 110
seconds. Tachycardia was terminated with accelerated junctional rhythm.
On follow-up echocardiography, left ventricular systolic function has
been improved. She is symptom-free for 2 years.

\textbf{Case 5}

A 21-year-old boy with a history of atriopulmonary anastomosis at the
age of two for tricuspid atresia and severe pulmonary stenosis underwent
ablation procedure for the atrial tachycardia documented in 24 hours
Holter ECG recordings. The EnSite NavX Precision system (St. Jude
Medical St. Paul, MN, USA) is used as three dimensional mapping system
and Advisor TM, HD grid mapping catheter and
Tacticath\textsuperscript{TM} Quartz Contact Force (St. Jude Medical St.
Paul, MN, USA) with Agilis NxT Steerable Introducer for mapping and
ablation procedure. Confluence of coronary veins was absent and they
drained to atria separately. Reference quadripolar esophageal (Esolo
FIAB, Italy) catheter inserted to esophagus with close relation to left
atria. During sinus rhythm voltage mapping, and tachycardia activation
and propagation mapping was performed with high definition catheter by
reference atrial signals receiving from esophageal recordings (figure
2b). Although atrial-sensing signals received perfectly, atrial capture
could not be achieved from esophagus due to dextrocardia (figure 3).
Therefore decapolar catheter was inserted to high atria for induction of
tachycardia. Focal atrial tachycardia originating from free wall of
right atria was detected and ablated successfully. Atrial activity was
130 ms earlier on target point when compared to esophageal signal.

\textbf{Discussion} :

Survival of complex congenital heart disease has improved dramatically
over the last two decades. Improved survival leads to facing different
types of arrhythmias developing due to hemodynamic effects of underlying
disease or corrective surgery. Radiofrequency catheter ablation (RFCA)
is an important therapeutic option for these arrhythmias. Accessing to
the heart in cases with complex congenital heart defects may become a
real obstacle for operators. Abnormalities of vascular structures
(absence of hepatic part of inferior vena cava, coronary sinus
anomalies, double superior vena cava without intercaval communication,
left superior vena cava), surgical boundaries, and obstructed femoral
veins are real challenges for electrophysiologists. Besides different
electrical properties of complex congenital heart diseases altered
myocardium acts as a substrate for atrial and ventricular arrhythmia. In
complex congenital hearts reentries involving atria and ventricle scar
areas are common with changing proportion to underlying disease or
surgery as well as atrio-ventricular or nodal reentries or ectopic
tachycardia. {[}4{]}

3D-electroanatomical mapping is recommended as class I for atrial and
ventricular tachycardia in congenital heart diseases {[}5{]} which is
reported to facilitate RFCA procedures for different types of arrhythmia
mechanisms. All the mapping systems based on reference signal, and
mapping catheter for electro anatomical mapping procedures. A stable
positioned reference catheter is mandatory for performing such complex
cases. Reference signal is generally acquired from intracardiac
structures such as high right atria or coronary sinus, the latter is
preferred mostly due to receiving signals both from atria, ventricle and
extends to other side of atrioventricular groove. In cases with limited
access resulting from congenital anomaly or size of the patient's
signals acquired from esophagus are very good alternative for
intracardiac electrograms. Signals from esophagus have both atrial and
ventricular potentials; additionally, close relation with left atria
provides information about left sided structures.

Esophageal catheters are generally used for semi invasive
electrophysiological studies in our center, which provides us useful
information about palpitation complaints during pediatric age group, or
overdrive pacing protocols for control of arrhythmia. A quadripolar
catheter (Esolo FIAB, Italy) which is compatible with both Carto and
EnSite NavX Precision system (St. Jude Medical St. Paul, MN, USA) with
stimulation/sensing electrodes was inserted through the nares, and
positioned, where the best atrial signals were received, approximately
one cm above the cardiac portion of the stomach. The same protocol was
applied during RFCA and mapping procedures successfully providing
reference signals and pacing atria form left side. The demographic and
clinical characteristics of patients are listed in Table 1, and
mechanism and management of the arrhythmias are summarized in Table 2.
Only in one patient atrial capture could not achieved due to
dextroposition of heart. No complications associated with esophageal
catheter were observed among our patients.

\textbf{Conclusion:}

Transesophageal catheters can be used as an alternative to the reference
catheter in the electrophysiology laboratory for provoking or
terminating arrhythmias, understanding mechanism of arrhythmias or as an
aid in mapping. To best our knowledge, it is the only case series in the
literature where the transesophageal electrode is used as a reference
catheter.

1. Van Hare, G.F., \emph{Challenges in Ablation of Complex Congenital
Heart Disease.} Card Electrophysiol Clin, 2019. \textbf{11} (4): p.
711-718.

2. Szili-Torok, T., E. Mikhaylov, and M.
Witsenburg,\emph{Transoesophageal electrophysiology study for children:
can we swallow the limitations?} Europace, 2009. \textbf{11} (8): p.
987-8.

3. Pehrson, S.M., et al., \emph{Clinical value of transesophageal atrial
stimulation and recording in patients with arrhythmia-related symptoms
or documented supraventricular tachycardia--correlation to clinical
history and invasive studies.} Clin Cardiol, 1994. \textbf{17} (10): p.
528-34.

4. Brouwer, C., M.G. Hazekamp, and K. Zeppenfeld, \emph{Anatomical
Substrates and Ablation of Reentrant Atrial and Ventricular Tachycardias
in Repaired Congenital Heart Disease.} Arrhythm Electrophysiol Rev,
2016. \textbf{5} (2): p. 150-60.

5. Kim, Y.H., et al., \emph{2019 APHRS expert consensus statement on
three-dimensional mapping systems for tachycardia developed in
collaboration with HRS, EHRA, and LAHRS.} J Arrhythm, 2020.\textbf{36}
(2): p. 215-270.\selectlanguage{english}
\begin{figure}[H]
\begin{center}
\includegraphics[width=0.70\columnwidth]{figures/image1/image1}

\end{center}
\end{figure}

Figure 1 - Catheter positions and ablation point of patient, esophageal
catheter and its relation with atria is seen on fluoroscopic images\selectlanguage{english}
\begin{figure}[H]
\begin{center}
\includegraphics[width=0.70\columnwidth]{figures/image2/image2}

\end{center}
\end{figure}

Figure 2 -- a) Ablation of left posteroseptal accessory pathway in
cc-TGA patient, reference esophageal catheter is red. Esophageal signals
can be seen on the right side. b) Mapping with Advisor TM, HD grid
mapping catheter on electro anatomical anatomy of right atria, arrow
indicates signals from posteriorly located esophageal catheter displayed
green.\selectlanguage{english}
\begin{figure}[H]
\begin{center}
\includegraphics[width=0.70\columnwidth]{figures/image3/image3}

\end{center}
\end{figure}

Figure 3 - Arrows pointing esophageal signals during mapping of atrial
tachycardia

\textbf{Table 1} - Demographic and clinical features of the patients\selectlanguage{english}
\begin{longtable}[]{@{}lllll@{}}
\toprule
Pt & Age & BW & Diagnosis & Surgery\tabularnewline
\midrule
\endhead
1 & 25 y & 48 & DORV, mitral atresia, LAI, PS, VSD, ASD &
-\tabularnewline
2 & 11 y & 26 & Ebstein anomaly & TVR\tabularnewline
3 & 15 y & 68 & cc-TGA, VSD, pulmonary atresia & Rastelli
procedure\tabularnewline
4 & 2 m & 6 & Tachycardia-induced cardiomyopathy & -\tabularnewline
5 & 21 y & 64 & Dextrocardia, Tricuspid atresia, PS & Fontan Procedure
(Atriopulmonary anastomosis)\tabularnewline
\bottomrule
\end{longtable}

\emph{y- year, m- month, BW- body weight, DORV- double outlet right
ventricle, LAI- left atrial isomerism, PS- pulmonary stenosis, VSD-
ventricular septal defect, ASD- atrial septal defect, TVR- tricuspid
valve replacement, cc-TGA- congenitally corrected transposition of the
great arteries}

Table 2 -- Mechanism and management of the arrhythmias of the patients\selectlanguage{english}
\begin{longtable}[]{@{}llll@{}}
\toprule
Pt & Arrhythmia & Indication of transesophageal electrode & Ablation
site\tabularnewline
\midrule
\endhead
1 & Atrial tachycardia & Absence of hepatic portion of IVC &
CTI\tabularnewline
2 & Atrial Flutter & Complex cardiac anatomy & Scar area of posterior
and superior region of RA, CTI\tabularnewline
3 & AVRT & Non-confluence of coronary veins & Posteroseptal region of
LA\tabularnewline
4 & Atypical AVNRT & Low body weight & Posterior region of the
RA\tabularnewline
5 & Focal atrial tachycardia & Non-confluence of coronary veins & Free
wall of RA\tabularnewline
\bottomrule
\end{longtable}

\emph{AVNRT- atrioventricular nodal reentrant tachycardia, AVRT-
atrioventricular reciprocating tachycardia, IVC- inferior vena cava, CTI
-- cavotricuspid isthmus, RA- right atrium, LA- left atrium}

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

