\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[ngerman,english]{babel}



\usepackage{float}








\begin{document}

\title{Re-definition of Blanking Period in Radiofrequency Catheter Ablation of
Atrial Fibrillation in the Contact Force Era}



\author[1]{Shunsuke Uetake}%
\author[2]{Yasushi Miyauchi}%
\author[1]{Tatsuya Mitsuishi}%
\author[3]{Mitsunori Maruyama}%
\author[1]{Seino Yoshihiko}%
\author[4]{Wataru Shimizu}%
\affil[1]{Nippon Medical School Chiba Hokusoh Hospital}%
\affil[2]{Nippon Medical School Chiba-Hokusoh Hospital}%
\affil[3]{Nippon Medical School Musashi-Kosugi Hospital}%
\affil[4]{Nippon Medical School}%


\vspace{-1em}



  
  \date{May 24, 2024}


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





\selectlanguage{english}
\begin{abstract}
Introduction: Early recurrence (ER) of atrial fibrillation (AF) is
defined as the recurrence of atrial tachyarrhythmias within 3 months
after AF ablation, however, this definition is based on data from the
era of radiofrequency catheter ablation (RFCA), without contact force
(CF) technology. We investigated the significance of ER as a risk factor
for late recurrence (LR) in paroxysmal AF (PAF) patients treated with CF
and non-CF-guided ablation. Methods and Results: We studied 395 patients
with PAF who underwent RFCA. Of these, 97 patients underwent RFCA
without CF technology (Non-CF group) and 298 underwent with CF
technology (CF group). Over a 2-year post-ablation follow-up period, LR
occurred in 54 of 97 (55.7\%) patients in the Non-CF group, and in 105
of 298 (35.2\%) patients in the CF group. ER had a more significant
relationship with LR in the CF than in the Non-CF group, and all
patients in the CF group with ER in the 3rd month developed LR.
Conclusion: ER in PAF patients who have undergone CF-guided ablation
have a greater risk of LR than those who have undergone non-CF-guided
ablation. ER in the 3rd month after CF-guided ablation may indicate an
absolute risk of LR. Blanking period could be defined as 2 months in the
CF era.%
\end{abstract}%



\sloppy


\textbf{Re-definition of Blanking Period in Radiofrequency Catheter
Ablation of Atrial Fibrillation in the Contact Force Era}

Shunsuke Uetake, MD, PhD\textsuperscript{1}, Yasushi Miyauchi, MD,
PhD\textsuperscript{1}, Tatsuya Mitsuishi, MD\textsuperscript{1},
Mitsunori Maruyama, MD, PhD\textsuperscript{2}, Yoshihiko Seino, MD,
PhD\textsuperscript{1}, Wataru Shimizu, MD, PhD\textsuperscript{3}

\textbf{Institution of authors:}

\textsuperscript{1}Department of Cardiovascular Medicine, Nippon Medical
School Chiba-Hokusoh Hospital

\textsuperscript{2}Department of Cardiovascular Medicine, Nippon Medical
School Musashi-Kosugi Hospital

\textsuperscript{3}Department of Cardiovascular Medicine, Nippon Medical
School

\textbf{Conflicts of all authors:} none declared.

\textbf{Funding sources:} none.

\textbf{Corresponding author}

Shunsuke Uetake, MD, PhD

Department of Cardiovascular Medicine, Nippon Medical School Chiba
Hokusoh Hospital

1715 Kamagari, Inzai, Chiba, 270-1694, Japan

E-mail address: s00-015@nms.ac.jp

\textbf{Abstract}

\textbf{Introduction:} Early recurrence (ER) of atrial fibrillation (AF)
is defined as the recurrence of atrial tachyarrhythmias within 3 months
after AF ablation, however, this definition is based on data from the
era of radiofrequency catheter ablation (RFCA), without contact force
(CF) technology. We investigated the significance of ER as a risk factor
for late recurrence (LR) in paroxysmal AF (PAF) patients treated with CF
and non-CF-guided ablation.

\textbf{Methods and Results} : We studied 395 patients with PAF who
underwent RFCA. Of these, 97 patients underwent RFCA without CF
technology (Non-CF group) and 298 underwent with CF technology (CF
group). Over a 2-year post-ablation follow-up period, LR occurred in 54
of 97 (55.7\%) patients in the Non-CF group, and in 105 of 298 (35.2\%)
patients in the CF group. ER had a more significant relationship with LR
in the CF than in the Non-CF group, and all patients in the CF group
with ER in the 3\textsuperscript{rd} month developed LR.

\textbf{Conclusion} : ER in PAF patients who have undergone CF-guided
ablation have a greater risk of LR than those who have undergone
non-CF-guided ablation. ER in the 3\textsuperscript{rd} month after
CF-guided ablation may indicate an absolute risk of LR. Blanking period
could be defined as 2 months in the CF era.

\textbf{Key Words} : Atrial fibrillation, contact force, early
recurrence, blanking period, ablation

\textbf{INTRODUCTION}

Electrical isolation of the pulmonary veins (PVI) is a radical treatment
for paroxysmal atrial fibrillation (PAF). Despite the acute success of
PVI, recurrence of atrial tachyarrhythmia is common. Recurrence of
atrial tachyarrhythmias within the first 3 months after an atrial
fibrillation (AF) ablation procedure is defined as early recurrence
(ER). ER is distinguished from late recurrence (LR) of atrial
tachyarrhythmia, because only half of patients with ER also have
LR.\textsuperscript{1} Accordingly, guidelines and expert consensus
statements do not recommend early re-ablation during the first 3 months.
However, some studies have shown that ER occurring in a later period was
more strongly associated with long-term ablation failure in patients who
underwent PVI using local electrode attenuation and impedance
drop-guided radiofrequency catheter ablation (RFCA) and more than 90\%
of patients with ER during the 3\textsuperscript{rd} month post-ablation
develop LR.\textsuperscript{2, 3}

Recently, the conventional ablation procedure has been replaced by
contact force (CF) technology for PVI, and some studies have shown that
CF-guided PVI is more effective in reducing AF recurrence than the
conventional non-CF-guided PVI.\textsuperscript{4} However, the
significance of ER episodes after CF-guided ablation in terms of LR
remains unclear. Therefore, the objective of this study was to compare
the significance of ER as a risk factor for LR in patients with
paroxysmal AF (PAF) treated by CF and non-CF-guided ablation procedures.

\textbf{METHODS}

\textbf{Study Population}

This study included 395 consecutive patients who underwent their first
RFCA procedure for PAF between February 2012 and June 2019 at Nippon
Medical School Chiba-Hokusoh Hospital. This study was approved by the
institutional review board. Patients were excluded from the study if any
of the following were present: (1) severe valvular disease, (2) left
ventricular ejection fraction \textless{} 35\%, (3) left atrial
dimension \textgreater{} 55 mm, (4) active thyroid disease, (5)
hypertrophic cardiomyopathy, (6) hemodialysis, or (7) use of
antiarrhythmic drugs during the blanking period. Ninety-seven patients
underwent conventional non-CF-guided ablation (Non-CF group) and 298
patients underwent CF-guided ablation (CF group: force-time integral
{[}FTI{]}-guided, 181 patients; ablation index {[}AI{]}-guided, 117
patients).

\textbf{Ablation Procedure}

We performed all RFCA procedures under deep sedation. A duo-decapolar
electrode catheter (BeeAT, Japan Lifeline, Tokyo, Japan) was inserted
into the coronary sinus (CS) from the right internal jugular vein. Two
long sheaths (Swarts and Agilis, Abbott, St. Paul, MN) were advanced
into the left atrium through a single transseptal puncture via the right
femoral vein. A duo-decapolar ring catheter (Lasso, Biosense Webster,
Irvine, CA) was used to record pulmonary vein (PV) potential. Patients
were anticoagulated with intravenous heparin to maintain an activated
clotting time \textgreater{} 300 seconds. All patients underwent
circumferential PVI by isolating the left and right PVs as ipsilateral
common ostia on the 3D-geometry of the left atrium (Carto 3, Biosense
Webster). In patients with a long superior vena cava (SVC) sleeve
(\textgreater{} 30 mm) or in whom ectopic beats originating from the SVC
triggered AF, electrical isolation of the SVC was performed as
previously described.\textsuperscript{5}Isolation of the posterior wall
of the left atrium (PLA) was performed depending on the operators'
discretion.\textsuperscript{6}

In the Non-CF group, ablation was performed with a 3.5-mm tip, 56-hole
irrigated catheter (THERMOCOOL SF; Biosense Webster). In the CF group, a
3.5-mm tip, 56-hole irrigated catheter with a CF sensor (THERMOCOOL
SMARTTOUCH SF, Biosense Webster) was used for ablation. Power settings
were 25--30 W for the posterior wall and 30--35 W for other regions of
the left atrium. In the Non-CF group, the RF current was delivered for
20--40 seconds to each lesion, until local bipolar electrograms
decreased. If intra-esophageal temperature rose \textgreater{} 39.5
during ablation, RF delivery was interrupted.

\textbf{CF-Guided Ablation}

In the CF group, FTI or AI targets were used, depending on the time
period of the ablation procedure. Real-time automated display of RF
applications (Visitag\selectlanguage{ngerman}®, Biosense Webster) was used with predefined
settings of catheter stability (1.5 mm for 3 seconds) and minimum CF
(25\% of the time \textgreater{} 3 gram). Each inter-lesion distance was
less than 6 mm. In patients who underwent FTI-guided ablation, operators
followed the EFFICAS I-based CF guidelines (minimum 400 gs
FTI).\textsuperscript{7} In AI-guided ablation, RF was delivered until
an AI of \selectlanguage{english}[?] 400 at the posterior wall and roof/bottom and \selectlanguage{english}[?] 550 at the
anterior wall was achieved, in accordance with the CLOSE
protocol.\textsuperscript{8}

\textbf{RF Delivery Time and Delivered RF Energy}

RF delivery time was defined as the total time of RF application during
PVI and, the delivered RF energy was defined as the total amount of RF
energy delivered during PVI.

\textbf{Biomarkers of Inflammation}

Blood samples were taken to determine white blood cell count (WBC) and
C-reactive protein (CRP) level before and at 1 day after the ablation
procedure. We evaluated the ratio of WBC and the difference in CRP level
between these two time-points.

\textbf{Postablation Follow-Up}

After the ablation procedures, all patients were discharged without
antiarrhythmic drugs, and were followed up at 1, 3, 6, 9, and 12 months
and then every 6 months thereafter until 24 months. At each hospital
visit, patient symptoms and a 12-lead ECG were recorded. If patients
reported symptoms, we asked them to undergo ECG with a portable
electrocardiographic monitor (HCG-901; OMRON, Kyoto, Japan) at least
twice a day and at any time they experienced palpitations during the
follow-up period. Twenty-four-hour Holter ECG was performed at 1, 3, 6,
12, 18, and 24 months post-procedure. Recurrence of atrial
tachyarrhythmia was defined as any documented atrial tachyarrhythmia (AF
or atrial tachycardia {[}AT{]}) lasting \textgreater{} 30 seconds on
either device. ER was defined as any atrial tachyarrhythmia occurring
during the first 3 months post-AF ablation and LR was defined as atrial
tachyarrhythmias occurring after the first 3 months post-AF ablation.

\textbf{Statistical Analysis}

Continuous variables are presented as the mean +- SD and categorical
variables as the number and percentage of patients. Two-group
comparisons were performed with either Student's \emph{t} -test or the
Mann--Whitney U test according to the results of the Shapiro--Wilk
normality test. Categorical variables were compared using Fisher's exact
test. The cumulative atrial tachyarrhythmia recurrence-free survival was
evaluated using the Kaplan--Meier method, and curves were compared using
the log-rank test. Hazard ratios were used to determine the impact of
the timing of the last ER on long-term atrial tachyarrhythmia recurrence
and were calculated using a Cox proportional hazards model.

A p value \textless{} 0.05 was considered statistically significant.
When comparing three groups, Bonferroni correction was used, and a p
value \textless{} 0.017 was considered significant. Analyses were
performed using IBM SPSS Statistics software version 21, (IBM
Corporation, Armonk, NY).

\textbf{RESULTS}

\textbf{Patient Characteristics}

Patients baseline characteristics are compared between the two groups in
Table 1. In the CF group, age and the
CHA\textsubscript{2}DS\textsubscript{2}-VASc score were significantly
higher, and disease duration of PAF was significantly longer than in the
Non-CF group. The other clinical characteristics and echocardiographic
data were comparable between the two groups.

\textbf{Results of Ablation}

Acute PVI, verified by entrance and exit blocks, was achieved in all
patients. In the Non-CF group, additional SVC or PLA isolation were
performed in 24 patients (24.7\%), while, in the CF group, additional
SVC or PLA isolation were performed in 102 patients (34.2\%).

Parameters associated with ablation are shown in Table 2. The CF group
had a shorter total RF delivery time and smaller amount of RF energy
delivered than the Non-CF group. Regarding the post-ablation
inflammatory response, the ratio of pre- to post-ablation WBC and the
elevation of CRP levels were significantly lower in the CF group than in
the Non-CF group.

\textbf{Incidence and Characteristics of Recurrence}

ER occurred in 159 patients overall (40.3\%). The incidence of ER was
significantly greater in the Non-CF group than in the CF group (Table 2,
55.7\% vs. 35.2\%; p \textless{} 0.001). In the CF group, the incidence
of ER was significantly lower in patients in whom AI- (18.8\%) than in
whom FTI-guidance (42.5\%) was used.

LR occurred in 42 patients (43.3\%) in the Non-CF group during an
average follow-up period of 14.8 months after a single procedure, and in
65 patients (21.8\%) in the CF group during an average follow-up period
of 12.4 months. The incidence of LR was significantly greater in Non-CF
group than in the CF group (Figure 1, Table 2).

\textbf{Clinical Characteristics of Patients with Early or Late
Recurrence}

In the Non-CF group, there was no significant difference in the baseline
patient characteristics, RF delivery time, and delivered RF energy
between the patients with and without ER (data not shown). On the other
hand in the CF group, the patients with ER included a higher proportion
of females, had a longer disease duration of PAF, higher pre-operative
plasma brain-type natriuretic peptide (BNP) level, longer RF delivery
time, and larger amount of RF delivery than those without ER (Female,
42.9\% vs. 24.9\%, p=0.001; disease duration of PAF, 41.2 +- 41.4 vs.
25.5 +- 24.4 months, p\textless{}0.001; BNP, 66.9 +- 58.7 vs. 43.5 +- 33.1
pg/ml, p\textless{}0.001; RF delivery time, 2185.4 +- 585.2 vs. 1963.4 +-
476.1 sec., p=0.017; amount of RF energy, 56349.7 +- 14616.6 vs. 52239.3
+- 12397.5 J, p=0.070).

In the Non-CF group, the baseline patient characteristics was not
different between those with and those without LR (data not shown). In
the CF group, the disease duration of PAF was longer in patients with LR
than in those without LR (37.4 +- 34.6 vs. 30.3 +- 34.6 months, p =
0.005), and the prevalence of hypertension, the
CHA\textsubscript{2}DS\textsubscript{2}-VASc score, and pre-procedural
BNP level were higher in those with than in those without
LR(Hypertension, 66.2\% vs. 49.8\%, p=0.013;
CHA\textsubscript{2}DS2-VASc score, 2.2 +- 1.2 vs. 1.8 +- 1.2, p=0.042;
BNP, 62.2 +- 51.2 vs. 50.3 +- 45.2 pg/ml, p=0.026).

\textbf{Timing of Early Recurrence}

The timing of ER is summarized in Figure 2. In each post-ablation month,
the incidence of ER was significantly greater in the Non-CF group. ER
occurred in multiple months in 35.1\% and in 9.1\% of the patients in
the Non-CF and CF group, respectively (p \textless{} 0.001). The last ER
most frequently occurred in the 3\textsuperscript{rd} month in the
Non-CF group but in the 1\textsuperscript{st} month in the CF-group
(Figure 3).

\textbf{Relationship between Early and Late Recurrence}

In the Non-CF group, 32 of 54 patients (59.3\%) with ER developed LR.
The proportion of patients with ER was significantly greater among
patients with LR than among those without LR (76.2\% vs. 40.0\%, p
\textless{} 0.001). There was no difference in the rate of a single ER
between patients with and without LR (23.3\% vs. 18.5\%, p = 0.373),
whereas the proportion of patients with ER occurring in multiple months
were significantly greater in patients with LR than in those without LR
(51.2\% vs. 22.2\% p = 0.001). Freedom from LR in patients with the last
ER in the 1\textsuperscript{st} or 2\textsuperscript{nd} month was
significantly greater than in those with the last ER in the
3\textsuperscript{rd} month (p \textless{} 0.001; Figure 4a).

Similarly, in the CF group, patients with LR had a higher rate of ER
than those without LR (84.6\% vs. 21.5\%, p \textless{} 0.001). However,
in the CF group, the proportions of patients with ER in both single
month and multiple months were significantly greater in patients with LR
than in those without LR (single ER: 47.7\% vs. 20.2\%, p \textless{}
0.001; multiple ER: 36.9\% vs. 1.3\%, p \textless{} 0.001). The rate of
freedom from LR in patients with the last ER occurring in the
1\textsuperscript{st} and 2\textsuperscript{nd} months was 69.8\% and
40.0\%, respectively, whereas all patients with the last ER occurring in
the 3\textsuperscript{rd} month had LR (Figure 4b).

When comparing patients with the last ER occurring in the
3\textsuperscript{rd} month in the CF and Non-CF groups, the CF group
was significantly less likely to be free from LR at 2 years
post-procedure than the Non-CF group (Figure 4c). The significance of ER
as a risk factor of LR is summarized in Table 3. Occurrence of the last
ER in the 1\textsuperscript{st} or 2\textsuperscript{nd} month was not a
significant risk factor for LR in the Non-CF group, whereas any ER at
any time-point was a significant risk factor for LR in the CF group. Of
note, occurrence of the last ER in the 3\textsuperscript{rd} month was
an absolute risk factor for LR in the CF group.

\textbf{Relationship between ER and PV Reconnection}

Among 157 patients with ER, 74 patients underwent repeat RFCA for LR
(Non-CF: 32 {[}59.3\%{]}; FTI: 34 {[}44.2\%{]}; AI: 8 {[}28.6\%{]}).
Patients without ER were excluded from the analysis. Reconnection of any
PV was observed in 93.8\%, 70.6\%, and 25\% of patients in the Non-CF,
FTI, and AI group, respectively (Figure 5). Patients who underwent
AI-guided ablation were less likely to have PV reconnection than those
who underwent FTI-guided ablation.

\textbf{DISCUSSION}

\textbf{Main Findings}

The main findings of this study were that patients who underwent
CF-guided ablation less frequently developed ER than those who underwent
non-CF-guided ablation. Moreover, all patients in the CF group with ER
occurring in the 3\textsuperscript{rd} month developed LR, although
22.2\% of patients in the Non-CF group who had ER in the
3\textsuperscript{rd} month were free-from LR during 2-year follow-up
period. These findings suggest that ER occurring in the
3\textsuperscript{rd} month is a specific risk factor for LR and that an
early redo-procedure may be reasonable in patients who underwent PVI
using CF technology.

\textbf{Mechanism of Early Recurrence}

Previous studies with patients in the non-CF era have reported an
approximately 50\% prevalence of ER after ablation and a higher
incidence of LR, ranging between 41.1\% and 90\%, in cases with ER
during the 3-month blanking period.\textsuperscript{3, 9, 10} The
present study showed that 55.7\% patients in the Non-CF group had ER
during the 3-month blanking period and 59.3\% of them had LR. These
results were consistent with those of previous studies. On the other
hand, in CF ablation cases, only 35.2\% cases experienced ER, and 52.4\%
of those with ER also had LR. These results were also consistent with
those of a previous study.\textsuperscript{11}

The mechanisms of ERs are considered to be post-ablation transient
factors, such as inflammatory changes, in addition to reconnection of PV
or residual extra-PV triggers.\textsuperscript{1} A previous
histopathological study had demonstrated that RF energy delivery causes
inflammatory responses after the ablation
procedure.\textsuperscript{12}Furthermore, a greater inflammatory
response after an RF ablation procedure has been associated with ER, and
a longer RF ablation time and total procedure time are significant
predictors for post-ablation inflammation and myocardial
injury.\textsuperscript{13} In the present study, the degree of
elevation in WBC and CRP levels after ablation was significantly smaller
in patients who underwent CF-guided ablation (Table 2). The RF delivery
time was shorter, and the amount of RF energy delivered was smaller in
patients who underwent CF-guided ablation (Table 2). Appropriate force
of tissue--catheter contact, and stability of RF delivery provided by CF
technology may result in more successful PVI, without excessive RF
delivery, and will reduce the inflammatory response. A lower
inflammatory response may partly explain the lower incidence of ER in
the CF-group.

\textbf{Different Time Course of Early Recurrence and Significance for
Late Recurrence}

A previous study has suggested that the incidence of ER decreases after
1-month post-ablation, in accordance with the normalization of the
systemic inflammatory response as assessed by WBC and CRP
levels.\textsuperscript{13} Histological examinations after RF delivery
have demonstrated that myocardial tissue conversion to fibrotic and
fatty tissue is not completed within 1 month, as macrophages and
lymphocytes are still present in the ablation lesion for 4--8 weeks
after ablation.\textsuperscript{14} Thus, local tissue inflammation may
persist after 1 month. In the present study, the greatest number of
patients experienced ER in the 1\textsuperscript{st}month after PAF
ablation, and ER occurrence decreased in the 2\textsuperscript{nd} and
even more in the 3\textsuperscript{rd} month, in both groups. A decrease
in the inflammatory changes can explain the time-dependent decrease in
the incidence of ER. However, the timing of the last ER for most
patients in the Non-CF group was the 3\textsuperscript{rd} month,
whereas it was the 1\textsuperscript{st}month in the CF group. Lower
initial inflammatory changes in the CF group may result in earlier
disappearance of inflammatory changes. Furthermore, 78\% of patients in
the Non-CF group with ER in the 3\textsuperscript{rd} month developed
LR, whereas 100\% of patients in the CF group with ER in the
3\textsuperscript{rd} month developed LR. Therefore, recurrence in the
3\textsuperscript{rd} month may be due to residual triggers, including
reconnection of the PVI lesion, in the CF group. With CF technology, the
blanking period can be defined as the first 2-month period, and patients
with ER in the 3\textsuperscript{rd}month can be good candidates for an
early redo-procedure. In addition, reconnection of the PV after the
2\textsuperscript{nd} procedure was less frequent in patients who
undergo an AI-based ablation than in those who undergo an FTI-based
ablation in the CF group, suggesting that AI-based ablation ensures more
durable PVI than FTI-based or non-CF catheter-based PVI.

\textbf{Limitations}

This was a retrospective, single-center study with a limited number of
cases. Multicenter randomized studies are necessary to verify the risk
for LR in cases with ER in the 3\textsuperscript{rd} month. Modification
of the autonomic nervous system (ANS) by RF ablation can be a transient
cause of ER; however, we did not assess changes in the ANS in this
study.

\textbf{Conclusions}

ER of atrial tachyarrhythmias in the 3\textsuperscript{rd} month after
PAF ablation with CF technology was a specific indicator of LR. The
blanking period can be defined as the first 2 months after ablation in
patients undergoing PVI with CF technology, and an early
2\textsuperscript{nd} ablation procedure could be encouraged in patients
who have ER in the 3\textsuperscript{rd} month.

\textbf{Acknowledgments:} none.

\textbf{REFERENCES}

\textbf{1.} Calkins H, Hindricks G, Cappato R, et al. 2017
HRS/EHRA/ECAS/APHRS/SOLAECE expert consensus statement on catheter and
surgical ablation of atrial fibrillation.\emph{Heart Rhythm} .
2017;14:e275-e444.

\textbf{2.} Themistoclakis S, Schweikert RA, Saliba WI, et al. Clinical
predictors and relationship between early and late atrial
tachyarrhythmias after pulmonary vein antrum isolation. \emph{Heart
Rhythm.} 2008;5:679-685.

\textbf{3.} Willems S, Khairy P, Andrade JG, et al.; ADVICE Trial
Investigators. Redefining the blanking period after catheter ablation
for paroxysmal atrial fibrillation: Insights from the ADVICE (adenosine
following pulmonary vein isolation to target dormant conduction
elimination) trial. \emph{Circ Arrhythm Electrophysiol} .
2016;9:e003909.

\textbf{4.} Jarman JWE, Panikker S, Das M, et al. Relationship between
contact force sensing technology and medium-term outcome of atrial
fibrillation ablation: a multicenter study of 600 patients. \emph{J
Cardiovasc Electrophysiol} . 2015;26:378-384.

\textbf{5.} Higuchi K, Yamauchi Y, Hirao K, et al. Superior vena cava as
initiator of atrial fibrillation: factors related to its
arrhythmogenicity. \emph{Heart Rhythm.}2010;7:1186-1191.

\textbf{6.} Sanders P, Hocini M, Jais P, et al. Complete isolation of
the pulmonary veins and posterior left atrium in chronic atrial
fibrillation. Long-term clinical outcome.\emph{Eur Heart J} .
2007;28:1862-1871.

\textbf{7.} Kautzner J, Neuzil P, Lambert H, et al. EFFICAS II:
optimization of catheter contact force improves outcome of pulmonary
vein isolation for paroxysmal atrial fibrillation. \emph{Europace} .
2015;17:1229-1235.

\textbf{8.} Taghji P, El Haddad M, Phlips T, et al. Evaluation of a
strategy aiming to enclose the pulmonary veins with contiguous and
optimized radiofrequency lesions in paroxysmal atrial fibrillation: A
pilot study. \emph{JACC Clin Electrophysiol} . 2018;4:99-108.

\textbf{9.} Lellouche N, Jais P, Nault I, et al. Early recurrences after
atrial fibrillation ablation: prognostic value and effect of early
reablation. \emph{J Cardiovasc Electrophysiol} . 2008;19:599-605.

\textbf{10.} Andrade JG, Khairy P, Verma A, et al. Early recurrence of
atrial tachyarrhythmias following radiofrequency catheter ablation of
atrial fibrillation. \emph{Pacing Clin Electrophysiol} .
2012;35:106-116.

\textbf{11.} Miyazaki S, Kuroi A, Hachiya H, et al. Early recurrence
after pulmonary vein isolation of paroxysmal atrial fibrillation with
different ablation technologies---Prospective comparison of
radiofrequency vs. second-generation cryoballoon ablation.
\emph{Circulation J} . 2016;80:346-353.

\textbf{12.} Grubman E, Pavri BB, Lyle S, Reynolds C, Denofrio D,
Kocovic DZ. Histopathologic effects of radiofrequency catheter ablation
in previously infarcted human myocardium. \emph{J Cardiovasc
Electrophysiol} . 1999;10:336-342.

\textbf{13.} Lim HS, Schultz C, Dang J, et al. Time course of
inflammation, myocardial injury, and prothrombotic response after
radiofrequency catheter ablation for atrial fibrillation. \emph{Circ
Arrhythm Electrophysiol} . 2014;7:83-89.

\textbf{14.} Tanno K, Kobayashi Y, Kurano K, et al. Histopathology of
canine hearts subjected to catheter ablation using radiofrequency
energy. \emph{Jpn Circ J} . 1994;58:123-135.

Table 1. Baseline patient characteristics\selectlanguage{english}
\begin{longtable}[]{@{}llll@{}}
\toprule
Characteristics & Non-CF (n = 97) & CF (n = 298) & p
value\tabularnewline
\midrule
\endhead
Age (year) & 63.7 \selectlanguage{ngerman}± 9.7 & 65.3 \selectlanguage{ngerman}± 9.9 & 0.085\tabularnewline
Female, n (\%) & 20 (20.6\%) & 93 (31.2\%) & 0.028\tabularnewline
BMI (kg/m\textsuperscript{2}) & 24.0 \selectlanguage{ngerman}± 3.1 & 24.1 \selectlanguage{ngerman}± 3.5 &
0.485\tabularnewline
PAF Disease Duration (months) & 24.9 \selectlanguage{ngerman}± 42.2 & 32.1 \selectlanguage{ngerman}± 33.5 &
0.023\tabularnewline
HT, n (\%) & 51 (52.6\%) & 159 (53.4\%) & 0.493\tabularnewline
CHF, n (\%) & 2 (2.1\%) & 14 (4.7\%) & 0.203\tabularnewline
DM, n (\%) & 13 (13.4\%) & 30 (10.1\%) & 0.230\tabularnewline
Previous stroke or TIA, n (\%) & 1 (1.0\%) & 10 (3.4\%) &
0.202\tabularnewline
Vascular disease, n (\%) & 1 (1.0\%) & 17 (5.7\%) & 0.055\tabularnewline
CHA\textsubscript{2}DS\textsubscript{2}-VASc score & 1.51 \selectlanguage{ngerman}± 1.13 & 1.94
\selectlanguage{ngerman}± 1.26 & 0.010\tabularnewline
T-cho (mg/dl) & 199.3 \selectlanguage{ngerman}± 34.5 & 190.9 \selectlanguage{ngerman}± 32.8 & 0.523\tabularnewline
LDL-cho (mg/dl) & 114.4 \selectlanguage{ngerman}± 29.9 & 108.4 \selectlanguage{ngerman}± 28.3 & 0.958\tabularnewline
Hba1c (\%) & 5.9 \selectlanguage{ngerman}± 0.6 & 5.9 \selectlanguage{ngerman}± 0.7 & 0.509\tabularnewline
BNP (pg/ml) & 45.2 \selectlanguage{ngerman}± 43.0 & 53.3 \selectlanguage{ngerman}± 46.9 & 0.081\tabularnewline
Ccr (ml/min) & 83.7 \selectlanguage{ngerman}± 23.1 & 77.4 \selectlanguage{ngerman}± 27.7 & 0.036\tabularnewline
\emph{Echocardiographic Data} & & &\tabularnewline
LAD (mm) & 40.6 \selectlanguage{ngerman}± 5.9 & 41.0 \selectlanguage{ngerman}± 6.0 & 0.709\tabularnewline
LA area (\selectlanguage{ngerman}×10\textsuperscript{2} mm\textsuperscript{2}) & 20.2 \selectlanguage{ngerman}± 5.4 &
21.4 \selectlanguage{ngerman}± 5.5 & 0.035\tabularnewline
EF (\%) & 65.5 \selectlanguage{ngerman}± 8.4 & 65.8 \selectlanguage{ngerman}± 7.7 & 0.863\tabularnewline
\emph{Catheter ablation procedure} & & &\tabularnewline
Additional SVC/PLA ablation & 24 (24.7\%) & 102 (34.2\%) &
0.082\tabularnewline
\bottomrule
\end{longtable}

Continuous variables are presented as mean \selectlanguage{ngerman}± SD.

AF, atrial fibrillation; BMI. body mass index; BNP, brain natriuretic
peptide; Ccr, creatinine clearance; CF, contact force; CHF, congestive
heart failure; DM, diabetes mellitus; EF, left ventricular ejection
fraction; HT, hypertension; LDL-cho; low-density lipoprotein
cholesterol; LAD, left atrial dimension; LA, left atrial; PLA, posterior
wall of the left atrium; SVC, superior vena cava; TIA, transient
ischemic attack; T-cho, total cholesterol

Table 2. Difference of ablation results between the Non-CF and the CF
group\selectlanguage{english}
\begin{longtable}[]{@{}llll@{}}
\toprule
Characteristics & Non-CF (n = 97) & CF (n = 298) & p
value\tabularnewline
\midrule
\endhead
RF delivery time (sec) & 2401.1 \selectlanguage{ngerman}± 733.4 & 2056.8 \selectlanguage{ngerman}± 534.5 &
\textless{}0.001\tabularnewline
delivered RF energy (J) & 59130.9 \selectlanguage{ngerman}± 19636.4 & 53698.4 \selectlanguage{ngerman}± 13487.2 &
0.031\tabularnewline
WBC ratio & 1.72 \selectlanguage{ngerman}± 0.33 & 1.53 \selectlanguage{ngerman}± 0.34 & \textless{}0.001\tabularnewline
Difference of CRP (mg/dl) & 1.21 \selectlanguage{ngerman}± 1.81 & 0.73 \selectlanguage{ngerman}± 0.93 &
0.001\tabularnewline
Early Recurrence & 54 (55.7\%) & 105 (35.2\%) &
\textless{}0.001\tabularnewline
AF & 44 (45.4\%) & 87 (29.2\%) & 0.003\tabularnewline
AT & 9 (9.3\%) & 12 (4.0\%) & 0.046\tabularnewline
Late Recurrence & 42 (43.3\%) & 65 (21.8\%) &
\textless{}0.001\tabularnewline
AF & 31 (32.0\%) & 63 (21.1\%) & 0.023\tabularnewline
AT & 16 (16.5\%) & 5 (1.7\%) & \textless{}0.001\tabularnewline
\bottomrule
\end{longtable}

Continuous variables are presented as mean \selectlanguage{ngerman}± SD.

AF, atrial fibrillation; AT, atrial tachycardia; CF, contact force; CRP,
C-reactive protein; LR, late recurrence; RF, radiofrequency; WBC, white
blood cell count; WBC ratio = post-ablation WBC / pre-ablation WBC,
Difference of CRP = post-ablation CRP -- pre-ablation CRP

Table 3. Characteristics and significance of early recurrence as the
risk factor for late recurrence\selectlanguage{english}
\begin{longtable}[]{@{}lllllll@{}}
\toprule
\begin{minipage}[b]{0.12\columnwidth}\raggedright\strut
\strut
\end{minipage} & \begin{minipage}[b]{0.12\columnwidth}\raggedright\strut
Non--CF (n = 97)\strut
\end{minipage} & \begin{minipage}[b]{0.12\columnwidth}\raggedright\strut
Non--CF (n = 97)\strut
\end{minipage} & \begin{minipage}[b]{0.12\columnwidth}\raggedright\strut
Non--CF (n = 97)\strut
\end{minipage} & \begin{minipage}[b]{0.12\columnwidth}\raggedright\strut
CF (n = 298)\strut
\end{minipage} & \begin{minipage}[b]{0.12\columnwidth}\raggedright\strut
CF (n = 298)\strut
\end{minipage} & \begin{minipage}[b]{0.12\columnwidth}\raggedright\strut
CF (n = 298)\strut
\end{minipage}\tabularnewline
\midrule
\endhead
\begin{minipage}[t]{0.14\columnwidth}\raggedright\strut
ER Characteristics\strut
\end{minipage} & \begin{minipage}[t]{0.14\columnwidth}\raggedright\strut
Late Recurrence\strut
\end{minipage} & \begin{minipage}[t]{0.14\columnwidth}\raggedright\strut
OR (95\% CI)\strut
\end{minipage} & \begin{minipage}[t]{0.14\columnwidth}\raggedright\strut
p Value\strut
\end{minipage} & \begin{minipage}[t]{0.14\columnwidth}\raggedright\strut
Late Recurrence\strut
\end{minipage} & \begin{minipage}[t]{0.14\columnwidth}\raggedright\strut
OR (95\% CI)\strut
\end{minipage} & \begin{minipage}[t]{0.14\columnwidth}\raggedright\strut
p Value\strut
\end{minipage}\tabularnewline
\begin{minipage}[t]{0.14\columnwidth}\raggedright\strut
Any ER\strut
\end{minipage} & \begin{minipage}[t]{0.14\columnwidth}\raggedright\strut
32 (59.3\%)\strut
\end{minipage} & \begin{minipage}[t]{0.14\columnwidth}\raggedright\strut
4.800 (1.968--11.709)\strut
\end{minipage} & \begin{minipage}[t]{0.14\columnwidth}\raggedright\strut
0.001\strut
\end{minipage} & \begin{minipage}[t]{0.14\columnwidth}\raggedright\strut
55 (52.4\%)\strut
\end{minipage} & \begin{minipage}[t]{0.14\columnwidth}\raggedright\strut
20.130 (9.577--42.311)\strut
\end{minipage} & \begin{minipage}[t]{0.14\columnwidth}\raggedright\strut
\textless{}0.001\strut
\end{minipage}\tabularnewline
\begin{minipage}[t]{0.14\columnwidth}\raggedright\strut
Single ER\strut
\end{minipage} & \begin{minipage}[t]{0.14\columnwidth}\raggedright\strut
10 (50.0\%)\strut
\end{minipage} & \begin{minipage}[t]{0.14\columnwidth}\raggedright\strut
3.300 (1.070--10.179)\strut
\end{minipage} & \begin{minipage}[t]{0.14\columnwidth}\raggedright\strut
0.038\strut
\end{minipage} & \begin{minipage}[t]{0.14\columnwidth}\raggedright\strut
31 (39.7\%)\strut
\end{minipage} & \begin{minipage}[t]{0.14\columnwidth}\raggedright\strut
8.657 (4.192--17.879)\strut
\end{minipage} & \begin{minipage}[t]{0.14\columnwidth}\raggedright\strut
\textless{}0.001\strut
\end{minipage}\tabularnewline
\begin{minipage}[t]{0.14\columnwidth}\raggedright\strut
Multiple ERs\strut
\end{minipage} & \begin{minipage}[t]{0.14\columnwidth}\raggedright\strut
22 (64.7\%)\strut
\end{minipage} & \begin{minipage}[t]{0.14\columnwidth}\raggedright\strut
6.050 (2.231--16.407)\strut
\end{minipage} & \begin{minipage}[t]{0.14\columnwidth}\raggedright\strut
\textless{}0.001\strut
\end{minipage} & \begin{minipage}[t]{0.14\columnwidth}\raggedright\strut
24 (88.9\%)\strut
\end{minipage} & \begin{minipage}[t]{0.14\columnwidth}\raggedright\strut
107.051 (28.487--402.294)\strut
\end{minipage} & \begin{minipage}[t]{0.14\columnwidth}\raggedright\strut
\textless{}0.001\strut
\end{minipage}\tabularnewline
\begin{minipage}[t]{0.14\columnwidth}\raggedright\strut
1\textsuperscript{st} month only\strut
\end{minipage} & \begin{minipage}[t]{0.14\columnwidth}\raggedright\strut
5 (38.5\%)\strut
\end{minipage} & \begin{minipage}[t]{0.14\columnwidth}\raggedright\strut
2.062 (0.555--7.740)\strut
\end{minipage} & \begin{minipage}[t]{0.14\columnwidth}\raggedright\strut
0.283\strut
\end{minipage} & \begin{minipage}[t]{0.14\columnwidth}\raggedright\strut
19 (30.2\%)\strut
\end{minipage} & \begin{minipage}[t]{0.14\columnwidth}\raggedright\strut
5.676 (2.599--12.395)\strut
\end{minipage} & \begin{minipage}[t]{0.14\columnwidth}\raggedright\strut
\textless{}0.001\strut
\end{minipage}\tabularnewline
\begin{minipage}[t]{0.14\columnwidth}\raggedright\strut
2\textsuperscript{nd} month only\strut
\end{minipage} & \begin{minipage}[t]{0.14\columnwidth}\raggedright\strut
3 (100\%)\strut
\end{minipage} & \begin{minipage}[t]{0.14\columnwidth}\raggedright\strut
undefined\strut
\end{minipage} & \begin{minipage}[t]{0.14\columnwidth}\raggedright\strut
\textless{}0.001\strut
\end{minipage} & \begin{minipage}[t]{0.14\columnwidth}\raggedright\strut
4 (57.1\%)\strut
\end{minipage} & \begin{minipage}[t]{0.14\columnwidth}\raggedright\strut
17.128 (3.459--84.819)\strut
\end{minipage} & \begin{minipage}[t]{0.14\columnwidth}\raggedright\strut
\textless{}0.001\strut
\end{minipage}\tabularnewline
\begin{minipage}[t]{0.14\columnwidth}\raggedright\strut
3\textsuperscript{rd} month only\strut
\end{minipage} & \begin{minipage}[t]{0.14\columnwidth}\raggedright\strut
2 (50.0\%)\strut
\end{minipage} & \begin{minipage}[t]{0.14\columnwidth}\raggedright\strut
3.300 (0.411--26.514)\strut
\end{minipage} & \begin{minipage}[t]{0.14\columnwidth}\raggedright\strut
0.261\strut
\end{minipage} & \begin{minipage}[t]{0.14\columnwidth}\raggedright\strut
8 (100\%)\strut
\end{minipage} & \begin{minipage}[t]{0.14\columnwidth}\raggedright\strut
Undefined\strut
\end{minipage} & \begin{minipage}[t]{0.14\columnwidth}\raggedright\strut
\textless{}0.001\strut
\end{minipage}\tabularnewline
\begin{minipage}[t]{0.14\columnwidth}\raggedright\strut
1\textsuperscript{st} + 2\textsuperscript{nd} month\strut
\end{minipage} & \begin{minipage}[t]{0.14\columnwidth}\raggedright\strut
3 (27.3\%)\strut
\end{minipage} & \begin{minipage}[t]{0.14\columnwidth}\raggedright\strut
1.237 (0.275--5.567)\strut
\end{minipage} & \begin{minipage}[t]{0.14\columnwidth}\raggedright\strut
0.781\strut
\end{minipage} & \begin{minipage}[t]{0.14\columnwidth}\raggedright\strut
5 (62.5\%)\strut
\end{minipage} & \begin{minipage}[t]{0.14\columnwidth}\raggedright\strut
21.410 (4.596--99.730)\strut
\end{minipage} & \begin{minipage}[t]{0.14\columnwidth}\raggedright\strut
\textless{}0.001\strut
\end{minipage}\tabularnewline
\begin{minipage}[t]{0.14\columnwidth}\raggedright\strut
1\textsuperscript{st} + 3\textsuperscript{rd} month\strut
\end{minipage} & \begin{minipage}[t]{0.14\columnwidth}\raggedright\strut
5 (71.4\%)\strut
\end{minipage} & \begin{minipage}[t]{0.14\columnwidth}\raggedright\strut
8.250 (1.383--49.213)\strut
\end{minipage} & \begin{minipage}[t]{0.14\columnwidth}\raggedright\strut
0.021\strut
\end{minipage} & \begin{minipage}[t]{0.14\columnwidth}\raggedright\strut
4 (100\%)\strut
\end{minipage} & \begin{minipage}[t]{0.14\columnwidth}\raggedright\strut
Undefined\strut
\end{minipage} & \begin{minipage}[t]{0.14\columnwidth}\raggedright\strut
\textless{}0.001\strut
\end{minipage}\tabularnewline
\begin{minipage}[t]{0.12\columnwidth}\raggedright\strut
2\textsuperscript{nd} +3\textsuperscript{rd} month\strut
\end{minipage} & \begin{minipage}[t]{0.12\columnwidth}\raggedright\strut
4 (100\%)\strut
\end{minipage} & \begin{minipage}[t]{0.12\columnwidth}\raggedright\strut
undefined\strut
\end{minipage} & \begin{minipage}[t]{0.12\columnwidth}\raggedright\strut
\textless{}0.001\strut
\end{minipage} & \begin{minipage}[t]{0.12\columnwidth}\raggedright\strut
4 (100\%)\strut
\end{minipage} & \begin{minipage}[t]{0.12\columnwidth}\raggedright\strut
Undefined\strut
\end{minipage} & \begin{minipage}[t]{0.12\columnwidth}\raggedright\strut
\textless{}0.001\strut
\end{minipage}\tabularnewline
\begin{minipage}[t]{0.14\columnwidth}\raggedright\strut
1\textsuperscript{st} +2\textsuperscript{nd} +3\textsuperscript{rd}
month\strut
\end{minipage} & \begin{minipage}[t]{0.14\columnwidth}\raggedright\strut
10 (83.3\%)\strut
\end{minipage} & \begin{minipage}[t]{0.14\columnwidth}\raggedright\strut
16.500 (3.091--88.085)\strut
\end{minipage} & \begin{minipage}[t]{0.14\columnwidth}\raggedright\strut
0.001\strut
\end{minipage} & \begin{minipage}[t]{0.14\columnwidth}\raggedright\strut
11 (100\%)\strut
\end{minipage} & \begin{minipage}[t]{0.14\columnwidth}\raggedright\strut
Undefined\strut
\end{minipage} & \begin{minipage}[t]{0.14\columnwidth}\raggedright\strut
\textless{}0.001\strut
\end{minipage}\tabularnewline
\begin{minipage}[t]{0.14\columnwidth}\raggedright\strut
Last ER in 1\textsuperscript{st} month\strut
\end{minipage} & \begin{minipage}[t]{0.14\columnwidth}\raggedright\strut
5 (38.5\%)\strut
\end{minipage} & \begin{minipage}[t]{0.14\columnwidth}\raggedright\strut
2.062 (0.555--7.740)\strut
\end{minipage} & \begin{minipage}[t]{0.14\columnwidth}\raggedright\strut
0.283\strut
\end{minipage} & \begin{minipage}[t]{0.14\columnwidth}\raggedright\strut
19 (30.2\%)\strut
\end{minipage} & \begin{minipage}[t]{0.14\columnwidth}\raggedright\strut
5.676 (2.599--12.395)\strut
\end{minipage} & \begin{minipage}[t]{0.14\columnwidth}\raggedright\strut
\textless{}0.001\strut
\end{minipage}\tabularnewline
\begin{minipage}[t]{0.14\columnwidth}\raggedright\strut
Last ER in 2\textsuperscript{nd} month\strut
\end{minipage} & \begin{minipage}[t]{0.14\columnwidth}\raggedright\strut
6 (42.9\%)\strut
\end{minipage} & \begin{minipage}[t]{0.14\columnwidth}\raggedright\strut
1.833 (0.499--6.742)\strut
\end{minipage} & \begin{minipage}[t]{0.14\columnwidth}\raggedright\strut
0.362\strut
\end{minipage} & \begin{minipage}[t]{0.14\columnwidth}\raggedright\strut
9 (60.0\%)\strut
\end{minipage} & \begin{minipage}[t]{0.14\columnwidth}\raggedright\strut
19.269 (5.938--62.528)\strut
\end{minipage} & \begin{minipage}[t]{0.14\columnwidth}\raggedright\strut
\textless{}0.001\strut
\end{minipage}\tabularnewline
\begin{minipage}[t]{0.14\columnwidth}\raggedright\strut
Last ER in 3\textsuperscript{rd} month\strut
\end{minipage} & \begin{minipage}[t]{0.14\columnwidth}\raggedright\strut
21 (77.8\%)\strut
\end{minipage} & \begin{minipage}[t]{0.14\columnwidth}\raggedright\strut
11.550 (3.655--36.497)\strut
\end{minipage} & \begin{minipage}[t]{0.14\columnwidth}\raggedright\strut
\textless{}0.001\strut
\end{minipage} & \begin{minipage}[t]{0.14\columnwidth}\raggedright\strut
27 (100\%)\strut
\end{minipage} & \begin{minipage}[t]{0.14\columnwidth}\raggedright\strut
Undefined\strut
\end{minipage} & \begin{minipage}[t]{0.14\columnwidth}\raggedright\strut
\textless{}0.001\strut
\end{minipage}\tabularnewline
\bottomrule
\end{longtable}

CF, contact force; ER, early recurrence

\textbf{Figure and Figure Legends}\selectlanguage{english}
\begin{figure}[H]
\begin{center}
\includegraphics[width=0.70\columnwidth]{figures/image1/image1}

\end{center}
\end{figure}

Figure 1. Freedom from atrial tachyarrhythmias in patients with
paroxysmal atrial fibrillation after a single ablation procedure with or
without contact force (CF) technology. Patients with CF-guided ablation
were more likely to achieve long-term ablation success.

Figure 2. Incidence of early recurrence episodes in each month during
the blanking period in patients with paroxysmal atrial fibrillation
ablated with and without contact force (CF) technology. In both groups,
the incidence of early recurrence (ER) was highest in the
1\textsuperscript{st} month. In each month after ablation, the incidence
of ER was higher in the non-CF group.\selectlanguage{english}
\begin{figure}[H]
\begin{center}
\includegraphics[width=0.70\columnwidth]{figures/image2/image2}

\end{center}
\end{figure}

Figure 3. The timing of the last occurrence of early recurrence (ER) of
atrial tachyarrhythmias in patients ablated with and without contact
force (CF) technology. In the Non-CF group, the last ER episode occurred
most frequently in the 3\textsuperscript{rd} month, whereas it occurred
most frequently in the 1\textsuperscript{st} month in the CF group.\selectlanguage{english}
\begin{figure}[H]
\begin{center}
\includegraphics[width=0.70\columnwidth]{figures/image3/image3}

\end{center}
\end{figure}\selectlanguage{english}
\begin{figure}[H]
\begin{center}
\includegraphics[width=0.70\columnwidth]{figures/image4/image4}

\end{center}
\end{figure}\selectlanguage{english}
\begin{figure}[H]
\begin{center}
\includegraphics[width=0.70\columnwidth]{figures/image5/image5}

\end{center}
\end{figure}

Figure 4. (a) Freedom from atrial tachyarrhythmia after the non-contact
force-guided ablation procedure in patients with early recurrence (ER)
in the 1\textsuperscript{st}, 2\textsuperscript{nd}, and
3\textsuperscript{rd} month post-ablation. (b) Freedom from atrial
tachyarrhythmia after a contact force (CF)-guided ablation procedure in
patients with ER in the 1\textsuperscript{st}, 2\textsuperscript{nd},
and 3\textsuperscript{rd} month post-ablation. (c) Comparison of atrial
tachyarrhythmia-free survival in patients who had ER in the
3\textsuperscript{rd} month, in both CF and Non-CF groups.

Figure 5. Incidence of pulmonary vein (PV) reconnection in patients with
paroxysmal atrial fibrillation with early recurrence (ER) after
ablation, who underwent a redo-procedure. CF; contact force, FTI;
force-time integral, AI; ablation index\selectlanguage{english}
\begin{figure}[H]
\begin{center}
\includegraphics[width=0.70\columnwidth]{figures/image6/image6}

\end{center}
\end{figure}

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

