\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{A clinical pathway for safely and effectively cardioverting emergency
department patients with atrial fibrillation greater than 48 hours}



\author[1]{Baha Zaro}%
\author[1]{Evan Avraham Alpert}%
\author[1]{Nechama Kaufman}%
\author[1]{David Rosenmann}%
\affil[1]{Shaare Zedek Medical Center}%


\vspace{-1em}



  
  \date{May 21, 2024}


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





\selectlanguage{english}
\begin{abstract}
Background: The current emergency medicine literature on cardioversion
for atrial fibrillation (AF), describes its performance on those who are
hemodynamically unstable, present within 48 hours of the onset of the
arrhythmia, or are on long term anticoagulants. This article describes a
clinical pathway comparing patients presenting to the emergency
department (ED) with atrial fibrillation (AF) of more than 48 hours who
underwent a transesophageal echocardiogram (TEE) and subsequent
cardioversion in the ED. The objective of this study is to evaluate such
a pathway looking at the time to cardioversion, length of hospital stay,
rate of successful cardioversion, and the rate of complications compared
to the traditional pathway of admitting patients directly to the
cardiology department for evaluation and treatment. Methods: This was a
retrospective observational study of patients who presented to the ED
with AF for more than 48 hours, underwent a transesophageal
echocardiogram, and then were electrically cardioverted either in the
emergency department versus the cardiology ward. Results: Electrical
cardioversion was performed in the ED on 92 patients (61\%) and the
cardiology department on 59 (39\%). Over 90\% of cardioversions were
successful in both groups. Time to cardioversion was significantly less
in the ED group versus the cardiology group (1.03 \selectlanguage{ngerman}± 0.8 days versus 4.17
± 1.9; p\textless{}0.001). Similarly, the mean length of hospital stay
was less for the ED group (1.5± 1.5 days versus 7.2 ± 3.5;
p\textless{}0.001). Conclusion: Patients who present in atrial
fibrillation for more than 48 hours and then have a TEE, undergo
electrical cardioversion faster in the ED compared to the cardiology
ward. This clinical pathway also results in a shorter length of hospital
stay without having more side effects.%
\end{abstract}\selectlanguage{ngerman}%



\sloppy


\textbf{A clinical pathway for safely and effectively cardioverting
emergency department patients with atrial fibrillation greater than 48
hours}

\textbf{Baha Zaro, MD\textsuperscript{a*}, Evan Avraham Alpert,
MD\textsuperscript{a*}, Nechama Kaufman, RN, MN\textsuperscript{b},
David Rosenmann, MD\textsuperscript{c}}

\begin{enumerate}
\tightlist
\item
  Department of Emergency Medicine, Shaare Zedek Medical Center, Shmu'el
  Bait St 12, Jerusalem, Israel, 9103102
\item
  Department of Quality and Safety, Shaare Zedek Medical Center, Shmu'el
  Bait St 12, Jerusalem, Israel, 9103102
\item
  Jesselson Integrated Heart Centre, Shaare Zedek Medical Center,
  Shmu'el Bait St 12, Jerusalem, Israel, 9103102
\end{enumerate}

*Equal contribution

\textbf{Acknowledgements:} The authors would like to acknowledge
Emilya~Zuty for her work contributing to maintaining the database used
for the project.

\textbf{Email Addresses:}

Baha Zaro, MD: drbahazaro87@gmail.com

Evan Avraham Alpert, MD: evanavrahamalpert@gmail.com

Nechama Kaufman, RN, MN: nechamak@szmc.org.il

David Rosenmann, MD: rosenmann@szmc.org.il

\textbf{Grant support:} none

\textbf{Declarations of interest:} none

\textbf{Keywords:} Transesophageal Echocardiography; Emergency
Department; Electrical Cardioversion; Atrial Fibrillation;
Cardiology~Hospital Service

\textbf{Correspondence:}

Evan Avraham Alpert, MD

Shaare Zedek Medical Center

Shmu'el Bait St 12, Jerusalem, 9103102

Evanavrahamalpert@gmail.com

\emph{TEE for atrial fibrillation in the emergency department}

\textbf{A clinical pathway for safely and effectively cardioverting
emergency department patients with atrial fibrillation greater than 48
hours}

\textbf{Background} : The current emergency medicine literature on
cardioversion for atrial fibrillation (AF), describes its performance on
those who are hemodynamically unstable, present within 48 hours of the
onset of the arrhythmia, or are on long term anticoagulants. This
article describes a clinical pathway comparing patients presenting to
the emergency department (ED) with atrial fibrillation (AF) of more than
48 hours who underwent a transesophageal echocardiogram (TEE) and
subsequent cardioversion in the ED.

The objective of this study is to evaluate such a pathway looking at the
time to cardioversion, length of hospital stay, rate of successful
cardioversion, and the rate of complications compared to the traditional
pathway of admitting patients directly to the cardiology department for
evaluation and treatment.

\textbf{Methods} : This was a retrospective observational study of
patients who presented to the ED with AF for more than 48 hours,
underwent a transesophageal echocardiogram, and then were electrically
cardioverted either in the emergency department versus the cardiology
ward.

\textbf{Results:} Electrical cardioversion was performed in the ED on 92
patients (61\%) and the cardiology department on 59 (39\%). Over 90\% of
cardioversions were successful in both groups. Time to cardioversion was
significantly less in the ED group versus the cardiology group (1.03 \selectlanguage{ngerman}±
0.8 days versus 4.17 ± 1.9; p\textless{}0.001). Similarly, the mean
length of hospital stay was less for the ED group (1.5± 1.5 days versus
7.2 ± 3.5; p\textless{}0.001).

\textbf{Conclusion:} Patients who present in atrial fibrillation for
more than 48 hours and then have a TEE, undergo electrical cardioversion
faster in the ED compared to the cardiology ward. This clinical pathway
also results in a shorter length of hospital stay without having more
side effects.

\textbf{What is already known on this topic?}

Atrial fibrillation is a common diagnosis in the emergency department.
Patients who present with new-onset atrial fibrillation less than 48
hours or are on long term anticoagulation can be safely cardioverted in
the emergency department. Patients who present with symptomatic atrial
fibrillation longer than 48 hours and not on anticoagulation are
traditionally admitted to the cardiology department for evaluation and
treatment.

\textbf{What does this article add?}

This article describes a clinical pathway whereby patients who present
in atrial fibrillation for more than 48 hours and then have a
transesophageal electrocardiogram showing no atrial clot, can return to
the emergency department and safely undergo cardioversion. This clinical
pathway also results in a faster time to cardioversion and shorter
length of hospital stay compared to those admitted to the cardiology
department.

\textbf{Keywords:} Transesophageal Echocardiography; Emergency
Department; Electrical Cardioversion; Atrial Fibrillation;
Cardiology~Hospital Service



\section*{Introduction}

{\label{introduction}}

Atrial fibrillation (AF) is the most frequently encountered dysrhythmia
seen in the United States, both in the outpatient and emergency
department (ED) settings.\textsuperscript{1} In 2014 in the United
States, over half a million people visited EDs for AF, leading to a 62\%
admission rate and \$10.1~billion in adjusted annual charges for
admitted patients.\textsuperscript{2}

The treatment of patients presenting with AF is dependent upon several
factors including the patient's hemodynamic status and the time of
onset. If the patient presents when hemodynamically unstable, immediate
conversion to sinus rhythm is required despite the time of onset of AF.
For hemodynamically stable patients the issue then becomes rate and
rhythm control. Rhythm control in the ED, whether by electrical or
pharmacologic means is acceptable for those who have been anticoagulated
for at least three weeks or if the atrial fibrillation is known to have
started less than 48 hours.\textsuperscript{3} The ``48-hour rule'' that
has been implemented in clinical practice is based on theoretical rather
than evidence-based data. The risk of thromboembolism in patients
undergoing cardioversion for AF of \textless{}48 hours duration is
extremely low and ranges between 0-0.9\%. However, cardioversion of
patients with AF \textgreater{}48 hours' duration without prior adequate
anticoagulation led to a 5-7\% risk of stroke thus leading to the
48-hour rule.\textsuperscript{4} Cardioverting patients (electrically or
pharmacologically) who present to the emergency department with AF of
less than 48 hours' duration can be done safely and effectively by
emergency physicians.\textsuperscript{5--8}

Current guidelines for those with AF more than 48 hours and not on
anticoagulation recommend either rate control and discharge from the ED
on anticoagulation for at least 3 weeks before and at least 4 weeks
after cardioversion, or performance of a transesophageal echocardiogram
(TEE) with subsequent cardioversion if there is no clot on the atria or
left atrial appendage.\textsuperscript{3}

The objective of this study is to describe the safety and efficacy of a
clinical pathway for patients who presented to the ED with AF
\textgreater{}48 hours, who underwent TEE, and then had synchronized
electrical cardioversion performed in the ED versus the cardiology
department. Major outcomes included time to cardioversion and length of
hospital stay. Secondary outcomes included the rate of successful
cardioversion, complications, and readmissions within 30 days of
hospital discharge.

\textbf{Methods}

\emph{Study design and setting}

This is a retrospective observational study of patients who presented to
the ED between January 1, 2010, and December 31, 2018, with a diagnosis
of AF for \textgreater{} 48 hours who then underwent a TEE. All of the
TEEs were ordered from the ED, but the actual examination was performed
by a board-certified cardiologist with additional training and extensive
experience with this procedure. Of the patients who did not have an
atrial clot or other contraindication to cardioversion, there was a
convenience sample who returned to the ED for electrical cardioversion
performed by emergency physicians versus a second group who were
cardioverted in the cardiology department. Regardless of the place where
electrical cardioversion was performed, all patients were sedated for
the procedure and received anticoagulation both before and after their
cardioversion as per protocol. The study site is a 1000-bed tertiary
care medical center that includes a comprehensive cardiology department.
Over 90,000 adult patients are seen annually in the ED. The
Institutional Review Board waived the requirement for written consent as
this was a retrospective study.

\emph{Selection of participants}

Databases of the hospital and cardiology department were searched for
patients from January 1, 2010, through Dec 31, 2018, who were diagnosed
with AF in the ED and then underwent a TEE. The patients' files were
then searched to establish the duration of the AF and whether the
patient underwent subsequent cardioversion after negative TEE results
during their hospitalization. Patients included in the study were those
\selectlanguage{english}[?] 18 years of age who presented to the ED with AF \textgreater{} 48
hours' duration and underwent TEE, who had subsequent synchronized
electrical cardioversion performed either in the ED or in the cardiology
department.

Excluded from the study were those who were: admitted directly to the
cardiology ward for cardioversion, hemodynamically unstable, had a clot
present on the atrium, with AF \textgreater{} 48 hours who underwent
pharmacological cardioversion, pregnant, or less than 18 years old.

\emph{Data collection and processing}

All data were collected from the hospital's proprietary database and the
hospital's cardiology database and entered into an Excel file (Redmond,
WA, USA: Microsoft). Data collected included demographic variables (e.g.
age, sex), past medical history, chief complaint, date of TEE
performance, clinical details of the TEE, date of electrical
cardioversion, complications post-cardioversion, and re-admissions
within 30 days of hospital discharge. Categorical variables were
compared using the Chi-square or Fisher's exact test where appropriate
with a p\textless{}0.05 considered statistically significant. Continuous
variables are described with mean and standard deviation and compared by
the Student's t-test where appropriate. The p-values for this are
two-tailed, and p\textless{}0.05 is considered statistically
significant.

\textbf{Results}

A total of 350 patients diagnosed with AF underwent TEE during the study
period. However, after applying the exclusion criteria, the study cohort
consisted of 151 patients (43\%). (Figure 1)

\emph{Patient and clinical details}

Patient gender was almost evenly dispersed; 51\% (n=77) of patients were
male. The mean age was 71+-12.4 years (median 73; 27-96). Electrical
cardioversion was performed in the ED on 92 patients (61\%) and the
cardiology department on 59 (39\%). Most patients' chief complaints were
similar between the groups. However, ``shortness of breath'' was more
common in patients cardioverted in the cardiology department (p=0.012).
Also, ``discovering AF as an incidental finding on a routine ECG'' was
experienced by seven (8\%) ED patients as opposed to no cardiology
department patients (p=0.043). Demographic details and chief complaints
of the cohort comparing those who were cardioverted in the ED versus
those converted in the cardiology department are described in Table 1.

Clinical details between the groups were also similar. Vital signs
showed no significant differences except for heart rate, which was a
mean nine beats per minute higher in those patients cardioverted on the
cardiology ward as opposed to those treated in the ED (p=0.044). Past
medical history, as well as lab results, showed no differences between
the groups. Troponin is described as ``positive'' or ``negative'' rather
than as a numerical value since the hospital utilized different methods
of troponin measurement during the study period. The term ``negative''
denotes a negative troponin value for the employed sensitivity test. The
highest troponin observed in the entire cohort was a troponin T of 130
ng/L. This patient was successfully cardioverted in the cardiology
department with no adverse effects. (Table 1)

\emph{Cardioversion details}

TEE results for the entire cohort showed no thrombus in the left atrium
or on the left atrial appendage. Additional echo details are described
in Table 2.

The study groups were divided based on where their cardioversion was
performed. If cardioversion performed in the ED failed, necessitating
hospitalization and re-cardioversion in the cardiology department, these
patients were classified as ``cardiology department'' patients (there
were two such patients in the study cohort). Most patients from both
cohorts had only one cardioversion attempt. ``Success of cardioversion''
was defined as sinus rhythm at hospital discharge. The great majority
(over 90\%) of cardioversions were successful in both groups (95\% in
the ED group and 91\% in the cardiology department group). There were
very few post-cardioversion complications. However, shortness of breath
(SOB) was 10\% more prevalent in those converted on the cardiology ward
(p=0.030), although the absolute numbers were relatively low (two
patients in the ED group vs. seven in the cardiology group). Neither
chest pain nor hypotension showed any difference between the groups.
(Table 2)

\emph{Temporal details}

All TEE's were performed within three days of patient arrival, with over
75\% of TEE's performed within the first day. Only seven tests were
performed on day three. The time to the performance of TEE was not
significantly different between the two groups. The time to
cardioversion, however, was significant between the groups. The ED
cardioversion group had a markedly shorter time to cardioversion than
the cardiology department group, with a mean difference of over 2.5 days
longer for the cardiology department patients (p\textless{}0.001). The
average time to cardioversion was a mean 1.03 +- 0.8 days in the ED group
versus 4.17 +- 1.9 days for the cardiology department group.
Correspondingly, the total length of stay (LOS) in the hospital was
significantly different between the groups with a mean of 1.49 +- 1.5
days for the ED patients versus a nearly five-fold increase of a mean of
7.2 +- 3.5 days for the cardiology department patients
(p\textless{}0.001). Patients were also kept in the hospital after their
cardioversions for significantly different periods of time. The
cardiology department cohort was discharged an average of three days
after the cardioversion, whereas the ED cohort was discharged less than
a day later on average (p\textless{}0.001). (Table 2)

\emph{Readmissions}

Readmissions (data only from the study hospital) were examined at
one-month post-hospital discharge. A total of 32 patients (21\%) were
readmitted to the study hospital one month after hospital discharge.
There were 10 fewer readmissions from the cardiology department cohort
(11 patients versus 21 patients from the ED cohort), but this difference
was not statistically significant (p=0.684). Causes of readmission were
most commonly recurrent AF in both cohorts (43\% for ED patients versus
46\% for cardiology department patients) but included other causes, both
related and unrelated to the primary admission. It was interesting to
note that four patients were readmitted to the ED for other cardiac
causes (primarily CHF), but no such readmissions reached the cardiology
department. No thromboembolic events were reported. Two patients
returned due to anticoagulation issues: one due to a high
routinely-drawn INR with no reported bleeding and one due to a bleeding
event that required no medical intervention. Readmissions occurred after
a mean of 11 or 12 days (ED cohort and cardiology department cohort,
respectively) and lasted a mean of 3.1 and 3.8 days respectively. (Table
3)

\textbf{Discussion}

This is a unique study that compared ED patients with AF for more than
48 hours' duration who subsequently underwent TEE and then electrical
cardioversion by emergency physicians back in the ED versus in the
cardiology department. Successful cardioversion, defined at discharge,
showed that over 90\% of cardioversions were successful in both groups.
Time to TEE was approximately one day for both groups. However, time to
cardioversion, time kept in the hospital post-procedure, and LOS in the
hospital were significantly shorter in the ED group versus the
cardiology department group. This was thought to be due to several
factors. All patients who were cardioverted underwent procedural
sedation. Those who had the procedure performed in the ED had the
sedation performed by a second ED physician which could be arranged
relatively quickly. However, at the time of the study, the patients who
underwent cardioversion in the cardiology department needed to wait for
an anesthesiologist to perform the sedation. As there was no dedicated
anesthesiologist, this could result in a significant waiting period.
Also, there was a logistical need to arrange for a monitored observation
area in the cardiology department. Some of the patients in the
cardiology department underwent additional workups and treatment for a
secondary issue such as anemia. Also, there may have been a trend to
quickly discharge post-procedure patients from a busy urban ED.
Interestingly there was no significant difference in the readmission
rate to the hospital one-month post-hospital discharge and no known
significant negative outcomes in the ED cardioversion group.

This study is the first to be done to examine ED cardioversion post-TEE
performance in patients whose atrial fibrillation was more than 48
hours' duration. Previous studies have described ED electrical
cardioversions of less than 48 hours' duration with success rates
ranging from 85.5 to 97\%.\textsuperscript{9} Burton et al. described a
7-day 10\% return of patients, of whom 78\% (25/32) returned due to a
recurrence of AF.\textsuperscript{1} A recent multicenter randomized
control trial assigned ED patients with recent-onset AF (\textless{}36
hours) who were symptomatic yet hemodynamically stable to be treated
either with early cardioversion or with a ``wait-and-see'' approach. At
4-week follow-up, AF recurred in 49/164 (30\%) in the delayed
cardioversion group versus in 50/171 (29\%) of the earlier cardioversion
group.\textsuperscript{10} Scheuermeyer et al. performed a random 30-day
follow-up chart review of 400/1233 AF patients who had undergone ED
electrical cardioversion. Only 22 patients (5.5\%) returned to the ED
within one month for symptoms that were deemed potentially related to
the index visit, with six patients (1.5\%) requiring repeat
cardioversion.\textsuperscript{8} The current study described an overall
94\% success rate of rhythm control at discharge (141/151), with an
overall 30-day return rate of 22\% (32/151), of whom only 44\% (14/32)
returned due to recurrent AF, constituting 9.3\% of the total study
population. It is interesting to note that in the current study, the ED
patients fared as well as those in the cardiology cohort. Clinical
backgrounds and reasons for ED return also did not differ between the
groups. Further investigation into the short-term and longer-term
success of ED electrical cardioversion of AF of \textgreater{}48 hours'
duration after TEE performance is necessary. It seems, based on the
results of the current study, that this approach may be at least as
successful as some reports of ED cardioversion of AF of \textless{}48
hours' duration.

It has been noted that patients with AF \textgreater{}48 hours' duration
who were treated with standard practice, i.e. weeks of anticoagulation
before cardioversion, were not always adequately
anticoagulated.\textsuperscript{11,12} TEE studies performed on patients
with AF \textless{}48 hours have shown left atrial thrombi in 1.4\% of
patients, of whom 63\% were receiving prior anticoagulation therapy,
whereas patients not on prior anticoagulation medication had a 4\%
prevalence of left atrial thrombi.\textsuperscript{13} The data from
these studies seem to point to the conclusion that timing of onset of AF
should not be the only factor in determining a therapeutic approach to
AF, and that performance of a TEE to rule out atrial thrombi may be
warranted despite prior anticoagulation for even a short duration of AF.
In a recent analysis of anticoagulation management with warfarin
involving more than 120,000 patients in the Veterans Affairs health care
system, the mean proportion of time in the therapeutic range was 58\%,
with significant variation across sites.\textsuperscript{14} With the
new oral anticoagulants, this becomes less of an
issue.\textsuperscript{15}

The most prominent results of the current study were the differences in
length of stay of patients based on where their cardioversion was
performed. Time to TEE performance was not significantly different, but
once it was performed, time to cardioversion, time to discharge, and
inevitably length of hospital stay were all significantly shorter
(p\textless{}0.001 for the latter three variables) for patients who were
cardioverted in the ED versus those cardioverted in the cardiology ward.

Differences in in-patient versus ED lengths of stay in AF patients have
previously been shown. Ptaszek et al. demonstrated a marked difference
in in-patient LOS after the creation of an AF pathway (64 hours
post-intervention versus 104 hours pre-intervention) with no significant
corresponding reduction in ED stay.\textsuperscript{16} Other ED studies
have cited shorter lengths of stay and higher patient satisfaction with
ED AF cardioversion.\textsuperscript{7,9} As the frequency of AF related
hospital visits is predicted to rise,\textsuperscript{2} it is necessary
to create strategies to reduce the length of stay, thereby reducing
hospital costs. The current study suggests that the performance of TEE
in patients with AF of \textgreater{} 48 hours' duration to rule out
thrombi, and subsequent performance of electrical cardioversion in the
ED reduces the length of hospital stay and is at least as safe as when
performed on the cardiology ward.

Some EDs with fast turn-around time may choose to put such patients into
an observation ward. While there is much literature on the use of an ED
observation ward to manage patients with atrial fibrillation, none
specifically look at the subcategory of those arriving more than 48
hours after onset.\textsuperscript{17--21} For those EDs that do have an
observation unit, this treatment strategy may be appropriate.

On the other hand, many EDs have problems with crowding resulting in the
boarding of patients.\textsuperscript{22-24} This strategy may also be
advantageous in this setting, potentially resulting in earlier discharge
from the hospital than having the patient wait to be treated on the
cardiology ward.

\emph{Limitations}

This study had several limitations. This was a retrospective study and
there was no recorded reason for the decision as to where to undertake
the cardioversion, nor were there data on the reasons to extend patient
stay in the cardiology ward. There may have been patient differences not
recorded in the data, or it may simply have been a matter of bed
allocation.

One of the original study intentions was to collect sedation data along
with immediate post-procedure complication data to see if these were
related to the sedation or the procedure, but this data was scarce and
was therefore ultimately not included in the study. Thus, post-procedure
complication data should be cautiously interpreted. Regression analysis
was not performed on the data, as most data were similar between the
groups.

Many emergency departments may have a policy of automatically admitting
patients with AF \textgreater{} 48 hours to a cardiology ward rather
than treating them in the ED or an observation unit. Finally, the study
was performed in one tertiary care medical center including a
comprehensive cardiac institute, where the practice of ordering a TEE
through the ED may not be generalizable to other institutions. Further
prospective studies, perhaps of a randomized control design, would be
better able to elucidate the safety and efficacy of performing TEE prior
to electrical cardioversion of AF \textgreater{} 48 hours' duration in
the ED setting.

\textbf{Conclusion}

In this retrospective, single-center study, patients who presented with
atrial fibrillation for more than 48 hours after a TEE negative for an
atrial clot, and who were cardioverted in the ED had a significantly
decreased time to cardioversion and decreased length of hospital stay
when compared to those cardioverted in the cardiological department.
There was no significant difference in complications or 30-day
readmission rates for either group. This clinical pathway may be
implemented in ED observation units. Prospective randomized controlled
trials should be conducted to determine the applicability and
cost-effectiveness of such a clinical pathway in other ED settings.

\textbf{References}

1. Burton JH, Vinson DR, Drummond K, Strout TD, Thode HC, McInturff JJ.
Electrical cardioversion of emergency department patients with atrial
fibrillation. Ann Emerg Med. 2004 Jul;44(1):20-30. doi:
10.1016/j.annemergmed.2004.02.016. Erratum in: Ann Emerg Med. 2004
Sep;44(3):294. PMID: 15226705.

2. Rozen G, Hosseini SM, Kaadan MI, et al. Emergency Department Visits
for Atrial Fibrillation in the United States: Trends in Admission Rates
and Economic Burden From 2007 to 2014. J Am Heart Assoc. 2018 Jul
20;7(15):e009024. doi: 10.1161/JAHA.118.009024. PMID: 30030215; PMCID:
PMC6201465.

3. January CT, Wann LS, Calkins H, et al. 2019 AHA/ACC/HRS Focused
Update of the 2014 AHA/ACC/HRS Guideline for the Management of Patients
With Atrial Fibrillation: A Report of the American College of
Cardiology/American Heart Association Task Force on Clinical Practice
Guidelines and the Heart Rhythm Society. J Am Coll Cardiol. 2019 Jul
9;74(1):104-132. doi: 10.1016/j.jacc.2019.01.011. Epub 2019 Jan 28.
Erratum in: J Am Coll Cardiol. 2019 Jul 30;74(4):599. PMID: 30703431.

4. Rankin AJ, Rankin SH. Cardioverting acute atrial fibrillation and the
risk of thromboembolism: not all patients are created equal\selectlanguage{english} . Clin Med
(Lond). 2017 Oct;17(5):419-423. doi: 10.7861/clinmedicine.17-5-419.
PMID: 28974590; PMCID: PMC6301939.

5. Fried AM, Strout TD, Perron AD. Electrical cardioversion for atrial
fibrillation in the emergency department: A large single-center
experience. Am J Emerg Med {[}Internet{]}. 2020;(xxxx):1--6. Available
from: https://doi.org/10.1016/j.ajem.2020.02.001

6. Stiell IG, Clement CM, Rowe BH, et al. Outcomes for Emergency
Department Patients With Recent-Onset Atrial Fibrillation and Flutter
Treated in Canadian Hospitals. Ann Emerg Med {[}Internet{]}.
2017;69(5):562-571.e2. Available from:
http://dx.doi.org/10.1016/j.annemergmed.2016.10.013

7. Jacoby JL, Cesta M, Heller MB, Salen P, Reed J. Synchronized
emergency department cardioversion of atrial dysrhythmias saves time,
money and resources. J Emerg Med. 2005 Jan;28(1):27-30. doi:
10.1016/j.jemermed.2004.07.011. PMID: 15657000.

8. Xavier Scheuermeyer F, Grafstein E, Stenstrom R, Innes G, Poureslami
I, Sighary M. Thirty-day outcomes of emergency department patients
undergoing electrical cardioversion for atrial fibrillation or flutter.
Acad Emerg Med. 2010 Apr;17(4):408-15. doi:
10.1111/j.1553-2712.2010.00697.x. PMID: 20370780.

9. Cohn BG, Keim SM, Yealy DM. Is emergency department cardioversion of
recent-onset atrial fibrillation safe and effective? J Emerg Med
{[}Internet{]}. 2013;45(1):117--27. Available from:
http://dx.doi.org/10.1016/j.jemermed.2013.01.027

10. Pluymaekers NAHA, Dudink EAMP, Luermans JGLM, Meeder JG, Lenderink
T, Widdershoven J, et al; RACE 7 ACWAS Investigators. Early or Delayed
Cardioversion in Recent-Onset Atrial Fibrillation. N Engl J Med. 2019
Apr 18;380(16):1499-1508. doi: 10.1056/NEJMoa1900353. Epub 2019 Mar 18.
PMID: 30883054.

11. Zaprutko J, Baszko A, Michalak M, et al. Safety of transesophageal
echocardiography\selectlanguage{english}-guided electrical cardioversion in patients with atrial
fibrillation and inadequate anticoagulation. Pol Arch Intern Med. 2017
Aug 9;127(7-8):524-531. doi: 10.20452/pamw.4031. Epub 2017 May 24. PMID:
28817542.

12. Choi EJ, Lee IH, Je NK. Inadequate stroke prevention in Korean
atrial fibrillation patients in the post-warfarin era. Int J Cardiol
{[}Internet{]}. 2016;220:647--52. Available from:
http://dx.doi.org/10.1016/j.ijcard.2016.06.177

13. Kleemann T, Becker T, Strauss M, Schneider S, Seidl K. Prevalence of
Left Atrial Thrombus and Dense Spontaneous Echo Contrast in Patients
With Short-Term Atrial Fibrillation \textless{} 48 Hours Undergoing
Cardioversion: Value of Transesophageal Echocardiography to Guide
Cardioversion. J Am Soc Echocardiogr {[}Internet{]}.
2009;22(12):1403--8. Available from:
http://dx.doi.org/10.1016/j.echo.2009.09.015

14. Rose AJ, Hylek EM, Ozonof A, Ash AS, Reisman JI, Berlowitz DR.
Risk-Adjusted percent time in therapeutic range as a quality indicator
for outpatient oral anticoagulation results of the veterans affairs
study to improve anticoagulation (varia). Circ Cardiovasc Qual Outcomes.
2011;4(1):22--9.

15. Chen ST, Patel MR. Comparison of Anticoagulant Therapy for Atrial
Fibrillation - Novel Oral Anticoagulants Versus Vitamin K Antagonists.
Prog Cardiovasc Dis. 2018 Jan-Feb;60(4-5):514-523. doi:
10.1016/j.pcad.2018.01.005. Epub 2018 Jan 13. PMID: 29339167.

16. Ptaszek LM, Baugh CW, Lubitz SA, et al. Impact of a
Multidisciplinary Treatment Pathway for Atrial Fibrillation in the
Emergency Department on Hospital Admissions and Length of Stay: Results
of a Multi-Center Study. J Am Heart Assoc. 2019;8(18):e012656.

17. Bellew SD, Bremer ML, Kopecky SL, et al. Impact of an Emergency
Department Observation Unit Management Algorithm for Atrial
Fibrillation. J Am Heart Assoc. 2016 Feb 8;5(2):e002984. doi:
10.1161/JAHA.115.002984. PMID: 26857070; PMCID: PMC4802469.

18. Conti A, Canuti E, Mariannini Y, et al. Clinical management of
atrial fibrillation: Early interventions, observation, and structured
follow-up reduce hospitalizations. Am J Emerg Med {[}Internet{]}.
2012;30(9):1962--9. Available from:
http://dx.doi.org/10.1016/j.ajem.2012.04.022

19. Cristoni L, Tampieri A, Mucci F, et al. Cardioversion of acute
atrial fibrillation in the short observation unit: comparison of a
protocol focused on electrical cardioversion with simple antiarrhythmic
treatment. Emerg Med J. 2011 Nov;28(11):932-7. doi:
10.1136/emj.2009.083196. Epub 2010 Oct 14. PMID: 20947916.

20. Decker WW, Smars PA, Vaidyanathan L, et al. A prospective,
randomized trial of an emergency department observation unit for acute
onset atrial fibrillation. Ann Emerg Med. 2008 Oct;52(4):322-8. doi:
10.1016/j.annemergmed.2007.12.015. Epub 2008 Mar 14. PMID: 18339449.

21. Koenig BO, Ross MA, Jackson RE. An emergency department observation
unit protocol for acute-onset atrial fibrillation is feasible. Ann Emerg
Med. 2002;39(4):374--81.

22. Olshaker JS, Rathlev NK. Emergency Department overcrowding and
ambulance

diversion: the impact and potential solutions of extended boarding of
admitted patients in the Emergency Department. J Emerg Med. 2006
Apr;30(3):351-6. doi: 10.1016/j.jemermed.2005.05.023. PMID: 16677993.

23. Kenny JF, Chang BC, Hemmert KC. Factors Affecting Emergency
Department

Crowding. Emerg Med Clin North Am. 2020 Aug;38(3):573-587. doi:
10.1016/j.emc.2020.04.001. Epub 2020 Jun 8. PMID: 32616280.

24. Berg E, Weightman AT, Druga DA. Emergency Department Operations II:
Patient

Flow. Emerg Med Clin North Am. 2020 May;38(2):323-337. doi:
10.1016/j.emc.2020.01.002. PMID: 32336328.

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

