Termination of recent-onset atrial fibrillation/flutter in the emergency department: a sequential approach with intravenous ibutilide and external electrical cardioversion

Clinical decision support to Optimize Care of patients with Atrial Fibrillation or flutter in the Emergency department: protocol of a stepped-wedge cluster randomized pragmatic trial (O'CAFÉ trial)

BACKGROUND

Management of adults with atrial fibrillation (AF) or atrial flutter in the emergency department (ED) includes rate reduction, cardioversion, and stroke prevention. Different approaches to these components of care may lead to variation in frequency of hospitalization and stroke prevention actions, with significant implications for patient experience, cost of care, and risk of complications. Standardization using evidence-based recommendations could reduce variation in management, preventable hospitalizations, and stroke risk.

METHODS

We describe the rationale for our ED-based AF treatment recommendations. We also describe the development of an electronic clinical decision support system (CDSS) to deliver these recommendations to emergency physicians at the point of care. We implemented the CDSS at three pilot sites to assess feasibility and solicit user feedback. We will evaluate the impact of the CDSS on hospitalization and stroke prevention actions using a stepped-wedge cluster randomized pragmatic clinical trial across 13 community EDs in Northern California.

DISCUSSION

We hypothesize that the CDSS intervention will reduce hospitalization of adults with isolated AF or atrial flutter presenting to the ED and increase anticoagulation prescription in eligible patients at the time of ED discharge and within 30 days. If our hypotheses are confirmed, the treatment protocol and CDSS could be recommended to other EDs to improve management of adults with AF or atrial flutter.

TRIAL REGISTRATION

ClinicalTrials.gov NCT05009225 .  Registered on 17 August 2021.

Adverse Events Associated With Electrical Cardioversion in Patients With Acute Atrial Fibrillation and Atrial Flutter

BACKGROUND

We sought to evaluate safety of electrical cardioversion (ECV) for patients with acute atrial fibrillation (AF) or atrial flutter (AFL) in the emergency department (ED).

METHODS

This was an analysis of data from 4 multicentre AF/AFL studies conducted from 2008 to 2019 at 23 large EDs. We included adult patients who received attempts at ECV and who had presented acutely after symptom onset. Staff manually reviewed study and clinical records to abstract data.

RESULTS

We evaluated 1736 ECV cases with a mean age of 60.1 years and 67.1% male. The overall success of ECV was 90.2% (95% confidence interval 88.7%-91.6%), with 4.9% of patients admitted. ED physicians performed the ECV in 95.2% and provided sedation in 96.5%; 13.9% (12.3%-15.7%) of cases experienced important adverse events that required treatment, and 0.4% were classified as life threatening. Another 5.6% had adverse events that did not require treatment. Logistic regression found that the RAFF-3 study cohort (odds ratio [OR] 2.0), age ≥ 85 years (OR 2.1), coronary artery disease (OR 1.5), midazolam (OR 1.9), and fentanyl (OR 1.5) were associated with important adverse events.

CONCLUSIONS

This large evaluation of the safety of ECV for acute AF/AFL in the ED found that while serious adverse events were rare, there were a concerning number of events following sedation that required intervention. Physicians should be aware that older age, coronary artery disease, and fentanyl are associated with higher risks of important adverse events. This study provides more information for shared decision making discussions with patients when choosing between drug-shock and shock-only cardioversion strategies.

Electrical versus pharmacological cardioversion for emergency department patients with acute atrial fibrillation (RAFF2): a partial factorial randomised trial

BACKGROUND

Acute atrial fibrillation is the most common arrythmia treated in the emergency department. Our primary aim was to compare conversion to sinus rhythm between pharmacological cardioversion followed by electrical cardioversion (drug-shock), and electrical cardioversion alone (shock-only). Our secondary aim was to compare the effectiveness of two pad positions for electrical cardioversion.

METHODS

We did a partial factorial trial of two protocols for patients with acute atrial fibrillation at 11 academic hospital emergency departments in Canada. We enrolled adult patients with acute atrial fibrillation. Protocol 1 was a randomised, blinded, placebo-controlled comparison of attempted pharmacological cardioversion with intravenous procainamide (15 mg/kg over 30 min) followed by electrical cardioversion if necessary (up to three shocks, each of ≥200 J), and placebo infusion followed by electrical cardioversion. For patients having electrical cardioversion, we used Protocol 2, a randomised, open-label, nested comparison of anteroposterior versus anterolateral pad positions. Patients were randomly assigned (1:1, stratified by study site) for Protocol 1 by on-site research personnel using an online electronic data capture system. Randomisation for Protocol 2 occurred 30 min after drug infusion for patients who had not converted and was stratified by site and Protocol 1 allocation. Patients and all research and emergency department staff were masked to treatment allocation for Protocol 1. The primary outcome was conversion to normal sinus rhythm for at least 30 min at any time after randomisation and up to a point immediately after three shocks. Protocol 1 was analysed by intention to treat and Protocol 2 excluded patients who did not receive electrical cardioversion. This study is registered at ClinicalTrials.gov, number NCT01891058.

FINDINGS

Between July 18, 2013, and Oct 17, 2018, we enrolled 396 patients, and none were lost to follow-up. In the drug-shock group (n=204), conversion to sinus rhythm occurred in 196 (96%) patients and in the shock-only group (n=192), conversion occurred in 176 (92%) patients (absolute difference 4%; 95% CI 0-9; p=0·07). The proportion of patients discharged home was 97% (n=198) versus 95% (n=183; p=0·60). 106 (52%) patients in the drug-shock group converted after drug infusion only. No patients had serious adverse events in follow-up. The different pad positions in Protocol 2 (n=244), had similar conversions to sinus rhythm (119 [94%] of 127 in anterolateral group vs 108 [92%] of 117 in anteroposterior group; p=0·68).

INTERPRETATION

Both the drug-shock and shock-only strategies were highly effective, rapid, and safe in restoring sinus rhythm for patients in the emergency department with acute atrial fibrillation, avoiding the need for return to hospital. The drug infusion worked for about half of patients and avoided the resource intensive procedural sedation required for electrical cardioversion. We also found no significant difference between the anterolateral and anteroposterior pad positions for electrical cardioversion. Immediate rhythm control for patients in the emergency department with acute atrial fibrillation leads to excellent outcomes.

FUNDING

Heart and Stroke Foundation of Canada and the Canadian Institutes of Health Research.

Impact of a novel protocol for atrial fibrillation management in outpatient gastrointestinal endoscopic procedures: a retrospective cohort study

BACKGROUND

Atrial fibrillation (AF) may result in procedure cancellations and emergency department (ED) referrals for patients presenting for outpatient GI endoscopic procedures. Such cancellations and referrals delay patient care and can lead to inefficient use of resources.

METHODS

All consecutive patients presenting in AF for a colonoscopy or upper endoscopy to the University of Wisconsin Digestive Health Center between October 2013 and September 2014 were defined as the pre-intervention group (Group 1). In 2015, a protocol was initiated for peri-procedural management of patients presenting in AF, new onset or previously known. All consecutive patients after initiation of the protocol from October 2015 to September 2016 were analyzed as the post intervention group (Group 2). Patients with heart failure, hypotension, or chest pain were excluded from the protocol.

RESULTS

One hundred nine and 141 patients were included in Groups 1 and Group 2, respectively. Following protocol initiation, patients were less likely to present to the ED (6.4% Group 1 vs. 1.4% Group 2, RR 0.22, p = 0.04). There was also a trend towards a reduction in procedure cancelations (5.5% Group 1 vs. 1.4% Group 2, RR 0.26, p = 0.08). All attempted procedures were completed and there were no complications in the intervention group.

CONCLUSIONS

Implementation of a standardized protocol for management of atrial fibrillation in patients presenting for outpatient gastrointestinal endoscopic procedures resulted in a significant decrease in emergency department visits with an additional trend toward decreased procedural cancellations without an increased risk of complications.

Management and Disposition of Atrial Fibrillation in the Emergency Department: A Systematic Review

Introduction

Management of atrial fibrillation (AF) and atrial flutter (AFL) in the emergency department (ED) varies greatly, and there are currently no United States guidelines to guide management with regard to patient disposition after ED treatment. The aim of this systematic review was to evaluate the literature for decision aids to guide disposition of patients with AF/AFLin the ED, and assess potential outcomes associated with different management strategies in the ED.

Methods and Results

A systematic review was done using PubMed (MEDLINE), Cochrane Central Register of Controlled Trials (CENTRAL), and EMBASE, combining the search terms "Atrial Fibrillation", "Atrial Flutter", "Emergency Medicine", "Emergency Service", and "Emergency Treatment". After removal of duplicates, 754 articles were identified. After initial screening of titles and abstracts, 69full text articles were carefully reviewed and 34 articles were ultimately included in the study based on inclusion and exclusion criteria. The articles were grouped into four main categories: decision aids and outcome predictors, electrical cardioversion-based protocols, antiarrhythmic-based protocols, and general management protocols.

Conclusion

This systematic review is the first study to our knowledge to evaluate the optimal management of symptomatic AF/AFLin the ED with a direct impact on ED disposition. There are several viable management strategies that can result in safe discharge from the ED in the right patient population, and decision aids can be utilized to guide selection of appropriate patients for discharge.

Implementation of an emergency department atrial fibrillation and flutter pathway improves rates of appropriate anticoagulation, reduces length of stay and thirty-day revisit rates for congestive heart failure

Objectives

An evidence-based emergency department (ED) atrial fibrillation and flutter (AFF) pathway was developed to improve care. The primary objective was to measure rates of new anticoagulation (AC) on ED discharge for AFF patients who were not AC correctly upon presentation.

Methods

This is a pre-post evaluation from April to December 2013 measuring the impact of our pathway on rates of new AC and other performance measures in patients with uncomplicated AFF solely managed by emergency physicians. A standardized chart review identified demographics, comorbidities, and ED treatments. The primary outcome was the rate of new AC. Secondary outcomes were ED length of stay (LOS), referrals to AFF clinic, ED revisit rates, and 30-day rates of return visits for congestive heart failure (CHF), stroke, major bleeding, and death.

Results

ED AFF patients totalling 301 (129 pre-pathway [PRE]; 172 post-pathway [POST]) were included; baseline demographics were similar between groups. The rates of AC at ED presentation were 18.6% (PRE) and 19.7% (POST). The rates of new AC on ED discharge were 48.6 % PRE (95% confidence interval [CI] 42.1%-55.1%) and 70.2% POST (62.1%-78.3%) (20.6% [p<0.01; 15.1-26.3]). Median ED LOS decreased from 262 to 218 minutes (44 minutes [p<0.03; 36.2-51.8]). Thirty-day rates of ED revisits for CHF decreased from 13.2% to 2.3% (10.9%; p<0.01; 8.1%-13.7%), and rates of other measures were similar.

Conclusions

The evidence-based pathway led to an improvement in the rate of patients with new AC upon discharge, a reduction in ED LOS, and decreased revisit rates for CHF.

Ibutilide Effectiveness and Safety in the Cardioversion of Atrial Fibrillation and Flutter in the Community Emergency Department

STUDY OBJECTIVE

Little is known about the use of ibutilide for cardioversion in atrial fibrillation and flutter outside of clinical trials. We seek to describe patient characteristics, ibutilide administration patterns, cardioversion rates, and adverse outcomes in the community emergency department (ED) setting. We also evaluate potential predictors of cardioversion success.

METHODS

Using a retrospective cohort of adults who received ibutilide in 21 community EDs between January 2009 and June 2015, we gathered demographic and clinical variables from electronic health records and structured manual chart review. We calculated rates of cardioversion and frequency of ventricular tachycardia within 4 hours and estimated adjusted odds ratios (aOR) in a multivariate regression model for potential predictors of cardioversion.

RESULTS

Among 361 patients, the median age was 61 years (interquartile range 53 to 71 years) and most had recent-onset atrial fibrillation and flutter (98.1%). Five percent of the cohort had a history of heart failure. The initial QTc interval was prolonged (>480 ms) in 29.4% of patients, and 3.1% were hypokalemic (<3.5 mEq/L). The mean ibutilide dose was 1.5 mg (SD 0.5 mg) and the rate of ibutilide-related cardioversion within 4 hours was 54.8% (95% confidence interval [CI] 49.6% to 60.1%), 50.5% for atrial fibrillation and 75.0% for atrial flutter. Two patients experienced ventricular tachycardia (0.6%), both during their second ibutilide infusion. Age (in decades) (aOR 1.3; 95% CI 1.1 to 1.5), atrial flutter (versus atrial fibrillation) (aOR 2.7; 95% CI 1.4 to 5.1), and no history of atrial fibrillation and flutter (aOR 2.0; 95% CI 1.2 to 3.1) were associated with cardioversion.

CONCLUSION

The effectiveness and safety of ibutilide in this community ED setting were consistent with clinical trial results despite less stringent patient selection criteria.

Vernakalant is superior to ibutilide for achieving sinus rhythm in patients with recent-onset atrial fibrillation: a randomized controlled trial at the emergency department

Aims

Ibutilide is a rapid-acting antiarrhythmic drug with worldwide use for conversion of recent-onset atrial fibrillation. Vernakalant, approved in the EU in 2010, is likewise used intravenously, with proven efficacy and safety compared with placebo and amiodarone in randomized clinical trials. The aim of our study was to compare the time to conversion and the conversion rate within 90 min in patients with recent-onset atrial fibrillation treated with vernakalant or ibutilide.

Methods and Results

A randomized controlled trial registered at clinicaltrials.gov (NCT01447862) was performed in 100 patients with recent-onset atrial fibrillation treated at the emergency department of a tertiary care hospital. Patients received up to two short infusions of vernakalant (n = 49; 3 mg/kg followed by 2 mg/kg if necessary) or ibutilide (n = 51; 1 mg followed by another 1 mg if necessary) according to the manufacturer's instructions. Clinical and laboratory variables, adverse events, conversion rates, and time to conversion were recorded. Time to conversion of AF to sinus rhythm was significantly shorter in the vernakalant group compared with the ibutilide group (median time: 10 vs. 26 min, P = 0.01), and likewise the conversion success within 90 min was significantly higher in the vernakalant group (69 vs. 43%, log-rank P = 0.002). No serious adverse events occurred.

Conclusion

Vernakalant was superior to ibutilide in converting recent-onset atrial fibrillation to sinus rhythm in the emergency department setting.

Atrial Fibrillation

Atrial fibrillation (AF) is a supraventricular tachyarrhythmia that results from the chaotic depolarization of atrial tissue. AF is the most common sustained cardiac dysrhythmia and the most common dysrhythmia diagnosed in US emergency departments. All patients with AF must have their cardioembolic risk assessed, even if sinus rhythm is restored. Novel oral anticoagulants may be considered instead of vitamin K antagonists for anticoagulation in patients with nonvalvular AF.

Association of the Ottawa Aggressive Protocol with rapid discharge of emergency department patients with recent-onset atrial fibrillation or flutter

Objective:

There is no consensus on the optimal management of recent-onset episodes of atrial fibrillation or flutter. The approach to these conditions is particularly relevant in the current era of emergency department (ED) overcrowding. We sought to examine the effectiveness and safety of the Ottawa Aggressive Protocol to perform rapid cardioversion and discharge patients with these arrhythmias.

Methods:

This cohort study enrolled consecutive patient visits to an adult university hospital ED for recent-onset atrial fibrillation or flutter managed with the Ottawa Aggressive Protocol. The protocol includes intravenous chemical cardioversion, electrical cardioversion if necessary and discharge home from the ED.

Results:

A total of 660 patient visits were included, 95.2% involving atrial fibrillation and 4.9% involving atrial flutter. The mean age of patients enrolled was 64.5 years. In total, 96.8% were discharged home and, of those, 93.3% were in sinus rhythm. All patients were initially administered intravenous procaïnamide, with a 58.3% conversion rate. A total of 243 patients underwent subsequent electrical cardioversion with a 91.7% success rate. Adverse events occurred in 7.6% of cases: hypotension 6.7%, bradycardia 0.3% and 7-day relapse 8.6%. There were no cases of torsades de pointes, stroke or death. The median lengths of stay in the ED were as follows: 4.9 hours overall, 3.9 hours for those undergoing conversion with procaïnamide and 6.5 hours for those requiring electrical conversion.

Conclusion:

This is the largest study to date to evaluate the Ottawa Aggressive Protocol, a unique approach to cardioversion for ED patients with recent-onset episodes of atrial fibrillation and flutter. Our data demonstrate that the Ottawa Aggressive Protocol is effective, safe and rapid, and has the potential to significantly reduce hospital admissions and expedite ED care.

Recommendations for the evaluation and management of observation services: a consensus white paper: the Society of Cardiovascular Patient Care

Observation Services (OS) was founded by emergency physicians in an attempt to manage "boarding" issues faced by emergency departments throughout the United States. As a result, OS have proven to be an effective strategy in reducing costs and decreasing lengths of stay while improving patient outcomes. When OS are appropriately leveraged for maximum efficiency, patients presenting to emergency departments with common disease processes can be effectively treated in a timely manner. A well-structured observation program will help hospitals reduce the number of inappropriate, costly inpatient admissions while avoiding the potential of inappropriate discharges. Observation medicine is a complicated multidimensional issue that has generated much confusion. This service is designed to provide the best possible patient care in a value-based purchasing environment where quality, cost, and patient satisfaction must continually be addressed. Observation medicine is a service not a status. Therefore, patients are admitted to the service as outpatients no matter whether they are placed in a virtual or dedicated observation unit. The key to a successful observation program is to determine how to maximize efficiencies. This white paper provides the reader with the foundational guidance for observational services. It defines how to set up an observational service program, which diagnoses are most appropriate for admission, and what the future holds. The goal is to help care providers from any hospital deliver the most appropriate level of treatment, to the most appropriate patient, in the most appropriate location while controlling costs.

Cardioversion in atrial fibrillation. Focus on recent-onset atrial fibrillation

Atrial fibrillation is the most common sustained arrhythmia encountered in clinical practice. Its prevalence is rising due to an increasing elderly population and the improvement in management of life-threatening diseases such as myocardial infarction and heart failure. Over the past few years effective non-pharmacological treatments, new antiarrhythmics drugs, and anticoagulants have been introduced. Regardless of rate-control or rhythm control strategy, adequate stroke prevention still remains a cornerstone in the treatment of this arrhythmia. This review aims to illustrate the main practical issues in the management of atrial fibrillation, focusing on patients with recent-onset and hemodynamically stable atrial fibrillation.

Thirty-day outcomes of emergency department patients undergoing electrical cardioversion for atrial fibrillation or flutter

OBJECTIVES

While the short-term (<7-day) safety and efficiency of electrical cardioversion for emergency department (ED) patients with atrial fibrillation or flutter have been established, the 30-day outcomes with respect to stroke, thromboembolic events, or death have not been investigated.

METHODS

A two-center cohort of consecutive ED patients undergoing cardioversion for atrial fibrillation or flutter between January 1, 2000, and September 30, 2007, was retrospectively investigated. This cohort was probabilistically linked with both a regional ED database and the provincial health registry to determine which patients had a subsequent ED visit or hospital admission, stroke, or thromboembolic event or died within 30 days. In addition, trained reviewers performed a detailed chart abstraction on 150 randomly selected patients, with emphasis on demographics, vital signs, medical treatment, and predefined adverse events. Hemodynamically unstable patients or those whose condition was the result of an underlying acute medical diagnosis were excluded. Data were analyzed by descriptive methods.

RESULTS

During the study period, 1,233 patients made 1,820 visits for atrial fibrillation or flutter to the ED. Of the 400 eligible patients undergoing direct-current cardioversion (DCCV), no patients died, had a stroke, or had a thromboembolic event in the following 30 days (95% confidence interval [CI] = 0.0 to 0.8% for all outcomes). A total of 141 patients were included in the formal chart review, with five patients (3.5%, 95% CI = 0.5% to 6.6%) failing cardioversion, six patients (4.3%, 95% CI = 0.9% to 7.6%) having a minor adverse event that did not change disposition, and five patients (3.5%, 95% CI = 0.5% to 6.6%) admitted to hospital at the index visit.

CONCLUSIONS

Cardioversion of patients with atrial fibrillation or flutter in the ED appears to have a very low rate of long-term complications.

A prospective, randomized trial of an emergency department observation unit for acute onset atrial fibrillation

STUDY OBJECTIVE

An emergency department (ED) observation unit protocol for the management of acute onset atrial fibrillation is compared with routine hospital admission and management.

METHODS

Adult patients presenting to the ED with atrial fibrillation of less than 48 hours' duration without hemodynamic instability or other comorbid conditions requiring hospitalization were enrolled. Participants were randomized to either ED observation unit care or routine inpatient care. The ED observation unit protocol included pulse rate control, cardiac monitoring, reassessment, and electrical cardioversion if atrial fibrillation persisted. Patients who reverted to sinus rhythm were discharged with a cardiology follow-up within 3 days, whereas those still in atrial fibrillation were admitted. All cases were followed up for 6 months and adverse events recorded.

RESULTS

Of the 153 patients, 75 were randomized to the ED observation unit and 78 to routine inhospital care. Eighty-five percent of ED observation unit patients converted to sinus rhythm versus 73% in the routine care group (difference 12%; 95% confidence interval [CI] -1% to 25%]; P=.06). The median length of stay was 10.1 versus 25.2 hours (difference 15.1 hours; 95% CI 11.2 to 19.6; P<.001) for ED observation unit and inhospital care respectively. Nine ED observation unit patients required inpatient admission. Eleven percent of the ED observation unit group had recurrence of atrial fibrillation during follow-up versus 10% of the routine inpatient care group (difference 1%; 95% CI -9% to 11%; P=.93). There was no significant difference between the groups in the frequency of hospitalization or the number of tests, and the number of adverse events during follow-up was similar in the 2 groups.

CONCLUSION

An ED observation unit protocol that includes electrical cardioversion is a feasible alternative to routine hospital admission for acute onset of atrial fibrillation and results in a shorter initial length of stay.

[Atrial fibrillation]

Atrial fibrillation represents the arrhythmia that most frequently leads to hospital admission. Due to the age structure of our population and the increasing morbidity and comorbidity, one has to assume that this arrhythmia will reach an even higher prevalence. The therapeutic successes are often insufficient. First of all, it is important to diagnose and treat the underlying disease. Secondly, antiarrhythmic therapy has to be considered in symptomatic patients. In those patients and in the case of a persistent form, electrical cardioversion should be performed. Repetitive cardioversions in asymptomatic patients yield no advantage for mortality. Antiarrhythmic therapy consists of drugs of the classes Ia, Ic, and III. Concomitant anticoagulation is necessary; ASS in indicated only in patients without structural heart disease and lacking thromboembolic risk factors. If risk factors are present, effective therapy with coumarin derivatives is required. Therapy with ACE inhibitors and AT blockers leads to an advantage in patients with arterial hypertension and/or heart failure concerning the stability of sinus rhythm after cardioversion and the incidence of arrhythmia. Newer medications for anticoagulation and newer antiarrhythmic drugs raise the hope of a future therapy with higher efficacy and lower rate of side effects.

Acute anticoagulation adjustment in patients with atrial fibrillation at risk for stroke: approaches, strategies, risks and benefits

The acute management of anticoagulation in patients with atrial fibrillation to prevent stroke and other thromboembolic complications includes the use of individualized strategies tailored to the patient and based on the situation (cardioversion, surgeries, dental procedures, cardiac interventions, other invasive procedures and initiation of, or adjustment to, warfarin dosing). The vast range of choices can cause confusion and few randomized controlled clinical trials in this area provide adequate guidance. Chronic anticoagulation management is more straightforward since clinical evidence is ample, randomized clinical trial data provides cogent informaiton and guidelines have been established. Acute management of anticoagulation in patients with atrial fibrillation to prevent thromboembolic complications is often unrecognized but is emerging as a crucial, but challenging, and increasingly complex aspect of the care of patients with atrial fibrillation. This review addresses issues regarding such patients who may be at risk for stroke and require acute adjustments of anticoagulation (in light of, or in lieu of, chronic anticoagulation). Several promising new strategies are considered in light of established medical care. This analysis provides practical recommendations based on available data and presents results from recent investigations that may provide insight into future strategies.

Ibutilide to expedite ED therapy for recent-onset atrial fibrillation flutter

OBJECTIVE

Ibutilide is a type III antiarrhythmic agent approved for the pharmacologic conversion of atrial fibrillation (AF) and atrial flutter (AFl). Previous studies conducted outside the ED setting have demonstrated conversion rates of 60% to 80%. This response has been highest in patients with recent-onset AF-AFl. These observations and the 4-hour half-life of ibutilide suggest that it may be an excellent drug with which to treat AF-AFl in the ED. The purpose of the study was to examine the efficacy and safety of ibutilide in terminating AF-AFl in patients who present to the ED with symptoms of less than 3 days' duration, neither angina nor heart failure, and no comorbid conditions that require admission.

METHODS

Among 36 enrolled patients, the admission electrocardiogram demonstrated AF in 26 and AFl in 10. Ibutilide 1 mg was administered intravenously for 10 minutes. If sinus rhythm was not present 10 minutes after the infusion concluded, a second infusion of 1 mg was given. Successful conversion was defined as restoration of sinus rhythm within 1 hour after the last dose of ibutilide.

RESULTS

Sixteen (61.5%) of 26 patients with AF and 9 (90%) of 10 patients with AFl converted to sinus rhythm (overall conversion rate=69%). The mean time to arrhythmia termination was 19+/-9 minutes. The mean stay in the ED was 16.2 hours. No significant complications occurred.

CONCLUSION

We conclude that ibutilide is an excellent therapy option for restoring sinus rhythm in the ED. Its use may obviate the need for admission, avoid the risks and inconveniences of general anesthesia to perform electrical cardioversion, and reduce the ED length of stay in selected patients with recent-onset atrial arrhythmias.

Biphasic cardioversion of acute atrial fibrillation in the emergency department

INTRODUCTION

There is a trend towards accelerated management of acute atrial fibrillation (AF) in the emergency department (ED). We report our experience with biphasic cardioversion of acute AF.

METHODS

This was a prospective, descriptive study at a tertiary hospital ED over a 6 month period. Acute AF was defined as symptoms that had been present for <48 hours. Patients who received biphasic cardioversion for acute AF in the ED were enrolled. Data collected included: patient demographics, past medical history, details of biphasic cardioversion, outcome, complications, disposition, and length of stay.

RESULTS

There were 34 attempts at cardioversion in 33 patients. The mean (SD) age was 56 (16) years and 21 patients (64%) were men. Biphasic cardioversion was successful in 31 attempts (91%). In 24 attempts (71%), 100 J was selected as the initial energy level. This was successful in 21 attempts (88%). There were three minor complications related to sedation. The mean (SD) length of stay was 5.6 (2.8) hours in the ED and 15 (25) hours in the hospital. The three patients who failed to revert were older (mean age 64 years), had underlying cardiovascular disease, and spent longer in hospital (50 v 12 hours, p = 0.01). Telephone follow up was conducted with 32 patients (97%) at 3 months. Recurrence of AF occurred in 7 patients (22%). Most patients (31, 97%) were satisfied with the biphasic cardioversion.

CONCLUSIONS

Biphasic cardioversion of acute AF is effective. The majority of patients can be managed as outpatients, and there is very high patient satisfaction with this approach. An initial shock energy level of 100 J is usually effective.

Ibutilide – recent molecular insights and accumulating evidence for use in atrial flutter and fibrillation

Ibutilide is a 'pure' class III antiarrhythmic drug, used intravenously against atrial flutter and fibrillation. At a cellular level it exerts two main actions: induction of a persistent Na+ current sensitive to dihydropyridine Ca2+ channel blockers and potent inhibition of the cardiac rapid delayed rectifier K+ current, by binding within the channel pore cavity upon channel gating. Ibutilide has been shown to terminate atrial flutter and fibrillation in animal studies, with some risk of ventricular pro-arrhythmia. Experimental models of hypertrophy/heart failure show altered sensitivity to ibutilide, with increased dispersion of repolarisation and incidence of pro-arrhythmia. Patient trials show that ibutilide is effective at terminating atrial arrhythmias when given alone, and that it can increase effectiveness and reduce energy requirements of electrical cardioversion. The risk to patients of polymorphic ventricular tachycardia necessitates careful patient selection and monitoring during and after treatment. An ibutilide analogue, trecetilide, requires further investigation but may offer a less readily metabolised and pro-arrhythmic alternative to ibutilide.

Pharmacological cardioversion of atrial fibrillation: current management and treatment options

Atrial fibrillation (AF) is the most common form of arrhythmia, carrying high social costs. It is usually first seen by general practitioners or in emergency departments. Despite the availability of consensus guidelines, considerable variations exist in treatment practice, especially outside specialised cardiological settings. Cardioversion to sinus rhythm aims to: (i) restore the atrial contribution to ventricular filling/output; (ii) regularise ventricular rate; and (iii) interrupt atrial remodelling. Cardioversion always requires careful assessment of potential proarrhythmic and thromboembolic risks, and this translates into the need to personalise treatment decisions. Among the many clinical variables that affect strategy selection, time from onset is crucial. In selected patients, pharmacological cardioversion of recent-onset AF can be a safely used, feasible and effective approach, even in internal medicine and emergency departments. In most cases of recent-onset AF, pharmacological cardioversion provides an important--and probably more cost effective--alternative to electrical cardioversion, which can then be employed as a second-line therapy for nonresponders. Class IC agents (flecainide or propafenone), which can be safely used in hospitalised patients with recent-onset AF without left ventricular dysfunction, can provide rapid conversion to sinus rhythm after either intravenous administration or oral loading. Although intravenous amiodarone requires longer conversion times, it is still the standard treatment for patients with heart failure. Ibutilide also provides good conversion rates and could be used for AF patients with left ventricular dysfunction (were it not for high costs). For long-lasting AF most pharmacological treatments have only limited efficacy and electrical cardioversion remains the gold standard in this setting. However, a widely used strategy involves pretreatment with amiodarone in the weeks before planned electrical cardioversion: this provides optimal prophylaxis and can sometimes even restore sinus rhythm. Dofetilide may also be capable of restoring sinus rhythm in up to 25-30% of patients and can be used in patients with heart failure. The potential risk of proarrhythmia increases the need for careful therapeutic decision making and management of pharmacological cardioversion. The results of recent trials (AFFIRM [Atrial Fibrillation Follow-up Investigation of Rhythm Management] and RACE [Rate Control versus Electrical Cardioversion for Persistent Atrial Fibrillation]) on rate versus rhythm control strategies in the long term have led to a generalised shift in interest towards rate control. Although carefully designed studies are required to better define the role of pharmacological rhythm control in specific AF settings, this alternative option remains a recommendable strategy for many patients, especially those in acute care.

Electrical cardioversion of emergency department patients with atrial fibrillation

STUDY OBJECTIVE

Electrical cardioversion of emergency department (ED) patients with atrial fibrillation has not been well investigated. The objective of this study is to identify the outcomes and complications associated with ED electrical cardioversion of patients with atrial fibrillation.

METHODS

This retrospective health records survey investigated a consecutive cohort of ED patients with atrial fibrillation who underwent electrical cardioversion in 4 EDs during a 42-month period. Trained personnel reviewed medical records for demographic characteristics, clinical descriptors, medical interventions, complications, and ED return visits within 7 days. Data were analyzed using descriptive statistics.

RESULTS

The study population consisted of 388 patients (mean age 61 years; range 20 to 93 years). Duration of atrial fibrillation was less than 48 hours in 99% of the cohort. Electrical cardioversion was successful in 332 (86%) patients. Twenty-eight complications were noted in 25 electrical cardioversion encounters: 22 attributed to procedural sedation and analgesia and 6 attributed to electrical cardioversion. Three hundred thirty-three (86%) patients were discharged to home from the ED: 301 after electrical cardioversion success and 32 with electrical cardioversion failure. Thirty-nine patients (10%) returned to the ED within 7 days, 25 of these patients (6% of successful electrical cardioversion patients) returned because of relapse of atrial fibrillation.

CONCLUSION

In this multicenter cohort, selected ED patients with atrial fibrillation had high rates of electrical cardioversion success, infrequent hospital admission, and few immediate and short-term complications.

Female preponderance in ibutilide-induced torsade de pointes

OBJECTIVE

Ibutilide, a class III antiarrhythmic agent used for pharmacological cardioversion of atrial arrhythmias, has a potential to cause QT-interval prolongation and torsade de pointes. Purpose of this study was to determine whether women are more prone to develop ibutilide-induced torsade de pointes.

METHODS

All clinical trials, cases, case series, and related articles in English-language in addition to 51 patients from our institution on the subject were examined.

RESULTS

In a database derived from 23 reports in literature and from our institution, 1720 patients received ibutilide for cardioversion of atrial arrhythmias. Only in 87% (n=1492) patients, data were reported whether or not ibutilide caused torsade de pointes. The overall incidence of torsade de pointes was 3.9% (n=58) patients. Data on sex distribution of ibutilide-induced torsade de pointes was available in 73% (n=1096) patients. Torsade de pointes developed in 17 (5.6%) of 304 women and 24 (3%) of 792 men (P=0.05). It occurred during or within 45 min after completion of the infusion of ibutilide. Treatment instituted was with intravenous magnesium sulfate alone in 14% (n=8) patients, magnesium sulfate plus lidocaine in 5% (n=3) patients, magnesium sulfate with electrical cardioversion in 17% (n=10) patients, electrical cardioversion alone in 19% (n=11) patients, and precordial thump in 3% (n=2) patients. In 41% (n=24) of patients who developed torsade de pointes, it resolved without treatment. There were no reported deaths secondary to torsade de pointes associated with ibutilide infusion.

CONCLUSION

Incidence of ibutilide-induced torsade de pointes is higher in women than in men. Greater caution must be observed while using ibutilide in women.

Ibutilide for pharmacological cardioversion of atrial fibrillation and flutter: impact of race on efficacy and safety

OBJECTIVE

To evaluate the racial differences in the efficacy and safety of ibutilide in patients with recent-onset (<2 weeks) atrial fibrillation and atrial flutter.

METHODS

This study included 58 consecutive patients with recent-onset atrial fibrillation (n = 34) and atrial flutter (n = 24). The mean age was 65.7 +/- 14.6 years (range, 37-86 years), 47% were women (n = 27) and 34% (n = 20) were African Americans. The duration of arrhythmia ranged from 3 hours to 2 weeks. All patients had echocardiography, were on therapeutic anticoagulation, had a fairly well controlled ventricular rate, normal QTc interval on 12-lead electrocardiography, and normal serum electrolytes. Ibutilide was administered as an intravenous infusion with a maximal dose of 2 mg.

RESULTS

The overall conversion rate to sinus rhythm was 66% (n = 38), with 62% (n = 21) with atrial fibrillation and 71% (n = 17) of atrial flutter. Most conversions (84%) occurred within 45 minutes of ibutilide infusion. The mean time to arrhythmia conversion was 37.4 +/- 59.8 minutes. Race had a significant impact on efficacy, with increased conversions seen in African Americans (P = 0.004) and increased nonconversion seen in whites (P = 0.02). Successful conversion was not affected by the left atrial size or the presence of valvular heart disease, hypertension, heart failure, coronary heart disease, and diabetes mellitus. QTc intervals were prolonged after drug administration, with a mean change of 24.6 milliseconds for all patients. The QTc prolongation after drug administration was greater in African Americans than in whites (27.4 vs. 23.3 milliseconds). Torsade de pointes occurred in 4 patients (3 African Americans) and was treated with intravenous magnesium sulfate and electrical cardioversion.

CONCLUSION

Ibutilide used for pharmacological cardioversion of atrial fibrillation and atrial flutter is more effective in African Americans but carries a higher risk of torsade de pointes.

Ibutilide in rapid conversion of atrial flutter in octogenarians

INTRODUCTION

Atrial flutter is a common sustained atrial tachyarrhythmia for which frequency increases with age. Ibutilide is a novel class III antiarrhythmic agent used for the rapid cardioversion of atrial fibrillation or atrial flutter.

AIM

The aim of our study was to assess the use of ibutilide in a selected population of very elderly patients (octogenarians) with recent-onset atrial flutter.

METHOD

Twenty-nine consecutive elderly patients (11 male, 18 female; mean age 83 +/- 3 years; interquartile range of 10) with recent-onset atrial flutter were included in the study; none of them had signs or symptoms of severe heart failure, angina or impaired renal or hepatic function. All patients underwent a 10-minute intravenous infusion of ibutilide (0.87 mg in 10 ml).

RESULTS

The rate of successful arrhythmia termination was 75.9% within a mean time of 31 +/- 20 minutes. No clinical variables were shown to be associated with successful cardioversion, although there was a tendency towards higher efficacy in patients with a shorter duration of arrhythmia. Two female patients (6.9%) developed torsade de pointes, requiring direct current cardioversion under general anaesthesia. Episodes of nonsustained ventricular tachycardia occurred in two other patients.

CONCLUSION

Ibutilide appears to be an effective and well tolerated drug for rapid conversion of recent-onset atrial flutter in octogenarian patients, and may represent a valid approach in the acute management of atrial flutter in this particular set of patients.

Ibutilide versus amiodarone in atrial fibrillation: a double-blinded, randomized study

OBJECTIVE

Ibutilide, a class III antiarrhythmic drug, has been shown to convert atrial fibrillation to sinus rhythm more rapidly than procainamide or sotalol. Our objective was to compare the efficacy and safety of ibutilide and amiodarone in patients after cardiac surgery.

DESIGN

Prospective, randomized, double-blinded study.

SETTING

Intensive care unit of a university hospital.

PATIENTS

Forty adults with an onset of atrial fibrillation within 3 hrs after admission.

INTERVENTIONS

Before the administration of antiarrhythmic drugs, a 24-hr Holter electrocardiograph was attached. Patients in the ibutilide group received ibutilide 0.008 mg/kg body weight over 10 mins; treatment was repeated if atrial fibrillation or flutter persisted. If sinus rhythm was not achieved within 4 hrs, amiodarone 5 mg/kg was administered over 30 mins, followed by amiodarone 15 mg/kg over 24 hrs. Patients in the amiodarone group received amiodarone 5 mg/kg over 30 mins, followed by amiodarone 15 mg/kg over 24 hrs if atrial fibrillation or flutter continued.

MEASUREMENTS AND MAIN RESULTS

Within the first 4 hrs, atrial fibrillation was converted in nine of 20 patients (45%) in group ibutilide and in ten of 20 patients (50%) in group amiodarone (not significant). Mean time for conversion overall was 385 mins in group ibutilide and 495 mins in group amiodarone (not significant). In group amiodarone, the protocol was discontinued in two patients because of severe arterial hypotension. Atrial fibrillation recurred in 11 of 20 patients (55%) in group ibutilide and in seven of 20 patients (35%) in group amiodarone (not significant). Ventricular arrhythmia did not occur during the first 24 hrs of the protocol.

CONCLUSIONS

Ibutilide has no significant advantage over amiodarone for the conversion of atrial fibrillation to sinus rhythm in either time to conversion or conversion overall, but severe hypotension was not seen with ibutilide.

Biphasic versus monophasic shock waveform for conversion of atrial fibrillation: the results of an international randomized, double-blind multicenter trial

OBJECTIVES

This study compared a biphasic waveform with a conventional monophasic waveform for cardioversion of atrial fibrillation (AF).

BACKGROUND

Biphasic shock waveforms have been demonstrated to be superior to monophasic shocks for termination of ventricular fibrillation, but data regarding biphasic shocks for conversion of AF are still emerging.

METHODS

In an international, multicenter, randomized, double-blind clinical trial, we compared the effectiveness of damped sine wave monophasic versus impedance-compensated truncated exponential biphasic shocks for the cardioversion of AF. Patients received up to five shocks, as necessary for conversion: 100 J, 150 J, 200 J, a fourth shock at maximum output for the initial waveform (200 J biphasic, 360 J monophasic) and a final cross-over shock at maximum output of the alternate waveform.

RESULTS

Analysis included 107 monophasic and 96 biphasic patients. The success rate was higher for biphasic than for monophasic shocks at each of the three shared energy levels (100 J: 60% vs. 22%, p < 0.0001; 150 J: 77% vs. 44%, p < 0.0001; 200 J: 90% vs. 53%, p < 0.0001). Through four shocks, at a maximum of 200 J, biphasic performance was similar to monophasic performance at 360 J (91% vs. 85%, p = 0.29). Biphasic patients required fewer shocks (1.7 +/- 1.0 vs. 2.8 +/- 1.2, p < 0.0001) and lower total energy delivered (217 +/- 176 J vs. 548 +/- 331 J, p < 0.0001). The biphasic shock waveform was also associated with a lower frequency of dermal injury (17% vs. 41%, p < 0.0001).

CONCLUSIONS

For the cardioversion of AF, a biphasic shock waveform has greater efficacy, requires fewer shocks and lower delivered energy, and results in less dermal injury than a monophasic shock waveform.

Pharmacologic conversion of atrial fibrillation: a systematic review of available evidence

This report reviews the efficacy of currently available antiarrhythmic agents for conversion of atrial fibrilation (AF) to normal sinus rhythm (NSR). A systematic search of literature in the English language was done on computerized databases, such as MEDLINE, EMBASE, and Current Contents, in reference lists, by manual searching, and in contact with expert informants. Published studies involving humans that described the use of antiarrhythmic therapy for conversion of AF to NSR were considered and only studies that examined the use of agents currently available in the United States were included. Studies exclusively describing antiarrhythmic therapy for conversion of postsurgical AF were excluded. The methodology and results of each trial were assessed and attempts were made to acquire additional information from investigators when needed. Assessment of methodological quality was incorporated into a levels-of-evidence scheme. Eighty-eight trials were included, of which 34 (39%) included a placebo group (level I data). We found in recent-onset AF of less than 7 days, intravenous (i.v.) procainamide, high-dose i.v. or high-dose combination i.v. and oral amiodarone, oral quinidine, oral flecainide, oral propafenone, and high-dose oral amiodarone are more effective than placebo for converting AF to NSR. In recent-onset AF of less than 90 days, i.v. ibutilide is more effective than placebo and i.v. procainamide. In chronic AF, oral dofetilide converts AF to NSR within 72 hours, and oral propafenone and amiodarone are effective after 30 days of therapy. We conclude than for conversion of recent-onset AF of less than 7 days, procainamide may be considered a preferred i.v. agent and propafenone a preferred oral agent. For conversion of recent-onset AF of longer duration (less than 90 days), i.v. ibutilide may be considered a preferred agent. For patients with chronic AF and left ventricular dysfunction, direct current cardioversion is the preferred conversion method. Larger, well-designed randomized controlled trials with clinically important endpoints in specific populations of AF patients are needed.

Atrial Flutter

Atrial flutter (AFl) is an arrhythmia resulting from reentry in a macroreentrant circuit, most commonly in the right atrium. Typical AFl uses the narrow isthmus of right atrial tissue between the tricuspid valve annulus and the inferior vena cava orifice as part of the macroreentrant circuit. The treatment of AFl is directed toward achieving the following four goals. 1) In the presence of AFl, adequate rate control is required, which can be achieved in most but not all patients by oral or intravenous digoxin, calcium channel blockers, or beta-blockers, alone or in combination. 2) Anticoagulation with warfarin should be considered in patients with recurrent AFl, especially those over 70 years of age, and those with a history of atrial fibrillation, stroke, or structural heart disease. 3) Conversion to sinus rhythm can be achieved in up to 70% of patients with intravenous ibutilide, but this should be reserved for patients with either normal hearts or only mild left ventricular dysfunction. Direct-current cardioversion is nearly 100% effective and is ideal for patients with left ventricular dysfunction. 4) Long-term maintenance of sinus rhythm may be achieved in up to 50% to 60% of patients by using antiarrhythmic drugs, including sotalol, amiodarone, dofetilide, propafenone, and flecainide, but with the potential for causing significant proarrhythmia and side effects. Radiofrequency catheter ablation may cure over 90% of patients with type 1 AFl (using the tricuspid valve to inferior vena cava isthmus), and from 70% to 90% of patients with atypical AFl. Newer mapping techniques, such as electroanatomic mapping, are likely to further reduce procedure time and improve success rates.