Randomized comparison of anterolateral versus anteroposterior electrode position for biphasic external cardioversion of atrial fibrillation

External electrical and pharmacological cardioversion for atrial fibrillation, atrial flutter or atrial tachycardias: a network meta-analysis

BACKGROUND

Atrial fibrillation (AF) is the most frequent sustained arrhythmia. Cardioversion is a rhythm control strategy to restore normal/sinus rhythm, and can be achieved through drugs (pharmacological) or a synchronised electric shock (electrical cardioversion).

OBJECTIVES

To assess the efficacy and safety of pharmacological and electrical cardioversion for atrial fibrillation (AF), atrial flutter and atrial tachycardias.

SEARCH METHODS

We searched CENTRAL, MEDLINE, Embase, Conference Proceedings Citation Index-Science (CPCI-S) and three trials registers (ClinicalTrials.gov, WHO ICTRP and ISRCTN) on 14 February 2023.

SELECTION CRITERIA

We included randomised controlled trials (RCTs) at the individual patient level. Patient populations were aged ≥ 18 years with AF of any type and duration, atrial flutter or other sustained related atrial arrhythmias, not occurring as a result of reversible causes.

DATA COLLECTION AND ANALYSIS

We used standard Cochrane methodology to collect data and performed a network meta-analysis using the standard frequentist graph-theoretical approach using the netmeta package in R. We used GRADE to assess the quality of the evidence which we presented in our summary of findings with a judgement on certainty. We calculated differences using risk ratios (RR) and 95% confidence intervals (CI) as well as ranking treatments using a P value. We assessed clinical and statistical heterogeneity and split the networks for the primary outcome and acute procedural success, due to concerns about violating the transitivity assumption.

MAIN RESULTS

We included 112 RCTs (139 records), from which we pooled data from 15,968 patients. The average age ranged from 47 to 72 years and the proportion of male patients ranged from 38% to 92%. Seventy-nine trials were considered to be at high risk of bias for at least one domain, 32 had no high risk of bias domains, but had at least one domain classified as uncertain risk, and one study was considered at low risk for all domains. For paroxysmal AF (35 trials), when compared to placebo, anteroapical (AA)/anteroposterior (AP) biphasic truncated exponential waveform (BTE) cardioversion (RR: 2.42; 95% CI 1.65 to 3.56), quinidine (RR: 2.23; 95% CI 1.49 to 3.34), ibutilide (RR: 2.00; 95% CI 1.28 to 3.12), propafenone (RR: 1.98; 95% CI 1.67 to 2.34), amiodarone (RR: 1.69; 95% CI 1.42 to 2.02), sotalol (RR: 1.58; 95% CI 1.08 to 2.31) and procainamide (RR: 1.49; 95% CI 1.13 to 1.97) likely result in a large increase in maintenance of sinus rhythm until hospital discharge or end of study follow-up (certainty of evidence: moderate). The effect size was larger for AA/AP incremental and was progressively smaller for the subsequent interventions. Despite low certainty of evidence, antazoline may result in a large increase (RR: 28.60; 95% CI 1.77 to 461.30) in this outcome. Similarly, low-certainty evidence suggests a large increase in this outcome for flecainide (RR: 2.17; 95% CI 1.68 to 2.79), vernakalant (RR: 2.13; 95% CI 1.52 to 2.99), and magnesium (RR: 1.73; 95% CI 0.79 to 3.79). For persistent AF (26 trials), one network was created for electrical cardioversion and showed that, when compared to AP BTE incremental energy with patches, AP BTE maximum energy with patches (RR 1.35, 95% CI 1.17 to 1.55) likely results in a large increase, and active compression AP BTE incremental energy with patches (RR: 1.14, 95% CI 1.00 to 1.131) likely results in an increase in maintenance of sinus rhythm at hospital discharge or end of study follow-up (certainty of evidence: high). Use of AP BTE incremental with paddles (RR: 1.03, 95% CI 0.98 to 1.09; certainty of evidence: low) may lead to a slight increase, and AP MDS Incremental paddles (RR: 0.95, 95% CI 0.86 to 1.05; certainty of evidence: low) may lead to a slight decrease in efficacy. On the other hand, AP MDS incremental energy using patches (RR: 0.78, 95% CI 0.70 to 0.87), AA RBW incremental energy with patches (RR: 0.76, 95% CI 0.66 to 0.88), AP RBW incremental energy with patches (RR: 0.76, 95% CI 0.68 to 0.86), AA MDS incremental energy with patches (RR: 0.76, 95% CI 0.67 to 0.86) and AA MDS incremental energy with paddles (RR: 0.68, 95% CI 0.53 to 0.83) probably result in a decrease in this outcome when compared to AP BTE incremental energy with patches (certainty of evidence: moderate). The network for pharmacological cardioversion showed that bepridil (RR: 2.29, 95% CI 1.26 to 4.17) and quindine (RR: 1.53, (95% CI 1.01 to 2.32) probably result in a large increase in maintenance of sinus rhythm at hospital discharge or end of study follow-up when compared to amiodarone (certainty of evidence: moderate). Dofetilide (RR: 0.79, 95% CI 0.56 to 1.44), sotalol (RR: 0.89, 95% CI 0.67 to 1.18), propafenone (RR: 0.79, 95% CI 0.50 to 1.25) and pilsicainide (RR: 0.39, 95% CI 0.02 to 7.01) may result in a reduction in this outcome when compared to amiodarone, but the certainty of evidence is low. For atrial flutter (14 trials), a network could be created only for antiarrhythmic drugs. Using placebo as the common comparator, ibutilide (RR: 21.45, 95% CI 4.41 to 104.37), propafenone (RR: 7.15, 95% CI 1.27 to 40.10), dofetilide (RR: 6.43, 95% CI 1.38 to 29.91), and sotalol (RR: 6.39, 95% CI 1.03 to 39.78) probably result in a large increase in the maintenance of sinus rhythm at hospital discharge or end of study follow-up (certainty of evidence: moderate), and procainamide (RR: 4.29, 95% CI 0.63 to 29.03), flecainide (RR 3.57, 95% CI 0.24 to 52.30) and vernakalant (RR: 1.18, 95% CI 0.05 to 27.37) may result in a large increase in maintenance of sinus rhythm at hospital discharge or end of study follow-up (certainty of evidence: low). All tested electrical cardioversion strategies for atrial flutter had very high efficacy (97.9% to 100%). The rate of mortality (14 deaths) and stroke or systemic embolism (3 events) at 30 days was extremely low. Data on quality of life were scarce and of uncertain clinical significance. No information was available regarding heart failure readmissions. Data on duration of hospitalisation was scarce, of low quality, and could not be pooled.

AUTHORS' CONCLUSIONS

Despite the low quality of evidence, this systematic review provides important information on electrical and pharmacological strategies to help patients and physicians deal with AF and atrial flutter. In the assessment of the patient comorbidity profile, antiarrhythmic drug onset of action and side effect profile versus the need for a physician with experience in sedation, or anaesthetics support for electrical cardioversion are key aspects when choosing the cardioversion method.

Antero-lateral vs. antero-posterior electrode position for cardioversion of atrial fibrillation: a systematic review and meta-analysis of randomized controlled trials

BACKGROUND

Multiple randomized controlled trials (RCTs) have compared the success of antero-lateral vs. antero-posterior electrode position for cardioversion of atrial fibrillation (AF). However, due to small sample size and conflicting results of these RCTs, the optimal electrode positioning for successful cardioversion remains uncertain.

METHODS

A systematic search of MEDLINE and EMBASE was conducted. Outcomes of interest included overall success of cardioversion with restoration of sinus rhythm, 1st shock success, 2nd shock success, mean shock energy required for successful cardioversion, mean number of shocks required for successful cardioversion, success of cardioversion at high energy (> 150 J) and success of cardioversion at low energy (< 150 J). Mantel-Haenszel risk ratios (RR) with 95% confidence intervals were calculated using random-effects model.

RESULTS

A total of 14 RCTs comprising 2445 patients were included. There was no statistically significant difference between two cardioversion approaches in the overall success of cardioversion (RR 1.02; 95% CI [0.97-1.06]; p = 0.43), first shock success (RR 1.14; 95% CI [0.99-1.32]), second shock success (RR 1.08; 95% CI [0.94-1.23]), mean shock energy required (mean difference 6.49; 95% CI [-17.33-30.31], success at high energy > 150 J (RR 1.02; 95% CI [0.92-1.14] and success at low energy < 150 J (RR 1.09; 95% CI [0.97-1.22]).

CONCLUSIONS

This meta-analysis of RCTs shows no significant difference in the success of cardioversion between antero-lateral vs. antero-posterior electrode position for cardioversion of AF. Large well-conducted and adequately powered randomized clinical trials are needed to definitively address this question.

Electrical energy by electrode placement for cardioversion of atrial fibrillation: a systematic review and meta-analysis

OBJECTIVE

Electrode patch position may not be critical for success when cardioverting atrial fibrillation (AF), but the relevance of applied electrical energy is unclarified. Our objective was to perform a meta-analysis of randomised trials to examine the dose-response relation between energy level and cardioversion success by electrode position in elective cardioversion.

METHODS

We searched PubMed, Embase, The Cochrane Library, Google Scholar and Scopus Citations. Inclusion criteria were randomised controlled trials using biphasic shock waves and self-adhesive patches, and publication date from 2000 to 2023. We used random-effects dose-response models to meta-analyse the relation between energy level and cardioversion success by anterolateral and anteroposterior position. Random-effects models estimated pooled risk ratios (RR) for cardioversion success after the first and the final shocks between the two electrode positions.

RESULTS

We included five randomised controlled trials (N=1078). After the first low-energy shock, the electrode position was not significantly associated with the likelihood of successful cardioversion (pooled RR anterolateral vs anteroposterior placement 1.28, 95% CI 0.93 to 1.76, with considerable heterogeneity). After a high-energy final shock, there was no evidence of an association between the electrode position and the cumulative chance of cardioversion success (pooled RR anterolateral vs anteroposterior 1.05, 95% CI 0.97 to 1.14). Regardless of electrode position, cardioversion success was significantly less likely with shock energy levels < 200J compared with 200J.

CONCLUSION

Evidence from contemporary randomised trials suggests that higher level of electrical energy is associated with higher conversion rate when cardioverting AF with a biphasic shockwave. Positioning of electrodes can be based on convenience.

Anteriolateral versus anterior-posterior electrodes in external cardioversion of atrial fibrillation: A systematic review and meta-analysis of clinical trials

The efficacy of anteriolateral versus anterior-posterior electrode positions in the success of atrial fibrillation's (AF) electrical cardioversion is unclear. Our aim is to perform a meta-analysis to compare the success rate of both electrode positions. PUBMED, WOS, OVID, and SCOPUS were searched. Inclusion criteria were clinical trials that compared anterior-lateral with anterior-posterior electrodes in external cardioversion of AF. After the full-text screening, 11 trials were included in the analysis. The total number of patients included in the study is 1845. The pooled analysis showed a statistically significant association between anterior-lateral electrode and increased cardioversion rate of AF (odds ratio [OR] = 1.40, 95% confidence interval [CI] = 1.02-1.92, p = .04). Subgroup analysis revealed a statistically significant association between the anterior-lateral electrode and increased cardioversion rate of AF in subgroups of less than five shocks, patients with 60 years old or more and patients with left atrial (LA) diameter >45 mm (OR = 1.72, 95% CI = 1.17-2.54, p = .006), (OR = 1.73, 95% CI = 1.18-2.54, p = .005), and (OR = 1.86, 95% CI = 1.04-3.34, p = .04), respectively. Anteriolateral electrode is more effective than anterior-posterior electrode in external cardioversion of AF, particularly in patients who have received less than 5 shocks, are 60 years old or older and have a LA diameter greater than 45 mm.

Techniques improving electrical cardioversion success for patients with atrial fibrillation: a systematic review and meta-analysis

AIMS

Electrical cardioversion is commonly used to restore sinus rhythm in patients with atrial fibrillation (AF), but procedural technique and clinical success vary. We sought to identify techniques associated with electrical cardioversion success for AF patients.

METHODS AND RESULTS

We searched MEDLINE, EMBASE, CENTRAL, and the grey literature from inception to October 2022. We abstracted data on initial and cumulative cardioversion success. We pooled data using random-effects models. From 15 207 citations, we identified 45 randomized trials and 16 observational studies. In randomized trials, biphasic when compared with monophasic waveforms resulted in higher rates of initial [16 trials, risk ratio (RR) 1.71, 95% CI 1.29-2.28] and cumulative success (18 trials, RR 1.10, 95% CI 1.04-1.16). Fixed, high-energy (≥200 J) shocks when compared with escalating energy resulted in a higher rate of initial success (four trials, RR 1.62, 95% CI 1.33-1.98). Manual pressure when compared with no pressure resulted in higher rates of initial (two trials, RR 2.19, 95% CI 1.21-3.95) and cumulative success (two trials, RR 1.19, 95% CI 1.06-1.34). Cardioversion success did not differ significantly for other interventions, including: antero-apical/lateral vs. antero-posterior positioned pads (initial: 11 trials, RR 1.16, 95% CI 0.97-1.39; cumulative: 14 trials, RR 1.01, 95% CI 0.96-1.06); rectilinear/pulsed biphasic vs. biphasic truncated exponential waveform (initial: four trials, RR 1.11, 95% CI 0.91-1.34; cumulative: four trials, RR 0.98, 95% CI 0.89-1.08) and cathodal vs. anodal configuration (cumulative: two trials, RR 0.99, 95% CI 0.92-1.07).

CONCLUSIONS

Biphasic waveforms, high-energy shocks, and manual pressure increase the success of electrical cardioversion for AF. Other interventions, especially pad positioning, require further study.

Anteroposterior Versus Anterolateral Electrode Position for Direct Current Cardioversion of Atrial Fibrillation: A Meta-Analysis of Randomised Controlled Trials

OBJECTIVE

Data regarding optimal electrode positioning for direct current cardioversion (DCCV) of atrial fibrillation (AF) has been inconsistent. This meta-analysis was conducted to systematically compare the efficacy of anteroposterior (AP) versus anterolateral (AL) electrode placement for DCCV of AF.

METHODS

Electronic databases were searched for randomised controlled trials (RCTs) comparing AP versus AL electrode positioning in patients undergoing DCCV for AF. Primary endpoints were first-shock success and overall DCCV success. Subgroup analysis was performed by defibrillator waveform (monophasic versus biphasic). Meta-regression analyses were performed to assess for significant moderators.

RESULTS

Twelve (12) RCTs, including a total of 2,046 patients, met inclusion criteria. Neither first-shock success (relative risk [RR] 0.92; 95% CI 0.79-1.07; p=0.28) nor overall DCCV success (RR 1.01; 95% CI 0.96-1.05; p=0.78) were significantly different with AP versus AL electrode positioning. The mean number of shocks (mean difference [MD] 0.3, 95% CI -0.4 to 0.9), energy level of first successful shock (MD 3 joules; 95% CI -20 to 27) and cumulative energy delivered (MD 39 joules; 95% CI -168 to 246) were similar in AP versus AL arms. In subgroup analysis of six RCTs using biphasic defibrillators, improvement in first-shock success (RR 0.85; 95% CI 0.69-1.03; p=0.10) and overall DCCV success (RR 0.97; 95% CI 0.93-1.01; p=0.09) with AL electrode positioning did not reach statistical significance. Meta-regression analyses identified older age, higher body mass index, and longer AF duration as significant moderators favouring AL electrode positioning.

CONCLUSIONS

Pooled analysis of randomised data overall does not show a significant difference in efficacy between AP versus AL electrode positioning. Meta-regression and subgroup analyses suggest that, in contemporary practice with use of biphasic defibrillators, there may be a subset of AF patients in whom AL electrode positioning improves efficacy of DCCV.

Anterior-Posterior versus anterior-lateral electrodes position for electrical cardioversion of atrial fibrillation: A meta-analysis of randomized controlled trials

Background

The optimal electrodes position for elective direct current (DC) cardioversion of patients with atrial fibrillation (AF) remains uncertain.

Methods

An electronic search of MEDLINE, EMBASE and COCHRANE databases was performed through March 2022 for randomized trials that examined the outcomes of anterior-posterior (AP) versus anterior-lateral (AL) electrodes position during cardioversion of (AF). The main outcome was the success rate of cardioversion. Data were pooled using random effects model.

Results

The final analysis included 10 RCTs with a total of 1677 patients. There was no difference in the rate of successful cardioversion between the AP versus AL groups (86.6 vs 87.9 %; RR 1.00; 95 % Confidence Interval (CI) 0.95 to 1.06). Subgroup analysis by the shock waveform showed no significant interaction between monophasic and biphasic waveforms (P_intercation = 0.23). meta-regression analyses showed no effect modification of primary outcome according to body mass index (p = 0.15), left atrial diameter (p = 0.64), valvular heart disease (p = 0.34), lone AF (p = 0.58), or the duration of AF (p = 0.70). There was no significant difference between the AP and AL electrode position groups in successful cardioversion at low energy (RR 0.94; 95 % CI 0.74 to 1.19), the number of the delivered shocks (standardized mean difference [SMD] −0.03; 95 % CI −0.32 to 0.26) or the mean energy of the delivered shocks (SMD −0.11 and 95 % CI −0.30 to 0.07). There was lower transthoracic impedance with AP versus AL electrode position (SMD −0.28; 95 %CI −0.47 to −0.10).

Conclusion

Meta-analysis of randomized data showed no difference between AP and AL electrode positions in the success rate of DC cardioversion of AF. Either AP or AL electrode positions should be acceptable approaches for elective DC cardioversion of patients with AF.

Anterior-Lateral Versus Anterior-Posterior Electrode Position for Cardioverting Atrial Fibrillation

BACKGROUND

Smaller randomized studies have reported conflicting results regarding the optimal electrode position for cardioverting atrial fibrillation. However, anterior-posterior electrode positioning is widely used as a standard and believed to be superior to anterior-lateral electrode positioning. Therefore, we aimed to compare anterior-lateral and anterior-posterior electrode positioning for cardioverting atrial fibrillation in a multicenter randomized trial.

METHODS

In this multicenter, investigator-initiated, open-label trial, we randomly assigned patients with atrial fibrillation scheduled for elective cardioversion to either anterior-lateral or anterior-posterior electrode positioning. The primary outcome was the proportion of patients in sinus rhythm after the first shock. The secondary outcome was the proportion of patients in sinus rhythm after up to 4 shocks escalating to maximum energy. Safety outcomes were any cases of arrhythmia during or after cardioversion, skin redness, and patient-reported periprocedural pain.

RESULTS

We randomized 468 patients. The primary outcome occurred in 126 patients (54%) assigned to the anterior-lateral electrode position and in 77 patients (33%) assigned to the anterior-posterior electrode position (risk difference, 22 percentage points [95% CI, 13-30]; P<0.001). The number of patients in sinus rhythm after the final cardioversion shock was 216 (93%) assigned to anterior-lateral electrode positioning and 200 (85%) assigned to anterior-posterior electrode positioning (risk difference, 7 percentage points [95% CI, 2-12]). There were no significant differences between groups in any safety outcomes.

CONCLUSIONS

Anterior-lateral electrode positioning was more effective than anterior-posterior electrode positioning for biphasic cardioversion of atrial fibrillation. There were no significant differences in any safety outcome. Registration: URL: https://www.clinicaltrials.gov; Unique identifier: NCT03817372.

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.

The efficacy of pad placement for electrical cardioversion of atrial fibrillation/flutter: a systematic review

OBJECTIVES

Electrical cardioversion is commonly used to treat patients with atrial fibrillation and atrial flutter to restore normal sinus rhythm. There has been considerable debate as to whether the electrode placement affects the efficacy of electrical cardioversion. The objective of this study was to examine the effectiveness of anteroposterior (A-P) versus anterolateral (A-L) electrode placement to restore normal sinus rhythm.

METHODS

A search of eight electronic databases, including Medline, EMBASE, CINAHL, and Cochrane was completed. Grey literature (hand-searching, Google, and SCOPUS) searching was also conducted. Studies were included if they were controlled clinical trials comparing the effectiveness of A-P versus A-L pad placement to restore normal sinus rhythm in adult patients with atrial fibrillation and flutter. Two independent reviewers judged study relevance, inclusion, and quality (e.g., risk of bias). Individual and pooled statistics were calculated as relative risks (RRs) with 95% confidence intervals (CIs) using a random-effects model, and heterogeneity (I(2) ) was reported.

RESULTS

From 788 citations, 13 studies were included; seven involved monophasic, five involved biphasic, and one analyzed both waveform devices. The included studies tended to report cumulative success rates to restoring normal sinus rhythm after one to five sequential shocks of increasing energy; the number of shocks and energy used differed among studies. The risk of bias of the studies was "unclear." After the first shock, pad placement was not associated with an increased likelihood of restoring normal sinus rhythm (RR = 0.88; 95% CI = 0.73 to 1.06); however, heterogeneity was high (I(2) = 63%). Subgroup comparisons revealed that the A-L position was more effective (RR = 0.77; 95% CI = 0.59 to 1.00) at restoring normal sinus rhythm when using biphasic shocks (comparison p = 0.04). Overall, the pooled results failed to identify a difference between A-P and A-L pad placement in restoring normal sinus rhythm at any time (RR = 1.00; 95% CI = 0.95 to 1.05); however, heterogeneity was high (I(2) = 61%). No significant subgroup differences were found. Side effects were reported in only three studies.

CONCLUSIONS

The published literature is restricted to persistent atrial fibrillation and atrial flutter, pad placement varied, and energy levels used were lower than currently recommended; however, the accumulated evidence suggests that electrical pad placement is not a critically important factor in successful cardioversion in atrial fibrillation and flutter (AF/AFL). A trial is urgently needed in recent-onset atrial fibrillation and atrial flutter patients using biphasic devices and high energy levels to resolve the debate.

Atrial fibrillation: a historical perspective

Atrial fibrillation (AF) undoubtedly has become one of the most well studied arrhythmias today in terms of pathophysiology and diagnostic and therapeutic (interventional) electrophysiology. Although it lends itself to an apparently easy diagnosis on a surface ECG, myriad electromechanical mechanisms underlie its origin. An era of technology has been reached that makes AF not only "treatable" but also potentially "curable." This article aims at walking through the historical corridors and maze that have led to the present-day understanding of this most common yet complex arrhythmia.

[Electrical and pharmacological strategies for early cardioversion of atrial fibrillation]

Cardioversion of atrial fibrillation as an element of rhythm control strategy is indicated in patients with first episode of atrial fibrillation, hemodynamic instability, recurrent atrial fibrillation with low probability of spontaneous conversion, or severe symptoms. Early cardioversion is performed within 48 h of onset of atrial fibrillation. The best point in time is still unknown. It can be performed by pharmacological, or, preferentially, by electrical cardioversion. The advantages of electrical cardioversion are higher efficacy and no proarrhythmic risk, however, short time general anaesthesia is needed. Electrical cardioversion is most effective when biphasic shocks are delivered. For pharmacological cardioversion, several antiarrhythmic drugs are available which have to be considered individually. Thromboembolic risk does not differ between the two methods. Early cardioversion and maintenance of sinus rhythm is most effective in atrial fibrillation of short duration, normal left atrial size and no or only mild structural heart disease.