Immediate Recurrence Of Atrial Fibrillation Research Articles

Safety and efficacy of a cardiologist-only approach to deep sedation for electrical cardioversion.

Electrical cardioversion is still the preferred method to restore sinus rhythm in patients with atrial fibrillation. The main disadvantage is that electrical cardioversion requires deep sedation, generally administered by anaesthesiologists, for safety concern. An exclusively cardiologic management of deep sedation should have the advantage to reduce resources and time consumed. All consecutive patients admitted to our division with persistent atrial fibrillation or atrial flutter to undergo elective electrical cardioversion from June 2002 to December 2016 were included. The sedation protocol was managed only by cardiologists and involved the administration of a 5-mg bolus of midazolam, followed by increasing doses of propofol to achieve the desired sedation level. Exclusion criteria were strictly observed. Complications were recorded. A retrospective analysis on a deidentified database has been performed. A total of 1188 electrical cardioversions were scheduled in our centre. A total of 1195 patients were scheduled in our centre, of whom 1188 met inclusion criteria. Electrical cardioversion was performed in 1073 cases (90.3%). Electrical cardioversion was successful in restoring sinus rhythm in 1030 (96.0%) patients. Immediate recurrence of atrial fibrillation occurred in 89 patients (8.3%). 99/1073 (9.22%) patients underwent trans-oesophagel echocardiography before cardioversion. Deep sedation, according to our protocol, was effective in 100% of cases. Midazolam was administered at a dosage of 5 mg to all patients, while propofol was administered at a dosage ranging from 20 to 80 mg (25.1 ± 11.0 mg SD). No anaesthesia-related complications were observed, neither significant respiratory depression requiring intubation nor anaesthesiologist support. The exclusively cardiological procedure of deep sedation seems to be safe and effective.

Abstract 12012: Relation Between Colchicine and Epicardial Adipose Tissue Volume Surrounding Left Atrium in Atrial Fibrillation Recurrence After Ablation

Background: Immediate recurrence of atrial fibrillation (AF) after AF ablation was related with inflammatory process. Colchicine treatment after AF ablation can reduce AF recurrence by suppression of such inflammatory reactions. The epicardial adipose tissue (EAT) has been shown to release activated pro-inflammatory cytokines and to associate with the development of AF. However, it is unclear whether colchicine treatment affects recurrence of AF according to EAT volume of left atrium (LA-EAT volume). The purpose of this study was to evaluate the relation between reduction of AF recurrence by colchicine treatment after AF ablation and LA-EAT volume. Methods: One hundred twenty two consecutive AF patients who underwent AF ablation and in whom multi-detector computed tomography was performed before ablation were included. Colchicine was prescribed to patients who approved colchicine treatment and was started at 0.5 mg/day for 2 weeks after AF ablation. We divided the study patients into larger LA-EAT group and smaller LA-EAT group according to the median (22.4 cm3) of LA-EAT volume. LA-EAT volume was obtained by semi-automatically tracing axial images from the bifurcation of the pulmonary artery to the coronary sinus and EAT was recognized using threshold attenuation values of -50 to -200 HU. In each group, we compared incidences of AF recurrence (AF > 30 sec) in 3 months and 12 months after ablation between colchicine group and non-colchicine group. Results: Forty-two patients received colchicine. In larger LA-EAT group (> 22.4 cm3) (n=60) incidence of AF recurrence in colchicine group showed lower tendency in 12 months after ablation (10.5% vs. 34.2%, p=0.06) while in smaller LA-EAT group (< 22.4 cm3) (n=62), incidence of AF recurrence was similar between colchicine group and non-colchicine group (Table). Conclusion: Colchicine treatment after AF ablation may reduce mid-term AF recurrence in AF patients with larger LA-EAT volume.

Prevention of immediate recurrence of atrial fibrillation with low-dose landiolol after radiofrequency catheter ablation

BackgroundImmediate recurrence of atrial fibrillation (AF) after radiofrequency (RF) catheter ablation is commonly observed within 3d after the procedure. The mechanism and pharmacological management of immediate AF recurrence remain unclear. MethodsA total of 50 consecutive patients with paroxysmal AF were randomized to receive either low-dose landiolol (landiolol group) or a placebo (placebo group). In the landiolol group, intravenous landiolol (0.5μgkg−1min−1) was administered for 3d after AF ablation. ResultsNo serious adverse event associated with RF catheter ablation or landiolol administration was observed. The prevalence of immediate AF recurrence (≤3d after RF catheter ablation) was significantly lower in the landiolol group than in the placebo group (16% vs. 48%, p=0.015). Although the postprocedural change in heart rate was significantly lower in the landiolol group compared to that in the placebo group, the changes in blood pressure and body temperature were not different between the two groups. Multiple logistic regression analysis revealed that landiolol treatment was the only independent predictor of immediate AF recurrence after ablation (odds ratio: 0.180; 95% confidence interval: 0.044–0.729; p=0.016). ConclusionsProphylactic administration of low-dose landiolol after AF ablation may be effective and safe for preventing immediate AF recurrence within 3d after AF ablation.

IMPACT OF SHORT DURATION COLCHICINE USE ON REDUCTION OF IMMEDIATE ATRIAL FIBRILLATION AFTER CATHETER ABLATION: PROSPECTIVE STUDY

It has been reported that immediate recurrence of atrial fibrillation (AF) after pulmonary vein isolation (PVI) was related with inflammatory response by ablation and treatment of colchicine after AF ablation reduced the mid-term recurrence of AF and decreased inflammatory mediators. However, it was

Catheter Ablation for Persistent Atrial Fibrillation

A new era of atrial fibrillation (AF) treatment began in 1997–1998 with the discovery that triggers within the pulmonary veins initiate AF and reports that elimination of these triggers is successful in treating AF in its paroxysmal form.1–3 However, in patients with persistent AF, the success rate of exclusive pulmonary vein isolation is substantially lower.4,5 To improve the outcome of persistent AF ablation, different ablation strategies have been explored, but to date the optimal strategy has not been defined. Although some groups argue that limited ablation, including pulmonary vein isolation and, if present, ablation of nonpulmonary vein triggers, is sufficient for persistent AF ablation, other groups, including ours, favor more extensive, substrate-based ablation in addition to pulmonary vein isolation. In this review, we will discuss the rationale for a substrate-based ablation strategy to treat persistent AF and show why elimination of triggers is not sufficient in most patients with persistent AF. Response by Roten et al on p 1232 In a simple model, an electric impulse in AF can form because of abnormalities in impulse generation (triggers) or can result from abnormal impulse propagation (reentry). By a strict definition, a trigger is a focal source of new impulse generation. The mechanism by which a new impulse can form is either abnormal automaticity or triggered activity. Trigger-ablation protocols target these sources of new impulse generation. Abnormal impulse propagation, on the other hand, depends on altered substrate properties causing nonuniform or slowed conduction. This in turn causes multiple forms of wave reentry thought to be responsible for AF perpetuation: random reentry (multiple wavelets), macro- and microreentry, or functional reentry (rotors). Substrate-based ablation strategies aim to abate abnormal impulse propagation and interrupt any form of atrial reentry. Triggers of paroxysmal AF are mainly located in the pulmonary …

Abstract 18612: Intravenous Infusion of Ultrashort-acting Beta-blocker, Landiolol, for Prevention of Immediate Recurrence of Atrial Fibrillation after Catheter Ablation

BACKGROUND: Immediate recurrence of atrial fibrillation (AF) after catheter ablation (CA) troubles with patients. We investigated whether intraveneous infusion of landiolol, an ultrashort-acting beta-blocker, could inhibit immediate AF recurrence after CA by randomized controlled trial. METHOD: atients with drug-resistant AF treated by CA were assigned to receive either landiolol or placebo after the procedure. In the landiolol group, landiolol was infused ntraveneously at speed of 1 μg/kg/min and continued for 3 days after the CA. The primary end point was occurrence/non-occurrence of AF, defined as supra-ventricular arrhythmia more than 5 min, up to 3-day after CA. Logistic regression analysis was performed to investigate risk factor. RESULT: 31 and 24 patients were assigned to landiolol group and placebo group, respectively. There were no significant difference between both groups in systolic blood pressure (SBP) before CA, diastolic blood pressure (DBP) before CA and changes from pre-CA to post-CA of SBP and DBP. AF recurrence occurred in 5 patients (10%) in landiolol group versus 11 patients (45%) in the placebo group (P=0.016, Figure). Multivariable analysis revealed that landiolol infusion significantly reduced the risk of transient AF recurrence after procedure (Hazard ratio: 0.208, 95% confidence interval of hazard ratio: 0.048-0.897, P=0.035). CONCLUSIONS: Short-term landiolol infusion successfully decreased immediate AF recurrence after CA without changing SBP and DBP. Administration of landiolol may become a new strategy to facilitate management after CA.

Fibroblasts, Focal Triggers, and Persistent Atrial Fibrillation

Ablation of persistent atrial fibrillation (AF) remains challenging, particularly as the duration of continuous AF before the procedure increases. Attainment of durable pulmonary vein (PV) isolation remains a fundamental goal in this population; continuous retriggering from focal peri-PV sources (both automaticity and localized reentry) as a potential mechanism for maintaining persistent AF was documented more than a decade ago.1 An area of continuing debate centers on the extent of additional atrial ablation outside the PV antra required for long-term maintenance of sinus rhythm. Two studies published in this issue of Circulation: Arrhythmia and Electrophysiology highlight important clinical aspects of this debate. Articles see p 287, 295, and 442 Inoue and colleagues2 report long-term follow-up of catheter ablation in 263 patients with persistent AF (mean duration of continuous AF, 11 months; >1 year in 50%). To identify triggers that may perpetuate AF, cardioversion was performed at procedure onset, followed by short-duration isoproterenol infusion if needed, to provoke immediate recurrence of AF. The immediate recurrence of AF occurred in 70 (27%) of 263 patients, one third arising from non-PV foci. These triggers were then targeted for ablation (successful in all peri-PV foci, but in only 6 of 23 patients with non-PV triggers). All patients subsequently underwent PV isolation, and 72% had additional non-PV left atrial ablation. At the last follow-up of 17 months (38% of patients receiving antiarrhythmic drugs [AADs], multiple procedures in ≈30%), 90% of patients were in sinus rhythm, although 16% continued to have paroxysmal episodes. Immediate recurrence of AF was associated with a greater risk of recurrent persistent AF during follow-up, predominantly a result of inability to localize and eliminate non-PV focal triggers. In a randomized trial of ablation for persistent AF, Dixit and coworkers3 evaluate 3 strategies for ablation of persistent AF: (1) …

Impact of Immediate Recurrence of Atrial Fibrillation after Ablation on Long-Term Outcome

Background: It had been reported that atrial fibrillation (AF) recurrence immediately after ablation of AF may be caused by acute inflammatory changes after ablation and does not always means long-term AF recurrence. However, the pre-procedural clinical background of that is unclear. Aim: To clarify the clinical background of patients who had AF recurrences within 3-days after ablation (immediate AF recurrence) and the impact of immediate AF recurrences on the long-term outcome. Method: The study included 113 patients (aged 23–78 years; 80% men) with symptomatic drug-resistant paroxysmal (n=89) or persistent AF (n=24) who underwent extensive pulmonary vein ablation. All patients were followed up for more than 3-months (mean 530 days) after the first ablation. Result: Eighteen patients (16%) had immediate AF recurrences (Group-A), 5 (4%) had early recurrences 4–30 days after ablation (Group-B), and the remaining 90 (80%) had no AF recurrences within 1 month after ablation (Group-C). Compared with Group-C, Group-A had more persistent AF patients (p=0.03), higher brain natriuretic peptide levels (p=0.047), larger left atrial volume (p=0.012) and higher E/e′ ratio which is an indicator of left ventricular diastolic dysfunction (p=0.006). The AF free rates after the first AF ablation without anti-arrhythmic drugs in Group-C was superior to that in Group-A and Group-B (P<0.0001 and P=0.02, respectively). Conclusion: The patients who had more left atrial remodeling and left ventricular diastolic dysfunction tend to immediate AF recurrence and poor long-term clinical outcome.

Sternal fracture after elective electrical cardioversion of atrial fibrillation

Sirs: A 69-year-old female was admitted to our institution for ablative treatment of paroxysmal atrial fibrillation (AF) after her amiodarone medication had to be discontinued due to visual side effects. She suffered from intermittent palpitations and had a history of hypertension, coronary artery disease, and ICD implantation for ventricular tachycardia. On echocardiography her left atrial diameter was found to be normal and her left ventricular ejection fraction mildly reduced. One day after catheter-based ablation and circumferential pulmonary vein isolation the patient experienced a symptomatic AF recurrence. After an internal cardioversion attempt with a synchronized 30-J ICD shock had failed, external cardioversion with an anterior–posterior (AP) electrode position was attempted, utilizing a hand-held paddle to apply firm pressure to the sternal electrode during application of a 150-and a 200-J biphasic shock. Sinus rhythm, however, was not maintained due to immediate recurrences of AF. As the patient recovered from sedation, she complained of a new, sharp pre-sternal chest pain that increased with deep breathing. On physical examination of the chest there was pre-sternal tenderness without crepitation on palpation. Findings were interpreted as an irritation of the musculoskeletal tissue from direct current application, and pain medication was prescribed. Over the following days, however, symptoms persisted. After conventional chest X-ray findings did not explain the symptoms, a computed tomography (CT) of the chest revealed a fracture of the sternal body, approximately 2.5 cm below the manubriosternal joint (Fig. 1). The patient had no history of prior chest trauma, and there were no overt medical conditions predisposing to fractures. Dual energy X-ray absorptiometry revealed normal bone mineral density, thereby ruling out osteoporosis. Conservative treatment with a chest bandage was added and pain medication was continued since the fracture was stable and not significantly dislocated. Fig. 1 Chest CT with intravenous administration of contrast material showing fracture in the upper portion of the sternal body (arrow) Since decades, electrical cardioversion is very frequently and widely applied to terminate persistent AF. Recent randomized controlled trials suggest that an AP electrode position [1] and the use of hand-held paddles [2] optimize cardioversion success rates without compromising on patient safety. The present case illustrates that application of this electrode configuration may carry a risk of sternal fracture, a complication usually caused by blunt chest trauma (e.g., traffic or sports accidents), but hitherto unrelated to electrical cardioversion of AF. Iatrogenic sternal fracture is known to occur after cardio-pulmonary resuscitation due to chest compression [3] or application of a pre-cordial thumb [4]. In the present case, electrical cardioversion caused sternal fracture because the electrodes for direct current application were attached in an AP position and because a hand-held paddle was pressed to the sternum. Manual application of firm pressure to the anterior sternal electrode enhances electrode–tissue contact and reduces transthoracic resistance, thereby increasing current flow to the heart and defibrillation success [5]. With an AP electrode position and hand-held paddles, however, pronounced pressure to the sternum may cause sternal fracture, as illustrated by the present case. Of note, this complication occurred in the absence of conditions that predispose to fractures, e.g., osteoporosis, and despite the fact that the procedure was carried out by a physician with substantial experience in electrical cardioversion. In conclusion, this case illustrates that sternal fracture should be considered as a potential complication of electrical cardioversion when an AP electrode position and hand-held paddles are utilized. With this electrode configuration, excessive pre-sternal pressure to the anterior electrode should be avoided.

Clinical and serological predictors for the recurrence of atrial fibrillation after electrical cardioversion

Although electrical cardioversion (CV) is effective in restoring sinus rhythm in patients with atrial fibrillation (AF), AF frequently recurs in spite of antiarrhythmic medications. We investigated the predictors of failed CV and AF recurrence after successful CV. In 81 patients (M:F = 63:18, 59.1 +/- 10.5 years old) with AF who underwent CV, clinical, image, and CV findings (energy requirement, immediate recurrence of AF < 15 min), and pre-CV serological markers were evaluated. (i) During 13.1 +/- 10.6 months of follow-up, 8.6% (7/81) showed failed CV, 59.26% (48/81) showed AF recurrence, and 32.1% (26/81) remained in sinus rhythm (no recurrence). (ii) Failed CV showed higher plasma levels of transforming growth factor (TGF)-beta (P = 0.0260) than those with successful CV. (iii) Patients with AF recurrence were older (60.4 +/- 9.0 years old vs. 55.3 +/- 12.5 years old, P = 0.0220), had a higher incidence of spontaneous echo contrast (SEC; 68.1 vs. 40.0%, P = 0.0106), a lower prescription rate of angiotensin-converting enzyme inhibitor (ACE-I)/angiotensin receptor blocker (ARB; 27.0 vs. 50.0%, P = 0.0248) or spironolactone (0.0 vs. 19.2%, P = 0.0007), and lower plasma levels of stromal cell-derived factor (SDF)-1alpha (P = 0.0105). Post-CV recurrence commonly occurs in patients with age >60 years, SEC, under-utilization of ACE-I/ARB or spironolactone, and low plasma levels of SDF-1alpha. High plasma level of TGF-beta predicts failed CV.

Transvenous electrical cardioversion of atrial fibrillation in six horses using custom made cardioversion catheters

Pharmacological conversion of atrial fibrillation (AF) to sinus rhythm in horses can be difficult. The objective of this study was to investigate the feasibility of transvenous electrical cardioversion with custom made catheters in eight horses, of which three had failed cardioversion using quinidine sulfate. Two cardioversion catheters and one pacing/sensing electrode were inserted via the right jugular vein and placed using ultrasound guidance into the left pulmonary artery, the right atrium and the right ventricle, respectively. Because immediate recurrence of AF was encountered in the second horse treated, pre-treatment with amiodarone was given to each of the remaining six horses. Induction of general anaesthesia was associated with dislocation of the cardioversion catheter in three horses, requiring a second catheterisation procedure. During general anaesthesia, biphasic R wave synchronised shocks of up to 360 J were delivered between both cardioversion electrodes. In six horses (75%), including two which had failed quinidine sulfate treatment, sinus rhythm was restored with a mean energy level of 295 ± 62 J. No side effects were observed. Blood analysis 3 h after cardioversion revealed normal parameters, including cardiac troponin I values. Transvenous electrical cardioversion of atrial fibrillation with custom made cardioversion catheters can be considered as a treatment option for atrial fibrillation in horses, especially when conventional drugs fail.

Prospective Randomized Trial of Transthoracic Versus Low-Energy Internal Cardioversion in Persistent Atrial Fibrillation Long Term Follow-up

Low energy internal cardioversion (ICV) is a relatively new method. This report describes the long-term follow-up results of a prospective randomized comparison of low energy ICV and transthoracic cardioversion (TT CV) in patients with persistent atrial fibrillation (AF). Fifty-two patients (mean age, 60.6 +/- 10.1 years, 23 males) with persistent AF were randomly assigned to either TT (n = 26) or ICV (n = 26). The baseline characteristics of the 2 groups were similar. Transthoracic CV was performed under sedation with hand-held electrodes in the apex-anterior position and high energy (100-360 J) monophasic shocks. ICV was performed by a dedicated balloon-directed catheter utilizing truncated, biphasic shocks of low energy (1-15 J). Sinus rhythm (SR) was restored in 24/26 (92%) patients in the ICV group and in 22/26 (85%) patients in the TT CV group (P > 0.05). Immediate recurrence of AF (IRAF), defined as reappearance of AF within 2 minutes of successful CV, occurred in 5 patients (21%) in the ICV group and in 1 patient (4.5%) in the TT group (P > 0.05). Successfully cardioverted patients in whom no IRAF occurred were followed-up for 18 months under both warfarin and Class 1 or 3 antiarrhythmic drugs, as guided by the current ACC/AHA/ESC Guidelines. The rate of SR at 1, 3, 6, 12, and 18 months of follow-up was not significantly different between the 2 groups, and in an intention-to-treat analysis at 18 months, SR was present in 6 patients (23%) in the ICV group and in 10 patients (38%) in the TT group (P > 0.05). The majority of AF recurrences occurred within a month of successful CV in both groups (8/12 [67%] in the TT group and 15/18 [83%] in the ICV group, P > 0.05). The mortality, thromboembolic, and bleeding complication rates were similar in the 2 groups. In this prospective randomized comparison of TT and low energy ICV in patients with persistent AF, the 18-month rates of SR and major adverse clinical events were found to be similar.

Comparison of acute and long-term effects of single-dose amiodarone and verapamil for the treatment of immediate recurrences of atrial fibrillation after transthoracic cardioversion

Amiodarone and verapamil have been employed to treat immediate recurrences of AF (IRAF) after cardioversion. This study compares the efficacy of these agents for the treatment of IRAF. One hundred and eighty-five patients underwent transthoracic cardioversion (CV) for AF. AF recurred within 10 min in 20 patients (10.8%). These patients were randomized to verapamil (seven patients), or amiodarone (13 patients). After administration of verapamil and repeat CV, five patients (71%) experienced IRAF, compared with seven patients (54%) receiving amiodarone (P = 0.4). Including the results after crossover, IRAF occurred in 8/10 patients (80%) who received verapamil, compared with 7/15 patients (47%) who received amiodarone (P = 0.1). The combination of these agents prevented IRAF in 10/20 patients (50%). After a follow-up of 319+/-189 days, 42% of the IRAF patients treated with verapamil and/or amiodarone remained in sinus rhythm, which did not differ from patients without IRAF (53%, P = 0.7). IRAF occurs in 10% of patients undergoing CV. Amiodarone and verapamil are effective in preventing IRAF and result in a sinus rhythm maintenance rate of 50%. Since there is no difference in the long-term maintenance of sinus rhythm between patients with and without IRAF, attempts to restore sinus rhythm after pharmacological pretreatment are justified.

Electrophysiologic characteristics and catheter ablation in patients with Lewis right atrial fibrillation

Extensive encircling isolation of ipsilateral both pulmonary veins (EEPVI) disconnects linearly the posterior junction between left atrium (LA) and PVs, and segmentally the anterior junction. EEPVI of arrhythmogenic PV (APV) can terminate persitent atrial fibrillation (AF) and prevent AF re-initiation by modifying the electrophysiologic properties of posterior LA-PV junction prior to achievement of PVI. Clinical implication of AF termination during posterior junction ablation of APV in persistent AF (PRAF, defined as not self-terminating) on the outcome of EEPVI was studied. Methods: We performed EEPVI targeting the arrhythmogenic ipsilateral PVs (APV) initially and then remaining couple of PVs at PV-LA junction during ongoing AF in 41 PRAF patients (pts) (mean age: 55 10 years, M / F 32/9), in whom multiple internal cardioversions (CVs) applied to identify APV at the beginning of EEPVI failed in maintaining sinus rhythm (SR) due to immediate recurrence of AF (IRAF). CV was applied again in pts with ongoing AF despite the most parts of posterior junction of APV ablated to disconnect anterior junction in sinus rhythm(late CV). All pts were followed-up without antiarrhythmic medications. Results: During posterior LA-PV junction ablation, AF terminated following organization and slowing of PV and LA electrical activities before APVI achieved in 15 pts (37%), whether repetitive firings from APV remaining or not (group-1). In the remaining 26 pts (63%), AF was terminated by late CV without IRAF before APVI achieved (group-2). In all pts, EEPVI was successfully achieved with sinus rhythm restored. During a mean follow-up of 15 7 months, 14 of 15 group-1 pts were free from AF, while 15 of 26 group-2 pts were free from AF (group-1 vs -2. p 0.015). Conclusions: Termination of ongoing AF during substrate-modification at posterior LA-PV junction appears to be strong predictor of successful outcome of EEPVI for PRAF. This suggests posterior LA-PV junction might be crucial substrates for initiation and perpetuation of AF in some subset of PRAF.

Steady -state and nonsteady-state action potentials in fibrillating canine atrium: Alternans of action potential and late phase 3 early afterdepolarization as a precursor to atrial fibrillation

The mechanism(s) responsible for immediate recurrence of atrial fibrillation (IRAF) after cardioversion is largely unknown. We hypothesized that rapid rates of excitation during atrial fibrillation (AF) induce calcium loading and abbreviate action potential duration (APD), which in turn promote APD alternans and delayed and/or early afterdepolarization after restoration of sinus rhythm.

Amiodarone versus Sotalol and Propafenone for prevention of immediate recurrence of atrial fibrillation after internal cardioversion: Importance of P wave analysis

Electrical cardioversion has become a routine procedure in converting chronic atrial fibrillation (AF) to sinus rhythm (SR). External and intra-atrial shocks are given in an attempt to convert AF to SR with a higher acute success rate of intra-atrial shocks but similar long-term recurrence rates of AF [1]. Despite successful conversion of AF to SR, immediate recurrence of AF (IRAF) after cardioversion is a major and largely unpredictable clinical problem and, little is known about preventive strategies of IRAF following the use of either one of these techniques [2–5].

Determinants and Prognostic Significance of Immediate Atrial Fibrillation Recurrence Following Cardioversion in Patients Undergoing Pulmonary Vein Isolation

Immediate recurrence of atrial fibrillation (IRAF) occurs frequently after electrical cardioversion, its electrophysiological determinants and prognostic significance have, however, not been studied in detail. This study aimed to explore (1) the association of IRAF with clinical characteristics, pulmonary vein (PV) arrhythmogenicity as well as atrial electrophysiologic properties and (2) the prognostic significance of IRAF for outcome of PV isolation for atrial fibrillation (AF). The subjects of this study were 41 consecutive patients (30 males, 11 females) who underwent PV isolation for drug-refractory AF. Following successful initial cardioversion, 19 patients (46%) had IRAF within 2 minutes. Coupling intervals of AF reinitiating beats arising from PVs were shorter (386 +/- 39 vs 490 +/- 136 ms, P = 0.008) and prematurity indices (0.38 +/- 0.06 vs 0.51 +/- 0.12, P = 0.01) smaller than those of premature beats not initiating AF. Patients with IRAF had more frequently AF duration <1 month, a longer P-wave duration, and a longer mid coronary sinus AF cycle length. Multivariate regression analysis revealed coronary sinus AF cycle length (beta= 0.186, P = 0.049), which was closely correlated with conduction time along the coronary sinus (R = 0.716, P = 0.003) to be independently associated with IRAF. While early AF recurrence rate (within the first 5 days) following the procedure was higher in the IRAF group (53 vs 18%, P = 0.02), outcome was not different between the two groups thereafter. (1) IRAF is common in patients undergoing PV isolation for AF, (2) is initiated by premature atrial beats with short coupling intervals, and (3) seems to be associated with conduction disturbances along the coronary sinus. It reflects susceptibility of arrhythmia recurrence within the first 5 days after the procedure, but not thereafter.

Mechanism of immediate recurrences of atrial fibrillation after restoration of sinus rhythm.

An immediate recurrence of AF may occur after restoration of sinus rhythm. Although pulmonary vein (PV) isolation has been shown to prevent immediate recurrence of AF, the specific trigger for immediate recurrence of AF has not been described. In 89 consecutive patients (mean age 53 +/- 11 years) who had sinus rhythm restored by spontaneous or transthoracic cardioversion in the course of a PV isolation procedure, electrograms recorded within a PV and in the adjacent left atrium were analyzed to determine the mechanism of initiation of immediate recurrence of AF. Immediate recurrence of AF was defined as a recurrence of AF within 90 seconds after restoration of sinus rhythm. There were 124 episodes of immediate recurrence of AF at a mean of 18 +/- 23 seconds after cardioversion. Recordings within the PV that triggered the immediate recurrence of AF were available in 23 (19%) of the 124 immediate recurrence of AF episodes. Among these 23 episodes of immediate recurrence of AF, all (100%) were triggered by a burst of PV tachycardia (P < 0.001). The coupling interval and prematurity index (coupling interval/preceding sinus cycle length) of the premature depolarizations that did and did not trigger immediate recurrence of AF were 246 +/- 67 ms and 0.30 +/- 0.11 vs 378 +/- 117 ms and 0.49 +/- 0.16, respectively (P < 0.01). Immediate recurrence of AF was abolished by PV isolation. The mechanism of immediate recurrence of AF is a burst of PV tachycardia, not a single premature depolarization. Immediate recurrence of AF identifies patients with AF in whom the PVs may play a major role in the initiation of AF.

Effect of Atrial Fibrillation Duration on Probability of Immediate Recurrence after Transthoracic Cardioversion

An immediate recurrence of atrial fibrillation (IRAF) appears to be more common after early restoration of sinus rhythm with an implantable atrial defibrillator than after elective transthoracic cardioversion, which suggests that the probability of IRAF may be related to the duration of AF. Transthoracic cardioversion was performed 85 +/- 187 days (range 7 minutes to 8 years) after the onset of atrial fibrillation in 315 patients (mean age 61 +/- 13 years). IRAF was defined as a recurrence of AF within 60 seconds after restoration of sinus rhythm. IRAF occurred in 56% of patients when cardioversion was performed within 1 hour of the onset of AF compared with 12% of patients when cardioversion was performed after 24 hours of AF (P < 0.001). The duration of AF was the only independent predictor of IRAF among the clinical variables of age, gender, structural heart disease, antiarrhythmic drug therapy, and cardioversion energy (P < 0.01). IRAF is more likely to occur when the duration of AF is <1 hour than when the duration is >24 hours. This observation has clinical implications for the most appropriate timing of cardioversion, particularly in patients who receive device therapy for AF.

Long-short sequence may predict immediate recurrence of atrial fibrillation after external cardioversion.

We thought, that analysis of surface electrocardiograms recorded immediately after electrical external cardioversion (EC) might enlighten the mechanisms responsible for immediate recurrence of atrial fibrillation (AF) and especially to test whether atrial ectopic beats (PAC) with long-short (LS) sequence are related to the recurrence of arrhythmia after cardioversion in patients with chronic AF. One hundred and thirty-seven patients (mean age 57+/-7 years) undergoing EC for chronic AF entered the study. Evaluation of the patients included clinical history, physical examination, ECG, routine laboratory tests, and transthoracic echocardiography. The cardioversion was performed with monophasic waveform shock and immediately after successful EC, 1 min of recording of the ECG lead II was analysed. One hundred and twenty patients (87%) of 137 patients enrolled in the study had had successful EC and 33 (27%) of them experienced immediate recurrence of AF within 1 min (Group I) and 87 patients had no arrhythmia recurrence (Group II). In group I in 24 patients (73%) recurrence of AF was initiated by PAC with LS sequence. In only 12 of 87 (13%) patients who did not experience immediate recurrence of AF (Group II) PACs were recorded. Atrial ectopic beats (PACs) with LS sequence, being responsible for AF relapse in about 70% of patients, might predict early re-initiation of arrhythmia after EC. Electrocardiograms, recorded immediately after EC, are a potentially feasible approach in establishing the patterns of AF relapse that may be useful in the management of AF recurrence.