Symptomatic Persistent Atrial Fibrillation Research Articles

Atrial Flutter with Alternating Cycle Lengths: Mechanism and Mapping

A 69-year-old woman with a 10-year history of paroxysmal atrial fibrillation was initially treated with propafenone and amiodarone. Four years ago her arrhythmia burden worsened and she developed recurrent episodes of symptomatic persistent atrial fibrillation. After several cardioversions, she was referred to our institution for radiofrequency catheter ablation. Her amiodarone was discontinued, and 1 year ago she underwent radiofrequency catheter ablation using a pulmonary vein antral isolation approach. Unfortunately, she developed recurrent atrial fibrillation and remained extremely symptomatic despite adequate control of her heart rate. Six months ago, she underwent a second radiofrequency catheter ablation procedure. Electrophysiology study revealed recurrent conduction between all four pulmonary veins and the left atrium, and the veins were reisolated and linear ablations were performed on the roof of the left atrium and the cavotricuspid isthmus. After the ablation, no atrial tachycardia or atrial fibrillation could be induced with aggressive pacing protocols. Unfortunately, she developed recurrent persistent atrial fibrillation within 1 week of the procedure. Four months later she underwent cardioversion with initiation of dofetilide. Two days after starting dofetilide she developed atypical atrial flutter and was referred for a third electrophysiology study. Surface ECG revealed upright P waves in leads V1 and V2 but were poorly seen in the other leads. At electrophysiology study, a circular mapping catheter placed in the four pulmonary veins demonstrated no electrical activity during atrial tachycardia, confirming adequate pulmonary vein isolation. At baseline the atrial tachycardia had stable alternating cycle lengths of 365 ms and 410 ms. Initial pacing maneuvers from the anterolateral right atrium and the proximal and distal coronary sinus yielded post-pacing intervals with long return cycle lengths. In addition, constant fusion and progressive fusion during pacing from the right atrium and the coronary sinus were observed. In order to delineate the tachycardia circuit a 64-electrode basket catheter was placed in the posterior left atrium (Figure 1). At baseline, electrograms could be recorded for 318 ms of the 363-ms and 411-ms cycle lengths (88% and 77% respectively) over a large area in the posterior left atrium. The deflection of the P wave corresponded to activation of the superior and anterior portions of the left atrium. We mapped the tachycardia circuit by identifying the initial site of cycle length change that localized the critical isthmus to the posterior roof of left atrium near the right superior pulmonary vein (Figure 2). When the mapping catheter was moved septally or laterally, split potentials suggestive of a line of conduction block were observed and a 20-electrode catheter revealed a fractionated electrogram that was the first site of cycle length change. Unfortunately, adequate capture could not be obtained despite pacing at maximal outputs from either electrode pair 17 and 18 of the 20-electrode reference catheter or an ablation catheter placed at the same fluoroscopic site. In addition, despite maximal gains, low amplitude electrograms could not be recorded with the The authors report no conflicts of interest for the published content. Manuscript received January 23, 2012, final version accepted February 13, 2012. Address correspondence to: Fred M. Kusumoto, MD, Electrophysiology and Pacing Service, Division of Cardiovascular Disease, Mayo Clinic, 4500 San Pablo Ave, Jacksonville, FL 32224. E-mail: Kusumoto.fred@mayo.edu The Journal of Innovations in Cardiac Rhythm Management, 3 (2012), 727–730

EFFICACY OF ANTIARRHYTHMIC DRUGS FOR ATRIAL FIBRILLATION IS DIFFERENTLY DEPENDENT ON LEFT ATRIAL REMODELING

Objectives: The association between the efficacy of AADs and LA size in AF management remains unclear. Methods: 383 patients with symptomatic paroxysmal or persistent AF (PeAF) (282 male, 59±12 years), who were treated with class Ic drug (n=343; flecainide, n=336 or propafenone, n=54) or amiodarone (n=155), were analyzed. Results: 165 (48%) did not respond to class Ic drug and 92 (59%) did not to amiodarone. Class Ic drug failure group had more PeAF (39% vs 14%, p 41 mm (61% vs 44%, p 0.05). Amiodarone failure group had more PeAF (49% vs 29%, p 0.05). PeAF (OR 4.5, 95% CI: 2.588∼7.823, p 41 mm (OR 1.7, 95% CI: 1.057∼2.703, p=0.03) were independent predictors of class Ic drug failure, whereas only PeAF was an independent predictor of amiodarone failure. Class Ic drug failure rates in paroxysmal AF with LAd 41 mm, PeAF with LAd 41 mm were 33%, 45%, 70% and 77% respectively (p<0.01). Conclusions: The efficacy of class Ic AADs was dependent on LA size and AF type synergistically, whereas the efficacy of amiodarone was not associated with LA size.

A rare complication from transseptal puncture-persistent aorto-right atrial shunt and puncture of noncoronary cusp of aortic valve

v A 62-year-old lady presented with symptomatic persistent atrial fibrillation. An attempt at left atrial ablation (LAA) was abandoned following difficulty in performing transseptal puncture under fluoroscopic guidance alone and concern that the puncture had caused right atrial puncture into the pericardial space. Echocardiography at the time demonstrated a small rim of pericardial fluid that was managed conservatively. Left ventricular pressure readings noted at the time were felt to represent the catheter having crossed the mitral valve following left atrial puncture during this compli-

Loss of the tip of a transseptal needle in the heart

A 71-year-old male with highly symptomatic persistent atrial fibrillation for 6 years (EHRA III) was admitted for pulmonary vein isolation after failure of antiarrhythmic drug therapy. After vascular access, a steerable decapolar catheter was placed into the coronary sinus via the left femoral vein (Livewire®, St Jude Medical, …

Effect of Telmisartan and Ramipril on Atrial Fibrillation Recurrence and Severity in Hypertensive Patients With Metabolic Syndrome and Recurrent Symptomatic Paroxysmal and Persistent Atrial Fibrillation

This study evaluated the effect of telmisartan, ramipril, and amlodipine on atrial fibrillation (AF) recurrence and severity in hypertensive patients with metabolic syndrome. A total of 391 hypertensive outpatients with metabolic syndrome, in sinus rhythm but with at least 2 episodes of AF in the previous 6 months were randomized to telmisartan, ramipril, or amlodipine for 1 year. At the first AF, ventricular rate (VR) and plasma cardiac troponin I (TnI) were evaluated. P-wave dispersion (PWD) and procollagen type I carboxy-terminal peptide (PIP) were evaluated before and after 12 months of treatment. Systolic blood pressure (SBP) and diastolic blood pressure (DBP) were similarly and significantly reduced by all treatments (P < .001). In all, 49% of patients treated with amlodipine had a recurrence of AF as did 25.5% of patients with ramipril and 12.9% of patients with telmisartan (P < .01 vs amlodipine and P < .05 vs ramipril). Ventricular rate and TnI at the first AF recurrence were significantly lower with telmisartan and ramipril than with amlodipine. P-wave dispersion was reduced by ramipril (-5.1 ms, P < .05) and even more by telmisartan (-11 ms, P < .01). Telmisartan and ramipril induced a similar PIP reduction (-52.8 and -49.8 µg/L, respectively, P < .01). These findings suggested that in these patients telmisartan was more effective than ramipril in reducing AF recurrence and severity as well as in improving PWD, despite a similar BP reduction and a similar improvement in cardiac fibrosis. This could be related to a specific effect of telmisartan on atrial electric remodeling.

Catheter ablation of persistent atrial fibrillation: anatomically based circumferential pulmonary vein ablation in combination with a potential-guided segmental approach to achieve complete pulmonary vein isolation

Catheter ablation has become the first line of therapy in patients with symptomatic, recurrent, drug-refractory atrial fibrillation. However, catheter ablation of persistent atrial fibrillation is still a challenge. Various rather complex ablation strategies exist and their results are not very favorable. Therefore, the aim of our study was to evaluate a well-defined reasonable approach to catheter ablation of persistent atrial fibrillation. The strategy consisted of a circumferential pulmonary vein ablation in combination with a potential-guided segmental approach to achieve complete pulmonary vein isolation and a linear lesion at the roof of the left atrium. A total of 43 patients (30 men, 13 women; mean age 55 years (SD ± 9 years)) with symptomatic persistent atrial fibrillation were enrolled in this study. All patients underwent catheter ablation of persistent atrial fibrillation using the above-mentioned approach (with the CARTO or the NAVX system). Additionally, catheter ablation of the mitral isthmus and the right atrial isthmus was performed in selected cases. In all patients, cardiac MRI or multi-detector spiral computed tomography was performed prior to the ablation procedure and a surface rendered model of the left atrium was created. After discharge, patients were scheduled for repeated visits at the arrhythmia clinic at 1, 3, 6, 9, and 12 months after the ablation procedure. The ablation procedure could be performed as planned in all 43 patients. Nine patients had to undergo a repeat ablation procedure, so that a total of 52 procedures were evaluated. An additional linear lesion was created at the mitral isthmus in three patients (7%) during the initial procedure and in one patient (2.3%) during the second procedure. Catheter ablation of the right atrial isthmus was performed in 11 patients (25.6%) during the first procedure and in four additional patients during the redo procedure (9.3%). Twenty-four out of 43 patients (55.8%) experienced an arrhythmia recurrence within the first 3 months after ablation requiring an electrical cardioversion. At 1-year follow-up, analysis of a 7-day Holter monitoring revealed no evidence for an arrhythmia recurrence in 26 of 43 patients (60.5%). In nine of 43 patients (20.9%), only short episodes of paroxysmal atrial fibrillation were documented. In eight patients (18.6%), a recurrence of persistent atrial fibrillation (>48 h) was revealed by the long-term recordings. A duration of persistent atrial fibrillation >3 months was the most powerful predictor for arrhythmia recurrences at 1-year follow-up. A subgroup analysis revealed a markedly higher rate of stable sinus rhythm at 1-year follow-up in patients with a short duration of atrial fibrillation (≤ 3 months) compared to patients with a longer duration of AF (>3 months) prior to the procedure (72.0% versus 44.4%). There were no major complications. Catheter ablation of persistent atrial fibrillation can be performed safely and effectively using this ablation strategy (especially in patients with short-lasting persistent atrial fibrillation (≤ 3 months)).

Chaotic Activity with Low Frequency Vibration in Fibrillary Waves Predicts AF Recurrence after Cardioversion in Patients with Persistent Atrial Fibrillation

Background: We hypothesized that mathematical analysis of atrial fibrillary waves may predict recurrence of atrial fibrillation (AF) after cardioversion. Methods: We included 51 patients with symptomatic persistent AF (40 males, 57±8 years). All patients were assessed by holter and echocardiography within 3 months before cardioversion. We extracted only atrial fibrillary waves from V1 lead in holter and measured three parameters including approximate entropy (Aprx), Lyapunov-exponent (Lya) and center-frequency (Cent) to quantify entropy, chaotic activity and frequency, respectively. Recurrence was defined as AF episodes documented by EKG/holter within 30 days after cardioversion. Results: The patients with recurrence (n=25) had higher Lya than those without recurrence (n=22) (0.258±0.157 vs 0.161±0.148, p=0.036), whereas Aprx was not related to recurrence (p>0.05). The patients with Lya≥0.05 had more recurrence than those with Lya<0.05 (64% vs 18%, p=0.008), and the patients with Cent<7.0 had more recurrence than those with high Cent≥7.0 (68% vs 35%, p=0.021). All patients were divided into three groups; group A, the patients with high-Lya and low-Cent, group B, those with high-Lya or low-Cent, group C, those with low-Lya and high-Cent. Group A showed more recurrence than group B, and group B did more recurrence than group C. By logistic regression, Lya and Cent scale were strong independent predictors of recurrence (OR=6.9, CI: 95% 2.0∼23.5, p=0.002). Conclusions: Chaotic activity with low frequency in fibrillary waves could predict AF recurrence within 1 month after cardioversion.

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.

Feasibility and Usefulness of Catheter Ablation for Atrial Fibrillation Using the Navx System

The aim of this study was to investigate the feasibility and usefulness of catheter ablation for atrial fibrillation (AF) guided by the NavX system. Thirty-nine patients (28 male, 60.9±8.4 years) who underwent radiofrequency catheter ablation with symptomatic paroxysmal (n=25), persistent (n=7) or long-lasting (n=7) AF were investigated. In all patients, extensive encircling pulmonary vein isolation (EEPVI) was performed after constructing the three-dimensional (3D) geometry of left atrium and four PVs, and fusion with CT imaging using the NavX system. When AF persisted, or AF or atrial tachycardia (AT) was induced by atrial burst pacing after bilateral EEPVI, complex fractionated atrial electrogram (CFAE) ablation and/or left atrial linear ablation was added. Simultaneous mapping by multipolar catheter in the NavX system was able to construct 3D activation map or CFAE map quickly, and helpful in detecting the gap of PVI or linear ablation line, or identifying CFAE areas. After a mean follow-up period of 7.1±4.4 months, 29 (74.3%) patients (18 in paroxysmal, 6 in persistent, 5 in long-lasting) were free of arrhythmia and symptoms (21 without antiarrhythmic agents (AA), 8 with AA), 27 after one session and 2 after two sessions. In conclusion, catheter ablation using NavX is feasible and useful for curing AF patients.

Efficacy of Antiarrhythmic Drugs for Atrial Fibrillation Is Differently Dependent on Left Atrial Remodeling

Objectives: The association between the efficacy of AADs and LA size in AF management remains unclear. Methods: 383 patients with symptomatic paroxysmal or persistent AF (PeAF) (282 male, 59±12 years), who were treated with class Ic drug (n=343; flecainide, n=336 or propafenone, n=54) or amiodarone (n=155), were analyzed. Results: 165 (48%) did not respond to class Ic drug and 92 (59%) did not to amiodarone. Class Ic drug failure group had more PeAF (39% vs 14%, p 41 mm (61% vs 44%, p 0.05). Amiodarone failure group had more PeAF (49% vs 29%, p 0.05). PeAF (OR 4.5, 95% CI: 2.588∼7.823, p 41 mm (OR 1.7, 95% CI: 1.057∼2.703, p=0.03) were independent predictors of class Ic drug failure, whereas only PeAF was an independent predictor of amiodarone failure. Class Ic drug failure rates in paroxysmal AF with LAd 41 mm, PeAF with LAd 41 mm were 33%, 45%, 70% and 77% respectively (p<0.01). Conclusions: The efficacy of class Ic AADs was dependent on LA size and AF type synergistically, whereas the efficacy of amiodarone was not associated with LA size.

Selective CFAE Targeting for Atrial Fibrillation Study (SELECT AF): Clinical Rationale, Design, and Implementation

Adjuvant ablation of complex fractionated atrial electrograms (CFAE) in addition to pulmonary vein isolation (PVI) likely improves procedural outcome compared to PVI alone, particularly in patients with persistent atrial fibrillation (AF). However, CFAE regions can be extensive, occasionally requiring a large amount of extra ablation. Some CFAE regions may also represent passive wavefront collision and may not require ablation. Thus, there is interest in identifying more selective CFAE sites that are critical to AF perpetuation, minimizing the amount of adjuvant ablation that must be performed. The SELECT AF study is a prospective, multicenter, randomized trial comparing a strategy of PVI plus generalized CFAE ablation versus a strategy of PVI plus selective CFAE ablation, focusing on regions of continuous electrical activity (CEA). The primary efficacy endpoint is freedom from atrial arrhythmia at 1 year and the primary safety endpoint is total radiofrequency (RF) delivery time per procedure. Patients undergoing a first time ablation procedure for symptomatic persistent AF will be included. Patients with permanent AF or with left atrial size ≥55 mm will be excluded. Patients will all receive PVI at the time of their ablation, but will be randomized 1:1 to receive adjuvant CFAE ablation using the traditional "generalized" approach, or a "selective" approach targeting only CEA regions. Both strategies will be guided by automated mapping algorithms. This study will enroll a minimum of 80 evaluable subjects; 40 in each randomization group. SELECT AF is a randomized trial in patients with persistent AF to evaluate the efficacy of selective versus generalized CFAE ablation in addition to traditional PVI.

Persistent Atrial Fibrillation Converts to Common Type Atrial Flutter during CFAE Ablation

Catheter ablation of persistent and long-standing persistent atrial fibrillation (AF) is still challenging. So far different ablation techniques have been reported, including pulmonary vein isolation, additional linear lesions, ablation of complex fractionated atrial electrograms (CFAE), and combinations of these techniques. During ablation of CFAE, the occurrence of left atrial (LA) tachycardia is well known. The occurrence of right atrial flutter on the other hand is less well described. Here, we report three patients who had been ablated because of symptomatic persistent atrial fibrillation. In all patients, AF changed into a cavotricuspid isthmus = dependent right atrial flutter during ablation of CFAE in the LA.

Paroxysmales und persistierendes Vorhofflimmern: Neue Therapiekonzepte der Pulmonalvenen-Isolation

Interventional therapy of atrial fibrillation (AF) is often associated with long examination- and fluoroscopy times. The use of mapping catheters in addition to the ablation catheter requires multiple transseptal sheets for left atrial access. The HDMA was introduced in 2007 for the the segmental and circumferentil ablation of paroxysmal atrial fibrillation. In small experimental study groups the new catheter system was validated for its electrophysiological properties. The purpose of this prospective study was to evaluate feasibility and safety of pulmonary vein (PV) isolation using the High Density Mesh Ablator (HDMA), a novel single, expandable electrode catheter for both mapping and radiofrequency (RF) delivery at the left atrium/PV junctions. 40 patients with highly symptomatic paroxysmal AF (PAF, 23/57,5 %) and persistent AF (CAF, 17/42,5 %) were studied. PV isolation via the HDMA was performed using a customized pulsed RF energy delivery program (target temperature 55 - 60 degrees, power 70 - 100 Watt, 600 - 1000 seconds RF application time/PV). All 158 PV in 40 patients could be mapped and ablated by the HDMA. Segmental PV isolation was achieved with a mean of 3,75 +/- 1,9 RF applications for a mean of 715 +/- 375 sec. Entrance conduction block was obtained in 93,5 % of all PV. Mean total procedure and fluoroscopy time was 152 +/- 34 min and 29 +/- 10 min respectively. None of the patients experienced severe complications. After 3 month 78 % of the patients with PAF and 41 % with CAF respectively were free of AF. In this first study of PV isolation using the HDMA, our findings suggest that this method is feasible, and yields good primary success rates. Due to single transseptal access the HDMA simplifies the complex procedure of AF ablation, favorably impacting procedure and fluoroscopy times.

Frequenzkontrolle versus Rhythmuskontrolle mit und ohne Herzinsuffizienz

Atrial fibrillation and congestive heart failure are frequently associated with complex interactions. Patients with both diseases bear a sophisticated therapeutic challenge for the attending physician. The approach to treat atrial fibrillation differs for patients with and without heart failure in several aspects. Basic requirements are the treatment of the underlying diseases and prophylaxis of thromboembolic complications. Rate and rhythm control are the two main therapeutic strategies for atrial fibrillation according to the current guidelines. Large trials including the recently published AF-CHF study (Atrial Fibrillation - Congestive Heart Failure) failed to demonstrate a difference in mortality for both strategies. Thus, the therapeutic decision is mainly based on the patient's symptoms to improve quality of life. Rate control should be applied to asymptomatic patients or if rhythm control has already failed. If beta-blockers and digoxin have failed to control heart rate, His ablation with pacemaker implantation can be considered. In patients without heart disease, class I antiarrhythmic drugs and, in case of ineffectiveness, amiodarone or catheter ablation are recommended for rhythm control. First data concerning catheter ablation of atrial fibrillation in heart failure are promising and randomized studies are on the way. Rhythm control remains first-line therapy in recent-onset or highly symptomatic paroxysmal or persistent atrial fibrillation patients with and without heart failure.

Abstract 4109: First experiences for Pulmonary Vein Isolation with the High Density Mesh Ablator

Interventional therapy of atrial fibrillation (AF) still is a complex procedure often associated with long examination- and fluoroscopy times. The use of mapping catheters in addition to the ablation catheter requires multiple transseptal sheats for left atrial access. The purpose of this prospective study was to evaluate feasibility and safety of pulmonary vein (PV) isolation using the high density mesh ablator (HDMA), a novel single, expandable electrode catheter for both mapping and radiofrequency (RF) delivery at the left atrium/PV junctions. 26 patients (PTS) with highly symptomatic paroxysmal AF (14, 53.8%) and persistent AF (12, 46.2%) were studied. Segmental PV isolation via the HDMA was performed using a customized pulsed RF energy delivery program (target temperature 55– 60 degrees, power 70 –100 Watt, 600 –900 seconds RFapplication time/PV). All 104 PV in 26 PTS could successfully be ablated by the HDMA. Segmental PV isolation was achieved with a mean of 3.25±1.4 RF applications for a mean of 603±185 sec. Entrance conduction block was obtained in &gt;94% of all PV. Mean total procedure and fluoroscopy time was 159.0±32 min and 33.5±8.6 min respectively. None of the PTS experienced severe complications. In this first study of PV isolation using the HDMA, our findings suggest that this method is safe and yields good primary success rates. Anatomical orientation and signal quality were good, allowing for excellent electrophysiological control. The HDMA simplifies the complex procedure of AF ablation, favorably impacting procedure and fluoroscopy times. Further studies are required to assess the long-term outcome.

Continuous vs Episodic Prophylactic Treatment With Amiodarone for the Prevention of Atrial Fibrillation

Amiodarone effectively suppresses atrial fibrillation but causes many adverse events. To compare major events in patients randomized to receive episodic amiodarone treatment with those who received continuous amiodarone treatment while still aiming to prevent atrial fibrillation. A randomized trial of 209 ambulatory patients with recurrent symptomatic persistent atrial fibrillation, conducted from December 2002 through March 2007 at 7 Dutch medical centers. Patients were randomly assigned to receive either episodic or continuous amiodarone treatment after electrical cardioversion following amiodarone loading. Episodic amiodarone treatment was discontinued after a month of sinus rhythm and reinitiated if atrial fibrillation relapsed (1 month peri-electrical cardioversion). In the continuous treatment group amiodarone was maintained throughout. The primary end point was a composite of amiodarone and underlying heart disease-related major events. The secondary end points were all-cause mortality and cardiovascular hospitalizations. After a median follow-up of 2.1 years (range, 0.4-2.5 years), 51 (48%) of those receiving episodic treatment vs 64 (62%) receiving continuous treatment had sinus rhythm (P = .05). There were 85 atrial fibrillation recurrences (80%) among the episodic treatment group vs 56 (54%) in the continuous treatment group (P < .001). No significant difference existed in the incidence of the primary composite end point between each group (37 [35%] episodic vs 34 [33%] continuous; incidence rate difference, 0.2; 95% confidence interval [CI], -10.2 to 10.6). However, there were nonstatistically significant differences in the incidence of amiodarone-related major events (20 [19%] episodic vs 25 [24%] continuous; incidence rate difference, -2.0; 95% CI, -8.7 to 4.6) and underlying heart disease-related major events (17 [16%] episodic vs 9 [9%] continuous; incidence rate difference, 3.6; 95% CI, -1.6 to 8.7). All-cause mortality and cardiovascular hospitalizations were higher among those receiving episodic treatment (56 [53%] vs 35 [34%], P = .02). In this study population, there was no difference in the composite of amiodarone and cardiac major adverse events between groups. However, patients receiving episodic treatment had a significantly increased rate of atrial fibrillation recurrence and a significantly higher rate of all-cause mortality and cardiovascular hospitalizations. clinicaltrials.gov Identifier: NCT00392431.

Is atrial fibrillation with very short cycle length suitable for ablation? A case report

We present a case of a 36-year-old woman with highly symptomatic persistent atrial fibrillation (AF) refractory to sotalol, flecainide, and external direct current (DC) cardioversion. The patient underwent biatrial mapping and ablation procedure for AF. Both atria were characterized by refractory properties which were much shorter than reported previously. Global fibrillatory activity was present with a median cycle length of 120 ms (range: 62-143). Extensive map-guided ablation sets had to be delivered to both left and right sides before effective DC cardioversion enabled sinus rhythm (SR) restoration. The patient remained in SR at 9 months of follow-up.

Impact of “hybrid therapy” on long-term rhythm control and arrhythmia related hospitalizations in patients with drug-refractory persistent and permanent atrial fibrillation

Recently, a "hybrid therapy" strategy has been used for successful rhythm control in persistent and permanent atrial fibrillation (AF) patients. The impact of this strategy on arrhythmia recurrences and subsequent AF related hospitalizations are unknown. Forty-seven patients (66 +/- 10 years) with symptomatic persistent (N = 26) or permanent (N = 21) AF underwent "hybrid therapy" and were followed for 24 +/- 15 months. All patients underwent linear right atrial ablation and implantation of pacemaker or atrioventricular defibrillator (AVICD) capable of continuous right atrial pacing with previously ineffective antiarrhythmic drug therapy for AF prevention. Device data-logs were used to monitor AF recurrences. Freedom from permanent AF was 97, 90, and 83% at 6 months, 2 and 3 years, respectively. Sixteen patients (34%) had no recurrent AF after "hybrid therapy." Thirty-one patients (66%) had a total of 55 AF recurrences (mean 1.8 per patient). There was a significant reduction in the mean AF related hospitalizations (from 3.5 +/- 2.8 to 0.57 +/- 1.1 per patient), cardioversion hospitalizations (from 3.5 +/- 2.2 to 0.38 +/- 0.5 per patient) and DC cardioversions (from 3.1 +/- 3.9 to 0.7 +/- 0.5 per patient) after hybrid therapy compared to event rates before therapy (p < 0.05 for all). Rhythm control improves significantly with hybrid therapy in patients with persistent and permanent AF refractory to drugs and cardioversion therapy. This improvement is associated with a significant reduction in AF related hospitalizations and need for cardioversion therapy.

Azimilide vs. placebo and sotalol for persistent atrial fibrillation: the A-COMET-II (Azimilide-CardiOversion MaintEnance Trial-II) trial

Treatment of atrial fibrillation remains a major clinical challenge owing to the limited efficacy and safety of anti-arrhythmic drugs, particularly in patients with structural heart disease. To evaluate the efficacy of azimilide, a new class III anti-arrhythmic drug, we studied 658 patients with symptomatic persistent atrial fibrillation, adequate anticoagulant therapy, and planned electrical cardioversion. Patients were randomized to placebo, azimilide (125 mg o.d.), or sotalol (160 mg b.i.d.). Primary efficacy analysis was based on event recurrence, which was defined as atrial fibrillation lasting>24 h, or requiring DC cardioversion. Median time to recurrence was 14 days for azimilide, 12 days for placebo, and 28 days for sotalol (P=0.0320 when comparing azimilide with placebo; P=0.0002 when comparing azimilide with sotalol). The placebo-to-azimilide hazard ratio was 1.291 (95% CI: 1.022-1.629) and the sotalol-to-azimilide hazard ratio was 0.652 (95% CI: 0.523-0.814). Adverse events causing patient withdrawal were more frequent (P<0.01) in patients on azimilide (12.3%) and on sotalol (13.9%) than on placebo (5.4%). Eight patients in the sotalol (3.5%) and 16 in the azimilide (7.6%) group interrupted the study because of QTc prolongation. Torsade de pointes was reported in five patients of the azimilide group. The percentage of patients who completed the 26 week study period without events were 19% for azimilide, 15% for placebo, and 33% for sotalol (P<0.01). Unsuccessful day 4 cardioversion, arrhythmia recurrence, and adverse events were the main causes of withdrawal from the study. This study demonstrates that the anti-arrhythmic efficacy of azimilide is slightly superior to placebo but significantly inferior to sotalol in patients with persistent AF. The modest anti-arrhythmic efficacy and high rate of torsade de pointes and marked QTc prolongation limit azimilide utilization for the treatment of AF.

AB29-1: Atriobronchial fistula formation as a devastating complication of left atrial catheter ablation for atrial fibrillation

A 53 y/o male was referred for catheter ablation for atrial fibrillation (AF). He had symptomatic persistent AF. He had failed medications and had prior segmental pulmonary vein isolation at another center 4 yrs prior. He was admitted for wide area circumferential ablation with CARTO mapping. The procedure was done under deep sedation. 133 applications of RF energy were applied with a 4 mm tip ablation catheter. Generator settings of 30W and 50C were used, with times not exceeding 40s (average 25.7s) targeting 50% reduction in egm height. Coughing did not occur during the procedure. Heparin was administered IV during for an ACT of 300s and was continued afterwards. The procedure went well without incident. The patient was discharged on post-operative day one. He presented the next day with steadily increasing hemoptysis for 18 hrs. He was intubated and underwent bronchoscopy. Bleeding was seen be coming from either the left upper or lingular lobe. He was irrigated with local epinephrine and clotting factor and the bleeding stopped. He did well for 2 days, and then started bleeding again. Intermittent bleeding and cessation occurred over the ensuing nine days. He then underwent surgical exploration via a left lateral thoracotomy. A clear fistula was identified from the superior-posterior aspect of the left superior pulmonary vein ostium, which was closed. However, the patient became unstable due to hypoxemia and arrested on post-operative day one.