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We read with interest the letters by Kosiuk et al, Skolnik, Turco, Liu and Yang, and Willey and Biviano. We thank these authors for their interest in our study. We agree with Kosiuk et al that the restoration of sinus rhythm in patients with heart failure and persistent atrial fibrillation (AF) is key to improving ejection fraction and 6-minute walk distance, and we agree with the authors’ data showing a reduction of inappropriate shocks attributable to atrial arrhythmias in patients undergoing ablation.1 Unfortunately, in our trial,2 we did not prospectively collect implantable cardioverter defibrillator inappropriate shocks, and we will not be able to provide solid data. We respectfully disagree with the idea of Dr Skolnik. As mentioned in the discussion and in the clinical perspective of the article, we are not proposing AF ablation in all patients with heart failure, but we are suggesting that this underused therapeutic approach is considered more and more in patients with heart failure.2 The PABA CHF (Comparison of Pulmonary Vein Isolation Versus AV Nodal Ablation With Biventricular Pacing for Patients With Atrial Fibrillation With Congestive Heart Failure) trial,3 although small, showed little improvement with the atrioventricular node ablation and cardiac resynchronization therapy (CRT) device implantation in comparison with ablation. In …

Background— Together with pulmonary veins, many extrapulmonary vein areas may be the source of initiation and maintenance of atrial fibrillation. The left atrial appendage (LAA) is an underestimated site of initiation of atrial fibrillation. Here, we report the prevalence of triggers from the LAA and the best strategy for successful ablation. Methods and Results— Nine hundred eighty-seven consecutive patients (29% paroxysmal, 71% nonparoxysmal) undergoing redo catheter ablation for atrial fibrillation were enrolled. Two hundred sixty-six patients (27%) showed firing from the LAA and became the study population. In 86 of 987 patients (8.7%; 5 paroxysmal, 81 nonparoxysmal), the LAA was found to be the only source of arrhythmia with no pulmonary veins or other extrapulmonary vein site reconnection. Ablation was performed either with focal lesion (n=56; group 2) or to achieve LAA isolation by placement of the circular catheter at the ostium of the LAA guided by intracardiac echocardiography (167 patients; group 3). In the remaining patients, LAA firing was not ablated (n=43; group 1). At the 12±3-month follow-up, 32 patients (74%) in group 1 had recurrence compared with 38 (68%) in group 2 and 25 (15%) in group 3 ( P Conclusions— The LAA appears to be responsible for arrhythmias in 27% of patients presenting for repeat procedures. Isolation of the LAA could achieve freedom from atrial fibrillation in patients presenting for a repeat procedure when arrhythmias initiating from this structure are demonstrated.

Background— Catheter ablation of atrial fibrillation is associated with the potential risk of periprocedural stroke, which can range between 1% and 5%. We developed a prospective database to evaluate the prevalence of stroke over time and to assess whether the periprocedural anticoagulation strategy and use of open irrigation ablation catheter have resulted in a reduction of this complication. Methods and Results— We collected data from 9 centers performing the same ablation procedure with the same anticoagulation protocol. We divided the patients into 3 groups: ablation with an 8-mm catheter off warfarin (group 1), ablation with an open irrigated catheter off warfarin (group 2), and ablation with an open irrigated catheter on warfarin (group 3). Outcome data on stroke/transient ischemic attack and bleeding complications during and early after the procedures were collected. Of 6454 consecutive patients in the study, 2488 were in group 1, 1348 were in group 2, and 2618 were in group 3. Periprocedural stroke/transient ischemic attack occurred in 27 patients (1.1%) in group 1 and 12 patients (0.9%) in group 2. Despite a higher prevalence of nonparoxysmal atrial fibrillation and more patients with CHADS2 (congestive heart failure, hypertension, age >75 years, diabetes mellitus, and prior stroke or transient ischemic attack) score >2, no stroke/transient ischemic attack was reported in group 3. Complications among groups 1, 2, and 3, including major bleeding (10 [0.4%], 11 [0.8%], and 10 [0.4%], respectively; P >0.05) and pericardial effusion (11 [0.4%], 11 [0.8%], and 12 [0.5%]; P >0.05), were equally distributed. Conclusion— The combination of an open irrigation ablation catheter and periprocedural therapeutic anticoagulation with warfarin may reduce the risk of periprocedural stroke without increasing the risk of pericardial effusion or other bleeding complications.

The treatment of atrial fibrillation has changed greatly in the past decade. Not long ago, the scientific community argued the benefits of a rate-control strategy versus a rhythm-control strategy.1 This argument was always hampered by the relative ineffectiveness of the antiarrhythmic medications used as rhythm-control agents. Ablation therapy for the treatment of atrial fibrillation has quickly evolved. Originally, ablation was focused on finding triggers of atrial fibrillation in the pulmonary veins.2,3 Now, ablation offers a potential curative strategy for patients with paroxysmal, persistent, or permanent atrial fibrillation. Recent data continue to show that atrial fibrillation ablation is superior to the currently available antiarrhythmic medications in the maintenance of sinus rhythm, and the Food and Drug Administration has approved devices labeled for the ablation of atrial fibrillation.4–6 It is estimated that >2 million people in the United States have atrial fibrillation.7 Although the number of atrial fibrillation ablations continues to increase year after year, offering this therapy to all potential candidates is impossible because of several limitations.8,9 A finite number of fellows are being trained in programs that offer a great deal of experience in atrial fibrillation ablation, and there is limited opportunity for practicing electrophysiologists to learn new techniques. Unlike supraventricular tachycardia ablation, atrial fibrillation ablation requires greater technical skill, significantly more lesions, and time. Like many other medical procedures, technological innovation is likely to be a contributing factor in making atrial fibrillation ablation a more commonplace and widely practiced therapy. Navigating the complex anatomy of the left atrium is also difficult to master. Imaging technologies have been used to orient the operator to the anatomy and the location of the ablation catheters in this anatomy. With fluoroscopy alone, it is difficult to determine anterior versus posterior orientation or the presence of the catheter in …

Implantable devices have become a readily available option for patients with heart failure. Not only do these patients develop bradycardia and ventricular tachycardia, but their ventricular dysfunction can often improve with cardiac resynchronization therapy. However, this is a complex and rapidly developing clinical science for which the physician chooses techniques and selects patients on the basis of the results of clinical trials, clinical experience, and rapidly evolving tools. The results depend on the interplay of these complex variables. Placement of the left ventricular lead has forced the device physician to develop new skills and/or interdisciplinary relationships with physicians with vascular intervention, imaging, and surgical skills. Familiarity with the cardiac venous anatomy, occlusive venography, venoplasty, guide wire tools, guiding catheters, stenting, and new intracardiac visualization and magnetic intracardiac lead positioning tools are examples of just a few of the novel skills that are useful in the delivery of cardiac resynchronization therapy. Beyond implantation, these patients and devices require specialized follow-up with continued medical therapy and echo-guided adjustments of device programming. Finally, there are ongoing controversies and many as yet unanswered questions that are the subject of ongoing and planned clinical trials.

Introduction: Remote magnetic navigation (RMN) and ablation with the magnetic irrigated tip catheter has been reported as a feasible and safe technique for the treatment of ventricular arrhythmias (VA). We compared the procedural benefit and the outcomes of patients with ischemic cardiomyopathy (IC) undergoing VAs ablation with the RMN versus the manual approach. Methods: Consecutive pts with IC undergoing VAs ablation both with RMN and with manual ablation at different Institutions were enrolled. Substrate mapping and ablation technique with scar homogenization were utilized for ablation with the end point of elimination of all abnormal electrograms within and or around the scar area. Procedural data and outcomes were analyzed. Post-ablation pacing maneuvers and isoproterenol were used to verify Vas inducibility. Results: A total of 218 consecutive pts (85.3% male, 69.2±7.7 years, LVEF 30.6±8.2) with IC were included with 80 pts undergoing manual ablation while 138 pts underwent RMN ablation. Patients with a scar size < 60 cm2 at the 3D voltage mapping system were excluded. The mean scar size was 140 ± 61 cm2. VT was inducible in 83% pts with a cycle length of 352.1±70.7 msec. The density of the substrate map was higher in the RMN group when compared to the manual ablation group (553±118 vs 347±97, p At 15.4±6.8 months follow-up the success rate in the RMN group was 81.2% (112) while in the manual ablation group 55 (69%) pts were recurrence free (p=0.037). There was one pericardial tamponade which required pericardiocentesis in the manual ablation group. Conclusion: This study shows that VAs ablation using RMN in pts with IC and a scar size greater than 60 cm2 increases success rate at follow up when compared to manual ablation. The better outcome might be due to the higher amount of time dedicated to RF applications to achieve scar homogenization rather than mapping

Introduction: The best treatment option for the management of patients (pts) with heart failure (HF) and persistent AF is unknown. The AATAC trial showed that catheter ablation (CA) is superior to Amiodarone in achieving freedom from AF at follow up. In this analysis we present the outcome sorted by type of AF procedure. Methods: AATAC was a randomized multicenter study. Pts with persistent AF, dual chamber ICD or CRTD, NYHA II-III and LV EF Results: PVI was performed in 22 patients undergoing ablation, while PVI+PW+NPV ablation was performed in 80 patients. Baseline characteristics were not different between the groups. At 26±8 months follow-up, the success rates in PVI, PVI+PW+NPV, and AMIO groups were 8 [36.4%] and 63 [78.8%] and 34 (34.0%) respectively, p Conclusion: This randomized study shows that PVI alone has a low success rate similar to Amiodarone when compared to PVI plus posterior wall plus non pv trigger in patients with heart failure and persistent AF.

Background— Whether catheter ablation (CA) is superior to amiodarone (AMIO) for the treatment of persistent atrial fibrillation (AF) in patients with heart failure is unknown. Methods and Results— This was an open-label, randomized, parallel-group, multicenter study. Patients with persistent AF, dual-chamber implantable cardioverter defibrillator or cardiac resynchronization therapy defibrillator, New York Heart Association II to III, and left ventricular ejection fraction P P P P =0.037). Conclusions— This multicenter randomized study shows that CA of AF is superior to AMIO in achieving freedom from AF at long-term follow-up and reducing unplanned hospitalization and mortality in patients with heart failure and persistent AF. Clinical Trial Registration— URL: http://www.clinicaltrials.gov . Unique identifier: NCT00729911.

Background— The role of pulmonary vein (PV) isolation in ablative treatment of atrial fibrillation (AF) has been debated in conflicting reports. We sought to compare PV conduction in patients who had no AF recurrence (group I), patients who could maintain sinus rhythm on antiarrhythmic medication (group II), and patients who had recurrent AF despite antiarrhythmic medication (group III) after PV antrum isolation (PVAI). Methods and Results— PV conduction was examined in consecutive patients undergoing second PVAI for AF recurrence. We also recruited some patients cured of AF to undergo a repeat, limited electrophysiological study at >3 months after PVAI. All patients underwent PVAI with an intracardiac echocardiography (ICE)–guided approach with complete isolation of all 4 PV antra (PVA). The number of PVs with recurrent conduction and the shortest atrial to PV (A-PV) conduction delay was measured with the use of consistent Lasso positions defined by ICE. Late AF recurrence was defined as AF >2 months after PVAI with the patient off medications. Patients in groups I (n=26), II (n=37), and III (n=44) did not differ at baseline (38% permanent AF; ejection fraction 53±6%). Recurrence of PV–left atrial (LA) conduction was seen in 1.7±0.8 and 2.2±0.8 PVAs for groups II and III but only in 0.2±0.4 for group I ( P =0.02). In patients with recurrent PV-LA conduction, the A-PV delay increased from the first to second procedure by 69±47% for group III, 267±110% for group II, and 473±71% for group I ( P Conclusions— The majority of patients with drug-free cure show no PV-LA conduction recurrence. Substantial A-PV delay is seen in patients able to maintain sinus rhythm on antiarrhythmic medication or cured of AF compared with patients who fail PVAI.

Background— Multiple morphologies, hemodynamic instability, or noninducibility may limit ventricular tachycardia (VT) ablation in patients with arrhythmogenic right ventricular dysplasia (ARVD). Substrate-based mapping and ablation may overcome these limitations. We report the results and success of substrate-based VT ablation in ARVD. Methods and Results— Twenty-two patients with ARVD were studied. Traditional mapping for VT was limited because of multiple/changing VT morphologies (n=14), nonsustained VT (n=10), or hemodynamic intolerance (n=5). Sinus rhythm CARTO mapping was performed to define areas of “scar” ( Conclusions— Substrate-based ablation of VT in ARVD can achieve a good short-term success rate. However, recurrences become increasingly common during long-term follow-up.

Introduction: Periprocedural anticoagulation management is key to minimize bleeding and thromboembolic complications during and after radiofrequency catheter ablation. Uninterrupted strategies with warfarin in high risk patients have shown superiority over interrupted strategies. We sought to assess the safety and feasibility uninterrupted rivaroxaban during atrial fibrillation (AF) ablation in patients with long standing persistent atrial fibrillation. Methods: One hundred and ninety six (196) consecutive patients undergoing AF ablation with uninterrupted rivaroxaban (last dose taken with food the night before the procedure and the following dose taken the night of the procedure) were matched by age and sex with an equal number of patients undergoing AF ablation with uninterrupted warfarin on a “therapeutic range”. All patients underwent pulmonary vein antrum isolation and ablation of non pulmonary vein triggers as disclosed by isoproterenol challenge test. Results: Baseline characteristics and procedural variables were similar between groups. Mean INR in warfarin group was 2.2 ± 0.5. CHADS2 Score was ≥ 2 in 141 (72%) in the rivaroxaban group and 130 (66%) in the warfarin patients (p=0.20). One pericardial tamponade and one groin hematoma occurred in rivaroxaban group while 2 patients in warfarin group developed groin hematoma. One TIA with positive MRI was present in the rivaroxaban group. Conclusions: Uninterrupted rivaroxaban therapy appears to be as safe and efficacious as uninterrupted warfarin strategy in preventing bleeding and thromboembolic events in patients undergoing long standing persistent AF ablation.

Introduction: Radiofrequency catheter ablation of atrial fibrillation is performed under fluoroscopic guidance and therefore carries radiation risk exposure for the both the patient and the operator. Three-dimensional mapping systems and newer technologies to allow non-fluoroscopic catheter visualization together with intracardiac echo have reduced but not abolished the fluoroscopy exposure. We aim to demonstrate the feasibility, the safety and the efficacy of catheter ablation for atrial fibrillation without the use of fluoroscopy. Methods: A totally fluoro-less approach was developed for AF ablation at our Institution. 94 consecutive AF patients underwent zero fluoroscopy catheter ablation for atrial fibrillation. In the zero fluoroscopy cases, the fluoroscopy arm was kept far away from the patient table. Access including double trans-septal, mapping with the Carto 3 system and ablation were all performed without fluoroscopy with the use of ICE and the Carto 3 system. These 94 patients were compared with 94 control patients matched for age, sex and type of AF who underwent AF ablation by the same operator with the use of fluoroscopy. Results: Baseline characteristics were similar between fluoroless (N=94, Age=64.5 ± 10.1, 75.5% male, 48% paroxysmal) and control (N=94, Age=65.1 ± 9.9, 72.3% male, 50% paroxysmal) group. Non-PV triggers were detected and ablated in 51 (54.3%) and 56 (59.6%) patients in fluoroless and control group respectively (p=0.5). Average fluoro time in control group was 10.1 ± 4.7 minutes. Procedure duration was comparable (120.4 ± 25.8 vs. 122.2 ± 28.7, p =0.6). After the short term median follow-up of 4.5 (4 – 6.5) months, 10 (10.6 %) patients in flourless and 9 (9.6%) patients in control group experienced recurrences (p=0.8).One pericardial effusion requiring pericardiocenteis occurred in the fluoroless group. Conclusions: Our series show that zero fluoroscopy ablation of atrial fibrillation with the use of newer technologies is feasible, safe and efficacious at the short term follow up. Importantly in our series the double transeptal was performed without fluoroscopy and the ablation was not limited to the pulmonary veins only but included ablation of the posterior wall, the coronary sinus and the left atrial appendage.

Introduction: Catheter ablation of atrial fibrillation (AF) is the most valid therapeutic option to achieve rhythm control. Pulmonary veins (PV) are the most known trigger of AF, although recently we have become more aware of the importance of non-PV triggers. Expression of microRNA (miRNA) has been shown to be regulated in many cardiovascular disease. We sought to study expression patterns of miRNA in patients (pts) with AF undergoing ablation to facilitate their application as both diagnostic and prognostic markers. Methods: As part of the standard procedure for AF ablation a double transseptal sample of myocardial tissue is obtained via a transseptal needle. The small piece of atrial septal tissue can be retrieved from the needle as a result of piercing the atrial septum. MiRNA was hybridized to microarrays to determine relative levels of miRNAs in the samples. For a subset of the miRNAs we validated expression through quantitative real time PCR. All pts underwent PV-antrum and non-PV trigger ablation guided by isoproterenol challenge test. Results: Atrial tissue of 11 pts undergoing AF ablation has been utilized for MiRNA assessment. Mean age was 61.27 ± 10.5 years and 8 (72.7%) pts were male. Six (54.5 %) pts had paroxysmal AF. During the ablation non-PV triggers were detected in 8 (72.7 %) pts. Recurrence of AF occurred in 3(27.3 %) pts. Expression of miR-21, miR-26a and miR-29a was higher in pts with non-PV triggers, while miR-30c had lower expression in pts who had recurrence of atrial tachyarrhythmias. Spearman’s nonparametric correlation coefficient was calculated and miR-21, miR-26a, miR-29a were positively correlated with non-PV triggers (r = 0.58, p=0.06 for all three miRNAs), while miR-30c level had inverse correlation (r = (-) 0.78 %, p=0.005) with recurrence (Figure). Conclusions: Expression of miR-21, miR-26a, miR-29a correlates with the presence of non-PV triggers. This information could be clinically relevant in planning patient specific procedures.

Introduction: Catheter ablation of persistent atrial fibrillation (AF) has a lower success rate when compared to paroxysmal AF patients. Whether in persistent AF patients ablation of the pulmonary vein antrum and posterior wall is sufficient to achieve long term freedom from AF is debated in the literature. We investigated if the ablation on non pv triggers from first procedure in addition to PV and posterior wall(PW) isolation could improve the procedural success rate. Methods: 622 consecutive pts with persistent AF undergoing the first AF ablation were analysed and divided into 2 groups according to their ablation strategy. In group 1, pulmonary vein plus posterior wall ablation was performed (n=203) while in group 2 pulmonary veins plus posterior wall plus sustained and non sustained non pv triggers as disclosed by isoproterenol challenge were ablated. (n=419). All patients were followed up with intensive holter and event monitoring. Results: Clinical baseline characteristics were not statistically different between groups. After 17.8 ± 8.8 months follow-up, 118(58.1%) Group I and 283 (67.5%) Group II patients were free from any atrial tachyarrhythmias (log-rank p= 0.027). After adjusting for age, gender and clinically relevant variables, PVI and PW ablation alone was associated with significantly high recurrence. (Hazard ratio: 1.4, 95% Confidence Interval = 1.1– 1.8, p=0.02). Further, Group I patients undergoing redo procedure after a failed ablation had more NPV trigger Group II (80% vs 60%, p = 0.002, respectively, figure), while the number of patients with PV reconnection were similar between groups (65% vs. 64%, p=1.0). Conclusions: The results of our study shows that after a single procedure the ablation of non PV triggers, improves the long-term success rate in patients with persistent AF.

Background— Periprocedural thromboembolic and hemorrhagic events are worrisome complications of catheter ablation for atrial fibrillation (AF). The periprocedural anticoagulation management could play a role in the incidence of these complications. Although ablation procedures performed without warfarin discontinuation seem to be associated with lower thromboembolic risk, no randomized study exists. Methods and Results— This was a prospective, open-label, randomized, parallel-group, multicenter study assessing the role of continuous warfarin therapy in preventing periprocedural thromboembolic and hemorrhagic events after radiofrequency catheter ablation. Patients with CHADS 2 score ≥1 were included. Patients were randomly assigned in a 1:1 ratio to the off-warfarin or on-warfarin arm. The incidence of thromboembolic events in the 48 hours after ablation was the primary end point of the study. The study enrolled 1584 patients: 790 assigned to discontinue warfarin (group 1) and 794 assigned to continuous warfarin (group 2). No statistical difference in baseline characteristics was observed. There were 39 thromboembolic events (3.7% strokes [n=29] and 1.3% transient ischemic attacks [n=10]) in group 1: two events (0.87%) in patients with paroxysmal AF, 4 (2.3%) in patients with persistent AF, and 33 (8.5%) in patients with long-standing persistent AF. Only 2 strokes (0.25%) in patients with long-standing persistent AF were observed in group 2 ( P P Conclusion— This is the first randomized study showing that performing catheter ablation of AF without warfarin discontinuation reduces the occurrence of periprocedural stroke and minor bleeding complications compared with bridging with low-molecular-weight heparin. Clinical Trial Registration— URL: http://www.clinicaltrials.gov . Unique identifier: NCT01006876.

Introduction: Left atrioesophageal fistula is a rare but devastating complication that can occur following catheter ablation of atrial fibrillation. Methods : Fifty patients undergoing AF ablation for paroxysmal and persistent/permanent symptomatic atrial fibrillation refractory to AAD have been enrolled and randomized into 2 groups: those undergoing the procedure under conscious sedation with fentanil or midazolam (25 patients, group and those receiving general anesthesia (25 patients, group All patients underwent esophageal temperature monitoring during the procedure. Radiofrequency energy was discontinued when the luminal temperature reached 39 C. After ablation all patients had capsule endoscopy to assess the presence for endoluminal tissue damage of the esophagus. Results : The results are shown in the table below Conclusion : The use of general anesthesia increases the risk of positive esophageal findings by capsule endoscopy