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Aims: Neither the long-term development of ablation lesions nor the capability of late gadolinium enhancement (LGE)-MRI to detect ablation-induced fibrosis at late stages of scar formation have been defined. We sought to assess the development of atrial ablation lesions over time using LGE-MRI and invasive electroanatomical mapping (EAM). Methods and results: Ablation lesions and total atrial fibrosis were assessed in serial LGE-MRI scans 3 months and >12 months post pulmonary vein (PV) isolation. High-density EAM performed in subsequent repeat ablation procedures served as a reference. Serial LGE-MRI of 22 patients were analyzed retrospectively. The PV encircling ablation lines displayed an average LGE, indicative of ablation-induced fibrosis, of 91.7% ± 7.0% of the circumference at 3 months, but only 62.8% ± 25.0% at a median of 28 months post ablation (p < 0.0001). EAM performed in 18 patients undergoing a subsequent repeat procedure revealed that the consistent decrease in LGE over time was owed to a reduced detectability of ablation-induced fibrosis by LGE-MRI at time-points > 12 months post ablation. Accordingly, the agreement with EAM regarding detection of ablation-induced fibrosis and functional gaps was good for the LGE-MRI at 3 months (κ .74; p < .0001), but only weak for the LGE-MRI at 28 months post-ablation (κ .29; p < .0001). Conclusion: While non-invasive lesion assessment with LGE-MRI 3 months post ablation provides accurate guidance for future redo-procedures, detectability of atrial ablation lesions appears to decrease over time. Thus, it should be considered to perform LGE-MRI 3 months post-ablation rather than at later time-points > 12 months post ablation, like for example, prior to a planned redo-ablation procedure.

Backgroud The long-term outcomes of this combined procedure remain elusive. This meta-analysis aimed to assess the long-term efficacy and safety of combined procedure. Methods PubMed, Embase, Cochrane Library, and Web of Science were systematically searched from the establishment of databases to 1 January 2021. Studies on the long-term (defined as a mean follow-up of approximately 12 months or longer) efficacy and safety outcomes of combined ablation and LAAC were included for meta-analysis. Results A total of 16 studies comprising 1,428 patients were included in the meta-analysis. The pooled long term freedom rate from atrial arrhythmia was 0.66 (95% confidence interval [CI], 0.59-0.71), long-term successful rate sealing of LAAC was 1.00 (95% CI, 1.00-1.00), and ischemic stroke/transient ischemic attack/systemic embolism during follow-up was 0.01 (95% CI, 0.00-0.02). Meanwhile, the rates of peri-procedural adverse events included phrenic nerve palsy, intracoronary air embolus, device embolization, peri-procedural death of 0.00 (95% CI, 0.00-0.00), procedure-related bleeding events of 0.03 (95% CI, 0.02-0.04), and pericardial effusion requiring or not requiring intervention of 0.00 (95% CI, 0.00-0.01). Moreover, the rates of long-term adverse events rate included device dislocation, intracranial bleeding, and pericardial effusion requiring or not requiring intervention, and all-cause mortality of 0.00 (95% CI, 0.00-0.00), device embolization of 0.01 (95% CI, 0.00-0.01), and other bleeding events of 0.01 (95% CI, 0.00-0.03). Conclusion This meta-analysis suggests that the strategy of combined atrial ablation and LAAC is effective and safe during long-term follow-up

AimsWe hypothesize that in patients with paroxysmal atrial fibrillation (AF), verapamil is associated with lower AF progression compared to beta blockers or no rate control.Methods and resultsIn this pre-specified post hoc analysis of the RACE 4 randomized trial, the effect of rate control medication on AF progression in paroxysmal AF was analysed. Patients using Vaughan-Williams Class I or III antiarrhythmic drugs were excluded. The primary outcome was a composite of first electrical cardioversion (ECV), chemical cardioversion (CCV), or atrial ablation. Event rates are displayed using Kaplan–Meier curves and multivariable Cox regression analyses are used to adjust for baseline differences. Out of 666 patients with paroxysmal AF, 47 used verapamil, 383 used beta blockers, and 236 did not use rate control drugs. The verapamil group was significantly younger than the beta blocker group and contained more men than the no rate control group. Over a mean follow-up of 37 months, the primary outcome occurred in 17% in the verapamil group, 33% in the beta blocker group, and 33% in the no rate control group (P = 0.038). After adjusting for baseline characteristics, patients using verapamil have a significantly lower chance of receiving ECV, CCV, or atrial ablation compared to patients using beta blockers [hazard ratio (HR) 0.40, 95% confidence interval (CI) 0.19–0.83] and no rate control (HR 0.64, 95% CI 0.44–0.93).ConclusionIn patients with newly diagnosed paroxysmal AF, verapamil was associated with less AF progression, as compared to beta blockers and no rate control.

Catheter ablation for atrial fibrillation (AF) has emerged as an important rhythm-control strategy and is by far the most common cardiac ablation procedure performed worldwide. Current guidelines recommend the procedure in symptomatic patients with paroxysmal or persistent AF who are refractory or intolerant to antiarrhythmic drugs. The procedure might also be considered as a first-line approach in selected asymptomatic patients. Data from large registries indicate that AF ablation might reduce mortality and the risk of heart failure and stroke, but evidence from randomized controlled trials is mixed. Pulmonary vein isolation using point-by-point radiofrequency or with the cryoballoon remains the cornerstone technique in AF ablation. Additional atrial ablation can be performed in patients with persistent AF, but its benefits are largely unproven. Technological advances in the past decade have focused on achieving durable vein isolation, reducing procedure duration and improving safety. Numerous exciting new technologies are in various stages of development. In this Review, we discuss the relevant data to support the recommended and evolving indications for catheter ablation of AF, describe the different ablation techniques, and highlight the latest advances in technology that aim to improve its safety and efficacy. We also discuss lifestyle modification strategies to improve ablation outcomes.

The use of transthoracic echocardiography (TTE) is common during cardiopulmonary resuscitation (CPR) from cardiac arrest, but logistic and practical challenges of obtaining satisfactory images without sacrificing the quality of CPR have resulted in some centers utilizing transesophageal echocardiography (TEE) during CPR. Although TEE avoids many of the downsides of TTE, several challenges exist in routine deployment. An alternative approach, intracardiac echocardiography (ICE), is routinely used by electrophysiologists during regular cardiac electrophysiologic procedures, such as atrial ablation for the treatment of atrial fibrillation. In this review, we evaluate various considerations in the potential for use of ICE as a novel means of enhancing resuscitation during CPR.

Background Catheter ablation is an important rhythm control therapy in patients with atrial fibrillation (AF) with concomitant heart failure (HF). The objective of this study was to assess the comparative efficacy of AF ablation patients with ischemic vs nonischemic heart failure. Methods We conducted a retrospective, observational cohort study of patients with HF who underwent AF ablation. Outcomes were compared based on HF etiology and included in‐hospital events, symptoms (Mayo AF Symptom Inventory [MAFSI]), and functional status (New York Heart Association class) and freedom from atrial arrhythmias at 12 months. Results Among 242 patients (n = 70 [29%] ischemic, n = 172 [71%] nonischemic), patients with nonischemic cardiomyopathy were younger (mean age 64 ± 11.5 vs 69 ± 9.1, P = .002), more often female (36% vs 17%, P = .004), and had higher mean left‐ventricular ejection fraction (47% vs 42%, P = .0007). There were no significant differences in periprocedural characteristics, including mean procedure time (243 ± 74.2 vs 259 ± 81.8 minutes, P = .1) and nonleft atrial ablation (17% vs 20%, P = .6). All‐cause adverse events were similar in each group (15% vs 17%, P = .7). NYHA and MAFSI scores improved significantly at follow‐up and did not differ according to HF etiology (P = .5; P = .10‐1.00 after Bonferroni correction). There were no significant differences in freedom from recurrent atrial arrhythmia at 12‐months between ischemic (74%) and nonischemic patients (78%): adjusted RR 0.63, 95% confidence interval 0.33‐1.19. Conclusions Catheter ablation in patients with AF and concomitant heart failure leads to significant improvements in functional and symptom status without significant differences between patients with ischemic vs nonischemic HF etiology., Catheter ablation is an important rhythm control therapy in patients with atrial fibrillation (AF) with concomitant heart failure (HF). The objective of this study was to assess the comparative efficacy of AF ablation patients with ischemic versus nonischemic heart failure. We found that catheter ablation in patients with AF and concomitant heart failure leads to significant improvements in functional and symptom status without significant differences between patients with ischemic versus nonischemic HF etiology.

Extensive atrial ablation in the setting of atrial fibrillation (AF) and atrial tachycardia (AT) can affect interatrial connections. A 76-year-old man with a history of tachycardia-induced cardiomyopathy and nine ablation procedures for AF/AT over 15 years presented with highly symptomatic recurrent AT. Previous ablation lesions included pulmonary vein isolation, left atrial posterior wall isolation, mitral isthmus line, cavotricuspid isthmus line, and the ablation of areas of fractionated electrograms. Electroanatomical mapping found the pulmonary veins and the left atrial posterior wall to be silent, as was the posterior interatrial septum and the mitral isthmus area. Activation mapping showed progression of electrograms in the left atrial appendage (LAA) from the septal aspect posteriorly, and in the coronary sinus from proximal to distal; implying the existence of a septal circuit, where extensive fractionation was noted. This was targeted, while monitoring conduction into the LAA using a multielectrode catheter. Ablation led to prompt termination of tachycardia and simultaneous LAA isolation. Immediate cessation of ablation led to recovery of conduction into LAA. Additional lesions in the interatrial septum were required to render the tachycardia noninducible, accompanied by temporary isolation of LAA. The ablation lesion sets employed while ablating AF and left AT can block many interatrial pathways, rendering conduction dependent on muscle bundles in the interatrial septum and, therefore, vulnerable to block by lesions in this area. LAA isolation has been associated with high incidence of LAA thrombus formation and stroke despite oral anticoagulation. Continuous observation of LAA electrograms during ablation can help to avoid this complication.

Scarring from atrial ablation carries a risk of developing stiff left atrium syndrome, which can mimic mitral valve disease. We present a case of a 73-year-old man whose stiff left atrium syndrome came to light after percutaneous mitral valve repair. (Level of Difficulty: Intermediate.), Graphical abstract, Scarring from atrial ablation carries a risk of developing stiff left atrium syndrome, which can mimic mitral valve disease. We present a case of…

Debridement is a standard part of wound care that is used on both acute and chronic wounds. Current methods of wound debridement include: autolytic based on the natural immune response, surgical, enzymatic based on application of exogenous proteases, mechanical using water jets and ultrasound, and biological using live organisms such as maggots. The choice of individual methods involves a trade-off between speed of treatment, selectivity, and pain. Irreversible electroporation via the application of pulsed electric fields has been used as a novel approach for deep tissue ablation, sometimes in conjunction with chemotherapy, as in the case of tumors, and also in cases where high precision is needed in otherwise very fragile tissues, such as for treating diabetic neuropathy and in epicardial atrial ablation. This method could be readily extended to wound care as it is both rapid and relatively painless, and it is also effective at decreasing bacterial load and clearing biofilms. Furthermore, the process primarily targets cells leaving the extracellular matrix relatively intact, thus providing a suitable natural scaffold for host cellular invasion and regrowth. A unique aspect of the use of pulsed electric fields is that around the region where ablation is perfomed, electric fields of lower energy are dissipated into the healthy tissue. There is a range of electric fields that are known to stimulate cellular functions, in particular migration and proliferation, and that may contribute to the healing process after electroporation. While irreversible electroporation is a potentially useful alternative to other debridement methods, future clinical application awaits technological advances in electrode design that will enable precise delivery of the therapy in wounds of various sizes and depths.

INTRODUCTION Multielectrode mapping catheters improve the ability to map within the heterogeneous scar. A novel Octaray catheter with eight spines and 48 electrodes may further improve the speed and resolution of atrial mapping. The aims of this study were to (1) establish the Octaray's baseline mapping performance and electrogram (EGM) characteristics in healthy atria and to (2) determine its utility for identifying gaps in a swine model of atrial ablation lines. METHODS AND RESULTS The right atria of eight healthy swine were mapped with Octaray and Pentaray catheters (Biosense Webster, Irvine, CA) before and after the creation of ablation lines with intentional gaps. Baseline mapping characteristics including EGM amplitude, duration, number of EGMs, and mapping time were compared. Postablation maps were created and EGM characteristics of continuous lines and gaps were correlated with pathology. Compared with Pentaray, the Octaray collected more EGMs per map (2178 ± 637 vs 1046 ± 238; P

An atrioesophageal fistula is an uncommon complication of atrial ablation with a mortality rate of 40–100%. Uniform treatment guidelines have yet to be established. Herein, we illustrate the successful surgical management of an atrioesophageal fistula, avoiding the need for an oesophageal surgical intervention by sealing and clipping of the oesophagus. This novel single-step hybrid approach combining cardiac surgical and gastroenterological techniques provides a less aggressive strategy with potentially a more favourable prognosis.

Background Minimally invasive access via partial sternotomy has been established for aortic valve surgery in the past years. But concomitant procedures like atrial ablation and aortic valve replacement via partial upper sternotomy have not been investigated so far. We therefore present our operative technique and results in terms of safety and efficacy, including follow-up and quality of life. Methods Between February 2007 and March 2014 a total of 67 patients undergoing isolated minimally invasive aortic valve replacement received concomitant left atrial ablation at our centre. Operative technique and short- and midterm results are described, including quality of life assessment using the SF-36 questionnaire. Results Operative techniqual success rate was 98.5%. We observed only one (1.5%) ablation-related conversion to full sternotomy. Operative times, reexploration and stroke rates as well as 30-day mortality are comparable to open procedures. Efficacy - The proportions of patients in sinus rhythm at discharge was 54.5% for paroxysmal AF patients and 27.7% overall. After a mean follow-up time of 38.0 ± 22.6 months the cardiac related mortality rate was 4.5%, the rate of sinus rhythm was 72.7% for paroxysmal AF patients and 36.8% overall. Of survivors, overall mean quality of life was 7.3 ± 2.1 as measured by SF- 36. Conclusions Concomitant left atrial ablation and aortic valve replacement can safely be performed via partial sternotomy and results are non-inferior to open surgery.

Objective: Local activation time (LAT) mapping of the atria is important for targeted treatment of atrial arrhythmias, but current methods do not interpolate on the atrial manifold and neglect uncertainties associated with LAT observations. In this paper, we describe novel methods to, first, quantify uncertainties in LAT arising from bipolar electrogram analysis and assignment of electrode recordings to the anatomical mesh, second, interpolate uncertain LAT measurements directly on left atrial manifolds to obtain complete probabilistic activation maps, and finally, interpolate LAT jointly across both the manifold and different S1–S2 pacing protocols. Methods: A modified center of mass approach was used to process bipolar electrograms, yielding a LAT estimate and error distribution from the electrogram morphology. An error distribution for assigning measurements to the anatomical mesh was estimated. Probabilistic LAT maps were produced by interpolating on a left atrial manifold using Gaussian Markov random fields, taking into account observation errors and characterizing LAT predictions by their mean and standard deviation. This approach was extended to interpolate across S1–S2 pacing protocols. Results: We evaluated our approach using recordings from three patients undergoing atrial ablation. Cross-validation showed consistent and accurate prediction of LAT observations both at different locations on the left atrium and for different S1–S2 intervals. Significance: Interpolation of scalar and vector fields across anatomical structures from point measurements is a challenging problem in biomedical engineering, compounded by uncertainties in measurements and meshes. New methods and approaches are required, and in this paper, we have demonstrated an effective method for probabilistic interpolation of uncertain LAT.

Low atrial endocardial bipolar voltage, measured during catheter ablation for atrial fibrillation (AF), is a commonly used surrogate marker for the presence of atrial fibrosis. Low voltage shows many useful associations with clinical outcomes, comorbidities and has links to trigger sites for AF. Several contemporary trials have shown promise in targeting low voltage areas as the substrate for AF ablation; however, the results have been mixed. In order to understand these results, a thorough understanding of voltage mapping techniques, the relationship between low voltage and the pathophysiology of AF, as well as the inherent limitations in voltage measurement are needed. Two key questions must be answered in order to optimally apply voltage mapping as the road map for ablation. First, are the inherent limitations of voltage mapping small enough as to be ignored when targeting specific tissue based on voltage? Second, can conventional criteria, using a binary threshold for voltage amplitude, truly define the extent of the atrial fibrotic substrate? Here, we review the latest clinical evidence with regard to voltage-based ablation procedures before analysing the utility and limitations of voltage mapping. Finally, we discuss omnipole mapping and dynamic voltage attenuation as two possible approaches to resolving these issues.

Two clinical ablation protocols, 2C3L and stepwise, have been routinely used in our group to treat atrial fibrillation (AF), but with a less than 60% long-term arrhythmia-free outcome achieved in patients. The goal of this study was to examine the underlying mechanism of low success in clinical outcome. MRI images from one patient were used to reconstruct a human atrial anatomical model, and fibrotic tissue was manually added to represent the arrhythmia substrate. AF was induced with standard protocols used in clinical practice. 2C3L and stepwise were then used to test the efficacy of arrhythmia termination in our model. The results showed that re-entries induced in our model could not be terminated by using either 2C3L or the stepwise protocol. Although some of the induced re-entries were terminated, others emerged in new areas. Ablation using only the 2C3L or stepwise method was not sufficient to terminate all re-entries in our model, which may partially explain the poor long-term arrhythmiafree outcomes in clinical practice. Our findings also suggest that computational heart modelling is an important tool to assist in the establishment of optimal ablation strategies.

MRI or CT imaging can be used to identify the esophageal location prior to left atrial ablation, but the esophagus may move making the location unreliable when ablating to minimize esophageal injury. The aim of this study was to evaluate esophageal position and movement based on serial MRI imaging with the goal of identifying imaging and clinical characteristics that can predict the esophageal movement. Fifty patients undergoing 190 MRI scans were analyzed. The relative position of the esophagus in each MRI along with clinical and imaging characteristics was quantified, including the gap between the left atrium (LA) and the vertebral body (GAP), an anatomic space in which the esophagus can move. A mean of 3.8 MRIs was analyzed per patient. Sixteen patients (32.0%) experienced significant lateral esophageal movement of more than 10 mm. In the significant movement group, body mass index (BMI) was higher (33.0 ± 6.5 vs 28.8 ± 5.3, p = 0.02) and the GAP was significantly larger (7.1 ± 2.5 vs 4.8 ± 5.1 mm, p = 0.04). Multivariate logistic regression analysis revealed that the GAP ≤ 4.5 mm was the only independent predictor of the esophagus not moving (odds ratio = 9.25, 95% confidence interval = 1.72 to 49.67, p = 0.0095). A GAP of less than 4.5 mm between the LA and the vertebral body is associated with lack of esophageal movement (

Background. Hypertrophic cardiomyopathy is one of the most common types of cardiomyopathy. The appearance of atrial fibrillation in patients with hypertrophic obstructive cardiomyopathy is associated with significant clinical worsening. Outcomes of surgical ablation and septal myectomy in these patients are limited.Aim. This retrospective study aimed to evaluate short-term outcomes of concomitant surgical ablation and septal myectomy in patients with obstructive hypertrophic cardiomyopathy and atrial fibrillation.Methods. Fifty-five patients with hypertrophic obstructive cardiomyopathy and atrial fibrillation who underwent concomitant surgical ablation and septal myectomy between 2014 and 2019 were analysed. Patients with paroxysmal atrial fibrillation predominantly underwent left atrial ablation, and those with nonparoxysmal atrial fibrillation predominantly underwent the Maze IV procedure. Surgical ablation was performed using cryoablation alone (83.6%) or in combination with radiofrequency energy (16.4%).Results. Hospital mortality was 1.8%. Incidence of major adverse events was 3.6%. Sinus node dysfunction and atrioventricular block occurred in 7.3% and 1.8% of patients, respectively. Bleeding requiring revision occurred in 2 (3.6%) patients. Forty-nine (89.1%) patients had stable sinus rhythm and five (9.1%) were on dual-chamber pacemaker stimulation at the time of discharge.Conclusion. Concomitant septal myectomy and surgical ablation are feasible and safe in patients with hypertrophic obstructive cardiomyopathy and atrial fibrillation.Received 5 April 2021. Revised 16 May 2021. Accepted 17 May 2021.Funding: The study did not have sponsorship.Conflict of interest: The authors declare no conflicts of interests.Contribution of the authorsConception and study design: A.S. Zalesov, A.V. Bogachev-ProkophievData collection and analysis: A.S. Zalesov, S.A. Budagaev, A.V. SapeginStatistical analysis: A.S. Zalesov, A.V. Afanasyev, R.M. SharifulinDrafting the article: A.S. ZalesovCritical revision of the article: A.V. Bogachev-Prokophiev, S.I. Zheleznev, I.I. DeminFinal approval of the version to be published: A.S. Zalesov, A.V. Bogachev-Prokophiev, A.V. Afanasyev, R.M. Sharifulin, A.V. Sapegin, S.A. Budagaev, S.I. Zheleznev, I.I. Demin

Assessment of the left atrial (LA) function is important aspect of comprehensive cardiovascular system estimation. Many cardiac diseases make an impact to LA work either by direct affect on myocardium or hemodynamic condition changing. It is considered, LA and left ventricle diastolic pressure is interrelated, thus without mitral valve disease LA expanding is a sign of LV filling pressure augmentation. Examination of LA size and function by analysis of atrial reservoir, conduit, and booster pump can predict cardiovascular outcomes in patients with cardiomyopathy, ischemic heart disease and valvular heart disease. The last two decades gave new technologies to accurate and comprehensive LA mechanics estimation, in the first place related to tissue Doppler imaging. Atrial strain and strain rate obtained using two-dimensional speckle-tracking echocardiography have proved to be feasible and reproducible techniques to evaluate LA mechanics. In physiological settings, LA is a highly expandable chamber with relatively low pressures. However in the presence of acute and chronic injury, LA wall stretches. LA stretching is a hallmark of structure changing with myocardial fibrosis and has influence on LA strain and strain rate. LA strain estimation could be useful in the prediction of sinus rhythm restoration and maintenance after cardioversion and catheter ablation. Low values of global longitudinal LA strain indicate irreversible LA remodeling and are related to the atrial fibrillation progression from paroxysmal to permanent forms. The most interesting in these circumstances is the potential contribution of echocardiography to thromboembolic risk stratification in atrial fibrillation and invasive procedures such as atrial ablation. Therefore, at present, the main task is to understand the ways of clinical application of data obtained during the LA study.

Purpose Cryoablation is used in the treatment of atrial fibrillation and other cardiac arrhythmias. This study evaluated a novel 10-cm flexible nitrous oxide cryoprobe in an ovine model of atrial ablation. Description Six sheep were anesthetized, underwent a left thoracotomy, and were placed on cardiopulmonary bypass. A left atriotomy was performed, and the cryoprobe was applied endocardially for 120 seconds at less than –40°C to 4 sites on the left atrium. The atrium was closed and the animals were allowed to recover. After 30 days, the animals were euthanized. Transmurality was evaluated in 5-mm sections of each lesion using 2,3,5-triphenyltetrazolium chloride (TTC) and Masson's trichrome staining. Evaluation All animals survived. One hundred four of 106 sections (98%) were transmural by TTC; 103 of 106 (97%) sections were transmural by trichrome staining. There was no late atrial perforation, intraluminal thrombus, or thromboembolism. Conclusions The device reliably produced transmural lesions in a chronic ovine model. Its performance was equivalent to that of other nitrous oxide cryoablation systems.

Electrophysiology procedures require fluoroscopic guidance, with the associated potentially adverse effects of ionizing radiation. Newer fluoroscopy systems have more features that enable dose-reduction strategies. This study aimed to investigate any reduction in radiation dose between an older fluoroscopy system (Philips Integris H5000, Philips Healthcare, Einhoven, Netherlands) and one of the latest systems (Siemens Artis Q, Siemens Healthcare, Erlangen, Germany), optimized with dose-reduction strategies. Radiation dose measures were collected over a 2-year period in a single electrophysiology laboratory. Procedures were separated into seven groups: devices, biventricular devices, electrophysiology studies, standard radiofrequency ablation, complex atrial ablation, ablation for ventricular arrhythmias, and pulmonary vein isolation. In the first year, an older fluoroscopy system was used, and in the second year, a new system, with dose reduction strategies. Comparisons were also made to the literature with regard to radiation dose levels. Patient characteristics, fluoroscopy times, number of digital acquisitions, procedural times, and procedural success were largely similar between the old and new system across procedure groups. Overall dose area product (DAP) was reduced by 91% (5.0 [2.0-17.0] to 0.45 [0.16-2.61] Gycm [P > 0.001]) with the new system and was lower across all groups. DAP readings with the new system are some of the lowest published in the literature in all groups. An optimized contemporary digital fluoroscopy system, with low radiation dose configuration and continued good procedural practice, can result in ultra-low radiation levels for all electrophysiology procedures, without compromising procedural time or procedural success.

The purpose of this study was to compare health care costs associated with repeat ablation of atrial fibrillation (AF) with health care costs associated with a successful first procedure.Catheter ablation has become established as a rhythm control strategy for symptomatic paroxysmal and persistent AF. The economic impact of ablation is not completely understood, and it may be affected by repeat procedures performed for recurrent AF.The source of data was the MarketScan (Truven Health, Ann Arbor, Michigan) administrative claims dataset from April 2008 to March 2013, including U.S. patients with private and Medicare supplemental insurance. Patients who underwent an outpatient atrial ablation procedure and a diagnosis of AF were identified. Total health care cost was calculated for 1 year before and after the ablation. Patients were categorized as having undergone a repeat ablation if an additional ablation was performed in the following year.Of 12,027 patients included in the study, repeat ablation was performed in 2,066 (17.2%) within 1 year. Patients with repeat ablation had higher rates of emergency department visits (43.4% vs. 32.2%; 0.001) and subsequent hospitalization (35.6% vs. 21.5%; p 0.001), after excluding hospitalizations for the repeat procedure. Total medical cost was higher for patients with repeat ablation ($52,821 vs. $13,412; p 0.001), and it remained 46% higher even after excluding the cost associated with additional ablations ($19,621 vs. $13,412; p 0.001).Health care costs are significantly higher for patients with a repeat ablation for AF than for patients with only a single ablation procedure, even though both groups have similar baseline characteristics. The increased costs persist even after excluding the cost of the repeat ablation itself. These results emphasize the economic benefit of procedural success in AF ablation.

Background Functional remodeling of left atrium (LA) after radiofrequency catheter ablation (RFCA) for atrial fibrillation (AF) has not been fully elucidated. This study aimed to determine the impact of RFCA on LA transport function in patients who maintained sinus rhythm (SR) after AF ablation. Methods and Results A total of 96 patients [paroxysmal AF (PAF) = 52] who maintained SR during 1 year after AF ablation were enrolled. Multi-slice computed tomography was performed to determine LA volume (LAV) and LA emptying fraction (LAEF) at pre-RFCA and 1-year post-RFCA. Creatine kinase-MB (CK-MB) and troponin-T levels were analyzed one-day post-RFCA. At 1-year post-RFCA, mean LAV and LAEF decreased in overall patients. Based on LAEF change (ΔLAEF) cut off of 5.0%, LAEF reduced in 41 patients (worsened group) and improved or showed no change in 55 patients (preserved group). Compared with preserved group, worsened group had a higher proportion of PAF, higher levels of CK-MB and troponin-T, and additional LA ablation. ΔLAEF was inversely correlated with CK-MB and troponin-T levels. Subgroup analysis showed that LAEF significantly decreased in PAF patients who underwent additional LA ablation. Multivariate analysis revealed that high baseline LAEF and additional LA ablation were independent predictors for worsened LAEF. Conclusions Although SR was maintained for 1 year after AF ablation, LAEF as well as LAV decreased. The extent of LAEF deterioration was significantly associated with the amount of iatrogenic myocardial damage. Our data indicate that extensive atrial ablation may lead to LA functional deterioration, especially in patients with PAF. This article is protected by copyright. All rights reserved

We report a case of an atrio-oesophageal fistula after biatrial cryomaze ablation for atrial fibrillation, a complication that has not yet been described in the literature for the cryomaze method. Our report also serves as a reminder of this rare but lethal complication- that it can occur after any method of ablation for atrial fibrillation and a high index of suspicion for its diagnosis must be maintained to allow for early surgical treatment which offers the best chance of survival.

A 69-year-old male had catheter-based ablation for atrial fibrillation. He was admitted with high fever and had neurological disorder; he was diagnosed with atrioesophageal fistula by CT scan. Intraoperative findings showed that the fistula existed adjacent to the left lower pulmonary vein with a vegetation. The esophageal fistula was repaired, and the left atrial fistula was closed. A nasogastric tube tip was placed in the esophagus for decompression and advanced into the stomach for nutritional support. After vomiting, the patient showed loss of consciousness and left hemiplegia. CT scan revealed a micro-air embolism to the brain. The nasogastric tube tip was pulled back into the esophagus. Gastrointestinal fiberscopy showed a pinhole at the fistula, and a percutaneous endoscopic gastrostomy was made. After conservative treatment, the esophageal fistula was closed and mediastinitis was improved. He was discharged with a little neurological deficit.

Introduction Patients with complete transposition of the great arteries (d-TGA) and atrial switch face a high lifetime risk of arrhythmias. Interventions in these patients are challenging because of their particular anatomy. Reports on ablation procedures in this patient population are scarce and missing for Switzerland. Method We retrospectively analyzed all ablation procedures performed in the above-mentioned population at a Swiss tertiary care center. Results Among 73 d-TGA pts. (71% male; N=37 Senning; N=36 Mustard) followed at our center, 17 ablations were performed in 11 pts. (15%; one ablation in 8 pts., two in 2 pts. and five in 1 patient). Median age at first ablation was 34 years (range 15–49 years). A total of 17 different intra-atrial reentry tachycardias (IART) and 3 AVNRT were targeted. Of the IART, 10 were cavotricuspid isthmus (CTI)-dependent and 7 were not. In two procedures (12%) only the systemic venous (SV) baffle was accessed for ablation. In 15 procedures (88%), ablation was performed within the pulmonary venous (PV) baffle. Access to the PV baffle was retrograde via the aorta in 6 cases (35%), via a baffle leak in 3 (18%) and via baffle puncture in 6 (35%). All procedures with retrograde approach to the PV baffle or with SV baffle only ablation were performed up to January 2012 and all remaining procedures afterwards. The 3 pts. requiring repeat procedures had retrograde or SV baffle approaches initially, and one additional ablation via baffle puncture was successful. The CTI was targeted in 10 pts. (91%) and ablation was finally successful in all with bidirectional block demonstrated in 8 pts. The coronary sinus was found to drain into the SV baffle in 5 pts. (46%) and useful for assessment of CTI block. The seven CTI-independent IART were scar-related micro-reentries. Ablation of all 3 AVNRTs was successful after one procedure without recurrence. Slow pathway ablation was performed in the SV baffle in two and in the PV baffle in one case (Figure). After a median follow-up of 7 months (range 2–186 months) 9 pts. are without recurrence and in 2 pts. rare self-limited arrhythmias still occur. No procedural complications occurred. Conclusion Arrhythmias in patients with complete d-TGA and atrial switch are mainly CTI-dependent IART or scar-related micro-reentries, and a few patients also have AVNRT. Ablation of these arrhythmias is safe and successful if PV baffle access is achieved via a baffle leak or baffle puncture.

Background Recent guidelines recommend a 3-month blanking period after atrial fibrillation (AF) ablations, which are based on clinical observation. Our goal was to quantify the timeline of the radiofrequency ablation lesion maturation using serial late gadolinium enhancement-magnetic resonance imaging (LGE-MRI) and to develop a blanking period estimate based on visible lesion maturation. Methods Inclusion criteria targeted patients who underwent AF ablation and at least four MRI scans: at baseline before ablation, within 24 hours after (acute), between 24 hours and 90 days after (subacute), and more than 90 days after ablation (chronic). Central nonenhanced (NE) and surrounding hyperenhanced (HE) area volumes were measured and normalized to chronic lesion volume. Results This study assessed 75 patients with 309 MRIs. The acute lesion was heterogeneous with a HE region surrounding a central NE region in LGE-MRI; the acute volume of the total (HE + NE) lesion was 2.62 ± 0.46 times larger than that of the chronic lesion. Acute T2-weighted imaging also showed a relatively large area of edema. Both NE and HE areas gradually receded over time and NE was not observed after 30 days. Larger initial NE volume was associated with a significantly greater chronic scar volume and this total lesion volume receded to equal the chronic lesion size at approximately 72.5 days (95% prediction interval: 57.4-92.2). Conclusion On the basis of serial MRI, atrial ablation lesions are often fully mature before the typical 90-day blanking period, which could support more timely clinical decision making for arrhythmia recurrence.

Introduction Focal impulse and rotor modulation (FIRM)-guided ablation has had mixed results of published success, and most studies have had a follow-up for a year or less. We aimed to study a consecutive group of patients followed for at least 1.5 years, subgrouped into those with an initial FIRM ablation and those with a previous, failed ablation who now received a FIRM guided one, to evaluate for success in each group and factors that might affect success. Methods Of 181 patients, 167 were available for analysis. Group 1 (n = 122) had a first or primary ablation (paroxysmal atrial fibrillation [PAF] 51; persistent atrial fibrillation [PeAF] 71) and group 2 (n = 45) had a redo ablation (PAF 18; PeAF 27). All patients were done under general anesthesia. FIRM mapping was done in the right atrium first and then the left, and only rotors consistently seen on multiple epochs were ablated, using 15 to 30 W. Rotor ablation was discontinued when remapping showed elimination of rotational activity at the site. Wide area catheter ablation was done for pulmonary vein isolation (PVI). Routine follow-up was at 3, 6, and 12 months of the first year, with a Holter monitor at 6 months, and then every 6 months thereafter. Event recorders were given to patients with potential arrhythmic symptoms. Results Mean follow-up was 16 months. Nearly 40% of patients had obstructive sleep apnea; mean body mass index was 32; and average left atrial size was 39.7 mm and 46.2 mm for PAF and PeAF patients, respectively. Freedom from atrial arrhythmia recurrence was: in group 1 patients, 82.4% for PAF and 67.6% for PeAF patients; in group 2 patients, 83.3% for PAF, but only 40.7% for PeAF patients. Comparing outcomes for the first 10 patients studied to the next 20 or more done by three operators showed no difference, suggesting no learning curve affecting the ablation results. Furthermore, the univariate analysis did not show any demographic factor to have an independent significance for ablation success or failure. Spontaneous termination during rotor ablation occurred in 76.8% of PAF and 27.6% of PeAF patients but did not affect the long-term outcomes for maintenance of sinus rhythm. Conclusions FIRM-guided atrial ablation plus PVI in our patient population resulted in good success from a recurrence of atrial arrhythmias in patients undergoing an initial ablation procedure. For those with persistent AF undergoing a second procedure now using FIRM guidance plus PVI, the results are lower. Further research is needed to define better the appropriate population for FIRM-guided ablation and the degree of ablation needed for success in these patients.

Background Many patients with atrial fibrillation (AF) or atrial flutter (Aflutter) have concomitant sinus node dysfunction (SND). Ablation may result in injury to the sinus node complex or its blood supply resulting in sinus arrest and need for temporary pacing. We sought to characterize patients who develop acute SND (ASND) during/immediately after AF/Aflutter ablation. Methods We performed a retrospective analysis of AF/Aflutter ablation patients between January 1, 2010 and February 28, 2015 to characterize those who required temporary pacemaker (TPM) implantation due to ASND (sinus arrest, sinus bradycardia

Currently, no guidelines have been established for the treatment of atrio-esophageal fistula (AEF) secondary to left atrial ablation therapy. After comprehensive literature review, we aim to make suggestions on the management of this complex complication and also present a case series. We performed a review of the existing literature on AEF in the setting of atrial ablation. Using keywords atrial fibrillation, atrial ablation, fistula formation, atrio-esophageal fistula, complications, interventions, and prognosis, a search was made using the medical databases PUBMED and MEDLINE for reports in English from 2000 to April 2015. A statistical analysis was performed to compare the three different intervention arms: medical management, stent placement and surgical intervention. The results of our systematic review confirm the high mortality rate associated with AEF following left atrial ablation and the necessity to diagnose atrio-esophageal injury in a timely manner. The mortality rates of this complication are 96% with medical management alone, 100% with stent placement, and 33 % with surgical intervention. Atrio-esophageal injury and subsequent AEF is an infrequent but potentially fatal complication of atrial ablation. Early, prompt, and definitive surgical intervention is the treatment of choice.

Atrial ablation has been recently utilized for curing atrial fibrillation. The success rate of empirical ablation is relatively low as often the exact locations of the arrhythmogenic sources remain elusive. Guided ablation has been proposed to improve ablation technique by providing guidance regarding the potential localization of the sources; yet to date no main technological solution has been widely adopted as an integral part of the ablation process. Here we propose a genetic algorithm optimization technique to map a major arrhythmogenic substance-non-conducting regions (NCRs). Excitation delays in a set of electrodes of known locations are measured following external tissue stimulation, and the spatial distribution of obstacles that is most likely to yield the measured delays is reconstructed. A forward problem module was solved to provide synthetic time delay measurements using a 2D human atrial model with known NCR distribution. An inverse genetic algorithm module was implemented to optimally reconstruct the locations of the now unknown obstacle distribution using the synthetic measurements. The performance of the algorithm was demonstrated for several distributions varying in NCR number and shape. The proposed algorithm was found robust to measurements with a signal-to-noise ratio of at least -20 dB, and for measuring electrodes separated by up to 3.2 mm. Our results support the feasibility of the proposed algorithm in mapping NCRs; nevertheless, further research is required prior to clinical implementation for incorporating more complex atrial tissue geometrical configurations as well as for testing the algorithm with experimental data.

Aim: To evaluate the effectiveness of using a smartphone-based electrocardiography (ECG) monitoring device (ECG Check) on the frequency of clinic or emergency room visits in patients who underwent ablation of atrial fibrillation (AF). Methods: Two groups of patients were identified and compared: The conventional monitoring group (CM group) included patients who were prescribed conventional event monitoring or Holter monitoring systems. The ECG Check group (EC group) included patients who were prescribed the ECG Check device for continuous monitoring in addition to conventional event monitoring. The primary outcome was the number of patient visits to clinic or emergency room. The feasibility, accuracy, and detection rate of mobile ECG Check were also evaluated. Results: Ninety patients were studied (mean age: 66.2 ± 11 years, 64 males, mean CHA2DS2-VASc score: 2.6 ± 2). In the EC group, forty-five patients sent an average of 52.8 ± 6 ECG records for either routine monitoring or symptoms of potential AF during the follow-up period. The rhythm strips identified sinus rhythm (84.7%), sinus tachycardia (8.4%), AF (4.2%), and atrial flutter (0.9%). Forty-two EC transmissions (1.8%) were uninterpretable. Six patients (13%) in the EC group were seen in the clinic or emergency room over a 100-day study period versus 16 (33%) in the standard care arm ( P value Conclusions: Use of smartphone-based ECG monitoring led to a significant reduction in AF-related visits to clinic or emergency department in the postablation period.

Background: The Lesion Index (LSI) is a proprietary algorithm from Abbott Medical combining contact force, radiofrequency application duration, and radiofrequency current. It can be displayed during ablation with the TactiCath contact force catheter. The LSI Index was designed to provide real-time lesion formation feedback and is hypothesized to estimate the lesion diameter. Methods and Results: Before ablation, animals underwent cardiac computed tomography to assess atrial tissue thickness. Ablation lines (n=2–3 per animal) were created in the right atrium of 7 Göttingen mini pigs with point lesions (25 W). Within each line of ablation, the catheter tip was moved a prescribed distance (D/mm) according to 1 of 3 strategies: D=LSI+0 mm; D=LSI+2 mm; or D=LSI+4 mm. Two weeks after ablation, serial sections of targeted atrial tissue were examined histologically to identify gaps in transmural ablation. LSI-guided lines had a lower incidence of histological gaps (4 gaps in 69 catheter moves, 5.8%) than LSI+2 mm lines (7 gaps in 33 catheter moves, 21.2%) and LSI+4 mm lines (15 gaps in 23 catheter moves, 65.2%, P Conclusions: In this model of chronic atrial ablation, delivery of uninterrupted transmural linear lesions may be facilitated by using LSI to guide catheter movement. When ΔLSI between adjacent lesions is ≤1.5 mm, no gaps in atrial linear lesions should be expected.

AimsTo investigate the radius of transmural (TM) ablation effect at the left atrial posterior wall (LAPW) during contact force (CF)-guided pulmonary vein isolation (PVI), using pure R unipolar electrogram (UE) morphology change – a histologically validated marker of radiofrequency (RF)-induced TM atrial ablation.MethodsFollowing PVI in 24 consecutive patients (30W, continuous RF), VISITAG™ Module and CARTOREPLAY™ (Biosense Webster Inc.) RF and UE data at left and right-sided LAPW annotated sites 1 and 2 were analysed.ResultsAcutely durable PVI without spontaneous / dormant recovery was achieved following 15s and 10-11s RF, at sites 1 and 2, respectively (pConclusionWhen the first and second-annotated LAPW RF sites were within 7mm, 73% second-annotated sites demonstrated immediate pure R UE morphology change. These analyses support a paradigm of shorter RF duration at immediately adjacent sites during continuous RF application, and may usefully inform the further development of “tailored” approaches towards CF-guided PVI.What’s known?The VISITAG™ Module and CARTOREPLAY™ permit investigations into the tissue effects of RF energy deliveryin vivo, via objective annotation methodology and retrospective evaluation of histologically validated unipolar electrogram (UE) criteria for transmural (TM) atrial ablation.Greater RF energy effect is seen at left compared to right-sided first-annotated left atrial posterior wall (LAPW) sites during pulmonary vein isolation (PVI).What’s new?Following ∼15s RF delivery at first-annotated LAPW sites and aiming for ≤6mm inter-ablation site distance during continuous RF delivery, 73% second-annotated sites demonstrated immediate TM UE morphology change.At second-annotated sites, ∼10s RF resulted in acutely durable PVI in all. Greater left-sided RF energy effect was observed, not explained by differences in RF duration, mean CF or catheter position stability.The radius of TM RF effect may be determined at the LAPW following CF and VISITAG™ Module-guided PVI.

AimsTo assess the occurrence of a histologically validated measure of transmural (TM) atrial ablation – pure R unipolar electrogram (UE) morphology change – at first-ablated left atrial posterior wall (LAPW) sites during contact force (CF)-guided pulmonary vein isolation (PVI).Methods and resultsExported VISITAG™ Module and CARTOREPLAY™ (Biosense Webster Inc.) UE morphology data was retrospectively analysed in 23 consecutive patients undergoing PVI under general anaesthesia. PVI without spontaneous / dormant recovery was achieved in all, employing 16.3[3.2] minutes (mean [SD]) of temperature-controlled RF at 30W. All first-ablated LAPW sites demonstrated RS UE morphology pre-ablation, with RF-induced pure R UE morphology change in 98%. Time to pure R UE morphology was significantly shorter at left-sided LAPW sites (4.9[2.1] s versus 6.7[2.5] s; p=0.02), with significantly greater impedance drop (median 13.5Ω versus 9.9Ω; p=0.003). Importantly, neither the first-site RF duration (14.9 versus 15.0s) nor the maximum ablation catheter tip distance moved (during RF) were significantly different, yet the mean CF was significantly higher at right-sided sites (16.5g versus 11.2g; p=0.002). Concurrent impedance and objectively annotated bipolar electrogram (BE) data demonstrated ~6-8Ω impedance drop and ~30% BE decrease at the time of first pure R UE morphology change.ConclusionUsing objective ablation site annotation, TM UE morphology change was typically achieved within 7s at the LAPW, with significantly greater ablative effect evident at left-sided sites. The methodology described in this report represents a novel and scientifically more rigorous foundation towards future research into the biological effects of RF ablation in vivo.Condensed abstractThrough appropriate use of the VISITAG™ Module and CARTOREPLAY™, unipolar electrogram morphology change indicative of histologically confirmed transmural atrial ablation in animal models, was proven to occur typically within 7s, during first-site contact force-guided ablation at the left atrial posterior wall during pulmonary vein isolation.

Radiofrequency Ablation with Visual Ablation CatheterAims To define the temporal characteristics of atrial lesion growth (lesion surface area), local electrogram amplitude attenuation, and circuit impedance decrement during in vivo radiofrequency (RF) ablation with direct endocardial visualization (DEV). Methods and Results A direct endocardial visualization catheter was used for real-time endoscopic visualization of atrial endocardial surface during RF ablation. Videos of lesion growth (surface area), circuit impedance, and local electrogram amplitude were recorded during ablation in 11 ovine. Fifty-two atrial ablations at 12 W, 14 W, and 16 W power for 30 seconds were analyzed. During 30-second RF ablation, the lesion matured (90% of final lesion dimension) in the first 23.0 ± 5.8 seconds. The local electrogram amplitude attenuation (80% decrement) and circuit impedance attenuation (20% decrement from initial) occurred 13.8 ± 8.2 seconds and 13.1 ± 7.9 seconds, respectively, before lesion maturity in a significant proportion of 30 second atrial ablations. Conclusion The DEV observations suggest that in smooth atrial surface ablations with significant local electrogram and impedance decrement in the first 10 seconds, further extension of ablation for 10–15 seconds could deliver optimal surface dimensions; however, real-time measurement of depth was not possible.

Background Atrial fibrillation (AF) is the most common sustained arrhythmia. About 60% of patients with rheumatic heart disease have persistent AF. Methods A total of 197 patients underwent valve replacement concomitant bipolar radiofrequency ablation (BRFA). Patients were divided into the biatrial ablation group and the simplified right atrial ablation group. In biatrial ablation group, the patients underwent a complete left and right atrial ablation. In simplified right atrial ablation group, the patients underwent a complete left atrial ablation and a simplified right atrial ablation. Results The conversion of sinus rhythm (SR) was high in both groups during the follow-up period. In the simplified right atrial ablation group, SR conversion rate was 88.29% at discharge. At six months and 12 months after surgery, 87.39% of patients and 86.49% of patients were in SR free of antiarrhythmic drugs, respectively. While in the biatrial ablation group, SA conversion rate was 89.53% at discharge. Percentage of patients in SR free of antiarrhythmic drugs was 88.37% and 88.37% at six months and 12 months after surgery, respectively. Echocardiography showed left atrial diameter decreased significantly after the surgery in the two groups. The ejection fraction and fractional shortening were improved significantly, without significant differences between the two groups. Conclusions The results suggest that the concomitant left atrial and simplified right atrial BRFA for AF in patients undergoing valve replacement can achieve similar early efficiency as biatrial ablation.

Introduction Atrial fibrillation (AF) may result in thromboembolism often from a thrombus in the left atrium or atrial appendage accounting for nearly 15% of all strokes in the US, with an annual incidence of stroke of up to 6% or higher in some patients. Atrial fibrillation ablation, if successful over the long-term, may reduce the risk of future stroke. New anticoagulants, such as dabigatran, rivaroxaban, and apixaban, have been shown to be superior to warfarin to reduce the risk of stroke in non-valvular atrial fibrillation (NVAF), but no solid data are available to show if they are appropriate to utilize as an alternative to warfarin in patients undergoing catheter ablation procedures. Our case illustrated that such therapy may not be efficient.

Electrogram-guided ablation has been recently developed for allowing better detection and localization of abnormal atrial activity that may be the source of arrhythmogeneity. Nevertheless, no clear indication for the benefit of using electrograms guided ablation over empirical ablation was established thus far, and there is a clear need of improving the localization of cardiac arrhythmogenic targets for ablation. In this paper, we propose a new approach for detection and localization of irregular cardiac activity during ablation procedures that is based on dimension reduction algorithms and principal component analysis (PCA). Using an $8\times 8$ electrode array, our method produces manifolds that allow easy visualization and detection of possible arrhythmogenic ablation targets characterized by irregular conduction. We employ mathematical modeling and computer simulations to demonstrate the feasibility of the new approach for two well established arrhythmogenic sources for irregular conduction--spiral waves and patchy fibrosis. Our results show that the PCA method can differentiate between focal ectopic activity and spiral wave activity, as these two types of activity produce substantially different manifold shapes. Moreover, the technique allows the detection of spiral wave cores and their general meandering and drifting pattern. Fibrotic patches larger than 2 mm 2 could also be visualized using the PCA method, both for quiescent atrial tissue and for tissue exhibiting spiral wave activity. We envision that this method, contingent to further numerical and experimental validation studies in more complex, realistic geometrical configurations and with clinical data, can improve existing atrial ablation mapping capabilities, thus increasing success rates and optimizing arrhythmia management.

Introduction Iatrogenic atrial tachyarrhythmias have increased with the widespread application of left atrial ablative procedures to treat atrial fibrillation. Methods and results Entrainment and activation mapping were utilized to study the mechanisms of atrial flutter in two patients who presented with atypical atrial flutter after high intensity focused ultrasound (HIFU) atrial ablation for persistent atrial fibrillation during the course of concomitant cardiac surgery. Case 1: Atrial flutter with CL of 340 ms was demonstrated to be mediated by entry into and exit from the partially isolated posterior left atrium (LA) with conduction delay across at least one of the connections. The exit site was near the left superior pulmonary vein (LSPV) and the entrance site was near the right inferior pulmonary vein (RIPV) as demonstrated by activation and entrainment mapping. Case 2: Entrainment mapping was highly suggestive of inferior exit from the HIFU ablation line between the two inferior pulmonary veins. Flutter terminated during trans-septal procedure and could not be re-induced. Activation mapping of the LA during pacing revealed the inferior exit and left superior entrance site, both of which were successfully ablated, isolating the posterior LA. Conclusions Re-entrant atrial flutter post-HIFU epicor Maze is caused by slow conduction at entry and exit sites from the otherwise isolated posterior LA wall. In both cases, gaps were found close to the LSPV and RIPV which may reflect difficulty in achieving proper contact between the HIFU device and the left atrial wall at these sites. These gaps are amenable to catheter ablation.

Air embolism developing from an atrial-esophageal fistula that was created as a complication from an atrial ablation procedure is a rare, yet usually fatal diagnosis. Neurologic manifestations such as meningitis, altered mental status, seizures, strokes, transient ischemic attacks (TIAs), psychiatric changes, and coma can ensue. Imaging of the brain might reveal infarcts, cerebral edema, as well as signs of pneumocephalus. This case describes a 42-year-old male with recent cardiac ablation procedure at an outside hospital for refractory atrial fibrillation (A-fib) who presented with altered mental status, dyspnea and diaphoresis. His initial head computed tomography (CT) scan revealed pneumocephalus. He was started on a heparin drip for a non-ST elevation myocardial infarction (NSTEMI), but developed severe coagulopathy. The patient's mental status quickly deteriorated. Given recent cardiac ablation procedure, the cause of his air embolism was thought to be from a created left atrial-esophageal fistula. Despite medical management, he was too unstable to undergo any surgical intervention for his atrial-esophageal fistula or to transfer to a hyperbaric oxygen therapy center, and expired on the second day following his hospital admission. To our knowledge, few reports have been published in the literature describing delayed cerebral air embolism from an atrial-esophageal fistula. Prompt diagnosis, hyperbaric oxygen therapy, and surgical intervention are essential to avoid mortality in these patients. This article aims to increase awareness of such a rare, but significant complication.

Case series Patient: Male, 72 • Male, 29 • Male, 75 Final Diagnosis: Atrio-esophageal fistula Symptoms: Altered mental state • chest pain • fever • melena Medication: — Clinical Procedure: — Specialty: Critical Care Medicine Objective: Rare disease Background: Percutaneous catheter radiofrequency ablation (RFA) and cryoablation of the left atrium and pulmonary vein ostia have become successful therapeutic modalities in the management of atrial fibrillation. Atrio-esophageal fistula is a rare complication. Awareness of complication risk is imperative because without prompt diagnosis and urgent surgical intervention, the outcome is often fatal. We present 3 cases of atrio-esophageal fistula following percutaneous catheter radiofrequency ablation (RFA). Case Reports: Case 1: A 72-year old white male presented 27 days after percutaneous RFA for atrial fibrillation with fever, altered mental status, and melena. Esophagogastroduodenoscopy (EGD) revealed a 1-cm defect in the mid-esophagus. Upon thoracotomy, severe hemorrhage ensued from a concomitant injury to the left atrium. Multiple attempts to repair the left atrial perforation were unsuccessful and the patient died. Case 2: A 71-year old white male presented 29 days after percutaneous RFA for atrial fibrillation with fever and tonic-clonic seizure. Recognition of possible atrio-esophageal fistula was considered and confirmed on thoracotomy. Surgical fixation of the left atria and esophagus were performed. The patient survived and was discharged to a skilled care facility. Case 3: A 75-year old white male presented 24 days after percutaneous RFA for atrial fibrillation with chest pain. An echocardiogram revealed a large pericardial effusion and pericardiocentesis was performed. Despite aggressive measures, the patient died. The autopsy demonstrated a communicating esophageal fistula with the right pulmonary vein. Conclusions: Clinicians tending to patients who have recently undergone atrial ablation need to be aware of atrio-esophageal fistula as a rare but highly fatal complication.

Saline irrigation improved the safety of radiofrequency (RF) ablation, but the thermal feedback for energy titration is absent.To allow temperature-controlled irrigated ablation, a novel irrigated RF catheter was designed with a diamond-embedded tip (for rapid cooling) and 6 surface thermocouples to reflect tissue temperature. High-resolution electrograms (EGMs) from the split-tip electrode allowed rapid lesion assessment. The authors evaluated the preclinical and clinical performance of this catheter for pulmonary vein (PV) isolation.Using the DiamondTemp (DT) catheter, pigs (n = 6) underwent discrete atrial ablation in a temperature control mode (60°C/50 W) until there was ∼80% EGM amplitude reduction. In a single-center clinical feasibility study, 35 patients underwent PV isolation with the DT catheter (study group); patients were planned for PV remapping after 3 months, regardless of symptomatology. A control group included 35 patients who underwent PV isolation with a standard force-sensing catheter.Porcine lesion histology revealed transmurality in 51 of 55 lesions (92.7%). In patients, all PVs were successfully isolated; no char or thrombus formation was observed. Compared with the control group, the study cohort had shorter mean RF application duration (26.3 ± 5.2 min vs. 89.2 ± 27.2 min; p 0.001), shorter mean fluoroscopic time (11.2 ± 8.5 min vs. 19.5 ± 6.8 min; p 0.001), and lower acute dormant PV reconduction (0 of 35 vs. 5 of 35; p = 0.024). At 3 months, 23 patients underwent remapping: 39 of 46 PV pairs (84.8%) remained durably isolated in 17 of these patients (73.9%).This first-in-human series demonstrated that temperature-controlled irrigated ablation produced rapid, efficient, and durable PV isolation. (ACT DiamondTemp Temperature-Controlled and Contact Sensing RF Ablation Clinical Trial for Atrial Fibrillation [TRAC-AF]; NCT02821351).

Aims The aim of this study was to investigate whether there is a similar mortality and thrombo-embolic risk, after an atrial ablation procedure, compared with an atrial fibrillation (AF) procedure. Methods and results Using data from nationwide Danish health registries, we identified patients aged 18–75 years undergoing a first-time atrial flutter or an AF ablation procedure in the period 2000–13. Cox proportional hazards regression was used to calculate hazard ratios (HRs) after 5 years of follow-up, adjusting for concomitant risk factors. A total of 1096 and 2266 patients underwent an ablation for atrial flutter or AF, respectively. Age distribution was similar in the two, but atrial flutter patients had more co-morbidities. During 5 years of follow-up, we observed 38 and 36 deaths in the atrial flutter and AF groups, corresponding to an almost two-fold higher mortality rate among atrial flutter patients [crude HR 1.92, 95% confidence interval (CI) 1.22–3.03]. The higher mortality rate persisted after adjustment for age, sex, diabetes mellitus, and hypertension (adjusted HR 1.68, 95% CI 1.05–2.69). The rate of thrombo-embolic events was similar in the two groups (crude HR 1.34, 95% CI 0.71–2.56; adjusted HR 1.22, 95% CI 0.62–2.41). Conclusion In this observational study, patients with atrial flutter had a significantly higher all-cause mortality rate compared with those with AF after an ablation procedure, but similar thrombo-embolic event rates. Future studies should elucidate the reason for this difference in mortality. [10.1093/europace/euw159][1] [1]: /lookup/doi/10.1093/europace/euw159