Ostial Ablation Research Articles

Ostial vs. wide area circumferential ablation guided by the Ablation Index in paroxysmal atrial fibrillation.

Pulmonary vein isolation (PVI) guided by the Ablation Index (AI) has shown high acute and mid-term efficacy in the treatment of paroxysmal atrial fibrillation (AF). Previous data before the AI-era had suggested that wide-area circumferential ablation (WACA) was preferable to ostial ablation. However, with the use of AI, we hypothesize that ostial circumferential ablation is non-inferior to WACA and can improve outcomes in paroxysmal AF. Prospective, multicentre, non-randomized, non-inferiority study of consecutive patients were referred for paroxysmal AF ablation from January 2020 to September 2021. All procedures were performed using the AI software, and patients were separated into two different groups: WACA vs. ostial circumferential ablation. Acute reconnection, procedural data, and 1-year arrhythmia recurrence were assessed. During the enrolment period, 162 patients (64% males, mean age of 60 ± 11 years) fulfilled the study inclusion criteria-81 patients [304 pulmonary vein (PV)] in the WACA group and 81 patients (301 PV) in the ostial group. Acute PV reconnection was identified in 7.9% [95% confidence interval (CI), 4.9-11.1%] of PVs in the WACA group compared with 3.3% (95% CI, 1.8-6.1%) of PVs in the ostial group [P < 0.001 for non-inferiority; adjusted odds ratio 0.51 (95% CI, 0.23-0.83), P = 0.05]. Patients in the WACA group had longer ablation (35 vs. 29 min, P = 0.001) and procedure (121 vs. 102 min, P < 0.001) times. No significant difference in arrhythmia recurrence was seen at 1-year of follow-up [11.1% in WACA vs. 9.9% in ostial, hazard ratio 1.13 (95% CI, 0.44-1.94), P = 0.80 for superiority]. In paroxysmal AF patients treated with tailored AI-guided PVI, ostial circumferential ablation is not inferior to WACA with regard to acute PV reconnection, while allowing quicker procedures with less ablation time.

Usefulness of simultaneous isolation of the coronary sinus and the left atrial inferior wall for persistent atrial fibrillation refractory to box isolation

Abstract Funding Acknowledgements Type of funding sources: None. Background In patients who are refractory to box isolation (BoxI) and have atrial fibrillation (AF) substrate in left atrial inferior wall (LAIW), LAIW isolation is effective, but the procedure is highly difficult because the connection between LAIW and coronary sinus (CS) is dense. In this study, we report four cases of persistent AF in which simultaneous isolation of LAIW and CS was so effective. Methods and Results Case 1 is a 76-year-old female with persistent AF who had undergone BoxI and failed mitral isthmus block (MIB) creation. However, AF and atrial tachycardia (AT) persisted. In the 4th session, chemical ablation of Marshall vein was performed, and AF/AT was terminated, and MIB was created. Thereafter, multiple ATs were still inducible by rapid atrial pacing. Because AT substrate seemed to be confined to LAIW, we attempted to isolate LAIW by performing linear ablation between the right inferior pulmonary vein (RIPV) and posteroseptal mitral annulus (MA) near CS ostium, and linear ablation parallel to CS along posterior MA. However, LAIW isolation could not be achieved. Finally, CS ostial ablation from right atrium (RA) succeeded in simultaneous isolation of LAIW and CS. CS burst pacing could induce AT confined to LAIW and CS although RA maintained sinus rhythm (SR). Rapid RA pacing could not induce AT/AF. Case 2 is a 78-year-old female with persistent AF who completed BoxI and MIB creation. Raid RA pacing induced AF. Because cycle length of LAIW was apparently shorter than RA, we attempted to isolate LAIW. Firstly, we performed linear ablation from RIPV ostium to posterior MA. During linear ablation, AF converted to AT, and finally RA returned to SR while AT was still sustained within LAIW and CS. This tachycardia was a reentrant tachycardia circling LAIW and CS. After this AT returned to SR by linear ablation within LAIW, LAIW and CS were not isolated during SR. CS ostial ablation from RA succeeded in simultaneous LAIW and CS isolation. Case 3 is a 74-year-old female with persistent AF refractory to BoxI. Although non-pulmonary vein (non-PV) trigger was documented in LAIW, the precise origin of non-PV trigger could not be identified due to infrequency. Case 4 is a 64-year-old male with persistent AF refractory to BoxI. He had undergone catheter ablation three times. Fractionation map showed that AF substrate was likely located in LAIW. Therefore, we attempted to isolate LAIW in Case 3 and 4. We performed MI ablation, linear ablation between RIPV ostium and posteroseptal MA, and CS ostial ablation from RA, which succeeded in simultaneous isolation of LAIW and CS in both cases. AF has never recurred in Case 1 and 2. SR could be maintained with antiarrhythmics in Case 3 and 4. Conclusions In patients with persistent AF refractory to BoxI, if LAIW has AF/AT substrate or non-PV triggers, simultaneous isolation of LAIW and CS may be a new therapeutic strategy. Simultaneous isolation of LAIW and CS requires ablation at CSos from RA.

3D-electroanatomical mapping of the left atrium and catheter-based pulmonary vein isolation in pigs: A practical guide.

To propose a standardized workflow for 3D-electroanatomical mapping guided pulmonary vein isolation in pigs. Danish female landrace pigs were anaesthetized. Ultrasound-guided puncture of both femoral veins was performed and arterial access for blood pressure measurement established. Fluoroscopy- and intracardiac ultrasound-guided passage of the patent foramen ovale or transseptal puncture was performed. Then, 3D-electroanatomical mapping of the left atrium was conducted using a high-density mapping catheter. After mapping all pulmonary veins, an irrigated radiofrequency ablation catheter was used to perform ostial ablation to achieve electrical pulmonary vein isolation. Entrance- and exit-block were confirmed and re-assessed after a 20-min waiting period. Lastly, animals were sacrificed to perform left atrial anatomical gross examination. We present data from 11 consecutive pigs undergoing pulmonary vein isolation. Passage of the fossa ovalis or transseptal puncture was uneventful and successful in all animals. Within the inferior pulmonary trunk 2-4 individual veins as well as 1-2 additional left and right pulmonary veins could be cannulated. Electrical isolation by point-by-point ablation of all targeted veins was successful. However, pitfalls including phrenic nerve capture during ablation, ventricular arrhythmias during antral isolation close to the mitral valve annulus and difficulties in accessing right pulmonary veins were encountered. Fluoroscopy- and intracardiac ultrasound-guided transseptal puncture, high-density electroanatomical mapping of all pulmonary veins and complete electrical pulmonary vein isolation can be achieved reproducibly and safely in pigs when using current technologies and a step-by-step approach.

Hot or cold? Feasibility, safety, and outcome after radiofrequency-guided versus cryoballoon-guided left atrial appendage isolation.

BackgroundLeft atrial appendage (LAA) isolation (LAAI) has been described as an adjunctive ablation strategy for patients with recurrent atrial tachyarrhythmia (ATa).ObjectivesWe compared the clinical impact of persistent durable LAAI between radiofrequency (RF)‐guided wide‐area LAAI and cryoballoon (CB)‐guided ostial LAAI.MethodsConsecutive patients who underwent RF‐ or CB‐guided LAAI were retrospectively analyzed. RF‐guided LAAI was performed by combining linear ablation. CB‐guided LAAI was performed by LAA ostial ablation. Following LAAI, the patients underwent an invasive remapping study. LAA closure was conducted if persistent durability was confirmed. The procedural data, LAAI durability, and ATa recurrence were assessed.ResultsA total of 260 patients (RF: n = 201; CB: n = 59) undergoing LAAI were identified. The acute rate of procedural LAAI was higher in the CB group (CB:94.9% vs. RF:82.6%, p = .02) with a lower pericardial effusion incidence (CB:0% vs. RF:7.5%, p = .03). The 6‐week durable LAAI was similar between the two groups (RF:78.3% vs. CB:66.0%, p = .103). During follow‐up, one gastrointestinal bleeding and four stroke events including one subsequent intracranial bleeding leading to death occurred in the RF group, while one gastrointestinal bleeding occurred in the CB group.The 1‐year ATa recurrence‐free rate was higher in patients with durable LAAI following RF‐guided LAAI (RF:76.3% vs. CB:56.7%, p = .0017). Multivariate analysis revealed RF‐guided LAAI as a predictor of freedom from ATa recurrence (HR: 0.478, 95%CI: 0.336–0.823, p = .017).ConclusionsLAAI can be more readily and safely achieved by CB‐guided ostial ablation. In patients with confirmed LAAI, however, the freedom from ATa recurrence was higher after RF‐guided wide‐area isolation.

Impact of left atrial appendage ridge ablation on the complex fractionated electrograms in persistent atrial fibrillation.

The left atrial appendage (LAA) is a possible key contributor to the maintenance of persistent atrial fibrillation (PsAF). The effect of LAA ostial ablation on global left atrial higher-frequency sources remains unclear. Complex fractionated electrograms (CFEs) and dominant frequency (DF) maps acquired with a NavX system in 58 PsAF patients were enrolled and examined before and after LAA posterior ridge ablation, which followed a stepwise linear ablation. High-density left atrial mapping identified continuous CFE sites in 50 % and high-DFs (≥ 8 Hz) in 53 % of patients at the LAA posterior ridge. In 44 patients in whom AF persisted despite pulmonary vein isolation (PVI) and linear ablation, LAA ablation significantly increased the mean CFE cycle length from 98 ± 29 to 108 ± 30 ms (P<0.0001) and decreased DF from 6.1 ± 0.8 to 5.9 ± 0.8 Hz (P<0.005) within the coronary sinus (CS). A multivariate analysis showed single-procedure failures could be predicted by the left atrial volume index and absence of continuous CFEs at the LAA posterior ridge region. The percent decrease in the global left atrial DF after LAA posterior ridge ablation was significantly lower in the patients with than in those without an enlarged left atrium (LA) (>90 mL/m(2)) (median 0 vs 4.8 %; P<0.01) and significantly lower in the patients with than in those without the absence of continuous CFEs in the LAA posterior ridge region (median 0.6 vs 4.8 %; P<0.05). These findings suggested that an approach incorporating an LAA posterior ridge ablation was effective in modifying higher-frequency sources in the global LA in PsAF patients, but a lesser effect was documented in patients with electroanatomical remodeling of the LA.

Diagnostic Accuracy of Cardiac Magnetic Resonance Imaging in the Detection and Characterization of Left Atrial Catheter Ablation Lesions: A Multicenter Experience

We tested the hypothesis that cardiovascular magnetic resonance (CMR) imaging can reliably distinguish the presence or absence of left atrial (LA) ablation lesions by blinded analysis of pre- and postablation imaging. Consecutive patients at 2 centers undergoing pulmonary vein isolation (PVI) for paroxysmal atrial fibrillation by either wide area circumferential radiofrequency ablation (WACA) or ostial ablation with a cryoballoon underwent CMR late gadolinium enhancement (LGE) imaging pre- and 3 months postablation. Imaging was anonymized for blinded analysis of (1) LGE images, and (2) a 3D fusion image with LGE projected onto a segmented LA surface. Scans were categorized using both assessment techniques separately as pre- or postablation, and if postablation, whether lesions were in an ostial or WACA distribution. LGE imaging was performed in 50 patients (aged 60 ± 10 years, 68% male, 24 underwent WACA and 26 had cryoablation). Sensitivity and specificity for detection of ablation lesions was 60% and 96% on LGE imaging. Sensitivity was higher using 3D fusion imaging (88%; P = 0.003). The proportion in whom lesions were both detected and the distribution correctly assessed as WACA or ostial was higher with 3D fusion imaging compared to LGE imaging (54% vs 28%; P = 0.014). There was no difference in the detection of radiofrequency ablation lesions compared to cryoablation lesions (58% vs 62%; P = 1.000). LGE imaging of atrial scar is not yet sufficiently accurate to reliably identify ablation lesions or to determine lesion distribution.

Complex Fractionated Atrial Electrograms

Since its inception in the 1990s, catheter ablation of atrial fibrillation (AF) has been a continuously evolving procedure. Ablation strategies have adapted to advances in technology including new catheter designs, innovations in mapping systems, and alternative energy sources. Moreover, catheter ablation has stimulated and responded to an improved understanding of the mechanisms of initiation and perpetuation of AF. Over the past 15 years, many centers have spent considerable effort in defining optimal ablation strategies for elimination of paroxysmal and nonparoxysmal AF. Article see p 143 The pulmonary veins were recognized early by Haissaguerre et al1,2 as a frequent source of triggers for AF. Pulmonary vein isolation quickly became the cornerstone of catheter ablation of AF and sparked its rise as a promising tool to eliminate symptomatic and drug-refractory AF.3,4 This was first performed by ostial ablation, but, because of the risk of pulmonary vein stenosis and recognition of vital antral drivers, an antral pulmonary vein isolation (APVI) strategy evolved.3,5 Adjuvants to APVI have been proposed, including ablation of complex fractionated atrial electrograms (CFAE). Initial experience suggested that CFAE ablation is a viable stand-alone strategy,6 but this experience has not been reproducible.7 …

Real-Time Contact Force Measurement for Catheter Ablation: Technology and Rationale

Pulmonary vein ostial ablation with the aim of electrically isolating the arrhythmogenic tissue is the commonest ablation strategy for AF. Attempts are being made to simplify pulmonary vein isolation by creating 3D versions of the atrial anatomy, and robotic as well as remote catheter navigation has been developed. Single shot circular ablation devices, using RF, ultrasound, cryo and laser energy, are under evaluation. Despite these different innovations, the most commonly used technique is the composite multiple point ablation lesion created with a fundamentally simple radiofrequency energy delivering ablation catheter. The high recurrence rate and low efficacy of current ablation procedures may be traced in large part to the inherent variability in individual lesion size with this technology. Real-time measurement of catheter tip contact force may allow electrophysiologists to avoid both ineffective lesions because of insufficient contact and complications due to excessive contact force. Currently, fiber-optic as well as electro-magnetic sensor based technologies offer the most precise real-time measurement although impedance and friction based measures are also available. The greatest experimental and clinical experience is with the fiber-optic technology, with more than 700 human patients. Three prospective human studies are underway evaluating the correlation between contact force and acute as well as chronic efficacy in isolating the pulmonary veins. This technology may help reduce re-do procedure rates for atrial fibrillation and also improve procedural safety.

A critical appraisal of cardiac ablation technology for catheter-based treatment of atrial fibrillation

The advent of catheter ablation has revolutionized the treatment of supraventricular cardiac arrhythmias, including in the last few years, atrial fibrillation. The discovery of electrically active sleeves of atrial myocardium extending into the pulmonary veins has led to the development of pulmonary vein ostial ablation, with the aim of electrically isolating or ‘walling-off’ the arrhythmogenic tissue. Despite different innovations, the most commonly used technique is the composite multiple-point ablation lesion created with a fundamentally simple radiofrequency energy-delivering ablation catheter. The high recurrence rate and low efficacy of current ablation procedures may be traced in large part to the inherent variability in individual lesion size with this technology. Arguably, real-time lesion monitoring, optimization and prediction are necessary to achieve significant improvements in efficacy and safety for catheter ablation of atrial fibrillation.

Pulmonary vein isolation with Mesh Ablator versus Cryoballoon Catheters: 6-month outcomes

We sought to compare the results of pulmonary vein (PV) ablation using the high-density Mesh Ablator catheter (MESH) versus the cryoballoon (CRYO). From August 2007 to November 2009, all patients with paroxysmal atrial fibrillation scheduled for a first procedure of PV isolation were screened by cardiac computed tomography for anatomical suitability to undergo ablation with a circumferential ostial ablation catheter. The procedure was finally performed in 79 out of 120 patients matching the criteria of four clearly separated PVs with an ostial diameter of 15-25mm. The first consecutive 43 patients were treated with the MESH; the following 36 consecutive patients were treated with the CRYO. The procedures were performed with up to 900s of either pulsed radiofrequency energy delivered by the MESH or cryoenergy applied with the CRYO. The clinical success rate was evaluated 6months after a single procedure. Isolation of all PVs could be achieved in 40 patients (93%) in the MESH group compared to 31 patients (89%) in the CRYO group (p = ns). Major complications consisted of one tamponade in the MESH group and one reversible phrenic nerve palsy in the CRYO group. After 6months, the clinical success rate was 44% (19/43 P) in the MESH versus 69% (25/36 P) in the CRYO group (p < 0.05). Both methods of simplified circumferential PV ablation reveal a high acute success rate. The clinical 6-month results of the MESH are statistically significant inferior compared to the CRYO.

Epicardial Connections Between the Pulmonary Veins and Left Atrium: Relevance for Atrial Fibrillation Ablation

Some observations support the existence of epicardial connections (ECs) between ipsilateral pulmonary veins (vein to vein ECs [VVECs]), and we have observed venoatrial ECs inserted at distance from the pulmonary vein ostium (vein to atrium ECs [VAECs]). Our aim was to determine the prevalence of ECs and their relevance for pulmonary vein isolation. We studied 100 consecutive patients with drug-refractory atrial fibrillation who underwent ostial pulmonary vein isolation by cooled radiofrequency catheter ablation. A VVEC was identified if pulmonary vein pacing activated the ipsilateral vein before the atrium, requiring ablation of both venous ostia to isolate either pulmonary vein. A VAEC was identified if pacing produced atrial breakthrough located at distance from the venous ostium, requiring extraostial ablation to isolate the pulmonary vein. Patients with ECs (20%) were younger (P = 0.02) and had a higher prevalence of structural heart disease (P = 0.01) than patients without ECs. VVECs and VAECs were identified in 32 pulmonary veins (10%) and VAECs in 10 veins (3%). Veins with ECs had a higher rate of early recurrence of conduction following isolation (29% vs 11%; P = 0.01). Twenty percent of patients with atrial fibrillation had ECs resistant to ostial ablation in one or more pulmonary veins. Isolating veins with ECs may require a different ablation approach. These connections are associated with an increased rate of early recurrence of conduction. (J Cardiovasc Electrophysiol, Vol. 22, pp. 149-159, February 2011).

Pulmonary venous isolation by antral ablation with a large cryoballoon for treatment of paroxysmal and persistent atrial fibrillation: medium-term outcomes and non-randomised comparison with pulmonary venous isolation by radiofrequency ablation

BackgroundTo prevent atrial fibrillation (AF) recurrence after catheter ablation, pulmonary venous isolation (PVI) at an antral level is more effective than segmental ostial ablation. Cryoablation around the pulmonary venous (PV)...

135 Combined radiofrequency and cryoablation for paroxysmal atrial fibrillation. A novel technique to reduce recurrences: Abstract 135 Table 1

<h3>Introduction</h3> We hypothesised that electrical isolation of the pulmonary veins (PV) by wide area circumferential ablation with radiofrequency (RFA) followed by selective PV ostial ablation using a cryoablation balloon (Cryo) would create parallel lines of block and reduce the incidence of PV reconnection.This would therefore improve first time success rates for paroxysmal atrial fibrillation (PAF). <h3>Methods</h3> A retrospective study examined 59 consecutive patients undergoing first time PV isolation for symptomatic PAF(&gt;1 year) and had failed at least two medical therapies. Patients received RFA alone, Cryo alone or combined RFA (to isolate PVs) followed by Cryo. Patients were followed up with 12 lead ECG, 7 day Holter monitoring and clinical review. Any atrial arrhythmia lasting greater than 30 s during a 3 month follow-up period was documented as a recurrence. <h3>Results</h3> Significantly fewer patients had symptomatic palpitations (with documented PAF) in the combined group, with a trend towards need for less redo procedures (Abstract 135 table 1). Complications were one phrenic nerve palsy and one haematoma in the Cryo group, one grounding plate burn in the RF group and one phrenic nerve palsy , one pericardial effusion and one haematoma in the combined group. Total procedure time was greater in the combined group (Abstract 135 table 1). <h3>Conclusion</h3> Preliminary results suggest that combination of RF and Cryoablation is superior to either alone. A prospective randomised trial is underway to confirm these findings.

A 50-Year-Old Woman With a History of Atrial Fibrillation Presents With Acute Dyspnea and Pleuritic Chest Pain

A 50-Year-Old Woman With a History of Atrial Fibrillation Presents With Acute Dyspnea and Pleuritic Chest Pain

A Transthoracic Echocardiographic Follow-Up Study After Catheter Ablation of Atrial Fibrillation: Can We Detect Pulmonary Vein Stenosis by Transthoracic Echocardiography?

Background and ObjectivesWhile pulmonary vein isolation (PVI) is an effective curative procedure for patients with atrial fibrillation (AF), pulmonary vein (PV) stenosis is a potential complication which may lead to symptoms that are often unrecognized. The aim of this study was to compare differences between ablation sites in pulmonary venous flow (PVF) measured by transthoracic Doppler echocardiography (TTE) before and after PVI.Subjects and MethodsOne hundred five patients (M : F=64 : 41; mean age 56±10 years) with paroxysmal AF (n=78) or chronic, persistent AF (n=27) were enrolled. PVI strategies consisted of ostial ablation (n=75; OA group) and antral ablation using an electroanatomic mapping system (n=30; AA group). The ostial diameter was estimated by magnetic resonance imaging (MRI) in patients with PVF ≥110 cm/sec by TTE after PVI.ResultsNo patient complained of PV stenosis-related symptoms. Changes in mean peak right PV systolic (-6.7±28.1 vs. 10.9±25.9 cm/sec, p=0.038) and diastolic (-4.1±17.0 vs. 9.9±25.9 cm/sec, p=0.021) flow velocities were lower in the AA group than in the OA group. Although the change in mean peak systolic flow velocity of the left PV before and after PVI in the AA group was significantly lower than the change in the OA group (-13.4±25.1 vs. 9.2±22.3 cm/sec, p=0.016), there was no difference in peak diastolic flow velocity. Two patients in the OA group had high PVF velocities (118 cm/sec and 133 cm/sec) on TTE, and their maximum PV stenoses measured by MRI were 62.5% and 50.0%, respectively.ConclusionPV stenosis after PVI could be detected by TTE, and PVI by antral ablation using an electroanatomic mapping system might be safer and more useful for the prevention of PV stenosis.

Pulmonary Vein Isolation using a High Density Mesh Ablator Catheter: Incorporation of three-Dimensional Navigation and Mappin.

Background: We evaluated the use of a novel High Density Mesh Ablator (HDMA) catheter in combination with three-dimensional navigation for the treatment of paroxysmal atrial fibrillation. Methods: The HDMA catheter was used to carry out pulmonary vein isolation in a consecutive series of patients. Three-dimensional geometry of the left atrial-pulmonary vein (LA-PV) junctions were first created with the HDMA catheter. Ostial, proximal and distal sites within the pulmonary veins were tagged with catheter shadows on the created geometry to allow for re-interrogation of these exact sites after ablation. Results: The HDMA catheter was successfully used to create three dimensional geometry of the LA-PV junction in a total of 20 pulmonary veins which involved 5 patients. In all cases, ostial ablation alone was sufficient to achieve electrical isolation. No significant pulmonary vein stenosis was seen acutely after ablation. Conclusion: We describe the successful use of the novel HDMA catheter to create three-dimensional geometry of the LA-PV junction to assist with pulmonary vein isolation.

Segmental pulmonary vein isolation in atrial fibrillation: new insights from the high density mesh mapper technique in an electrophysiologically guided approach

As opposed to fundamental investigations into the nature of atrial fibrillation (AF) current clinical studies of AF ablation techniques sometimes only contain sparse information about the underlying electrophysiological properties. The purpose of this prospective, pilot study was to evaluate acute therapeutic success and clinical outcome after 6 month of segmental ostial ablation (SOA) using the High Density Mesh Mapper catheter (HDMM, BARD Electrophysiology, Lowell, MA, USA) for an electrophysiological guided approach. The HDMM is a novel, single expandable basket electrode catheter for high resolution recordings at the left atrium/pulmonary vein (PV) junction. SOA was performed by irrigated radiofrequency (RF) application around the HDMM. Entry- and exit conduction block, as well as decreased local electrode amplitude, were endpoints for short-term successful ablation. Seventy-two patients with highly symptomatic paroxysmal AF (PAF; 47, 65.2%), persistent AF (12, 16.7%) and permanent AF (13, 18.1%) were studied. Entrance conduction block was obtained in 93%, exit conduction block in 81% of all PV. After 6 month no PV stenosis was observed, 62 patients (86.1%) improved clinically, whereas 52 patients (72.2%) were free from arrhythmias and sinus rhythm was present favoring patients with PAF. In this first prospective study of PV isolation using the HDMM, our findings suggest, that this method is safe and yields good primary success rates and favourable clinical outcome at 6 month. The new technology based on high resolution recordings, offers beside good anatomical orientation a direct electrophysiological control for monitoring of bidirectional conduction block.

A nationwide survey on the prevalence of atrioesophageal fistula after left atrial radiofrequency catheter ablation

There are limited data on the prevalence of atrioesophageal fistula (AEF) after left atrial radiofrequency catheter ablation for atrial fibrillation (AF). The purpose of this study was to determine the prevalence and factors associated with AEF using a nationwide anonymous survey. The information solicited included the practice setting, number of left atrial ablations performed for AF, prevalence of AEF, clinical presentation and outcome of these patients, ablation strategy, type of ablation catheter, and energy settings used to deliver radiofrequency energy. The survey was mailed to 1,874 members of the Heart Rhythm Society within the US and 585 physicians responded (31%). AEF was reported in six of the 20,425 patients who underwent a left atrial ablation procedure (0.03%). All six patients suffered from major cerebrovascular events. Five of the six patients died (83%). The patient who survived had residual hemiparesis. There was no association between the risk of AEF and the case volume. In five patients, wide area circumferential ablation was performed. In the remaining patient, pulmonary vein isolation by ostial ablation was employed. In all cases an 8-mm tip ablation catheter was used. The power in patients who did and did not develop AEF were 58 +/- 13 and 41 +/- 9 W, respectively (P = 0.03). In one patient AEF occurred despite <1 degrees C rise recorded from an esophageal temperature probe. In the remaining patients no specific method was used to visualize the location of the esophagus. Based on the responses to the survey, the risk of AEF appears to be <1%. However, AEF is associated major cerebrovascular events and leads to death in >80% of the patients.

Catheter Ablation for Atrial Fibrillation in Patients with Obesity.

Methods A cohort of 523 patients with symptomatic AF undergoing radiofrequency ablation at a single institution was included in this study. Body weight was determined and patients were stratified by body mass index into three groups: lean (BMI < 25 kg/m2), overweight (BMI 25-29.9 kg/m2) and obese (BMI ≥ 30 kg/m2). Two techniques for atrial fibril lation ablation were employed: 298 patients underwent pulmonary vein ostial ablation with a 5mm tip ablation catheter and 222 patients underwent wide-area circumferential ablation outside the pulmonary vein ostia with an 8mm tip ablation catheter. Patients in this second group also underwent creation of linear lesions and ablation of focal triggers of AF identified during isoproterenol infusion. Patients were followed up with a 24-hour Holter monitor 3 months after the ablation. Follow-up after that time was performed by telephone, annual questionnaires, and with intermittent monitor ing, though the method and timing of monitoring is not well-described. Quality of life questionnaires were administered 3 and 12 months after ablation. Outcomes are reported at 12 and 24 months after ablation but Kaplan-Meier curves are not provided.

Incidence of Adenosine-Induced Pulmonary Vein Reconnection Following Catheter Ablation of Paroxysmal Atrial Fibrillation

Introduction: Adenosine has significant effects on cellular electrophysiology. Previous studies have shown recovery of pulmonary venous (PV) potentials following exogenous administration of adenosine after apparently successful pulmonary venous isolation in 25–56%of veins. The population studied and method and site of ablation may influence the rate of PV reconnection. We sought to characterise adenosine-induced reconnection in a homogeneous group of patients undergoing first catheter ablation for paroxysmal atrial fibrillation utilising three-dimensional mapping systems. Methods: The effect of intravenous adenosine following successful isolation of 64 veins in 17 patients with paroxysmal AF (15male) was studied. Segmental ostial ablation was performed with an irrigated catheter at the venoatrial junction guided by circular mapping catheter and a three-dimensional mapping system. Intravenous adenosine (12–24mg) was administered 20min post-isolation during coronary sinus pacing to achieve at least one nonconducted atrial paced beat. (LVH; wall thickness range 1.4–2.4 cm) and left atrial (LA) enlargementwerepresent in all cases. LV systolic dysfunctionwaspresent in 2/5.Nopatients had lowECG limb lead voltages, neither did any have ECG evidence of LVH by voltage criteria. On the presenting ECG, 4/5 had either AF (1/5), intraventricular conductiondelay (2/5) orfirst degree AV block (2/5). At presentation 1/5 was in chronic AF. During a mean follow-up of 24± 11 months 4/5 developed AF and 3/5 required permanent cardiac pacing for symptomatic heart block. AF was chronic in 3 and paroxysmal in 1. In 2/4 TEE guided AF cardioversion was attempted andbothhadpoorLAappendageemptyingvelocitieswith spontaneous LA echo contrast. Non-cardiac symptoms due to SCA were rare with painful peripheral neuropathy in 2/5. One patient died from progressive heart failure. Conclusion: SCA may be suspected by the presence of echocardiographic LVH without hypertension nor ECG evidence of LVH in an elderly male presenting with shortness of breath. The development of AF and/or heart block appear common during medium term follow-up.