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Background: Although Lesion size index (LSI) has been reported to highly predict radiofrequency lesion size in vitro, its accuracy in lesion size and steam pop estimation has not been well investigated for every possible scenario., Methods: Initially, radiofrequency ablations were performed on porcine myocardial slabs at various power, CF, and time settings with blinded LSI. Subsequently, radiofrequency power at 20, 30, 40, 50, and 60 W was applied at CF values of 5, 10, 20, and 30 g to reach target LSIs of 4, 5, 6, and 7. Lesion size and steam pops were recorded for each ablation., Results: Lesion size was positively correlated with LSI regardless of power settings (p < 0.001). The linear correlation coefficients of lesion size and LSI decreased at higher power settings. At high power combined with high CF settings (50 W/20 g), lesion depth and LSI showed an irrelevant correlation (p = 0.7855). High-power ablation shortened ablation time and increased the effect of resistive heating. LSI could predict the risk of steam pops at high-power settings with the optimal threshold of 5.65 (sensitivity, 94.1%; specificity, 46.1%). The ablation depth of the heavy heart was shallower than that of the light heart under similar ablation settings., Conclusions: LSI could predict radiofrequency lesion size and steam pops at high power settings in vitro, while synchronous high power and high CF should be avoided. Lighter hearts require relatively lower ablation settings to create appropriate ablation depth., (© 2023 Wiley Periodicals LLC.)

Introduction: Atrial Fibrillation (AF) is a common arrhythmia often comorbid with systolic or diastolic heart failure (HF). Catheter ablation is a more effective treatment for AF with concurrent left ventricular dysfunction, however, the optimal timing of use in these patients is unknown., Methods: All patients that received a catheter ablation for AF(n = 9979) with 1 year of follow-up within the Intermountain Healthcare system were included. Patients with were identified by the presence of structural disease by ejection fraction (EF): EF ≤ 35% (n = 1024) and EF > 35% (n = 8955). Recursive partitioning categories were used to separate patients into clinically meaningful strata based upon time from initial AF diagnosis until ablation: 30-180(n = 2689), 2:181-545(n = 1747), 3:546-1825(n = 2941), and 4:>1825(n = 2602) days., Results: The mean days from AF diagnosis to first ablation was 3.5 ± 3.8 years (EF > 35%: 3.5 ± 3.8 years, EF ≤ 35%: 3.4 ± 3.8 years, p = .66). In the EF > 35% group, delays in treatment (181-545 vs. 30-180, 546-1825 vs. 30-180, >1825 vs. 30-180 days) increased the risk of death with a hazard ratio (HR) of 2.02(p < .0001), 2.62(p < .0001), and 4.39(p < .0001) respectively with significant risks for HF hospitalization (HR:1.44-3.69), stroke (HR:1.11-2.14), and AF recurrence (HR:1.42-1.81). In patients with an EF ≤ 35%, treatment delays also significantly increased risk of death (HR 2.07-3.77) with similar trends in HF hospitalization (HR:1.63-1.09) and AF recurrence (HR:0.79-1.24)., Conclusion: Delays in catheter ablation for AF resulted in increased all-cause mortality in all patients with differential impact observed on HF hospitalization, stroke, and AF recurrence risks by baseline EF. These data favor earlier use of ablation for AF in patients with and without structural heart disease., (© 2023 Wiley Periodicals LLC.)

Background: Catheter ablation is an increasingly used treatment for symptomatic atrial fibrillation (AF). However, there are limited prospective, nationwide data on patient selection and procedural characteristics. This study describes patient characteristics, techniques, treatment patterns, and safety outcomes of patients undergoing AF ablation., Methods: A total of 3139 patients undergoing AF ablation between 2016 and 2018 in the Get With The Guidelines-Atrial Fibrillation registry from 24 US centers were included. Patient demographics, medical history, procedural details, and complications were abstracted. Differences between paroxysmal and patients with persistent AF were compared using Pearson χ 2 and Wilcoxon rank-sum tests., Results: Patients undergoing AF ablation were predominantly male (63.9%) and White (93.2%) with a median age of 65. Hypertension was the most common comorbidity (67.6%), and patients with persistent AF had more comorbidities than patients with paroxysmal AF. Drug refractory, paroxysmal AF was the most common ablation indication (class I, 53.6%) followed by drug refractory, persistent AF (class I, 41.8%). Radiofrequency ablation with contact force sensing was the most common ablation modality (70.5%); 23.7% of patients underwent cryoballoon ablation. Pulmonary vein isolation was performed in 94.6% of de novo ablations; the most common adjunctive lesions included left atrial roof or posterior/inferior lines, and cavotricuspid isthmus ablation. Complications were uncommon (5.1%) and were life-threatening in 0.7% of cases., Conclusions: More than 98% of AF ablations among participating sites are performed for class I or class IIA indications. Contact force-guided radiofrequency ablation is the dominant technique and pulmonary vein isolation the principal lesion set. In-hospital complications are uncommon and rarely life-threatening.

Background: High power, shorter duration (HPSD) ablation strategies have been advocated to increase efficacy and minimize posterior wall deep tissue thermal injury during atrial fibrillation (AF) ablation., Objective: The purpose of this study was to determine the long-term outcomes of arrhythmia-free survival from AF and atrial flutter (AFL) between HPSD and low power, longer duration (LPLD) ablation strategies., Methods: Of a total of 1333 first time AF ablation procedures with 3 years of follow-up, propensity-matched populations for baseline risk factors were created, comprising 402 patients treated with LPLD ablation (30 W for 5 seconds: posterior wall; 30 W for 10-20 seconds: anterior wall) and 402 patients treated with HPSD ablation (50 W for 2-3 seconds: posterior wall; 50 W for 5-15 seconds: anterior wall). AF/AFL outcomes after a 90-day blanking period were assessed., Results: HPSD ablation was associated with shorter procedure and fluoroscopy times (P < .0001 for both). The recurrence of AF at 1 year (12.9% vs 16.2%; P = .19) and 3 years (26.5% vs 30.7%; P = .23) was similar between LPLD and HPSD groups. AFL was higher at 1 year (7.2% vs 11.2%; P = .03) and 3 years (16.1% vs 21.8%; P = .06; P = .04 after multivariate adjustment) with HPSD ablation. Patients who underwent an LPLD approach had lower rates of need for repeat ablation (21% vs 30%; P = .002)., Conclusion: Long-term freedom from AF rates were not significantly different between both approaches. An HPSD ablation strategy compared with an LPLD approach was associated with an increased risk of AFL and need for repeat ablation but with lowered procedure times., (Copyright © 2019 Heart Rhythm Society. Published by Elsevier Inc. All rights reserved.)

Observational trials have shown that atrial fibrillation ablation favorably impacts long-term outcomes in systolic heart failure. These outcomes have been confirmed by randomized prospective trials highlighting the favorable impact of ablation on left ventricular function and remodeling, risk of heart failure hospitalization, and mortality. Ablation along with established heart failure medications is new and supported conceptually by the value of restoring sinus rhythm, avoiding long-term antiarrhythmic drugs, and minimizing drug-drug interactions. Observational data suggest a potential long-term benefit of beta-blockers with ablation that becomes augmented as follow-up is extended from 1 to 5 years., (Copyright © 2019 Elsevier Inc. All rights reserved.)

Background: Many centers use radiofrequency (RF) energy at 25-35 W for 30-60 seconds. There is a safety concern about using higher power, especially on the posterior wall., Objective: The purpose of this study was to examine complication rates for atrial fibrillation (AF) ablations performed with high-power, short-duration RF energy., Methods: We examined the complication rates of 4 experienced centers performing AF ablations at RF powers from 45-50 W for 2-15 seconds per lesion. In total, 13,974 ablations were performed in 10,284 patients. On the posterior wall, 11,436 ablations used 45-50 W for 2-10 seconds, and 2538 ablations used power reduced to 35 W for 20 seconds. Esophageal temperature monitoring was used in 13,858 (99.2%)., Results: Demographics were age 64 ± 11 years, male 68%, left atrial size 4.4 ± 0.7 cm, paroxysmal AF 37%, persistent AF 42%, longstanding AF 20%, antiarrhythmic drugs failed 1.4 ± 0.7, hypertension 54%, diabetes 15%, previous cerebrovascular accident/transient ischemic attack 7%, and CHA 2 DS 2 -VASc score 2.1 ± 1.4. Procedural time was 116 ± 41 minutes. Complications were death in 2 (0.014%; 1 due to stroke and 1 due to atrioesophageal fistula), pericardial tamponade in 33 (0.24%; 26 tapped, 7 surgical), strokes <48 hours in 6 (0.043%), strokes 48 hours-30 days in 6 (0.043%), pulmonary vein stenosis requiring intervention in 2 (0.014%), phrenic nerve paralysis in 2 (0.014%; both resolved), steam pops 2 (0.014%) without complications, and catheter char 0 (0.00%). There was 1 atrioesophageal fistula in 11,436 ablations using power 45-50 W on the posterior wall and 3 in 2538 ablated with 35 W on the posterior wall (P = .021), although 2 of the 3 had no esophageal monitoring during a fluoroless procedure., Conclusion: AF ablations can be performed at 45-50 W for short durations with very low complication rates. High-power, short-duration ablations have the potential to shorten procedural and total RF times and create more localized and durable lesions., (Copyright © 2018 The Authors. Published by Elsevier Inc. All rights reserved.)

Background: Catheter ablation of atrial fibrillation (AF) is an established therapeutic rhythm approach. Patients with a prior history of a stroke (CVA) represent a unique high-risk population for recurrent thromboembolic events. The role of antiarrhythmic treatment on the natural history of stroke recurrence in these patients is not fully understood., Methods: Three patient groups with a prior CVA and 5 years of follow-up were matched 1:3:3 by propensity score (±0.01): AF ablation patients receiving their first ablation (n  =  139), AF patients that did not receive an ablation (n  =  416), and CVA patients without clinical AF (n  =  416). Prior CVA was determined by medical chart review. Patients were followed for outcomes of recurrent CVA, heart failure, and death., Results: The average age of the population was 69 ± 11 years and 51% male. AF ablation patients had higher rates of hypertension and heart failure (P < 0.0001), but diabetes prevalence was similar between the groups (P  =  0.5). Note that 5-year risk of CVA (HR  =  2.26, P < 0.0001) and death (HR  =  2.43, P < 0.0001) were higher in the AF, no ablation group compared those that were ablated. When comparing AF, ablation to no AF patients, there was not a significant difference in 5-year risk of for CVA (HR  =  0.82, P  =  0.39) and death (HR  =  0.92, P  =  0.70); however, heart failure risk was increased (HR  =  3.08, P  =  0.001)., Conclusion: In patients with AF and a prior CVA, patients undergoing ablation have lower rates of recurrent stroke compared to AF patients not ablated. Although the full mechanisms of benefit are unknown, as CVA rates are similar to patients without AF these data are suggestive of a potential altering of the natural history of disease progression., (© 2017 Wiley Periodicals, Inc.)

Background: Stroke risk is a significant concern in patients with atrial fibrillation (AF). Low stroke risk patients (CHADS 2 VASc 0-2) are often treated long-term with aspirin after catheter ablation. Defining the long-term risks versus benefits of aspirin therapy, after an ablation, is essential to validate this common clinical approach., Methods: A total of 4,124 AF ablation patients undergoing their index ablation were included in this retrospective observational study. We compared 1- and 3-year outcomes for cerebrovascular accident (CVA), transient ischemic attack (TIA), gastrointestinal (GI) bleeding, genitourinary (GU) bleeding, any bleeding, and AF recurrence among patients receiving: none, aspirin, or warfarin as long-term therapies., Results: Patient distribution by CHADS 2 VASc scores was as follows: 0: 1,143 (28%), 1: 1,588 (39%), and 2: 1,393 (34%). Significantly higher incidents of: female gender, hypertension, diabetes mellitus, heart failure, and vascular disease were seen with higher CHADS 2 VASc scores (P < 0.0001 for all). At 3 years, 238 (5.9%) patients were on warfarin, 743 (18.6) on aspirin, and 3,013 (75.5%) on no therapy; with occurrences of CVA/TIA (1.4%, 3.0%, 3.9%, P < 0.0001, respectively), GI bleeding (0.8%, 1.9%, 1.1%, P = 0.06, respectively), and GU bleeding (1.7%, 2.8%, 2.1%, P = 0.008, respectively) that increased with advancing CHA 2 DS 2 VASc score. There was a significantly increased risk for both CVA/TIA with aspirin therapy, when compared to no therapy or warfarin therapy in general, and across all CHA 2 DS 2 VASc scores., Conclusions: After catheter ablation, low risk patients do not benefit from long-term aspirin therapy, but are at risk for higher rates of bleeding when compared to no therapy or warfarin., (© 2017 Wiley Periodicals, Inc.)

Background: While the body of evidence showing the benefit of contact force (CF)-sensing catheters in improving atrial fibrillation ablation success rate is growing, real-world safety data of this technology are limited., Objective: The aim of this study was to report the complication rate in patients undergoing ablation using a specific CF-sensing catheter (TactiCath Quartz CF ablation catheter, Abbott, St. Paul, MN) in a large worldwide database., Methods: User-reported adverse event data from January 1, 2014 to December 31, 2015 were reviewed for the ablation catheter. These adverse events included cardiac perforation, cerebrovascular accident, atrioesophageal (AE) fistula, steam pop, and death. Rates of these adverse events, including geographic and temporal relationships, were calculated., Results: Adverse events were reported in 178 of 41,709 patients (adverse event rate 0.427%). Adverse events included 117 cardiac perforations (0.281%), 5 cerebrovascular accidents (0.012%), 10 AE fistulas (0.024%), 53 audible steam pops (0.127%), and 13 deaths (0.031%). The total event rate in European countries was 0.53% vs 0.38% in the United States (P = .0082). The AE fistula event rate peaked in late 2014 and early 2015 at 0.06% and decreased over time to a steady-state 0.01%, corresponding to the initial US release, subsequent increased use, and training on the manufacturer recommended settings., Conclusion: Complication rates while using the TactiCath CF ablation catheter appear to decrease with training and experience. The major complication rate associated with this technology is low in the context of similar reports of conventional radiofrequency catheters., (Copyright © 2017 Heart Rhythm Society. Published by Elsevier Inc. All rights reserved.)

Introduction: The role of atrial fibrillation (AF) substrates is unclear in patients with paroxysmal AF (PAF) that recurs after pulmonary vein isolation (PVI). We hypothesized that patients with recurrent post-ablation (redo) PAF despite PVI have electrical substrates marked by rotors and focal sources, and structural substrates that resemble persistent AF more than patients with (de novo) PAF at first ablation., Methods: In 175 patients at 11 centers, we compared AF substrates in both atria using 64 pole-basket catheters and phase mapping, and indices of anatomical remodeling between patients with de novo or redo PAF and first ablation for persistent AF., Results: Sources were seen in all patients. More patients with de novo PAF (78.0%) had sources near PVs than patients with redo PAF (47.4%, p=0.005) or persistent AF (46.9%, p=0.001). The total number of sources per patient (p=0.444), and number of non-PV sources (p=0.701) were similar between groups, indicating that redo PAF patients had residual non-PV sources after elimination of PV sources by prior PVI. Structurally, left atrial size did not separate de novo from redo PAF (49.5±9.5 vs. 49.0±7.1mm, p=0.956) but was larger in patients with persistent AF (55.2±8.4mm, p=0.001)., Conclusions: Patients with paroxysmal AF despite prior PVI show electrical substrates that resemble persistent AF more closely than patients with paroxysmal AF at first ablation. Notably, these subgroups of paroxysmal AF are indistinguishable by structural indices. These data motivate studies of trigger versus substrate mechanisms for patients with recurrent paroxysmal AF after PVI.

Background: Catheter ablation of atrial fibrillation (AF) is an established therapeutic rhythm approach in symptomatic patients. Obesity is a dominant driver of AF recurrence after ablation. However, being both overweight and underweight drives long-term cardiac and general health risks. Long-term data are needed to understand the influence of body mass index (BMI) on outcomes after ablation in regard to arrhythmia recurrence and cardiovascular outcomes., Methods: All patients who underwent an index ablation with a BMI recorded and at least 3 years of follow-up were included (n = 1558). The group was separated and compared by index ablation BMI status (≤20, 21-25, 26-30, >30 kg/m(2)). Long-term outcomes included AF recurrence, stroke/TIA, heart failure (HF) hospitalization, and death., Results: Patients with advancing BMI status were more likely to be male and have hypertension, a smoking history, diabetes, HF, and a prior cardioversion. Patients with a BMI ≤20 were more likely to have a moderate-high congestive heart failure, hypertension, age >75, diabetes, stroke (CHADS2) score. At 3 years, recurrence rates of AF increased significantly with increasing BMI status (p = 0.02); paradoxically, there was a trend for increased stroke risk with decreasing BMI (p = 0.06). Long-term death rates tended to increase inversely with BMI status, and HF rates were greatest in the highest and lowest BMI groups., Conclusions: Lower weight at AF ablation lowers arrhythmia recurrence risk. However, AF ablation patients who are normal or underweight remain at high risk of other cardiovascular outcomes including increased stroke risk with less AF burden.

Background: Remote magnetic navigation (RMN) and contact force (CF) sensing technologies have been utilized in an effort to improve safety and efficacy of catheter ablation. A comparative analysis of the relative short- and long-term outcomes of AF patients has not been performed. As such, we comparatively evaluated the safety and efficacy of these technologies., Methods: A total of 627 patients who underwent catheter ablation with either a manual irrigated tip catheter: (312, 49.8%) or by RMN: (315, 50.2%) were included in this single-center cohort study. Patients treated with CF (59) were analyzed separately as well. One- and 3-year endpoints included death, HF hospitalization, stroke, TIA, and atrial flutter or AF recurrence., Results: Age averaged 65.1 ± 10.7 years and 64.1% male. One- and 3-year endpoints of death, HF hospitalization, stroke, TIA, and atrial flutter or AF recurrence were statistically similar between manual and RMN treated groups. Fluoroscopy times were significantly lower in the RMN group compared to the manual ablation group (8.47 ± 0.45 vs. 9.63 ± 4.06 minutes, P < 0.0001). CF guided patients had 1-year recurrence rate of AF/atrial flutter statistically identical to patients treated with RMN (36.8% vs. 38.6%; P = 1.00)., Conclusion: RMN results in outcomes similar to manual navigation. The addition of CF sensing catheters did not improve relative procedural outcome or safety profile in comparison to RMN guided ablation in this large observational study of AF ablation., (© 2016 Wiley Periodicals, Inc.)

Background: Catheter ablation of atrial fibrillation (AF) is an established therapeutic rhythm approach in symptomatic patients. Many studies have shown that age has little to no impact on outcomes during the first year after ablation. However, AF is a disease of aging and age-based substrate for arrhythmia is likely to progress. To this regard, we examined patients with 5-year outcome data following an index AF ablation procedure to define the impact of age on long-term outcomes., Methods: A total of 923 patients that underwent their index AF ablation and had 5 years of follow-up were studied. Patients were followed up for atrial flutter/AF recurrence, heart failure, stroke, death, and cardiac function. Patients were separated and compared in 5 age-based groups (<50, 51-60, 61-70, 71-80, >80)., Results: The average age of the population was 66 ± 11 years and 59% were male. The AF was paroxysmal in 55%, persistent in 27%, and longstanding persistent in 18%. Older patients were more likely female and had higher rates of cardiovascular diseases. For every 10-year increase in age there was a higher multivariate-adjusted risk of atrial flutter/AF recurrence (HR: 1.13, P = 0.01), death (HR:1.91, P < 0.0001), and major adverse cardiac events (HR: 1.09, P = 0.07). Although atrial flutter/AF recurrence rates by age were similar at 1 year, at 5 years, younger patients had significantly lower rates of recurrences., Conclusion: Age significantly impacts outcomes after AF ablation when analyzed with long-term follow-up. These data highlight the progressive nature of AF and the need to consider interventions early., (© 2015 Wiley Periodicals, Inc.)

Background: There are a paucity of data about the long-term natural history of adult Wolff-Parkinson-White syndrome (WPW) patients in regard to risk of mortality and atrial fibrillation. We sought to describe the long-term outcomes of WPW patients and ascertain the impact of ablation on the natural history., Methods and Results: Three groups of patients were studied: 2 WPW populations (ablation: 872, no ablation: 1461) and a 1:5 control population (n=11 175). Long-term mortality and atrial fibrillation rates were determined. The average follow-up for the WPW group was 7.9±5.9 (median: 6.9) years and was similar between the ablation and nonablation groups. Death rates were similar between the WPW group versus the control group (hazard ratio, 0.96; 95% confidence interval, 0.83-1.11; P=0.56). Nonablated WPW patients had a higher long-term death risk compared with ablated WPW patients (hazard ratio, 2.10; 95% confidence interval: 1.50-20.93; P<0.0001). Incident atrial fibrillation risk was higher in the WPW group compared with the control population (hazard ratio, 1.55; 95% confidence interval, 1.29-1.87; P<0.0001). Nonablated WPW patients had lower risk than ablated patients (hazard ratio, 0.39; 95% confidence interval, 0.28-0.53; P<0.0001)., Conclusions: Long-term mortality rates in WPW patients are low and similar to an age-matched and gender-matched control population. WPW patients that underwent the multifactorial process of ablation had a lower mortality compared to nonablated WPW patients. Atrial fibrillation rates are high long-term, and ablation does not reduce this risk., (© 2015 American Heart Association, Inc.)

Background: Risk stratification tools are needed to select the right candidates for catheter ablation of atrial fibrillation (AF). Both the CHADS2 and CHA2DS2-VASc scores have utility in predicting AF-related outcomes and guiding anticoagulation treatment., Objective: We sought to determine whether these risk scores predict long-term outcomes after AF ablation and whether one risk score provides comparatively superior performance., Methods: CHADS2 and CHA2DS2-VASc scores were calculated in 2179 patients who underwent a first ablation procedure for AF enrolled in the Intermountain Heart Collaborative Study. CHADS2 and CHA2DS2-VASc scores were categorized as 0-1, 2-4, and ≥5. Patient outcomes were analyzed over 5 years for AF/atrial flutter recurrence and major adverse cardiovascular events (MACE: composite of death, stroke, and heart failure hospitalization)., Results: The mean age was 65.7 ± 10.5 years, and 61.1% were men. Both scores incrementally predicted risk of AF recurrence, stroke, heart failure, and death at 5 years. Increasing CHADS2 (hazard ratio [HR] 1.19; P < .001) and CHA2DS2-VASc (HR 1.15; P < .0001) scores were both associated with AF/atrial flutter recurrence. The results were similar for MACE where increasing CHADS2 (HR 1.54; P < .0001) and CHA2DS2-VASc (HR 1.32; P < .0001) scores were associated with risk. When CHADS2 and CHA2DS2-VASc scores were modeled together, only CHA2DS2-VASc scores significantly predicted AF recurrence (HR 1.13; P = .001), but both were associated with MACE., Conclusion: Both the CHADS2 and CHA2DS2-VASc scores were excellent in stratifying patients for 5-year outcomes after AF ablation. However, the CHA2DS2-VASc score was superior to the CHADS2 score in predicting AF recurrence and AF-related morbidities., (Copyright © 2015 Heart Rhythm Society. Published by Elsevier Inc. All rights reserved.)

Background: Pulmonary vein isolation (PVI) of the remnant pulmonary vein (PV) stumps in pneumonectomy patients has not been well characterized., Methods: This is a multicenter observational study of patients with a remnant PV stump after pneumonectomy. Consecutive patients with a history of pneumonectomy and who had undergone RF ablation for drug refractory AF were identified from the AF database at the participating institutions., Results: There were 15 patients in whom pneumonectomy was performed, for resection of tumors in 10, infection in 4, and bullae in 1 patient and who underwent RF ablation for AF. The mean age was 63 ± 7 years. The stumps were from the right lower PV in 5, left upper PV in 5, left lower PV in 3, and right upper PV in 2 patients. All the PV stumps were electrically active with PV potentials and 9 (60%) of them had triggered activity. PVI was performed in 14 and focal isolation in 1 patient. At 1-year follow-up, 80% were free of AF, off of antiarrhythmic medications., Conclusion: PV stumps in AF patients with previous pneumonectomy are electrically active and are frequently the sites of active firing. Isolation of these PV stumps can be accomplished safely and effectively using catheter ablation with no practical concern for PV stenosis or compromising PV stump integrity., (© 2015 Wiley Periodicals, Inc.)

Background: Catheter ablation of atrial fibrillation (AF) is an established therapy for symptomatic patients. The long-term efficacy and impact of catheter ablation among patients with severe systolic heart failure (SHF) requires additional study to understand if outcomes achieved at 1 year are maintained and mechanisms of AF recurrence., Methods: Three groups with SHF and 5 years of follow-up were matched 1:4:4 by age (±5 years) and sex: AF ablation patients receiving their first ablation (n = 267), AF patients that did not receive an ablation (n = 1,068), and SHF patient without AF (n = 1,068). SHF was based upon clinical diagnosis and an ejection fraction (EF) ≤35%. Patients were followed for 5-year primary outcomes of AF recurrence, heart failure, stroke, death, and cardiac function., Results: At 5 years, 60.7% of patients had clinical recurrence of AF. Diabetes and a prior heart attack were significant predictors of long-term risk of AF recurrence. Long-term mortality rates were 27%, 55%, 50%, in the AF ablation, AF, and no AF groups, respectively (P < 0.0001), with the lower rates attributed to lower cardiovascular mortality. At 5 years, there was no difference in EF, yet HF hospitalizations were lower following AF ablation compared to patients with AF and no ablation. Stroke rates at 5 years trended to be lower in the AF ablation group, but the difference was not statistically significant., Conclusion: Recurrence rates of AF in patients with SHF after ablation are common at 5 years with an anticipated ongoing increase. Long-term AF-related comorbidities tended to be less in the AF ablation group., (© 2014 Wiley Periodicals, Inc.)

Introduction: The success of pulmonary vein isolation (PVI) for atrial fibrillation (AF) may be improved if stable AF sources identified by Focal Impulse and Rotor Mapping (FIRM) are also eliminated. The long-term results of this approach are unclear outside the centers where FIRM was developed; thus, we assessed outcomes of FIRM-guided AF ablation in the first cases at 10 experienced centers., Methods: We prospectively enrolled n = 78 consecutive patients (61 ± 10 years) undergoing FIRM guided ablation for persistent (n = 48), longstanding persistent (n = 7), or paroxysmal (n = 23) AF. AF recordings from both atria with a 64-pole basket catheter were analyzed using a novel mapping system (Rhythm View(TM) ; Topera Inc., CA, USA). Identified rotors/focal sources were ablated, followed by PVI., Results: Each institution recruited a median of 6 patients, each of whom showed 2.3 ± 0.9 AF rotors/focal sources in diverse locations. 25.3% of all sources were right atrial (RA), and 50.0% of patients had ≥1 RA source. Ablation of all sources required a total of 16.6 ± 11.7 minutes, followed by PVI. On >1 year follow-up with a 3-month blanking period, 1 patient lost to follow-up (median time to 1st recurrence: 245 days, IQR 145-354), single-procedure freedom from AF was 87.5% (patients without prior ablation; 35/40) and 80.5% (all patients; 62/77) and similar for persistent and paroxysmal AF (P = 0.89)., Conclusions: Elimination of patient-specific AF rotors/focal sources produced freedom-from-AF of ≈80% at 1 year at centers new to FIRM. FIRM-guided ablation has a rapid learning curve, yielding similar results to original FIRM reports in each center's first cases., (© 2014 Wiley Periodicals, Inc.)

Background: Ventricular arrhythmias in patients with implantable cardioverter-defibrillators (ICDs) adversely affect outcomes. Antiarrhythmic approaches to ventricular tachycardia (VT) have variable efficacy and may increase risk of ventricular arrhythmias, worsening cardiomyopathy, and death. Comparatively, VT ablation is an alternative approach that may favorably affect outcomes., Objective: To further explore the effect on long-term outcomes after catheter ablation of VT, we compared patients with history of ICD shocks who did not undergo ablation, patients with a history of ICD shocks that underwent ablation, and patients with ICDs who had no history of ICD shocks., Methods: A total of 102 consecutive patients with structural heart disease who underwent VT ablation for recurrent ICD shocks were compared with 2088 patients with ICDs and no history of appropriate shocks and 817 patients with ICDs and a history of appropriate shocks for VT or ventricular fibrillation. Outcomes considered were mortality, heart failure hospitalization, atrial fibrillation, and stroke/transient ischemic attack., Results: The mean age of 3007 patients was 65.4 ± 13.9 years. Over long-term follow-up, 866 (28.8%) died, 681 (22.7%) had a heart failure admission, 706 (23.5%) developed new-onset atrial fibrillation, and 224 (7.5%) had a stroke. The multivariate-adjusted risks of deaths and heart failure hospitalizations were higher in patients with history of ICD shocks who were treated medically than in patients with ICDs and no history of shock (hazard ratio [HR] 1.45; P < .0001 vs HR 2.00; P < .0001, respectively). The multivariate-adjusted risks were attenuated after VT ablation with death and heart failure hospitalization rates similar to those of patients with no shock (HR 0.89; P = .58 vs HR 1.38; P = .09, respectively). A similar nonsignificant trend was seen with stroke/transient ischemic attack., Conclusions: Patients treated with VT ablation after an ICD shock have a significantly lower risk of death and heart failure hospitalization than did patients managed medically only. The adverse event rates after VT ablation were similar to those of patients with ICDs but without VT., (Copyright © 2014 Heart Rhythm Society. Published by Elsevier Inc. All rights reserved.)

Background: Many patients who develop atrial fibrillation (AF) will experience a worsening of their arrhythmia over time. The optimal time to proceed with catheter ablation during the disease course is unknown. Further, whether delays in treatment will negatively influence outcomes is unknown., Objective: The purpose of this study was to examine the impact of delay in treatment after the first clinical diagnosis of AF on ablation-related outcomes., Methods: A total of 4535 consecutive patients who underwent an AF ablation procedure that had long-term established care within an integrated health care system were evaluated. Recursive partitioning was used to determine categories associated with changes in risk from the time of first AF diagnosis to first AF ablation: 1: 30-180 (n = 1152), 2: 181-545 (n = 856), 3: 546-1825 (n = 1326), and 4: >1825 (n = 1201) days. Outcomes evaluated include 1-year AF recurrence, stroke, heart failure hospitalization, and death., Results: With increasing time to treatment, surprisingly patients were older (1: 63.7 ± 11.1, 2: 62.6 ± 11.8, 3: 66.4 ± 10.2, 4: 67.6 ± 9.7; P <.0001) and had more hypertension (1: 53.0%, 2: 59.0%, 3: 53.8%, 4: 39.0%; P <.0001). For each strata of time increase, there was a direct increase of 1-year AF recurrence (1: 19.4%, 2: 23.4%, 3: 24.9%, 4: 24.0%: P trend = .02). After adjustment, clinically significant differences in risk of recurrent AF were found when compared to the 30-180 day time category: 181-545: odds ratio (OR) = 1.23, P = .08; 546-1825: OR = 1.27, P = .02; and >1825: OR = 1.25, P = .05. No differences were observed for 1-year stroke among the groups. Death (1: 2.1%, 2: 3.9%, 3: 5.7%, 4: 4.4%: P trend = .001) and heart failure hospitalization (1: 2.6%, 2: 4.1%, 3: 5.4%, 4: 4.4%; P trend = .009) rates at 1 year were higher in the most delayed groups., Conclusion: Delays in treatment with catheter ablation impact procedural success rates independent of temporal changes to the AF subtype at ablation., (Copyright © 2013 Heart Rhythm Society. Published by Elsevier Inc. All rights reserved.)

Background: Esophageal injury during left atrial ablation is associated with a significant risk of mortality and morbidity. There are no validated approaches to reduce injury outside of avoidance, a strategy critically dependent on a precise understanding of the esophageal anatomy and location. Intracardiac ultrasound (ICE) can provide a real-time assessment of the esophagus during ablation. We hypothesized that ICE can accurately define esophageal anatomy and location to enhance avoidance strategies during ablation., Methods: Fifty patients underwent atrial fibrillation (AF) ablation. The left atrium and pulmonary vein anatomies were rendered by traditional electroanatomic mapping (CARTO). A Navistar catheter within the esophagus was used to create a traditional electroanatomic esophageal anatomy. ICE imaging was used to create a second geometry of the esophagus. The traditional and ICE anatomies of the esophagus were compared and the greatest border dimensions used to avoid injury., Results: The average age was 66 ± 10 years, 45% had persistent/longstanding persistent AF, and 18% had a prior AF ablation. The esophagus location was leftward in 17 (34%), midline in 22 (44%), and rightward in 11 (22%). Traditional esophagus and ICE imaging correlated within 1 cm in the greatest distance in 26 (52%) patients. Traditional imaging underestimated the esophageal location by >1-1.5 cm in 9 (18%) and >1.5 cm in 15 (30%). In those with poor correlation (>1.5 cm), the most common cause was the presence of a hiatal hernia. Ablation energy delivery was performed outside the greatest esophagus anatomy borders. Of those with 12-month follow-up, 75% were AF/atrial flutter free without antiarrhythmic drugs. No esophageal injuries were observed. One patient experienced a TIA greater than 6 months postablation., Conclusion: These data demonstrate that traditional means of mapping the esophagus using a catheter within the esophagus are insufficient and often grossly underestimate the actual anatomy. Imaging techniques that define the complete esophageal lumen should be considered to truly minimize esophageal injury risk., (© 2012 Wiley Periodicals, Inc.)

As elderly patients present significant challenges for long-term pharmacologic management, nonpharmacologic treatment of atrial fibrillation (AF) will continue to be a vital option in improving the quality of life and function of these patients. This review discusses nonpharmacologic approaches for AF in the elderly. Observational studies of catheter ablation suggest similar long-term efficacy and safety rates in elderly and younger groups. Minimally invasive surgical approaches have distinct advantages in certain populations. Further research, adequately powered to assess age-related differences, is needed to confirm the findings of observational studies of elderly patients who have undergone nonpharmacologic approaches to rhythm control., (Copyright © 2012 Elsevier Inc. All rights reserved.)

Introduction:  Atrial fibrillation (AF) adversely impacts mortality, stroke, heart failure, and dementia. AF ablation eliminates AF in most patients. We evaluated the long-term impact of AF ablation on mortality, heart failure (HF), stroke, and dementia in a large system-wide patient population., Methods:  A total of 4,212 consecutive patients who underwent AF ablation were compared (1:4) to 16,848 age/gender matched controls with AF (no ablation) and 16,848 age/gender matched controls without AF. Patients were enrolled from the large ongoing prospective Intermountain AF study and were followed for at least 3 years., Results:  Of the 37,908 patients, mean age 65.0 ± 13 years, 5,667 (14.9%) died, 1,296 (3.4%) had a stroke, and 1,096 (2.9%) were hospitalized for HF over >3 years of follow-up. AF ablation patients were less likely to have diabetes, but were more likely to have hypertension, HF, and significant valvular heart disease. AF ablation patients had a lower risk of death and stroke in comparison to AF patients without ablation. Alzheimer's dementia occurred in 0.2% of the AF ablation patients compared to 0.9% of the AF no ablation patients and 0.5% of the no AF patients (P < 0.0001). Other forms of dementia were also reduced significantly in those treated with ablation. Compared to patients with no AF, AF ablation patients had similar long-term rates of death, dementia, and stroke., Conclusions:  AF ablation patients have a significantly lower risk of death, stroke, and dementia in comparison to AF patients without ablation. AF ablation may eliminate the increased risk of death and stroke associated with AF., (© 2011 Wiley Periodicals, Inc.)

Background: Patients with prosthetic valves have a high prevalence of atrial fibrillation (AF). We report a multicenter experience of performing pulmonary vein antral isolation (PVAI) in this challenging, high-risk cohort of patients., Objective: The purpose of this study was to assess the feasibility, safety, and efficacy of radiofrequency (RF) ablation for sinus rhythm restoration in AF patients with mitral or aortic mechanical prosthetic valves., Methods: A total of 50 patients with prosthetic valves (group I) who underwent RF ablation for AF between January 1, 2007, and April 30, 2009, were identified prospectively at four tertiary care centers. A matched group of 50 patients (group II) acted as controls., Results: Total procedural time (199.4 ± 49 minutes vs 166.6 ± 27.5 minutes, P <.001) and fluoroscopy time (60 ± 17 minutes vs 53.8 ± 6.8 minutes, P <.01) were prolonged, with a higher incidence of atrial flutter at 3 months in group I (18% vs 6%, P = .1) compared to group II. At 12 months, 80% of patients in the valve group were in sinus rhythm after an average of 1.3 procedures, and 82% of controls were in sinus rhythm after an average 1.2 procedures (P = .9). There was a trend toward a higher nonfatal complication rate in the valve group than in the control group (8% vs 4%, P = .1)., Conclusion: In patients with prosthetic valves, RF ablation for AF is feasible, safe, and efficacious, with a trend toward a higher nonfatal complication rate and an increased rate of postablation atrial flutter., (Copyright © 2011. Published by Elsevier Inc.)

Background: Ablation of ventricular tachycardia (VT) reduces implantable cardioverter defibrillator shocks. Intracardiac ultrasound (ICE) can visualize and quantify the function of all left ventricular wall segments. We thus hypothesized that ICE could identify scar tissue and provide a guide to facilitate substrate-guided VT ablation., Methods: Eighteen patients underwent VT ablation with real time ICE mapping from the right atrium and ventricle with online 3D-image reconstruction of scar segments. The left ventricle was also scar mapped by traditional electroanatomic mapping (CARTO) for comparison. Images from these 2 scar mapping techniques were compared to each other as well as to a preprocedure transthoracic echocardiogram., Results: The average age was 65 +/- 12 years and 12 (67%) were male (15 [83%] had ischemic cardiomyopathy). Two patients (12%) had recurrence of their clinical VT (1 remained on an antiarrhythmic medication, the other had a repeat ablation) over a follow-up of 127 +/- 33 days. No periprocedural or long-term adverse events occurred. A total of 248 wall segments were analyzed. All 3 modalities were concordant in scar identification in 193 (78%) segments. The ICE segments correlated with the electroanatomic map in 213 (86%) segments versus 198 (80%), which correlated with transthoracic echocardiography and electroanatomic mapping (P = 0.046). Specifically, the ICE wall motion scores were closer to the electroanatomic mapping in the basal segments and showed a higher accuracy in ischemic heart disease., Conclusion: These data demonstrate that real time ICE images provide accurate chamber geometries and scar boundaries of the left ventricle. These scar borders were more accurate than transthoracic echocardiography and illustrate the feasibility of ICE for substrate-based ablation for VT.

Background: Radiofrequency ablation is an effective treatment for atrial fibrillation (AF). With improved safety, the therapy has been offered to increasingly older populations. Arrhythmia mechanisms, medical comorbidities, and safety may vary in the very elderly population., Methods: Patients presenting for AF ablation were divided into two groups [> or =80 years (n = 35), <80 years (n = 717)]. AF ablation consisted of pulmonary vein antral isolation with or without additional linear lesions. A successful outcome was defined as no further AF and off all antiarrhythmic medications >3 months following 1 + ablation procedures., Results: The type of AF was similar in both groups (paroxysmal: 46% in the older group vs 54% in the younger, P = 0.33). Older patients were more likely to have a higher CHADS2 score, coronary artery disease, and less likely to have had a prior ablation. The hospital stay on average was longer in the older cohort (2.9 +/- 7.7 vs 2.1 +/- 1.1 days, P = 0.001). There was no increased risk of peri-procedural complications. One-year survival free of AF or flutter was 78% in those >80 and 75% in those younger (P = 0.78). There was no difference between groups if the AF was paroxysmal (P = 0.44) or persistent/chronic (P = 0.74). Over a 3-year follow-up period, five patients died and four strokes occurred all in the younger cohort., Conclusion: Octogenarian patients, despite more coexistent cardiovascular diseases, have favorable outcomes after AF ablation measured by successful rhythm management. On an average their hospital stay is longer, but no significant increase in short- or long-term complications was observed. These data support AF ablation in select octogenarians.

Background: The recently published HRS/EHRA/ECAS AF Ablation Consensus Statement recommended that warfarin should be used for at least 2 months following an AF ablation in all patients regardless of stroke risk factors. The objective of the study was to assess outcomes based upon anticoagulation practice after atrial fibrillation (AF) ablation to determine relative risk of a strategy of aspirin only in low-risk patients., Methods: A total of 630 consecutive patients who underwent 934 ablation procedures using an open irrigated tip catheter for symptomatic AF were evaluated. Outcomes were compared between patients treated with warfarin (goal INR: 2-3) versus aspirin only (325 mg/day) in CHADS2 0-1 patients after ablation., Results: Of the 690 patients, 123 (20%) were treated with aspirin and 507 (80%) with warfarin. Prevalences of the CHADS2 scores of patients on aspirin were (0: 40.7%, 1: 59.3%) and on warfarin (0: 13.6%, 1: 31.6%, > or = 2: 54.8%), P < 0.0001. Patients in the warfarin group were older, had on average a lower ejection fraction, and had higher rates persistent/permanent AF, repeat ablations, hypertension, prior stroke/TIA, and diabetes. The 1-year survival free of AF for the total study population was 71.6%. There were no strokes/TIA in the aspirin group and 4 events (4 strokes, 0 TIAs) in the warfarin group. Two patients in the warfarin group died of fatal hemorrhage (1 intracranial, 1 gastrointestinal)., Conclusion: Select low-risk patients with a low CHADS2 (0-1) score who undergo left atrial ablation with an aggressive anticoagulation strategy with heparin and use of an open irrigated tip catheter with low CHADS2 scores can safely be discharged following their procedure on aspirin alone.

The approach to catheter-based radiofrequency ablation of atrial fibrillation has evolved, and as a consequence, more energy is delivered in the posterior left atrium, exposing neighboring tissue to untoward thermal injury. Simultaneously, catheter technology has advanced to allow more efficient energy delivery into the myocardium, which compounds the likelihood of collateral injury. This review focuses on the basic principles of thermodynamics as they apply to energy delivery during radiofrequency ablation. These principles can be used to titrate energy delivery and plan ablative approaches in an effort to minimize complications during the procedure.

Background: Left atrial catheter ablation (LACA) has emerged as a successful method to eliminate atrial fibrillation (AF). Recent reports have described atrio-esophageal fistulas, often resulting in death, from this procedure. Temporary esophageal stenting is an established therapy for malignant esophageal disease. We describe the first case of successful temporary esophageal stenting for an esophageal perforation following LACA., Case: A 48-year-old man with symptomatic drug refractory lone AF underwent an uneventful LACA. Fifty-nine ablations with an 8-mm tip ablation catheter (30 seconds, 70 Watts, 55 degrees C), as guided by 3-D NavX mapping, were performed in the left atrium to isolate the pulmonary veins as well as a left atrial flutter and roof ablation line. In addition, complex atrial electrograms in AF and sites of vagal innervation were ablated. Two weeks later, he presented with sub-sternal chest pain, fever, and dysphagia. A chest CT showed a 3-mm esophageal perforation at the level of the left atrium with mediastinal soiling and no pericardial effusion. An urgent upper endoscopy with placement of a PolyFlex removable esophageal stent to seal off the esophago-mediastinal fistula was performed. After 3 weeks of i.v. antibiotics, naso-jejunal tube feedings, and esophageal stenting, the perforation resolved and the stent was removed. Over 18 months of follow-up, there have been no other complications, and he has returned to a physically active life and remains free from AF on previously ineffective anti-arrhythmic drugs., Conclusion: Early diagnosis of esophageal perforations following LACA may allow temporary esophageal stenting with successful esophageal healing. Prompt chest CT scans with oral and i.v. contrast should be considered in any patient with sub-sternal chest pain or dysphagia following LACA.

Abstract: Background: Vagus nerve injury during catheter ablation for atrial fibrillation can significantly impact quality of life and result in lingering gastrointestinal symptoms. This study was designed to define risk factors of vagus nerve injury, symptoms, prevalence, and temporal resolution. Methods: A total of 100 patients undergoing radiofrequency catheter ablation (RFCA) were enrolled and consented to participate in the study. Patients completed a 22‐item questionnaire that included questions specific to vagus nerve injury symptomatology during their baseline visit and at 1 and 3 months post‐RFCA. Results: The average age of the population was 63 ± 10.6 years and 68% were male. A total of 100 patients completed their baseline questionnaire (90 patients completed the 1‐month questionnaires and 85 patients completed the 3‐month questionnaires). Symptoms rated as moderate were prevalent at baseline (trouble swallowing 13%, bloating 26%, feeling full 20%), and increased in all categories analyzed at 1 month and with the exception of trouble swallowing returned to the preablation percentages at 3 months (heartburn 22.4%, trouble swallowing 18.8%, bloating 16.5%, nausea 8.2%, vomiting 3.5%, constipation 18.8%, diarrhea 16.4%, feeling full 15.3%). Severe rated symptoms of trouble swallowing (2–5.5%), bloating (5–7.6%), and early satiety (5–9.8%) increased at 1 month and bloating and early satiety percentages remained approximately two times higher at 3 months (trouble swallowing 2.4%, bloating 8.2%, early satiety 7.1%). Conclusion: The majority of symptoms were resolved by 3 months, although those patients who rate bloating and early satiety at a severe rating may have persistent symptoms. [ABSTRACT FROM AUTHOR]

Background: Ventricular arrhythmias in patients with implantable cardioverter-defibrillators (ICDs) adversely affect outcomes. Antiarrhythmic approaches to ventricular tachycardia (VT) have variable efficacy and may increase risk of ventricular arrhythmias, worsening cardiomyopathy, and death. Comparatively, VT ablation is an alternative approach that may favorably affect outcomes. Objective: To further explore the effect on long-term outcomes after catheter ablation of VT, we compared patients with history of ICD shocks who did not undergo ablation, patients with a history of ICD shocks that underwent ablation, and patients with ICDs who had no history of ICD shocks. Methods: A total of 102 consecutive patients with structural heart disease who underwent VT ablation for recurrent ICD shocks were compared with 2088 patients with ICDs and no history of appropriate shocks and 817 patients with ICDs and a history of appropriate shocks for VT or ventricular fibrillation. Outcomes considered were mortality, heart failure hospitalization, atrial fibrillation, and stroke/transient ischemic attack. Results: The mean age of 3007 patients was 65.4 ± 13.9 years. Over long-term follow-up, 866 (28.8%) died, 681 (22.7%) had a heart failure admission, 706 (23.5%) developed new-onset atrial fibrillation, and 224 (7.5%) had a stroke. The multivariate-adjusted risks of deaths and heart failure hospitalizations were higher in patients with history of ICD shocks who were treated medically than in patients with ICDs and no history of shock (hazard ratio [HR] 1.45; P < .0001 vs HR 2.00; P < .0001, respectively). The multivariate-adjusted risks were attenuated after VT ablation with death and heart failure hospitalization rates similar to those of patients with no shock (HR 0.89; P = .58 vs HR 1.38; P = .09, respectively). A similar nonsignificant trend was seen with stroke/transient ischemic attack. Conclusions: Patients treated with VT ablation after an ICD shock have a significantly lower risk of death and heart failure hospitalization than did patients managed medically only. The adverse event rates after VT ablation were similar to those of patients with ICDs but without VT. [Copyright &y& Elsevier]

Background: Atrial fibrillation (AF) is a leading cause of total and fatal ischemic stroke. Stroke risk after AF ablation appears to be favorably affected; however, it is largely unknown whether the benefit extends to all stroke CHADS2 risk profiles of AF patients. Objective: To determine if ablation of atrial fibrillation reduces stroke rates in all risk groups. Methods: A total of 4212 consecutive patients who underwent AF ablation were compared (1:4) with 16,848 age-/sex-matched controls with AF (no ablation) and to 16,848 age-/sex-matched controls without AF. Patients were enrolled from the large ongoing prospective Intermountain Atrial Fibrillation Study and were followed for at least 3 years. Results: Of the 37,908 patients, the mean age was 65.0 ± 13 years and 4.4% (no AF), 6.3% (AF, no ablation), and 4.5% (AF ablation) patients had a prior stroke (P < .0001). The profile of CHADS2 scores between comparative groups was similar: 0–1 (69.3%, no AF; 62.3%, AF, no ablation; 63.6%, AF ablation), 2–3 (26.5%, no AF; 29.7%, AF, no ablation; 28.7%, AF ablation), and ≥4 (4.3%, no AF; 8.0%, AF, no ablation; 7.7%, AF ablation). A total of 1296 (3.4%) patients had a stroke over the follow-up period. Across all CHADS2 profiles and ages, AF patients with ablation had a lower long-term risk of stroke compared to patients without ablation. Furthermore, AF ablation patients had similar long-term risks of stroke across all CHADS2 profiles and ages compared to patients with no history of AF. Conclusions: In our study populations, AF ablation patients have a significantly lower risk of stroke compared to AF patients who do not undergo ablation independent of baseline stroke risk score. [Copyright &y& Elsevier]

Strategy of Rapid Cardioversion. Background: The significance of early recurrent atrial tachyarrhythmias after atrial fibrillation (AF) ablation is unclear. Atrial remodeling driven by these tachyarrhythmias can result in electrical, contractile, and structural changes that may impair long-term therapy success. Aggressive attempts to restore sinus rhythm in the temporal period of healing after ablation might improve outcomes. Methods: A total of 1,759 AF ablations were performed at Intermountain Medical Center or LDS Hospital. A total of 455 of those were among patients requiring repeat ablations. Patients were instructed to take their pulse daily and, if greater than 100 bpm or irregular, present the following business day fasting to the clinic for evaluation and cardioversion if AF or atrial flutter (AFL) were present. Results: Of the ablations performed, a total of 515 (29%, age: 65.6 ± 11.2 years, male: 57.9%) developed AF/AFL that required cardioverison. The majority of these arrhythmias first occurred in the initial 90 days (63.7%) postablation. During this period, 62.8% were on an antiarrhythmic drug (AAD). Only 25.1% were using an AAD at 3 months. The majority of ablations (75.6%) who experienced AF/AFL within the first 90 days after ablation were in sinus rhythm with no AAD at 1 year. Further, 48% of those with the first recurrence from 90 to 180 days were in sinus rhythm with no AAD at 1 year. Conclusions: The time at which the first recurrence of AF/AFL occurs impacts long-term outcomes. An aggressive strategy of rapid cardioversion postablation reduces the significance of recurrent AF/AFL during the first 6 months. (J Cardiovasc Electrophysiol, Vol. 22, pp. 761-766, July 2011) [ABSTRACT FROM AUTHOR]

The author reflects on L. W. Lo and colleagues' paper that reports the results of patients, who underwent mapping and ablation techniques for atrial fibrillation (AF) and recurrence of AF. An overview of several papers that highlight the perplexities of catheter ablation for AF is offered. The author also comments on the underlying mechanisms of therapeutic ablation for AF.