Clinical presentation, diagnosis, and treatment of atrioesophageal fistula resulting from atrial fibrillation ablation.

BACKGROUND: Atrioesophageal fistula (AEF) is a worrisome complication of atrial fibrillation (AF) ablation. Its clinical manifestations and time course are unpredictable and may contribute to diagnostic and treatment delays. We conducted a systematic review of all available cases of AEF, aiming at characterizing clinical presentation, time course, diagnostic pitfalls, and outcomes. METHODS: The digital search retrieved 150 studies containing 257 cases, 238 (92.6%) of which with a confirmed diagnosis of AEF and 19 (7.4%) of pericardioesophageal fistula. RESULTS: The median time from ablation to symptom onset was 21 days (interquartile range [IQR]: 11-28). Neurological abnormalities were documented in 75% of patients. Compared to patients seen by a specialist, those evaluated at a walk-in clinic or community hospital had a significantly greater delay between symptom onset and hospital admission (median: 2.5 day [IQR: 1-8] vs. 1 day [IQR: 1-5); p = .03). Overall, 198 patients underwent a chest scan (computed tomography [CT]: 192 patients and magnetic resonance imaging [MRI]: 6 patients), 48 (24.2%; 46 CT and 2 MRI) of whom had normal/unremarkable findings. Time from hospital admission to diagnostic confirmation was significantly longer in patients with a first normal/unremarkable chest scan (p < .001). Overall mortality rate was 59.3% and 26.0% survivors had residual neurological deficits at the time of discharge. CONCLUSIONS: Since healthcare professionals of any specialty might be involved in treating AEF patients, awareness of the clinical manifestations, diagnostic pitfalls, and time course, as well as an early contact with the treating electrophysiologist for a coordinated interdisciplinary medical effort, are pivotal to prevent diagnostic delays and reduce mortality.

Epicardial Ablation Complications.

The percutaneous epicardial approach has become an adjunctive tool for electrophysiologists to treat disparate cardiac arrhythmias, including accessory pathways, atrial tachycardia, and particularly ventricular tachycardia. This novel technique prompted a strong impulse to perform epicardial access as an alternative strategy for pacing and defibrillation, left atrial appendage exclusion, heart failure with preserved ejection fraction, and genetically engineered tissue delivery. However, because of the incremental risk of major complications compared with stand-alone endocardial ablation, it is still practiced in a limited number of highly experienced centers across the world.

Toward a Uniform Ablation Protocol for Paroxysmal, Persistent, and Permanent Atrial Fibrillation.

Atrial fibrillation catheter ablation has emerged as the most effective strategy to restore and maintain sinus rhythm. The cornerstone of atrial fibrillation ablation is elimination of triggers from the pulmonary veins by pulmonary vein isolation. Nevertheless, some patients may experience atrial tachyarrhythmia recurrences even with permanent pulmonary vein antral isolation. Whether and in which patients pulmonary vein antral isolation should be considered as the only ablation strategy remains a matter of debate. This review aims to summarize the rationale and effectiveness of different ablation approaches and identify key points for a uniform atrial fibrillation ablation strategy.

Thromboembolic events and need for anticoagulation therapy following left atrial appendage occlusion in patients with electrical isolation of the appendage.

INTRODUCTION: Electrical isolation of the left atrial appendage (LAA) is an important adjunctive ablation strategy in patients with nonparoxysmal atrial fibrillation (AF). Patients who have impaired LAA contractility following isolation may require long-term oral anticoagulant (OAC) therapy irrespective of their CHADS2 -VASc score. Percutaneous LAA occlusion (LAAO) is a potential alternative to life-long OAC therapy. We aimed to assess the rate of OAC discontinuation and thromboembolic (TE) events following percutaneous LAAO in patients who underwent LAA electrical isolation (LAAI). METHODS: This is a retrospective two-center study of patients who underwent percutaneous LAAO following LAAI. Patients with at least 3-month follow-up were included in the study. The antithrombotic therapy and TE events at the time of the last follow-up were noted. RESULTS: The LAA was successfully occluded in 162 (with Watchman device in 140 [86.4%] and Lariat in 22 [13.6%]). A total of 32 patients had leaks detected on the 45-day transesophageal echocardiogram (TEE); 21 (15%) Watchman and 11 (50%) Lariat cases (P = 0.0001). Two (one Watchman and one Lariat) of the 32 leaks were more than 5 mm. After the 45-day TEE, 150 (92.6%) patients were off-OAC. No TE events were reported in the 150 patients who stopped the anticoagulants. Four (2.47%) patients experienced stroke following the LAAO (three Watchman and one Lariat) procedure while on-OAC, two of which were fatal. At the median follow-up of 18.5 months, 159 (98.15%) patients were off-anticoagulant. CONCLUSION: Up to 98% of patients with LAAI could safely discontinue OAC after undergoing the appendage closure procedure.

Prevalence of right atrial non-pulmonary vein triggers in atrial fibrillation patients treated with thyroid hormone replacement therapy.

BACKGROUND: Thyroid hormone (TH) is known to enhance arrhythmogenicity, and high-normal thyroid function is related with an increased recurrence of atrial fibrillation (AF) after catheter ablation. However, the impact of thyroid hormone replacement (THR) on AF ablation is not well known. METHODS: This study evaluated 1163 consecutive paroxysmal AF patients [160 (14%) on THR and 1003 (86%) without THR] undergoing their first catheter ablation. A total of 146 patients on THR and 146 controls were generated by propensity matching, based on calculated risk factor scores, using a logistic model (age, sex, body mass index, and left atrium size). The presence of non-pulmonary vein (PV) triggers was disclosed by a high-dose isoproterenol challenge (up to 30 µg/min) after PV isolation. RESULTS: Clinical characteristics were not different between the groups. When compared to the control, non-PV triggers were significantly greater in the THR patients [112 (77%) vs. 47 (32%), P < 0.001], and most frequently originated from the right atrium (95 vs. 56%, P < 0.001). Other sources of non-PV triggers were the interatrial septum (25 vs. 11%, P = 0.002), coronary sinus (70 vs. 52%, P = 0.01), left atrial appendage (47 vs. 34%, P = 0.03), crista terminalis/superior vena cava (11 vs. 8%, P = 0.43), and mitral valve annulus (7 vs. 5%, P = 0.45) (THR vs. control), respectively. After mean follow-up of 14.7 ± 5.2 months, success rate was lower in patients on THR therapy [94 (64.4%)] compared to patients not receiving THR therapy [110 (75.3%), log-rank test value = 0.04]. CONCLUSIONS: Right atrial non-PV triggers were more prevalent in AF patients treated with THR. Elimination of non-PV triggers provided better arrhythmia-free survival in the non-THR group.

Association of pretreatment with angiotensin-converting enzyme inhibitors with improvement in ablation outcome in atrial fibrillation patients with low left ventricular ejection fraction.

BACKGROUND: Angiotensin-converting enzyme inhibitors (ACEIs) reduce the incidence of atrial fibrillation (AF). OBJECTIVE: The purpose of this study was to assess the impact of upstream ACEI therapy on postablation AF recurrence and hospitalization in patients with low left ventricular ejection fraction (LVEF). METHODS: Three hundred forty-five consecutive patients undergoing first AF ablation with low LVEF (≤45%) were classified into group 1 (ACEI+, n = 187 [54%], of whom 44 patients [23.5%] had paroxysmal AF [PAF]) or group 2 (ACEI-, n = 158 [46%]; 31 of these 158 patients [19.6%] had PAF). Additionally, 703 consecutive patients with LVEF >45% undergoing first AF ablation were included for a secondary analysis to evaluate the effect of ACEI treatment in normal ejection fraction. In group 1, ACEI therapy started ≥3 months before ablation and continued through follow-up. RESULTS: Baseline characteristics were similar except for hypertension, which was significantly more prevalent in ACEI+ (71% vs 51%, P < .001). At 24 ± 7 months of follow-up, 109 nonparoxysmal AF patients in group 1 (76%) and 81 (64%) in group 2 (P = .015) were recurrence free. In multivariate analysis, ACEI therapy was an independent predictor of recurrence (hazard ratio for ACEI-, 1.7, 95% confidence interval 1.1-2.7; P = .026]. However, among PAF patients, ACEI use was not associated with ablation success (80% vs 77% in ACEI+ and ACEI-, respectively; P = .82). In the normal-EF population, the success rates between ACEI+ and ACEI- cohorts were similar (71% vs 74%, P = .31). After the index procedure, 17 patients (9.1%) in the ACEI+ group and 28 (17.7%) in the ACEI- cohort (P= .02) required rehospitalization, for a 49% relative risk reduction (relative risk 0.51, 95% confidence interval 0.29-0.90). CONCLUSION: Preablation use of an ACEI is associated with improvement in ablation outcome in patients with nonparoxysmal AF with low LVEF.

Effect of catheter ablation and periprocedural anticoagulation regimen on the clinical course of migraine in atrial fibrillation patients with or without pre-existent migraine: results from a prospective study.

BACKGROUND: We examined the influence of catheter ablation and periprocedural anticoagulation regimen on trajectory of migraine in atrial fibrillation patients with or without migraine history. METHODS AND RESULTS: Forty patients with (group 1: 64 ± 8 years; men 78%) and 85 (group 2: 61 ± 10 years; men 73%) without migraine history undergoing atrial fibrillation-ablation were enrolled. Migraine status and quality of life were evaluated using standardized questionnaires. Diffusion magnetic resonance imaging of brain was performed for all at pre and 24 hours post procedure. Catheter ablation was performed with (88, 70%) or without (37, 30%) continuous warfarin treatment. Fifty-four patients (11 and 43 from groups 1 and 2, respectively) had subtherapeutic international normalized ratio on procedure day. At 17 ± 5 months follow-up, from group 1, 25 (63%) reported no migraine, 10 (25%) had < 1, and 3 (8%) had 2 to 3 monthly symptoms. Intensity of pain decreased from baseline 7 (Q1-Q3, 4-8) to 2 (0-4) scale points at follow-up (P < 0.001) and duration of headache from median 8 (Q1-Q3, 4-15) to 0.5 (Q1-Q3, 0-2) hours (P < 0.001). Two patients from group 1 reported increased migraine severity and 2 from group 2 had new-onset migraine. Follow-up diffusion magnetic resonance imaging revealed new infarcts in 9.6% (12/125) patients; of which 11 had subtherapeutic preprocedural international normalized ratio on or off continuous warfarin. Quality of life improved significantly in patients with successful ablation, being more pronounced in group 1. CONCLUSIONS: In most patients, migraine symptoms improved substantially after catheter ablation. Interestingly, the only cases of new migraine and aggravation of pre-existent headache had subtherapeutic international normalized ratio during the procedure and new cerebral infarcts.

Effect of periprocedural amiodarone on procedure outcome in patients with longstanding persistent atrial fibrillation undergoing extended pulmonary vein antrum isolation: results from a randomized study (SPECULATE).

BACKGROUND: The impact of amiodarone on ablation outcome in longstanding persistent atrial fibrillation (LSPAF) patients is not known yet. OBJECTIVE: The purpose of this study was to assess the effect of amiodarone on procedural-outcomes in LSPAF patients undergoing catheter ablation. METHODS: We enrolled 112 LSPAF patients on amiodarone and scheduled to undergo atrial fibrillation (AF) ablation. Patients were randomized to amiodarone discontinuation 4 months before ablation (group 1, n = 56) and a control group (group 2, n = 56) in which ablation was performed without amiodarone discontinuation. All patients underwent pulmonary vein (PV) antrum and posterior wall isolation, defragmentation and extra PV triggers ablation. Patients were followed up for recurrence for 32 ± 8 months post-ablation. Repeat procedures in all recurrent patients were performed off amiodarone. RESULTS: During ablation, AF termination was more frequent in group 2 compared to group 1 [44 (79%) vs 32 (57%), P = .015]. After high-dosage isoproterenol, more non-PV triggers were disclosed in group 1 compared to group 2 (42 [75%] vs 24 [43%] respectively, P <.001). Group 2 had lower procedure, radiofrequency and fluoroscopy times compared to group 1 (2.7 ± 1 vs 3.1 ± 1 h, 69 ± 13 min vs 87 ± 11 min and 64 ± 14 min vs 85 ± 18 min respectively, p < .05). At 32 ± 8 month follow-up, on or off antiarrhythmic drug success rate was 37 (66%) in group 1 and 27 (48%) in group 2 (P = .04). During redo, new non-PV trigger sites were identified in group 2 patients. CONCLUSION: Periprocedural continuous amiodarone was associated with higher organization rate and lower radiofrequency ablation rate. However, masking non-PV triggers increased the late recurrence rate.

Outcomes of atrioesophageal fistula following catheter ablation of atrial fibrillation treated with surgical repair versus esophageal stenting.

INTRODUCTION: Atrioesophageal fistula (AEF) is a rare but devastating complication of radiofrequency catheter ablation (RFCA) of atrial fibrillation (AF). Surgical repair and esophageal stents are available treatment options for AEF. We report outcomes of these 2 management strategies. METHODS: Nine patients with AEF post-RFCA for AF were included in this study. AEF was diagnosed based on symptoms and chest CT imaging. Of the 9 patients, 5 received stents and 4 underwent surgical repair of fistula. RESULTS: AF ablation was performed under general anesthesia (n = 4) or conscious sedation (n = 5). During ablation, RF power was maintained between 25 and 35 Watts in areas close to the esophagus and energy delivery discontinued when esophageal temperature reached 38 °C. Seven patients underwent ablation with 3.5-mm open-irrigated catheter, 1 with 8-mm nonirrigated catheter, and 1 had surgical epicardial ablation. Seven patients received proton pump inhibitor and sucralfate before and after procedure. AEF symptoms developed within 2­6 weeks from ablation. Esophageal stenting was performed in 5 patients (median age 58 years, median time from RFCA 4 weeks) and 4 underwent surgical repair (median age 54 years, median time from RFCA 4 weeks) within 2­4 hours from diagnosis. All 5 patients receiving stents died within 1 week of the procedure due to cerebral embolism, septic shock, or respiratory failure. On the other hand, the 4 patients that received surgical repair were alive at median follow-up of 2.1 years (P = 0.005). CONCLUSIONS: Esophageal stenting should be discouraged and prompt surgical repair is crucial for survival in patients with atrioesophageal fistula.

Catheter ablation of asymptomatic longstanding persistent atrial fibrillation: impact on quality of life, exercise performance, arrhythmia perception, and arrhythmia-free survival.

BACKGROUND: Impact of catheter ablation on exercise performance, quality of life (QoL) and symptom perception in asymptomatic longstanding persistent AF (LSP-AF) patients has not been reported yet. METHODS AND RESULTS: Sixty-one consecutive patients (mean age 62 ±13 years, 71% males) with asymptomatic LSP-AF undergoing first catheter ablation were enrolled. Extended pulmonary vein antrum isolation plus ablation of complex fractionated atrial electrograms and nonpulmonary vein triggers was performed in all. QoL survey was taken at baseline and 12-months postablation, using Short Form-36 (SF-36). Information on arrhythmia perception was obtained using a standard questionnaire and corroborating symptoms with documented evidence of arrhythmia. Exercise tests were performed on 38 patients at baseline and 5 months after procedure. Recurrence was assessed using event recorder, cardiology evaluation, electrocardiogram, and 7-day holter monitoring. After 20 ± 5 months follow-up, 36 (57%) patients remained recurrence-free off-AAD. Of the 25 patients experiencing recurrence, 21 (84%) were symptomatic. Compared to baseline, follow-up SF-36 scores improved significantly in many measures. For patients with successful ablation, physical component summary (PCS) and mental component summary (MCS) demonstrated substantial improvement ( MCS: 64.2 ± 22.3 to 70.1 ± 18.6 [P = 0.041]; PCS: 62.6 ± 18.4 to 70.0 ± 14.4 [P = 0.032]). Postablation exercise study in recurrence-free patients showed significant reduction in resting and peak heart rate (75 ± 11 vs. 90 ± 17 and 132 ± 20 vs. 154.5 ± 36, respectively, P < 0.001), increase in peak oxygen pulse (13.4 ± 3 vs. 18.9 ± 16 mL/beat, Δ5.5 ± 15, P = 0.001), peak VO2 /kg (19.7 ± 5 to 23.4 ± 13 mL/kg/min [Δ 3.7 ± 10, P = 0.043]), and corresponding MET (5.6 ± 1 to 6.7 ± 4 [Δ1.1 ± 3, P = 0.03]). No improvement was observed in patients with failed procedures. CONCLUSION: Successful ablation improves exercise performance and QoL in asymptomatic LSP-AF patients.

Long-term outcome of catheter ablation in atrial fibrillation patients with coexistent metabolic syndrome and obstructive sleep apnea: impact of repeat procedures versus lifestyle changes.

INTRODUCTION: Metabolic syndrome (MS) and obstructive sleep apnea (OSA) are well-known independent risk factors for atrial fibrillation (AF) recurrence. This study evaluated ablation outcome in AF patients with coexistent MS and OSA and influence of lifestyle modifications (LSM) on arrhythmia recurrence. METHODS AND RESULTS: We included 1,257 AF patients undergoing first catheter ablation (30% paroxysmal AF). Patients having MS + OSA were classified into Group 1 (n = 126; 64 ± 8 years; 76% male). Group 2 (n = 1,131; 62 ± 11 years; 72% male) included those with either MS (n = 431) or OSA (n = 112; no CPAP users) or neither of these comorbidities (n = 588). Patients experiencing recurrence after first procedure were divided into 2 subgroups; those having sporadic events (frequency < 2 months) remained on previously ineffective antiarrhythmic drugs (AAD) and aggressive LSM, while those with persistent arrhythmia (incessant or ≥2 months) underwent repeat ablation. After 34 ± 8 months of first procedure, 66 (52%) in Group 1 and 386 (34%) in Group 2 had recurrence (P < 0.001). Recurrence rate in only-MS, only-OSA, and without MS/OSA groups were 40%, 38%, and 29%, respectively. Patients with MS + OSA experienced substantially higher recurrence compared to those with lone MS or OSA (52% vs. 40% vs. 38%; P = 0.036). Of the 452 patients having recurrence, 250 underwent redo-ablation and 194 remained on AAD and LSM. At 20 ± 6 months, 76% of the redo group remained arrhythmia-free off AAD whereas 74% of the LSM group were free from recurrence (P = 0.71), 33% of which were off AAD. CONCLUSIONS: MS and OSA have additive negative effect on arrhythmia recurrence following single procedure. Repeat ablation or compliant LSM increase freedom from recurrent AF.

Biomarkers of myocardial injury with different energy sources for atrial fibrillation catheter ablation.

BACKGROUND: Our study aims to compare acute myocardial injury biomarker rise after atrial fibrillation ablation performed with different technologies. METHODS AND RESULTS: One hundred and ten patients were treated with pulmonary vein isolation with 4 different technologies: open-irrigated tip radiofrequency (RF) catheter in35 patients (Group A), cryoballoon in 35 patients (Group B), visually guided laser balloon in 20 patients (Group C), open-irrigated tip RF catheter with contact-force-sensing technology in 20 patients (Group D). Post-procedure samples of cardiac troponin I (cTnI) and creatinine kinase-MB (CK-MB) were collected at 19 ± 3 h and 43 ± 3 h after ablation. At the first postprocedural sample, cTnI and CK-MB levels were found elevated in all 110 patients with a median value of 2.11 ng/mL and 8.95 ng/mL, respectively. Group B showed cTnI levels increased (median 5.96 ng/mL) compared to other groups (median Group A: 1.72 ng/mL, Group C: 1.54 ng/mL, Group D: 2.0 ng/mL; p < 0.001). Also CK-MB levels resulted higher in cryoablation (median 26.4 ng/mL) compared to other groups (median Group A: 6.40 ng/mL, Group C: 7.15 ng/mL, Group D: 6.50 ng/mL; p < 0.001). No significant association was observed between biomarker levels and recurrences of atrial fibrillation after a mean follow-up of 369 ± 196 days. CONCLUSIONS: Highest markers for myocardial injury were observed in the cryoballoon group. It is possible that a longer delivery energy duration and other factors affecting lesion size resulted in higher amount of cardiac injury in cryoablation. The higher levels of cardiac biomarkers did not translate into a better outcome and its physiologic significance is unknown.

Impact of Metabolic Syndrome on Ablation-Outcome in Patients with Atrial Fibrillation: A Systematic Review.

Metabolic syndrome (MS), a pro-inflammatory state with hypertension, diabetes, dyslipidemia and obesity is presumed to be a close associate of atrial fibrillation (AF). However, the exact mechanism by which MS facilitates perpetuation of AF is yet to be fully understood. Moreover, the impact of the components of MS as well as MS as a group, on ablation-outcome in AF is not clearly elucidated until now. This review has compiled the results from major studies that have looked into those risk factors and defined their significance in influencing ablation-outcome in AF. It has also overviewed the impact of life-style changes that might improve the success rate of AF-ablation by effectively addressing the different constituents of MS.

Impact of metabolic syndrome on procedural outcomes in patients with atrial fibrillation undergoing catheter ablation.

OBJECTIVES: The aim of this study was to investigate impact of metabolic syndrome (MS) on outcomes of catheter ablation in patients with atrial fibrillation (AF) in terms of recurrence and quality of life (QoL). BACKGROUND: MS, a proinflammatory state with hypertension, diabetes, dyslipidemia, and obesity, is presumed to be a close associate of AF. METHODS: In this prospective study, 1,496 consecutive patients with AF undergoing first ablation (29% with paroxysmal AF, 26% with persistent AF, and 45% with long-standing persistent AF) were classified into those with MS (group 1; n = 485) and those without MS (group 2; n = 1,011). Patients were followed for recurrence and QoL. The Medical Outcomes Study SF-36 Health Survey was used to assess QoL at baseline and 12 month after ablation. RESULTS: After 21 ± 7 months of follow-up, 189 patients in group 1 (39%) and 319 in group 2 (32%) had arrhythmia recurrence (p = 0.005). When stratified by AF type, patients with nonparoxysmal AF in group 1 failed more frequently compared with those in group 2 (150 [46%] vs. 257 [35%], p = 0.002); no difference existed in the subgroup with paroxysmal AF (39 [25%] vs. 62 [22%], p = 0.295). Group 1 patients had significantly lower baseline scores on all SF-36 Health Survey subscales. At follow-up, both mental component summary (Δ5.7 ± 2.5, p < 0.001) and physical component summary (Δ9.1 ± 3.7, p < 0.001) scores improved in group 1, whereas only mental component summary scores (Δ4.6 ± 2.8, p = 0.036) were improved in group 2. In the subgroup with nonparoxysmal AF, MS, sex, C-reactive protein ≥0.9 mg/dl, and white blood cell count were independent predictors of recurrence. CONCLUSIONS: Baseline inflammatory markers and the presence of MS predicted higher recurrence after single-catheter ablation only in patients with nonparoxysmal AF. Additionally, significant improvements in QoL were observed in the post-ablation MS population.

Influence of body mass index on quality of life in atrial fibrillation patients undergoing catheter ablation.

BACKGROUND: Obesity increases the risk of atrial fibrillation (AF), and AF seriously impairs the quality of life (QoL). However, it is not known whether body mass index (BMI) has any direct influence on QoL in AF. OBJECTIVE: To study the association between baseline BMI and QoL improvement in patients with AF following catheter ablation. METHODS: Six hundred sixty patients with AF (62 ± 10 years, male 69%, paroxysmal AF 27%, persistent AF 31%, long-standing persistent AF 42%) made up the study population. On the basis of the baseline BMI, patients were categorized into 2 groups: normal (BMI < 25) and overweight/obese (BMI ≥ 25). The QoL survey was done at baseline and at 12-month postablation by using the Medical Outcomes Study Short Form-36 (SF-36), Beck Depression Inventory (BDI), Hospital Anxiety and Depression (HAD) scale, and State-Trait Anxiety Inventory (STAI). RESULTS: At baseline, dyslipidemia, hypertension, diabetes, coronary artery disease, and large left atrium had higher prevalence in the overweight/obese population. In addition, the preprocedure QoL scores on the SF-36, HAD scale, and STAI were significantly lower in this group than in the normal-BMI group. At the 12-month postablation assessment, no significant improvement in QoL score was noted in the normal-BMI group. However, in the overweight/obese group, QoL scores improved significantly in all scales, except the physical functioning and bodily pain categories of SF-36. Long-term ablation success was not different across the groups (69% normal BMI, 63% high BMI, log-rank P = .109). Patients with successful ablation showed significant improvement in QoL scores compared with those who failed. The multivariable analysis revealed the baseline QoL score and BMI ≥ 25 to be independent predictors of QoL improvement. CONCLUSION: Obese patients with AF tend to have a better postablation QoL outcome than do their nonobese counterparts.

Baseline B-type natriuretic peptide: a gender-specific predictor of procedure-outcome in atrial fibrillation patients undergoing catheter ablation.

BACKGROUND: Close association between atrial fibrillation (AF) and brain natriuretic peptide (BNP) has been demonstrated by several studies. Important gender differences exist in AF patients including a higher plasma BNP level in women. Therefore, it is imperative to evaluate the relationship between AF and BNP separately in men and women. OBJECTIVE: This study examined possible gender-specific role of BNP in predicting procedure outcome in AF patients undergoing catheter ablation. METHOD: The study population included 568 consecutive patients (age 62 ± 10, male 73%, paroxysmal 25%, persistent 38%, and long-standing persistent AF 37%) undergoing AF ablation, who had structurally normal heart and left ventricular ejection fraction ≥45%. Baseline BNP was measured in all. Patients were grouped into "normal" and "high" BNP based on gender-specific cut-off values (<50 and ≥50 pg/mL in males, <100 and ≥ 100 pg/mL in females). RESULT: Baseline BNP was significantly higher among women than men (126 ± 112 versus 87 ± 99, P = 0.009). At 12 ± 6 month follow-up, 304 of 414 (73%) males and 98 of 154 (64%) females were AF/atrial tachycardia-free off antiarrhythmic drugs (log-rank P = 0.018). In multivariable analysis, BNP remained an independent predictor of AF recurrence (BNP ≥ 50: hazard ratio [HR] 2.54, P = 0.006) in males. No such association was observed among females (BNP ≥ 100: HR 0.79, 95% CI 0.43-1.42; P = 0.426). CONCLUSION: Baseline BNP was found to be an independent predictor of AF recurrence in male patients undergoing ablation. This correlation between BNP and AF recurrence was not observed in females. Thus, BNP plays a gender-specific prognostic role in AF.

Prevention of phrenic nerve injury during epicardial ablation: comparison of methods for separating the phrenic nerve from the epicardial surface.

BACKGROUND: The proximity of the phrenic nerve (PN) to cardiac tissue relevant to arrhythmias may increase the risk of PN injury. Strategies for preventing PN injury in the pericardial space are limited. OBJECTIVE: The purpose of this study was to compare methods for separating the PN from the epicardial surface in order to prevent PN injury. METHODS: Eight patients referred for epicardial ablation of arrhythmias were enrolled in the study. All patients required ablation near the PN. Endocardial and epicardial access was obtained in all patients. A three-dimensional mapping system was used to guide mapping and ablation. All patients underwent epicardial catheter ablation. Pacing via the ablation catheter identified the location of the PN. In order to prevent PN injury, four new strategies were tested in each patient. We sought to increase the distance between the epicardium and the PN by (1) placing a large-diameter balloon between the nerve and the myocardium, (2) introducing saline in steps of 20 ml until PN capture was lost or blood pressure dropped below 60 mmHg, (3) introducing air until PN capture was lost or blood pressure dropped below 60 mmHg, or (4) introducing a combination of saline and air until PN capture was lost or blood pressure dropped below 60 mmHg. RESULTS: At each step, epicardial pacing was performed to assess for PN stimulation. The combination of air and saline resulted in the greatest decrease of PN stimulation. Saline only failed in all cases. Air only and balloon placement were infrequently successful. CONCLUSION: Controlled and progressive inflation of air and saline together with careful monitoring of hemodynamic parameters appears to be the best strategy for preventing PN injury during epicardial ablation. Placement of a large balloon in the appropriate location can be difficult.

Catheter ablation of atrial fibrillation.

Atrial fibrillation is a common arrhythmia associated with significant morbidity, including angina, heart failure, and stroke. Medical therapy remains suboptimal, with significant side effects and toxicities, and a high recurrence rate. Catheter ablation or modification of the atrioventricular node with pacemaker implantation provides rate-control but exposes patients to the hazards associated with implantable devices and does nothing to reduce the risk for stroke. Pulmonary vein antrum isolation offers a nonpharmacologic means of restoring sinus rhythm, thereby eliminating the morbidity of atrial fibrillation and the need for antiarrhythmic drugs.