Shane Bailey

Left Atrial Appendage An Underrecognized Trigger Site of Atrial Fibrillation

Background— Together with pulmonary veins, many extrapulmonary vein areas may be the source of initiation and maintenance of atrial fibrillation. The left atrial appendage (LAA) is an underestimated site of initiation of atrial fibrillation. Here, we report the prevalence of triggers from the LAA and the best strategy for successful ablation. Methods and Results— Nine hundred eighty-seven consecutive patients (29% paroxysmal, 71% nonparoxysmal) undergoing redo catheter ablation for atrial fibrillation were enrolled. Two hundred sixty-six patients (27%) showed firing from the LAA and became the study population. In 86 of 987 patients (8.7%; 5 paroxysmal, 81 nonparoxysmal), the LAA was found to be the only source of arrhythmia with no pulmonary veins or other extrapulmonary vein site reconnection. Ablation was performed either with focal lesion (n=56; group 2) or to achieve LAA isolation by placement of the circular catheter at the ostium of the LAA guided by intracardiac echocardiography (167 patients; group 3). In the remaining patients, LAA firing was not ablated (n=43; group 1). At the 12±3-month follow-up, 32 patients (74%) in group 1 had recurrence compared with 38 (68%) in group 2 and 25 (15%) in group 3 (P<0.001). Conclusions— The LAA appears to be responsible for arrhythmias in 27% of patients presenting for repeat procedures. Isolation of the LAA could achieve freedom from atrial fibrillation in patients presenting for a repeat procedure when arrhythmias initiating from this structure are demonstrated.

Safety and Efficacy of Pulmonary Vein Antral Isolation in Patients With Obstructive Sleep Apnea The Impact of Continuous Positive Airway Pressure

Background—Obstructive sleep apnea (OSA) may be associated with pulmonary vein antrum isolation (PVAI) failure. The aim of the present study was to investigate if treatment with continuous positive airway pressure (CPAP) improved PVAI success rates. Methods and Results—From January 2004 to December 2007, 3000 consecutive patients underwent PVAI. Patients were screened for OSA and CPAP use. Six hundred forty (21.3%) patients had OSA. Patients with OSA had more procedural failures (P=0.024) and hematomas (P<0.001). Eight percent of the non-OSA paroxysmal atrial fibrillation patients had nonpulmonary vein antrum triggers (non-PV triggers) and posterior wall firing versus 20% of the OSA group (P<0.001). Nineteen percent of the non-OSA nonparoxysmal atrial fibrillation population had non-PV triggers versus 31% in the OSA group (P=0.001). At the end of the follow-up period (32±14 months), 79% of the non-CPAP and 68% of the CPAP group were free of atrial fibrillation (P=0.003). Not using CPAP in addition to having non-PV triggers strongly predicted procedural failure (hazard ratio, 8.81; P<0.001). Conclusions—OSA was an independent predictor for PVAI failure. Treatment with CPAP improved PVAI success rates. Patients not treated with CPAP in addition to having higher prevalence of non-PV triggers were 8 times more likely to fail the procedure.

Outcomes and complications of catheter ablation for atrial fibrillation in females

BACKGROUND Most atrial fibrillation (AF) ablation studies have consisted predominantly of males; accordingly, there is a paucity of information on the safety and efficacy of catheter ablation in a large cohort of female AF patients. OBJECTIVE The purpose of this study was to evaluate catheter ablation for AF in female patients. METHODS From January 2005 to May 2008, 3265 females underwent pulmonary vein antrum isolation. Success rates, patient profiles, and complications were collected. RESULTS Approximately 16% of our population was female (P <.001). Females were older (59 +/- 13 vs. 56 +/- 19 years; P <.01) and had a lower prevalence of paroxysmal atrial fibrillation (PAF; 46% vs. 55%; P <.001). Females failed more antiarrhythmics (4 +/- 1 vs. 2 +/- 3; P = .04) and were referred later for catheter ablation (6.51 +/- 7 vs. 4.85 +/- 6.5 years; P = .02) than males. More females failed ablation (31.5% vs. 22.5%; P = .001) and had nonantral sites of firing than males (P <.001). Female patients had 11 (2.1%) hematomas versus 27 (0.9%) in males. CONCLUSIONS Five times as many males underwent catheter ablation than females. Females failed more ablations possibly because of a higher prevalence of nonantral firing, non-PAF, and longer history of AF. Females had more bleeding complications than males.

General anesthesia reduces the prevalence of pulmonary vein reconnection during repeat ablation when compared with conscious sedation: Results from a randomized study

BACKGROUND Radiofrequency catheter ablation of atrial fibrillation can be performed under general anesthesia or conscious sedation at the physicians preference. OBJECTIVE We randomized a series of consecutive patients with paroxysmal atrial fibrillation (AF) undergoing radiofrequency catheter ablation to either general anesthesia or conscious sedation to assess differences in pulmonary vein (PV) reconnection during redo procedures and impact on success rate. METHODS A total of 257 consecutive patients with paroxysmal AF undergoing AF ablation were enrolled and randomized to either conscious sedation with fentanyl or midazolam (128 patients, group 1) and general anesthesia (129 patients, group 2). In all patients, a high dosage of isoproterenol up to 30 μg/min was used to disclose PV reconnection or extra PV firings. RESULTS Baseline clinical characteristics were not significantly different between the 2 groups. At 17 ± 8 month follow-up after the first ablation, 88 (69%) patients in group 1 were free of atrial arrhythmias off all antiarrhythmic drugs (AAD), as compared with 114 (88%) in group 2 (log-rank P <.001). All patients with recurrence had a second procedure. At the repeat procedure, 42% (66 of 158) of PVs in group 1 had recovered PV conduction, compared with 19% (11 of 57) in group 2 (P = .003). Compared with group 1, group 2 had a significantly shorter fluoroscopy time (53 ± 9 min vs. 84 ± 21 min, P <.001) and procedure time (2.4 ± 1.4 h vs. 3.6 ± 1.1 h, P <.001). CONCLUSION The use of general anesthesia is associated with higher cure rate with a single procedure, and it seems to reduce the prevalence of PV reconnection observed at the time of repeat ablation.

Ablation of Atrial Fibrillation Utilizing Robotic Catheter Navigation in Comparison to Manual Navigation and Ablation: Single-Center Experience

Background: Robotic catheter navigation and ablation either with magnetic catheter driving or with electromechanical guidance have emerged in the recent years for the treatment of atrial fibrillation.

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.

Strategies for the Safe Magnetic Resonance Imaging of Pacemaker-Dependent Patients

Objective: To determine if strategies used to safely scan nonpacemaker‐dependent patients could be applied to facilitate safe MRI of pacemaker‐dependent patients.

Transseptal access and atrial fibrillation ablation guided by intracardiac echocardiography in patients with atrial septal closure devices.

BACKGROUND Percutaneous positioning of closure devices is a well-established treatment of atrial septal defects (ASDs). However, patients who have undergone the procedure are at increased risk for developing atrial fibrillation (AF), and treatment by catheter ablation is underutilized due to the perceived difficulty of obtaining transseptal access in the presence of the closure device. OBJECTIVE The purpose of this study was to report the acute and long-term results of radiofrequency catheter ablation of AF in patients with ASD closure devices. METHODS Thirty-nine patients (age 54 ± 6 years, 72% males) with drug-refractory AF (33% paroxysmal, 51% persistent, 16% long-standing persistent) and ASD closure devices (82% Amplatzer, 18% CardioSEAL) underwent radiofrequency catheter ablation. A double transseptal access guided by intracardiac echocardiography was obtained in all patients. RESULTS In 35 of 39 patients (90%), the transseptal access was obtained in a portion of the native septum, whereas in 4 of 39 patients (10%), a direct access through the device was required. The latter group had a significantly longer time for achieving the double transseptal access (73.6 ± 1.1 minutes vs. 4.3 ± 0.4 minutes, P < .001), longer fluoroscopy time (122 ± 5 minutes vs. 80 ± 8 minutes, P < .001), and total procedural time (4.1 ± 0.2 hours vs. 3.1 ± 0.3 hours, P < .001). At follow-up of 14 ± 4, months the overall success rate was 77% (85% in paroxysmal AF, 73% in nonparoxysmal AF). Transthoracic contrast-enhanced echocardiography with the Valsalva maneuver, performed between 3 and 6 months after the procedure, failed to detect shunt in all patients. CONCLUSION Radiofrequency catheter ablation of AF is feasible, safe, and effective in patients with ASD closure devices. Transseptal access can be obtained in portions of the native septum in the majority of cases. Direct transseptal puncture of the device is feasible and safe but requires longer time for each transseptal access.

Locating the right phrenic nerve by imaging the right pericardiophrenic artery with computerized tomographic angiography: Implications for balloon-based procedures

BACKGROUND Phrenic nerve (PN) injury, a known complication of radiofrequency (RF) catheter ablation of atrial fibrillation (AF), has been more commonly reported with balloon-based pulmonary vein isolation. OBJECTIVE We present a novel approach to locating the PN and predicting patients at higher risk of this complication. METHODS The study included 2 groups of patients. In the first group of 71 patients, computerized tomographic angiography (CTA) with 3-dimensional reconstruction of the left atrium (LA) was obtained prior to an RF ablation procedure. The location of the right pericardiophrenic artery (RPA) was identified on the axial CTA images, and the artery distance to the right superior pulmonary vein (RSPV) ostium was measured in the 3-dimensional image. During ablation, the location of the right PN was identified by pacing maneuvers. The distance to the ostium of the RSPV was measured by venography and compared with the CTA artery measurement. In the second group, CTA imaging from 37 subjects who were enrolled in 3 investigational balloon ablation trials were analyzed using the same PN location technique and compared against the clinical outcomes. In this analysis, the CTA segmentation and PN location was performed in a blinded fashion as to any clinical evidence of PN injury. RESULTS The mean measurement difference between PN capture and imaged RPA was 0.8 mm (P = .539). In all cases, the imaged RPA could reliably identify the approximate location of the right PN (R-square 0.984, P < .001). Moreover, this analysis suggests that a PN location within 10 mm of the RSPV poses a higher risk of PN injury using these balloon ablation devices. CONCLUSION Imaging the right pericardiophrenic artery can reliably locate the right phrenic nerve. This technique might identify anatomy more vulnerable to phrenic nerve injury using balloon-based ablation systems.

Administration of isoproterenol and adenosine to guide supplemental ablation after Pulmonary Vein Antrum Isolation

Pulmonary vein antrum isolation (PVAI) remains associated with atrial fibrillation (AF) recurrence. We administered adenosine and isoproterenol (ISP) after PVAI to uncover non‐PV atrial triggers and PV reconnection, potentially increasing ablation success rate.