Search

INTRODUCTION Monomorphic ventricular tachycardia (VT) is an important cause of morbidity and mortality. Use and outcome data of catheter ablation for VT in nonischemic cardiomyopathy (NICM) are limited. METHODS AND RESULTS We obtained data from the 2003-2014 National Inpatient Sample databases. We used propensity score matching to compare patients undergoing catheter ablation versus medical therapy of VT related to NICM, and described the temporal trends in utilization and in-hospital outcomes of catheter ablation of VT in patients with NICM in the United States. From 2003 to 2014, of 133,529 patients hospitalized with the principal diagnosis of VT in NICM, 14,651 (11.0%) underwent catheter ablation. In this period, there was an increasing trend in utilization of catheter ablation (9.3% in 2003-2004 to 12.1% in 2003-2014, adjusted OR [per year], 1.12; 95% CI, 1.08-1.16; Ptrend

AIMS This study investigated the impact of weight loss in longstanding persistent (LSPAF) patients undergoing catheter ablation (CA). METHODS Ninety consecutive obese LSPAF patients were approached; 58 volunteered to try weight loss interventions for up to 1 year (group 1), while 32 patients declined weight loss interventions and were included as a control (group 2). Both groups remained on antiarrhythmic drugs. If they continued to experience AF, CA was performed. Body weight was measured at 6-month intervals and arrhythmia status was assessed by event recorder, electrocardiogram (ECG), and Holter monitoring. Symptom severity and quality of life (QoL) were evaluated by AFSS and SF-36 survey, respectively. A scoring algorithm with two summary measures, physical component score (PCS) and mental component score (MCS), was prepared for QoL analysis. RESULTS Significant reduction in body weight (median -24.9 (IQR -19.1 to -56.7) kg, P

The objective of this study was to evaluate the long-term efficacy of FIRM ablation with PVAI vs PVAI plus posterior wall isolation (PWI) and non-PV trigger ablation in persistent (PeAF) and long-standing persistent AF (LSPAF) patients. The procedure time was recorded to be 180.6 ± 35.9 and 124.03 ± 45.4 minutes in the FIRM+PVI and PVI + PWI + non-PV trigger ablation group respectively. At 24-month follow-up, 24% (95% CI 8.7%–37.8%) in the FIRM-ablation group and 48% (95% CI 27.6–63.3%) in the non-PV trigger ablation group remained arrhythmia-free off-antiarrhythmic drugs after a single procedure. Clinical Trial Registration: ClinicalTrials.gov (Identifier: NCT02533843 ).

Background Obstructive sleep apnea (OSA) is associated with atrial remodeling, atrial fibrillation (AF), and increased incidence of arrhythmia recurrence after pulmonary vein (PV) isolation. We aimed to characterize the atrial substrate, including AF triggers in patients with paroxysmal AF and OSA. Methods and Results In 86 patients with paroxysmal AF (43 with ≥moderate OSA [apnea–hypopnea index ≥15] and 43 without OSA [apnea–hypopnea index P =0.0005; left atrial, P =0.0001), slower conduction velocities (right atrial, P =0.02; left atrial, P =0.0002), and higher prevalence of electrogram fractionation ( P =0.0001). The areas of atrial abnormality were consistent among patients, most commonly involving the left atrial septum (32/43; 74.4%). At baseline, the PVs were the most frequent triggers for AF in both groups; however, after PV isolation patients with OSA had increased incidence of additional extra-PV triggers (41.8% versus 11.6%; P =0.003). The 1-year arrhythmia-free survival was similar between patients with and without OSA (83.7% and 81.4%, respectively; P =0.59). In comparison, control patients with paroxysmal AF and OSA who underwent PV isolation alone without ablation on extra-PV triggers had increased risk of arrhythmia recurrence (83.7% versus 64.0%; P =0.003). Conclusions OSA is associated with structural and functional atrial remodeling and increased incidence of extra-PV triggers. Elimination of these triggers resulted in improved arrhythmia-free survival.

Aims Superior vena cava (SVC) isolation might be difficult to achieve because of the vicinity of the phrenic nerve (PN) and sinus node. Based on its embryogenesis, we hypothesized the presence of preferential conduction from the right atrial (RA) posterior wall, making it possible to isolate the SVC antrally, sparing its anterior and lateral aspect. Methods and results This is a descriptive cohort study of 105 consecutive patients in which SVC isolation was obtained with radiofrequency ablation, starting in the septal aspect of the SVC-RA junction and continued posteriorly and inferiorly targeting sites of early activation until electrical isolation was obtained. Acute SVC isolation was achieved in 103 (98%) patients; the mean distance between the site of SVC isolation and the SVC-RA junction was 19.9 ± 5.3 (range 9.7-33.7) mm. During follow-up, 2 (2%) patients developed symptomatic diaphragmatic paralysis due to transient right PN injury; 13 patients underwent a repeat ablation: SVC reconnection was observed in 5 patients, and re-isolation was easily achieved by targeting the corresponding sites of early activation. Conclusion Superior vena cava isolation can be completed by targeting its septal segment and sites of early activation in the posterior SVC-RA junction and RA posterior wall; this is a feasible alternative ablation strategy in patients in which SVC isolation cannot be completed with the standard approach. The risk of sinus node injury or SVC stenosis are eliminated; PN injury is still possible but can easily be prevented with high-output pacing to exclude a true posterior course of the PN.

Special attention must be paid to detect, diagnose, and optimize management of reversible or treatable causes of long-standing persistent atrial fibrillation (LSPAF) such as obesity, obstructive sleep apnea (OSA), hypertension, hypo or hyperthyroidism, inflammatory and infectious diseases, and stress. Though, we strongly believe that the role of the pulmonary veins (PVs) is more pronounced in paroxysmal atrial fibrillation (AF) than in persistent AF, performing an adequate pulmonary vein isolation is still key in LSPAF. Patients with LSPAF will frequently require a more aggressive mapping and ablative approach. We do not encourage the use of empiric lines or complex fractionated atrial electrograms. Ablation of sites associated with non-PV triggers such as the entire posterior wall, the roof, the anterior part of the left atrium septum, left atrial appendage (LAA), the CS and SVC has been shown to improve the freedom from AF at follow-up when combined with PVs isolation. During the isoproterenol challenge, non-PV triggers are detected in most patients with AF. Mapping non-PV triggers is guided by multiple catheters positioned along both the right and left atriums: a 10-pole circular mapping catheter in the left superior PV recording the far-field LAA activity, the ablation catheter in the right superior PV that records the far-field interatrial septum and a 20-pole catheter with electrodes spanning from the SVC to the CS. With this simple catheter setup, when focal ectopic atrial activity is observed (a single ectopic beat is enough) their activation sequence is compared to that of sinus rhythm, allowing to quickly identify their area of origin. For significant non-PV triggers (repetitive isolated beats, focal atrial tachycardias or beats triggering AF/atrial flutter, a more detailed activation mapping is performed in the area of origin. They are subsequently targeted with focal ablation, exception being the triggers originating from the SVC, LAA or CS, in which cases complete isolation of these structures is the ablation strategy of choice. We truly believe the LAA deserves special consideration when managing patients with persistent AF and LSPAF.

Ventricular tachycardia (VT) ablation is usually performed with an ablation catheter that delivers unipolar radiofrequency (RF) energy to eliminate the re-entry circuit responsible for VT. However, there are some instances when unipolar RF ablation fails, notably in VTs with a deep intramural origin, or cases in which epicardial access is not attainable due to prior cardiac surgery. To overcome these limitations, several alternative approaches have been used in clinical practice, including alcohol ablation or coil embolization, simultaneous unipolar or bipolar RF ablation, surgical ablation, or noninvasive ablation with stereotactic radiosurgery. This review article describes some of these alternative techniques.

Aims To compare the long-term outcomes of standard ablation of stable ventricular tachycardia (VT) vs. substrate modification, and of complete vs. incomplete substrate modification in patients with structural heart disease (SHD) presenting with VT. Methods and results An electronic search was performed using major databases. The main outcomes were a composite of long-term ventricular arrhythmia (VA) recurrence and all-cause mortality of standard ablation of stable VT vs. substrate modification, and long-term VA recurrence in complete vs. incomplete substrate modification. Six studies were included for the comparison of standard ablation of stable VT vs. substrate modification, with a total of 396 patients (mean age 63 ± 10 years, 87% males), and seven studies were included to assess the impact of extensive substrate modification, with a total of 391 patients (mean age 64 ± years, 90% males). More than 70% of all the patients included had ischaemic cardiomyopathy. Substrate modification was associated with decreased composite VA recurrence/all-cause mortality compared to standard ablation of stable VTs [risk ratio (RR) 0.57, 95% confidence interval (CI) 0.40-0.81]. Complete substrate modification was associated with decreased VA recurrence as compared to incomplete substrate modification (RR 0.39, 95% CI 0.27-0.58). Conclusion In patients with SHD who had VT related mainly to ischaemic substrates, there was a significantly lower risk of the composite primary outcome of long-term VA recurrence and all-cause mortality among those undergoing substrate modification compared to standard ablation. Long-term success is improved when performing complete substrate modification.

Occluders for the left atrial appendage that are patient-specific, thus ensuring better fitting and potentially less complications, can be made by 3D-printing inflatable polymer devices on the basis of data derived from computed tomography scans.

We evaluated the association of BMI with comorbidities such as hypertension (HTN) and diabetes (DM) and long-term ablation success in AF patients undergoing catheter ablation A total of 4,236 consecutive AF patients undergoing AF ablation were included in the analysis. Based on the baseline BMI

Atrial fibrillation (AF), is seen in up to 40% of patients following coronary artery bypass graft (CABG) surgery and 5-25% of post-MAZE cases. However, the source of arrhythmia in this subset of AF population is not clearly defined yet. We sought to assess the prevalence of non-pulmonary vein (NPV)

Surface ECG is pivotal in the differential diagnosis of wide QRS complex tachycardia (WCT). We evaluated a new ECG based algorithm pattern on limb leads in identifying ventricular tachycardia (VT) as a complement to existing methods. A total of 130 ECG with WCT were evaluated using Opposing QRS

Cardioesophageal fistulas (CEFs) are uncommon but life-threatening complications of radiofrequency (RF) catheter ablation of atrial fibrillation (AF). They are usually, but not exclusively, related to ablation of the left atrial posterior wall. We report a case of a 73-year-old man that presented with CEF following RF ablation in the coronary sinus, highlighting the importance of esophageal temperature monitoring whenever ablating in the posterior heart.

Background In the stroke prevention trials of left atrial appendage closure with the Watchman device (Boston Scientific), a postimplantation antithrombotic regimen of 6 weeks of warfarin was used. Objective Given the clinical complexity of warfarin use, the purpose of this study was to study the relative feasibility and safety of using non-warfarin oral anticoagulants (NOACs) instead of warfarin during the peri- and initial postimplantation periods after Watchman implantation. Methods This was a retrospective multicenter study of consecutive patients undergoing Watchman implantation and receiving peri- and postprocedural NOACs or warfarin. Transesophageal echocardiography or chest computed tomography was performed between 6 weeks and 4 months postimplant to assess for device-related thrombosis. Bleeding and thromboembolic events also were evaluated at the time of follow-up. Results In 5 centers, 214 patients received NOACs (46% apixaban, 46% rivaroxaban, 7% dabigatran, and 1% edoxaban) in either an uninterrupted (82%) or a single-held-dose (16%) fashion. Compared to a control group receiving uninterrupted warfarin (n = 212), the rates of periprocedural complications, including bleeding events, were similar (2.8% vs 2.4%, P = 1). At follow-up, the rates of device-related thrombosis (0.9% vs 0.5%, P = 1), composite of thromboembolism or device-related thrombosis (1.4% vs 0.9%, P = 1), and postprocedure bleeding events (0.5% vs 0.9%, P = .6) also were comparable between the NOAC and warfarin groups. Conclusion NOACs proved to be a feasible peri- and postprocedural alternative regimen to warfarin for preventing device-related thrombosis and thromboembolic complications expected early after appendage closure with the Watchman device, without increasing the risk of bleeding.

Contact-force (CF) sensing catheters are increasingly used in electrophysiological procedures due to their efficacy and safety profile. As data about the accuracy of fiberoptic CF technology are scarce, we sought to quantify it using in vitro experiments.A force sensor was built with a flexible membrane to allow exact reference force measurements for each set of experiments. A TactiCath Quartz (TCQ) ablation catheter was brought in contact with the force sensor membrane in order to compare the TCQ force measurements to sensor reference force measurements. Measurements were performed at different tip angles (0°/perpendicular contact, 45°, 90°/parallel contact), with fluid irrigation, different degrees of catheter deflection, and using a sheath. The accuracy of the TCQ force measurements was 0.9 ± 0.9 g (0°), 0.8 ± 0.8 g (45°) and 1.2 ± 1.3 g (90°), 0.8 ± 0.7 g (irrigation), 0.8 ± 0.8 g (deflection), and 0.8 ± 0.9 g (sheath); this was not significantly different among all experimental conditions. The precision was ≤3.8%.CF measurements using a fiberoptic sensing technology show a high level of accuracy and precision, without being significantly influenced by tip angle, fluid irrigation, catheter deflection or use of a sheath.

Nonrandomized studies have reported focal impulse and rotor modulation (FIRM)-guided ablation to be superior to pulmonary vein antrum isolation (PVAI) for persistent atrial fibrillation and long-standing persistent atrial fibrillation.This study sought to compare efficacy of FIRM ablation with or without PVAI versus PVAI plus non-PV trigger ablation in randomized persistent atrial fibrillation and long-standing persistent atrial fibrillation patients.Nonparoxysmal atrial fibrillation (AF) patients undergoing first ablation were randomized to FIRM only (group 1), FIRM + PVAI (group 2) or PVAI + posterior wall + non-PV trigger ablation (group 3). Primary endpoint was freedom from atrial tachycardia/AF. The secondary endpoint was acute procedural success, defined as AF termination, ≥10% slowing, or organization into atrial tachycardia.A total of 113 patients were enrolled at 3 centers; 29 in group 1 and 42 each in groups 2 and 3. Group 1 enrollment was terminated early for futility. Focal drivers or rotors were detected in all group 1 and 2 patients. Procedure time was significantly shorter in group 3 versus groups 1 and 2 (p 0.001). In groups 1 and 2, acute success after rotor-only ablation was achieved in 12 patients (41%) and 11 (26%), respectively. After 12 ± 7 months' follow-up, 4 patients (14%), 22 (52.4%), and 32 (76%) in groups 1, 2, and 3, respectively, were AF/atrial tachycardia-free while off antiarrhythmic drugs (log-rank p 0.0001). Group 3 patients experienced higher success compared with groups 1 (p 0.001) and 2 (p = 0.02).Outcomes were poor with rotor-only ablation. PVAI + rotor ablation had significantly longer procedure time and lower efficacy than PVAI + posterior wall + non-PV trigger-ablation. (Outcome of Different Ablation Strategies in Persistent and Long-Standing Persistent Atrial Fibrillation [OASIS]; NCT02533843).

Atrial fibrillation (AF) is the most common sustained cardiac rhythm disorder, and increases in prevalence with increasing age and the number of cardiovascular comorbidities. AF is characterized by a rapid and irregular heartbeat that can be asymptomatic or lead to symptoms such as palpitations, dyspnoea and dizziness. The condition can also be associated with serious complications, including an increased risk of stroke. Important recent developments in the clinical epidemiology and management of AF have informed our approach to this arrhythmia. This Primer provides a comprehensive overview of AF, including its epidemiology, mechanisms and pathophysiology, diagnosis, screening, prevention and management. Management strategies, including stroke prevention, rate control and rhythm control, are considered. We also address quality of life issues and provide an outlook on future developments and ongoing clinical trials in managing this common arrhythmia.

Scar homogenization improves long-term ventricular arrhythmia-free survival compared with standard limited-substrate ablation in patients with post-infarction ventricular tachycardia (VT). Whether such benefit extends to patients with nonischemic cardiomyopathy and scar-related VT is unclear.The aim of this study was to assess the long-term efficacy of an endoepicardial scar homogenization approach compared with standard ablation in this population.Consecutive patients with dilated nonischemic cardiomyopathy (n = 93), scar-related VTs, and evidence of low-voltage regions on the basis of pre-defined criteria on electroanatomic mapping (i.e., bipolar voltage 1.5 mV) underwent either standard VT ablation (group 1 [n = 57]) or endoepicardial ablation of all abnormal potentials within the electroanatomic scar (group 2 [n = 36]). Acute procedural success was defined as noninducibility of any VT at the end of the procedure; long-term success was defined as freedom from any ventricular arrhythmia at follow-up.Acute procedural success rates were 69.4% and 42.1% after scar homogenization and standard ablation, respectively (p = 0.01). During a mean follow-up period of 14 ± 2 months, single-procedure success rates were 63.9% after scar homogenization and 38.6% after standard ablation (p = 0.031). After multivariate analysis, scar homogenization and left ventricular ejection fraction were predictors of long-term success. During follow-up, the rehospitalization rate was significantly lower in the scar homogenization group (p = 0.035).In patients with dilated nonischemic cardiomyopathy, scar-related VT, and evidence of low-voltage regions on electroanatomic mapping, endoepicardial homogenization of the scar significantly increased freedom from any recurrent ventricular arrhythmia compared with a standard limited-substrate ablation. However, the success rate with this approach appeared to be lower than previously reported with ischemic cardiomyopathy, presumably because of the septal and midmyocardial distribution of the scar in some patients.

VT ablation is based on percutaneous catheter insertion under fluoroscopic guidance to selectively destroy (i.e., ablate) myocardial tissue regions responsible for the initiation or propagation of ventricular arrhythmias. Although the last decade has witnessed a rapid evolution of ablation equipment and techniques, the control over catheter movement during manual ablation has remained largely unchanged. Moreover, the procedures are long, and require ergonomically unfavorable positions, which can lead to operator fatigue. In an attempt to overcome these constraints, several technical advancements, including remote magnetic navigation (RMN), have been developed. RMN utilizes a magnetic field to remotely manipulate specially designed soft-tip ablation catheters anywhere in the x, y, or z plane inside the patient's chest. RMN also facilitates titration of the contact force between the catheter and the myocardial tissue, which may reduce the risk of complications while ensuring adequate lesion formation. There are several non-randomized studies showing that RMN has similar efficacy to manual ablation, while complication rates and total radiation exposure appears to be lower. Although these data are promising, larger randomized studies are needed to prove that RMN is superior to manual ablation of VT.

Whether ablation of non-pulmonary vein (PV) triggers after pulmonary vein antrum isolation (PVAI) improves the long-term procedure outcome in patients with paroxysmal atrial fibrillation (PAF) and left ventricular systolic dysfunction is unknown.We sought to evaluate whether a more extensive ablation procedure improves outcomes at follow-up.Consecutive patients with PAF refractory to antiarrhythmic drugs presenting for PVAI were prospectively studied. Patients were categorized into 2 groups: patients with left ventricular ejection fraction (LVEF) ≤35% (group I; n = 175) and patients with LVEF ≥50% (group II; n = 545). Patients in group I were further divided according to whether additional ablation of non-PV triggers was performed (group IA; n = 88) or not (group IB; n = 87). Long-term ablation success off antiarrhythmic drugs after a single procedure was analyzed.Patients in group I had more non-PV triggers than did patients in group II (69.1% vs 26.6%; P.001). During a follow-up of 15.8 ± 4.7 months, fewer patients in group I remained free from recurrences than those in group II (53.7% vs 81.7%; P.001). Long-term ablation success was higher in group IA than in group IB (75.0% vs 32.2%; P.001) and similar to that in group II (75.0% vs 81.7%; P = .44). In multivariate analysis, LVEF ≤35% (hazard ratio 1.68; P = .003) and non-PV triggers (hazard ratio 3.12; P.001) were independent predictors of recurrences.In patients with PAF and left ventricular systolic dysfunction, ablation of non-PV triggers in addition to PVAI significantly improves their long-term procedure outcome.

Background Transesophageal echocardiography (TEE) is recommended in patients undergoing atrial fibrillation (AF) ablation, but use of this strategy is variable. Objective To evaluate whether TEE is necessary before AF ablation in patients treated with novel oral anticoagulants (NOACs). Methods We performed a prospective multicenter registry of AF patients undergoing radiofrequency catheter ablation on uninterrupted NOACs (apixaban and rivaroxaban). All patients were on NOACs for at least 4 weeks before ablation. Heparin bolus was administered to all patients before transseptal catheterization to maintain a target activated clotting time above 300 seconds. A subset of 86 patients underwent brain diffuse magnetic resonance imaging (dMRI) to detect silent cerebral ischemia (SCI). Results A total of 970 patients (514 [53%] apixaban patients and 456 [47%] rivaroxaban patients) were enrolled for this study. The mean age was 69.5 ± 9.0 years, with 824 patients (85%) having nonparoxysmal AF, and 636 patients (65.6%) were male. The average CHA 2 DS 2 -VASc score was 3.01 ± 1.3 and CHADS 2 score was ≥2 in 609 patients (62.8%). Intracardiac echocardiogram ruled out left atrial appendage thrombus in all patients whose left atrial appendage was visualized (692, 71%), and detected "smoke" in 407 patients (42%). SCI at postprocedure dMRI was detected in 2.3% (2/86). One thromboembolic event (transient ischemic attack) (0.10%) with positive dMRI occurred in a patient on uninterrupted rivaroxaban with longstanding persistent AF. Conclusion Our study illustrates that performing AF ablation while on uninterrupted apixaban and rivaroxaban without TEE is feasible and safe. This finding has important clinical and economic relevance.

Ablation of longstanding persistent atrial fibrillation (LSPAF) is the most challenging procedure in the treatment of AF, either by surgical or by percutaneous approach.We investigated the difference in success and complication rates between combined surgical epicardial and endocardial catheter ablation procedure and our standard endocardial ablation procedure.Twenty-four consecutive patients (group 1) with LSPAF and enlarged left atrium (4.5 cm) underwent a combined procedure, consisting of surgical, closed-chest, epicardial, radiofrequency ablation (nContact, NC, USA) via pericardial access, and concomitant endocardial ablation (hybrid procedure). Procedural complications and long-term outcomes were compared to those of 35 consecutive patients who refused the hybrid procedure and underwent standard endocardial only ablation (group 2). Baseline characteristics were comparable. In group 1, 1 patient (4.2%) developed post-procedural cardio-embolic stroke and 3 (12.5%) died (1 atrio-esophageal fistula, 1 fatal stroke, 1 of unknown cause in early follow-up), while no strokes or deaths occurred in group 2. Overall complication rates were higher for group 1 (P = 0.036). At 24-month follow-up, 4 (19%) patients in group 1 and 19 (54.3%) in group 2 were arrhythmia-free after a single procedure, on or off antiarrhythmic drugs (P0.001). Total procedural time (276.9 ± 63.5 vs. 203.15 ± 67.3 minutes) and length of hospital stay (5 [IQR 3-8] vs. 1 [IQR 1-3] days were significantly shorter for group 2 (P0.001).In patients with LSPAF and enlarged left atrium, a concomitant combined surgical/endocardial ablation approach increases complication rate and does not improve outcomes when compared to extensive endocardial ablation only.

Although cardiac resynchronization therapy (CRT) is an important treatment of symptomatic heart failure patients in sinus rhythm with low left ventricular ejection fraction and ventricular dyssynchrony, its role is not well defined in patients with atrial fibrillation (AF). CRT is not as effective in patients with AF because of inadequate biventricular capture and loss of atrioventricular synchrony. Both can be addressed with catheter ablation of AF. It is still unclear if these therapies offer additive benefits in patients with ventricular dyssynchrony. This article discusses the role and techniques of catheter ablation of AF in patients with heart failure, and its application in CRT recipients.

Introduction: Remote magnetic navigation (RMN) and ablation with the magnetic irrigated tip catheter has been reported as a feasible and safe technique for the treatment of ventricular arrhythmias (VA). We compared the procedural benefit and the outcomes of patients with ischemic cardiomyopathy (IC) undergoing VAs ablation with the RMN versus the manual approach. Methods: Consecutive pts with IC undergoing VAs ablation both with RMN and with manual ablation at different Institutions were enrolled. Substrate mapping and ablation technique with scar homogenization were utilized for ablation with the end point of elimination of all abnormal electrograms within and or around the scar area. Procedural data and outcomes were analyzed. Post-ablation pacing maneuvers and isoproterenol were used to verify Vas inducibility. Results: A total of 218 consecutive pts (85.3% male, 69.2±7.7 years, LVEF 30.6±8.2) with IC were included with 80 pts undergoing manual ablation while 138 pts underwent RMN ablation. Patients with a scar size < 60 cm2 at the 3D voltage mapping system were excluded. The mean scar size was 140 ± 61 cm2. VT was inducible in 83% pts with a cycle length of 352.1±70.7 msec. The density of the substrate map was higher in the RMN group when compared to the manual ablation group (553±118 vs 347±97, p At 15.4±6.8 months follow-up the success rate in the RMN group was 81.2% (112) while in the manual ablation group 55 (69%) pts were recurrence free (p=0.037). There was one pericardial tamponade which required pericardiocentesis in the manual ablation group. Conclusion: This study shows that VAs ablation using RMN in pts with IC and a scar size greater than 60 cm2 increases success rate at follow up when compared to manual ablation. The better outcome might be due to the higher amount of time dedicated to RF applications to achieve scar homogenization rather than mapping

Background: Atrial fibrosis or scar is considered a substrate change related to atrial fibrillation (AF); by slowing conduction and increasing heterogeneity it could provide a substrate for AF. However, it is still not known whether AF causes the profibrotic changes in the left atrial wall or simply facilitates the manifestation of an existing aging-related structural remodeling in older patients. We examined scar prevalence and severity in patients aged ≥ 75 years with and without AF to address this question. Method: Five hundred seventy one patients undergoing radio-frequency catheter ablation for AF or supraventricular tachycardia (SVT) were included in this prospective analysis and classified into 2 groups; group 1: patients with AF (n=308, 62% male, median 77.8 (75 to 91) years, 46% paroxysmal and 64% persistent AF) and group 2: patients with diagnosis of SVT (n=263, 56% male, median 80 (75 to 88) years). Left atrial (LA) scarring was determined by three-Dimensional (3D) voltage mapping. Scar was defined as an area with a bipolar voltage amplitude ≤ 0.05 mV, indistinguishable from noise. The degree of scar was described as a percentage of the LA area (mild 60%) involved. Results: Age and gender distribution was similar in both groups. Left atrial scar was detected in 172 (56%) patients in group 1 and 134 (51%) in group 2 (p=0.24). After adjusting for age and gender in multivariable logistic model, diagnosis of AF or SVT did not show to have any association with the incidence of scar (p=0.22). Based on the 3D mapping, 52(30%) patients were classified as having mild LA scarring, 88(51%) moderate scar and 32(19%) with severe scar in group 1. Distribution of scar severity in group 2 was: mild 50(37%), moderate 67(50%), and severe in 17(13%), which was similar to that of AF patients (p=0.248). Conclusion: Similar prevalence and distribution of severity of the left atrial scarring in elderly patients with and without atrial fibrillation suggest age-dependent substrate remodeling to be the major contributor of scar formation. Our results indicate that scar could facilitate atrial fibrillation in predisposed subjects only.

Introduction: Atrial fibrillation (AF) is common after coronary artery bypass grafting (CABG). Ranolazine is a novel drug used in the treatment of angina, which also has antiarrhythmic properties. Recent studies demonstrated the benefit of ranolazine in preventing post-operative AF (POAF) in patients undergoing CABG. Hypothesis: To assess the role of ranolazine in preventing POAF in patients undergoing CABG surgery. Methods: We performed comprehensive search of PubMed, MEDLINE, and Cochrane library database on the study assessing the effectiveness of ranolazine in preventing POAF by comparing it with standard therapy. Meta-analysis was performed by fixed effect model by entering POAF events and the total population from each study. Data are expressed as Odds ratio (OR) with 95% confidence interval (CI). Results: A total of three studies with 628 patients (259 pts in ranolazine group, 369 pts in standard therapy group) were included in the meta-analysis. In pooled analysis, ranolazine was associated with 54% reduction in post-operative AF events compared to standard therapy [odds ratio = 0.46 (0.31, 0.70), P Conclusions: Ranolazine may prove beneficial in the prevention of POAF following CABG. However, because of small number of studies further research with large randomized clinical trial is warranted to determine specific dose and duration of ranolazine therapy.

Introduction: The objective of this retrospective multicenter study is to report the initial long-term performance results after percutaneous exclusion of the LAA with the endo-epicardial Lariat device to prevent AF-related thromboembolic events. Methods and results: Patients with successful LAA ligation and at least 1-year follow-up were analyzed (N=355). At 1 year, TEE follow-up was present in 172 patients. A leak was defined as presence of flow into the LAA as assessed by TEE. At 6 months, 19 (11%) patients had a leak; 2 strokes occurred: 1 in a patient without a leak and 1 associated with mesenteric ischemia in a patient without a known acute leak, who died before repeat TEE could be performed. At 12 months, 34 (20%) patients had a leak; 6 patients developed a neurological event (5 strokes and 1 TIA), 4 in patients with a leak, 2 in patients without a leak. 3% were followed-up for more than one 1 year (with a mean of 21±9 months). 1 additional thromboembolic event (TIA) occurred 14 months post-implant in a patient without anticoagulation and with a partially excluded LAA (stump), although no leak or thrombus were detected on standard TEE. Among patients with a leak (36% of those with long-term follow-up), 75% were on long-term anticoagulation and no additional TE events were detected. Out of 355 patients, 9 (2.5%) patients had a neurological event: 4 with a leak, 4 without a leak and 1 in a patient where TEE was not repeated. Considering those with known LAA status, thromboembolic events were more common in patients with a leak (4/34 vs 4/136; RR 4, 95% CI 1.1-15.4). Conclusion: In this multicenter experience with the Lariat device, the rate of leaks was high (20% of those with TEE follow-up at 1 year). Thromboembolic events were not rare (overall, 2.5%), and occurred more frequently in patients with a leak (RR 4).

Background: Radiofrequency catheter ablation is widely-used to target frequent premature ventricular complexes (PVCs) in patients with and without structural heart disease, with reported ablation-success rate being in the 80% range. However the risk-factors that correlate with ablation-failure have not been defined yet. We aimed to assess the prevalence of recurrent PVCs in the immediate post-ablation period and their relevance in relation to the clinical outcome of catheter ablation of PVCs. Methods: A consecutive series of 104 patients (age: 58±15 years, male 57%, LVEF 54±10.8) with frequent PVCs and without structural heart disease referred for catheter ablation at our center, were included in this prospective analysis. Successful ablation was defined as the absence of spontaneous or induced clinical PVC, both with or without isoproterenol at the end of the procedure. Arrhythmia burden was assessed at baseline and follow-up using 24-hour Holter recording. Telemetry was performed for at least 12 hours in the immediate post-ablation period. Ablation success was defined as ≥ 90% reduction of the initial PVC burden at 3-month follow-up. Results: At baseline, the mean number of PVC morphologies was 1.4± 2.2 and the predominant PVCs commonly originated from right ventricular outflow tract [34 (32.6%)], coronary cusps [28 (27%)], interventricular septum [16 (15.3%)] and left ventricular outflow tract [13 (12.5%)]. Elimination of predominant PVCs was achieved in all patients. In the 12-hour post-ablation period, recurrence of PVCs was observed in 16 (15%) patients, which were transitory and never documented at follow-up monitoring. The most common sites of origin of these early PVCs were anterior cardiac veins, papillary muscles and mitral valve annulus. At follow-up, recurrence was reported in 5 of the 104 patients (4.8%) of which only one had early PVCs during the 12-hour post-ablation period. Conclusions: Recurrence of PVCs in the immediate post-ablation period is transient and not indicative of the failure of the index procedure. Furthermore, pre-discharge PVCs do not demonstrate any definite correlation with the risk of late recurrence. This is most likely the result of myocardial irritation secondary to the trauma of the ablation procedure.

Introduction: Focal impulse and rotor modulation (FIRM)-guided ablation targets localized sources that are thought to sustain AF. In previous reports, it has been shown that FIRM is effective in terminating or organizing AF. We sought to evaluate the acute success of FIRM in patients with persistent and LSP AF undergoing ablation in our centers. Methods: This was a multicenter prospective observational study. FIRM was performed alone or before conventional ablation. Rotors were ablated as confirmed by their absence during remapping and acute success was defined as AF termination, organization or slowing 10%. Results: 57 patients were enrolled (mean age 63 ± 10; 7% LSP). Rotors-only ablation was performed in 56% of patients, and preceded conventional ablation in 44%. There were no major periprocedural adverse events. No focal impulses were found, while rotors were present in all patients (3.9 ± 1.2 per patient; 66% in the LA). In the RA, the majority of rotors were in the lateral wall (53%) and in the septum (30%). In the LA, most of the rotors were in proximity of the pulmonary veins (48%), with the second most common locations being around the mitral annulus or in the septum (17% and 13% respectively). Mean procedural time for FIRM only procedures was 226 ± 52 minutes vs a median of 210 (168-240) minutes for FIRM + conventional ablation procedures (p = NS). Overall acute success was achieved in 35% of patients (3% AF termination, 16% AF organization, 16% AF slowing) with a mean RF time to complete FIRM ablation of 30 ± 15 minutes; no difference in acute success was found when comparing persistent to LSP patients (28% vs 50%; p = NS). Conventional ablation following FIRM did not significantly increase the rate of acute success (1 additional patient converted to sinus rhythm during pulmonary vein isolation). Conclusion: Rotors were present in all patients undergoing ablation for non-paroxysmal AF, most commonly the right atrial lateral wall, septum or around the pulmonary veins. Their ablation was not effective in obtaining AF organization/termination during the procedure.

Introduction: We sought to investigate the characteristics and outcomes of patients who underwent RF ablation of PM ventricular arrhythmias (VA) in our center. Results: 26 patients were included, median age was 66 years (16 to 85), 46% female, all with normal LVEF. PM VAs were PVCs in 68% patients, and PVC + VT in 32%. Site of origin was the LV infero-septal PM in 73%, LV antero-lateral PM in 15% and right ventricular RV septal PM in 12%. 46% of patients showed other VAs in addition to the one originating from the PMs; in 33% of these patients, additional VAs were 2 or more. These VAs were mostly PVCs (92%), localized in the LVOT (64% - 56 % in the basal LV and 44% in the aortic cusps) and the septal RVOT (36%). The only additional VT was fascicular. All the PMs and mappable additional VAs were ablated with RF energy through an irrigated catheter and the aid of ICE; a remote magnetic navigation system (RMS) was used in half of the procedures. In one case, PVC suppression required additional epicardial ablation. Major complications occurred in 2 patients (8%): 1 pericardial effusion (the patient underwent ablation of a crista terminalis premature atrial complex in the same procedure) and 1 pseudoaneurysm. Acute success (PM VA suppression/non-inducibility) was achieved in 96% of patients (the patient with pericardial effusion could be anticoagulated further and the procedure was stopped). After a median follow-up period of 8 (4-14) months, long-term success (no PM VT recurrence or PVC burden reduced by 80% off antiarrhythmic drugs) was 92% after a single procedure, 96% after repeat procedures. When considering additional VAs, the only recurrence was a parahisian RVOT PVC. No difference in acute or overall long-term success was observed when comparing RMS-guided vs standard procedures (respectively 92% vs 100 % and 100% vs 92%; P = NS). Conclusion: PM VAs are most commonly PVCs originating from the LV infero-septal PM and are frequently (48%) associated with an additional ventricular focus (LVOT > RVOT >> fascicular VT). RF ablation is safe and effective in eliminating or significantly reduce the burden of PM VAs, as well the extra-PM foci that are commonly encountered in this population. RMS guided ablation is not inferior to standard ablation in this subset of patients.

Introduction: Bipolar voltage mapping detects areas of scar and guides ablation of VT. The role of endocardial unipolar voltage mapping is not well defined. We examined the endo-epicardial substrate in a mixed cohort of patients with structural heard disease (SHD) to determine whether an endocardial unipolar low voltage area predicts the presence and location of an epicardial scar. Results: Data from 24 consecutive patients with SHD (11 ICM, 6 NICM, 3 HCM, 2 ARVC, 1 myocarditis, 1 Brugada) with a detailed (mean points per map 200) combined endocardial-epicardial substrate mapping were retrospectively reviewed. Maps were obtained using a 3D mapping system (CARTO 3) and normal thresholds used were ≤1.5 mV for bipolar voltage, and ≤5.5 (RV) or ≤8.3 mV (LV) for unipolar voltage. Mapping was performed in the LV in 17 patients, in the RV in 6 patients, in both in 1 patient. An endocardial unipolar low voltage area was found in 21/25 maps. In 12/21 maps there was no corresponding epicardial scar, while in 3/4 cases an epicardial scar was detected despite a negative unipolar map (PPV=43%, NPV=25%, P=NS; Fig. 1). In the 9 cases with both positive endocardial unipolar and epicardial bipolar maps, the epicardial scar was found in the corresponding ventricular region of the endocardial low-voltage area, although unipolar area had a tendency to overestimate the area of the scar (115 vs 95 cm 2 ). Conclusion: In this series of patients with SHD, analysis of unipolar voltage maps could not reliably predict the epicardial arrhythmogenic substrate. There is a modest correlation between areas of endocardial unipolar low voltage and epicardial scars (57% of patients with an abnormal unipolar map had a normal epicardial substrate). Moreover, an epicardial substrate cannot be safely excluded based on a normal unipolar endocardial map. Fig. 1 Abnormal bipolar epicardial map (left) with corresponding normal unipolar endocardial map (right) in a patient with ARVC. Pink dots represent area of defragmentation.

We read with interest the paper by Seitz et al. [(1)][1] focusing on mapping areas of spatiotemporal electrogram dispersion in patients with atrial fibrillation (AF). According to the authors, these areas represent “AF drivers” and their ablation is a personalized, more effective strategy than

This study examined if baseline anxiety influences ablation-outcome in terms of achievement of sinus rhythm and quality of life (QoL) in AF patients. 720 patients undergoing first catheter ablation were enrolled. QoL survey was done at baseline and 12-months post-ablation using Medical Outcome

We tested the hypothesis that NPAF patients entering the EP lab with sinus rhythm (SR) have shorter procedure time and better ablation-outcome than those with AF as the entry-rhythm. Total of 1047 consecutive NPAF patients undergoing catheter ablation were included. Based on the presenting rhythm