Search

Background Preclinical and clinical studies have utilized periprocedural parameters to optimize cryoballoon ablation dosing, including acute time-to-isolation (TTI) of the pulmonary vein, balloon rate of freezing, balloon nadir temperature, and balloon-thawing time. This study sought to predict the Arctic Front Advance (AFA) vs Arctic Front Advance Pro (AFA Pro) ablation durations required for transmural pulmonary vein isolation at varied tissue depths. Methods A cardiac-specific, three-dimensional computational model that incorporates structural characteristics, temperature-dependent cellular responses, and thermal-conductive properties was designed to predict the propagation of cold isotherms through tissue. The model assumed complete cryoballoon-to-pulmonary vein (PV) circumferential contact. Using known temperature thresholds of cardiac cellular electrical dormancy (at 23°C) and cellular nonviability (at -20°C), transmural time-to-isolation electrical dormancy (TTIED ) and cellular nonviability (TTINV ) were simulated. Results For cardiac thickness of 0.5, 1.25, 2.0, 3.0, 4.0, and 5.0 mm, the 23°C isotherm passed transmurally in 33, 38, 46, 62, 80, and 95 seconds during cryoablation utilizing AFA and 33, 38, 46, 63, 80, and 95 seconds with AFA Pro. Using the same cardiac thicknesses, the -20°C isotherm passed transmurally in 40, 55, 78, 161, 354, and 696 seconds during cryoablation with AFA and 40, 54, 78, 160, 352, and 722 seconds with AFA Pro. Conclusion This model predicted a minimum duration of cryoballoon ablation (TTINV ) to obtain a transmural lesion when acute TTI of the PV was observed (TTIED ). Consequently, the model is a useful tool for characterizing CBA dosing, which may guide future cryoablation dosing strategies.

Background: The second-generation cryoballoon (CB2) provides effective and durable pulmonary vein isolation (PVI) associated with encouraging and reproducible clinical outcome data. The latest- -generation cryoballoon (CB3) incorporates a 40% shorter distal tip, thus allowing for an increased rate of PVI real-time signal recording and facilitating individualized ablation strategies taking the time-to- -effect (TTE) into account. However, whether this characteristic translates into favorable clinical success has not been evaluated yet. Herein was investigated 1-year clinical success after CB3 in comparison to CB2 based-PVI. Methods: One hundred and ten consecutive patients with paroxysmal or short-standing persistent atrial fibrillation (AF) underwent CB2 (n = 55 patients) -or CB3 (n = 55 patients) -based PVI. The freeze-cycle duration was set to TTE + 120 s if TTE could be recorded, otherwise a fixed freeze-cycle duration of 180 s was applied. Results: A total of 217/218 (99%, CB3) and 217/217 (100%, CB2) pulmonary veins (PV) were successfully isolated. The real-time PVI visualization rate was 69.2% (CB3) and 54.8% (CB2; p = 0.0392). The mean freeze-cycle duration was 194 ± 77 s (CB3) and 206 ± 85 s (CB2; p = 0.132), respectively. During a median follow-up of 409 days (interquartile range [IQR] 378–421, CB3) and 432 days (IQR 394–455, CB2) 73.6% (CB3) and 73.1% of patients (CB2) remained in stable sinus rhythm after a single procedure (p = 0.806). Conclusions: A higher rate of real-time electrical PV recordings was seen using the CB3 as compared to CB2. There was no difference in 1-year clinical follow-up.

Perimitral atrial flutter is commonly treated by deployment of a mitral isthmus line. However, the creation of a contiguous, transmural linear lesion across the anterior mitral isthmus using radiofrequency energy ablation is technically challenging and can be associated with major complications. Herein, we describe the successful deployment of a superolateral mitral isthmus line using the 28-mm cryoballoon in combination with a new mapping system.

Background Second-generation cryoballoon (CB2)-based pulmonary vein isolation (PVI) has demonstrated encouraging clinical results for the treatment of paroxysmal atrial fibrillation (AF) and persistent AF. However, rhythm follow-up after PVI is mainly based on Holter electrocardiography of limited duration. Objective The purpose of this study was to assess the real AF burden following CB2-based PVI in patients with implanted cardiac devices. Methods A total of 670 consecutive patients underwent CB2-based PVI at 3 electrophysiology centers. In 66 patients (9.9%), an implantable cardiac device with continuous monitor function was independently implanted before the procedure (device group). This patient cohort was compared to propensity score-matched patients without cardiac devices (n = 66; control group). Results A total of 254 of 258 PVs (98.4%0 in the device group were successfully isolated using only CB2. Postprocedural device interrogation found no device or lead malfunction related to the procedure. Periprocedural complications were registered in 7 of 66 patients (11%) in the device group and in 6 of 66 patients (9%) in the control group (P = .770). Phrenic nerve palsy occurred in 6 of 66 patients (9%) in the device group) and in 2 of 66 patients (3%) in the control group) (P = .274). Clinical success in terms of freedom from AF recurrence after a 1-year follow-up period was 63.8% (95% confidence interval 53–77) in the device group and 77.3% (95% confidence interval 68–88) in the control group (P = .038). In the device group, AF/AT burden decreased from 41.8% ± 35.0% before the procedure to 10.2% ± 22.4% after 1 year (P Conclusion CB2-PVI seems safe and feasible in patients with an implanted cardiac device. A significantly higher AF/AT burden was seen in patients with an implanted cardiac device compared to a control group.

Aims Catheter ablation of ventricular arrhythmias (VA) has proven to be an effective therapeutic option for secondary arrhythmia prophylaxis. We sought to assess the procedural efficacy, safety and in-hospital mortality of a large patient cohort with and without structural heart disease undergoing VA ablation. Methods A total of 1417 patients (804 patients with structural heart disease) undergoing 1792 endo- and epicardial procedures were analyzed. Multivariable risk factor analysis for occurrence of major complications and intrahospital mortality was obtained and a score to allow preprocedural risk assessment for patients undergoing VA ablation procedures was established. Results Major complication occurred in 4.4% of all procedures and significantly more often in patients with structural heart disease than in structurally normal hearts (6.0 vs. 1.8%). The frequency of these periprocedural complications was significantly different between procedures with sole right ventricular and a combination of RV and LV access (0.5 vs. 3.1%). The most common complication was cardiac tamponade in 46 cases (3.0%). Intrahospital death was observed in 32 patients (1.8%). Logistic regression model revealed presence of ischemic heart disease, epicardial ablation, presence of oral anticoagulation or dual antiplatelet therapy as independent risk factors for the occurrence of complications or intrahospital death, while a history of previous heart surgery was an independent predictor with a decreased risk. Based on this analysis a risk score incorporating 5 standard variables was established to predict the occurrence of complications and intrahospital mortality. Conclusions Safety of VA catheter ablation mainly relies on patient baseline characteristics and the type of access into the ventricles or epicardial space.

The cryoballoon (CB) is a popular ablation technology used for pulmonary vein isolation. The fourth-generation CB, Arctic Front Advance PRO features a 40% shorter distal tip but retains the internal design from its second-generation predecessor. The Arctic Front Advance PRO and the second-generation CB demonstrated similar thermodynamic characteristics in a computational model. Several observational and retrospective studies established the acute safety and efficacy of the Arctic Front Advance PRO. Real-time electrical isolation was observed in 75–85% of pulmonary veins targeted with the Arctic Front Advance PRO resulting in shorter fluoroscopy and procedure times.

Background Pulmonary vein isolation (PVI) using the second-generation cryoballoon (CB2) for atrial fibrillation (AF) treatment has demonstrated encouraging procedural success rates and mid-term results. However, long-term follow-up data on outcome is sparse. The current study is reporting on five-year clinical outcomes following CB2-based PVI in patients with paroxysmal AF (PAF) and persistent AF (PersAF). Methods A total of 139 patients underwent index CB2-based PVI patients (PAF: n = 105, 76% and PersAF: n = 34, 34%) in two electrophysiology centers. Freeze-cycle duration was 240 s. After successful PVI a bonus freeze-cycle of the same duration was applied in the first 71 patients while the bonus-freeze was omitted in 68 following patients. Three patients (2.2%) were lost to follow-up. Results After a median follow-up duration of 60 months (interquartile range: 46, 72 months) 74/136 (54.4%) patients remained in stable sinus rhythm (PAF: 62/104, 59.6%; PersAF: 15/32, 46.9%). Significant differences were observed concerning 5-year clinical outcome between PAF and PersAF patients (p = 0.0315). After a mean of 1.32 ± 0.6 procedures (2nd and 3rd procedure by radiofrequency ablation) and a median follow-up duration of 60 (37, 68) months 90/136 (66.2%) patients remained in stable sinus rhythm (PAF: 72/104 (69.2%), PersAF: 21/32 (65.6%), p = 0.0276). For the comparison of bonus-freeze vs no-bonus-freeze protocols no differences were observed (53.5% vs 57.4%, p = 0.650). Conclusions The five-year single-procedure success rate for CB2-based PVI was 54.4% and increased to 66.2% following repeat RF-based procedures. No differences were detected comparing bonus-freeze and no-bonus-freeze protocols.

Introduction The aim of this study was to assess the use of a novel noninvasive epicardial and endocardial electrophysiology system (NEEES) for mapping of ventricular arrhythmias. Methods Eight patients (2 females, mean age 50 ± 17 years) with ischemic (n = 3) and nonischemic (n = 5) cardiomyopathy and inducible ventricular arrhythmias during electrophysiology study were enrolled. Noninvasive mapping of ventricular arrhythmias was performed using the NEEES based on body-surface electrocardiograms and computed tomography imaging data. Arrhythmia patterns were analyzed using noninvasive phase mapping. Results Macro-reentrant VT circuits were observed in 3 ischemic and 1 nonischemic cardiomyopathy patient, respectively. In the remaining 4 patients, phase mapping revealed relatively stable rotor activity and multiple wavelets. Conclusions Noninvasive cardiac mapping was able to visualize the macro-reentrant circuits in patients with scar-related VT. In patients without myocardial scar only polymorphic VT or VF was inducible, and rotor activity and multiple wavelets were observed.

Left atrial appendage occlusion (LAAO) with the Watchman device (Boston Scientific, Natick, MA) is frequently performed as a nonpharmacologic, second-line therapy for stroke prevention in patients with atrial fibrillation (AF)1, 2 and contraindications to long-term anticoagulation. Although combined catheter pulmonary vein isolation (PVI) and Watchman procedures may be performed successfully for patients with symptomatic AF, a simultaneous approach is not always feasible or in some cases PVI may not be clinically indicated at the time of Watchman implantation. Staged radiofrequency PVI and left atrial (LA) catheter ablation following Watchman device placement has been shown to be feasible3, 4, 5; however, other modalities for PVI have not been reported in the postimplant population.

Higher contact force (CF) theoretically increases the risk of blood charring, diminishing lesion formation. We aimed to investigate the relationship between CF, impedance change, and char formation during pulmonary vein isolation (PVI).CF was assessed during PVI in 65 patients. Radiofrequency ablation (RFA) with power-controlled mode was applied in the point-by-point manner. The RFA were divided into five groups: group A (CF 10 g), group B (10 g ≤ CF 20 g), group C (20 g ≤ CF 30 g), group D (30 g ≤ CF 40 g), and group E (CF ≥ 40 g). Gradual impedance rise (gIR) was defined as 5 Ω increase during each 10-second period of RFA. Catheter tip was assessed for charring during, and at the end of each procedure.In total, 2,064 applications were analyzed. During 0-10 seconds, impedance was significantly decreased in groups with higher CF (P 0.05). During 10-20 seconds, an impedance decrease was not significantly different among the five groups. During 20-30 seconds, mean impedance increased in group E. A gIR was noted at least once during RFA in 63 patients (97%). The incidence of gIR during RFA after 20 seconds was significantly higher in groups D and E (77/504 [15.3%] vs. 90/1560 [5.8%], P 0.001). Charring occurred in 8 of 65 (12%) patients. A gIR after 20 seconds was significantly associated with a higher incidence of macroscopic charring (6/20 [30%] vs. 2/45 [4%], P 0.01).gIR was noted with higher applied CFs after 20 seconds of RFA. This impedance rise may be avoided by keeping the applied CF under 26.9 g with negative predictive value of 95%. Our data suggested that gIR may be related to the incidence of charring.

Background Extensive ablation strategies are currently performed in addition to pulmonary vein isolation (PVI) to improve the clinical outcome of patients with drug-refractory persistent atrial fibrillation (AF). Ablation of complex fractionated atrial electrograms (CFAEs), linear lesions, and/or isolation of the left atrial appendage (LAA) are thought to improve arrhythmia-free survival. Objective The purpose of this study was to assess the durability of wide-area left atrial appendage isolation (LAAI) achieved by PVI, an anterior line, and a mitral isthmus line. Methods Seventy-one patients with intentional or incidental LAAI during repeat catheter ablation for treatment of persistent AF were included. The initial ablation strategy was PVI. Additional ablation strategies were performed only if PVI failed to maintain stable sinus rhythm. Durability of LAAI was assessed during a subsequent ablation procedure for arrhythmia recurrences (n = 23) or a subsequent percutaneous LAA closure (n = 48). Results LAAI was performed after a mean of 3 ± 1 procedures. Ablation strategies included circumferential PVI in 71 patients (100%), mitral isthmus line in 64 (90%), anterior line in 60 (85%), CFAE in 27 (38%), and roof line in 13 (18%). LAAI occurred after ablation and bidirectional block of LA linear lesions in 63 patients (89%) and during extensive CFAE ablation in 8 patients (11%). After a median of 105 [61;426] days, the LAA remained electrically isolated in 52 of 71 patients (73%). Conclusion Wide-area LAAI after extensive catheter ablation for persistent AF is durable in the majority of patients. The potential clinical benefit of LAAI for maintaining stable sinus rhythm requires further investigation.

Rotor Locations and 1 Year Outcomes of FIRM AblationIntroduction Pulmonary vein isolation (PVI) is currently the gold standard for catheter ablation of atrial fibrillation (AF). The mechanism for AF-maintenance is still controversial. The concept of rapidly activating spiral rotors perpetuating AF has led to the development of several rotor-mapping systems. We present our experience with focal impulse and rotor modulation (FIRM) using a 64-electrode basket catheter and computational system and evaluate its feasibility in conjunction with PVI to treat AF. Methods and Results Twenty-five patients underwent FIRM mapping and ablation to treat AF (paroxysmal = 10, 40%). A basket catheter was used for rotor identification within the right atrium (RA) then left atrium (LA). Radiofrequency energy was applied at and around each rotor core for 300 seconds and rotor-mapping and ablation was repeated until all rotors were eliminated before circumferential PVI was performed. Three (1.0, 4.0) rotors were identified per patient, predominantly in the LA (LA = 59). Note that 7/59 left-sided rotors were located 8/59 at the PV antrum. Twelve (48%) patients had either AF termination (termination = 6/12) or conversion to another rhythm, or cycle length (CL) prolongation ≥10% after rotor ablation. After a single procedure, 13 (52%) patients were free of atrial tachyarrhythmia after a follow-up period of 13 ± 1 months. Conclusion Early results suggest that FIRM-ablation can terminate AF in a significant number of patients. Rotors were frequently identified in the PVs and PV antrum, supporting PVI as the cornerstone of AF ablation.

Patients with ischemic cardiomyopathy (ICM) are prone to scar-related ventricular tachycardia (VT). The success of VT ablation depends on accurate arrhythmogenic substrate localization, followed by optimal delivery of energy provided by constant electrode-tissue contact. Current manual and remote magnetic navigation (RMN)-guided ablation strategies aim to identify a reentry circuit and to target a critical isthmus through activation and entrainment mapping during ongoing tachycardia. The MAGNETIC VT trial will assess if VT ablation using the Niobe™ ES magnetic navigation system results in superior outcomes compared to a manual approach in subjects with ischemic scar VT and low ejection fraction. This is a randomized, single-blind, prospective, multicenter post-market study. A total of 386 subjects (193 per group) will be enrolled and randomized 1:1 between treatment with the Niobe ES system and treatment via a manual procedure at up to 20 sites. The study population will consist of patients with ischemic cardiomyopathy with left ventricular ejection fraction (LVEF) of ≤35% and implantable cardioverter defibrillator (ICD) who have sustained monomorphic VT. The primary study endpoint is freedom from any recurrence of VT through 12 months. The secondary endpoints are acute success; freedom from any VT at 1 year in a large-scar subpopulation; procedure-related major adverse events; and mortality rate through 12-month follow-up. Follow-up will consist of visits at 3, 6, 9, and 12 months, all of which will include ICD interrogation. The MAGNETIC VT trial will help determine whether substrate-based ablation of VT with RMN has clinical advantages over manual catheter manipulation. Clinicaltrials.gov identifier: NCT02637947

Background It has been suggested that endocardial and epicardial ablation of ventricular tachycardia ( VT ) improves outcome in arrhythmogenic right ventricular cardiomyopathy/dysplasia. We investigated our sequential approach for VT ablation in patients with arrhythmogenic right ventricular cardiomyopathy/dysplasia in a single center. Methods and Results We included 47 patients (44±16 years) with definite (81%) or borderline (19%) arrhythmogenic right ventricular cardiomyopathy/dysplasia between 1998 and 2016. Our ablation strategy was to target the endocardial substrate. Epicardial ablation was performed in case of acute ablation failure or lack of an endocardial substrate. Single and multiple procedural 1‐ and 5‐year outcome data for the first occurrence of the study end points (sustained VT /ventricular fibrillation, heart transplant, and death after the index procedure, and sustained VT /ventricular fibrillation for multiple procedures) are reported. Eighty‐one radiofrequency ablation procedures were performed (mean 1.7 per patient, range 1–4). Forty‐five (56%) ablation procedures were performed via an endocardial, 11 (13%) via an epicardial, and 25 (31%) via a combined endo‐ and epicardial approach. Complete acute success was achieved in 65 (80%) procedures, and partial success in 13 (16%). After a median follow‐up of 50.8 (interquartile range, [18.6; 99.2]) months after the index procedure, 17 (36%) patients were free from the primary end point. After multiple procedures, freedom from sustained VT /ventricular fibrillation was 63% (95% CI , 52–75) at 1 year, and 45% (95% CI , 34–61) at 5 years, with 36% of patients receiving only endocardial radiofrequency ablation. A trend (log rank P =0.058) towards an improved outcome using a combined endo‐/epicardial approach was observed after multiple procedures. Conclusion Endocardial ablation can be effective in a considerable number of arrhythmogenic right ventricular cardiomyopathy/dysplasia patients with VT , potentially obviating the need for an epicardial approach.

Significant Delayed ET Drop After CB-Based PV Vein IsolationBackground The second-generation cryoballoon (CB2) has demonstrated superior clinical outcome. Potential procedural complications include esophageal thermal lesions due to excessive esophageal temperature (ET). Safety cut-offs for the ET have previously been published. A safety margin was incorporated due to a delayed esophageal temperature decline even after termination of the CB2 freeze cycle. The extent of these delayed temperature drops requires further systematic evaluation. Methods and Results The study enrolled 29 patients with paroxysmal or shortstanding persistent AF who underwent CB2-based PVI. Freeze cycle duration was 240 seconds. No bonus freeze was applied after successful PVI. The intraluminal ET was continuously measured via a transorally inserted probe (SensiTherm, St. Jude Medical, Inc.). The CB2 temperature and ET were recorded throughout the procedure using a camera setup. The mean number of freeze cycles per patient was 4.3 ± 2. A total of 147 cryoenergy applications were analyzed. A delayed decline in ET of >0.5 °C was recorded following termination of 23.1% of freeze cycles. The maximum drop in delayed ET was 6.4 °C. Excessive esophageal cooling during the freeze cycle exceeding 8.5 °C/min may result in ET ≤10 °C. Conclusions Following termination of cryoenergy delivery, the ET may decline an additional 6.4 °C. Proposed ET safety cut-offs during CB2-based PVI need to account for a significant ET drop that may occur even after termination of the individual freeze cycle.

Aims The prevalence of atrial fibrillation (AF) increases with age. Catheter ablation is an established treatment option for patients with symptomatic AF. We sought to determine the safety and long-term clinical efficacy of AF ablation in patients ≥75 years. Methods and results Patients ≥75 years with symptomatic, drug-refractory AF were included in the study. Circumferential pulmonary vein isolation (PVI) was performed in all patients, extended to ablation of complex fractionated atrial electrograms, and/or linear lesions in PVI non-responders. Retrospective follow-up (FU) was based on routine outpatient clinic visits and regular telephone interviews. A total of 94 patients (54 male, age 78 ± 2 years, and left atrium diameter 46 ± 6 mm) with drug-refractory AF [55/94 (59%) paroxysmal AF (PAF), 29/94 (31%) persistent AF, and 10/94 (11%) long-standing persistent AF] underwent ablation. Follow-up was obtained in 93/94 (99%) patients. Following a single procedure, 35/93 (38%) patients were in stable sinus rhythm (SR; 46% PAF, 31% persistent AF, and 10% long-standing persistent AF) after a mean FU of 37 ± 20 months. After a mean of 1.5 ± 0.6 procedures, 55/93 (59%) patients were ultimately in stable SR (76% PAF, 41% persistent AF, and 20% long-standing persistent AF). In a total of 137 procedures, 8 major (5.8%) and 26 minor (19%) complications occurred. Conclusions Catheter ablation in patients ≥75 years is associated with a favourable clinical long-term outcome in patients with PAF, while results are less promising in persistent or long-standing persistent patients. The safety profile of AF ablation in patients ≥75 years is comparable with patients of younger age.

The population of patients with congenital heart disease (CHD) is continuously increasing with more and more patients reaching adulthood. A significant portion of these young adults will suffer from arrhythmias due to the underlying congenital heart defect itself or as a sequela of interventional or surgical treatment. The medical community will encounter an increasing challenge as even most of the individuals with complex congenital heart defects nowadays become young adults. Within the past 20 years, management of patients with arrhythmias has gained remarkable progress including pharmacological treatment, catheter ablation, and device therapy. Catheter ablation in patients with CHD has paralleled the advances of this technology in pediatric and adult patients with structurally normal hearts. Growing experience and introduction of new techniques like the 3D mapping systems into clinical practice have been particularly beneficial for this growing population of patients with abnormal cardiac anatomy and physiology. Finally, device therapies allowing maintanence of chronotropic competence and AV conduction, improving haemodynamics by cardiac resynchronization, and preventing sudden death are increasingly used. For pharmacological therapy, ablation procedures, and device therapy decision making requires a deep understanding of the individual pathological anatomy and physiology as well as detailed knowledge on natural history and long-term prognosis of our patients. Composing expert opinions from cardiology and paediatric cardiology as well as from non-invasive and invasive electrophysiology this position paper was designed to state the art in management of young individuals with congenital heart defects and arrhythmias.

There is a genetic predisposition to early-onset atrial fibrillation (EOAF) in European American individuals. However, the role of family history in the pathogenesis of EOAF in racial and ethnic minorities remains unclear.To determine whether probands with EOAF across racial and ethnic groups have a higher rate of AF in first-degree family members than racially and ethnically matched control patients with non-early-onset AF (non-EOAF).In this cohort study, patients prospectively enrolled in a clinical and genetic biorepository were administered baseline questionnaires that included questions about family history of AF. Early-onset AF was defined as AF occurring in probands aged 60 years or younger in the absence of structural heart disease. All other forms were categorized as non-EOAF. Recruitment took place from July 2015 to December 2017. Analysis was performed in January 2018.Primary analysis of reported family history of AF in first-degree relatives with sensitivity analysis restricted to those in whom a family history was confirmed by medical record review and electrocardiogram.Of 664 patients enrolled (mean [SD] age, 62 [12] years; 407 [61%] male), 267 (40%) were European American; 258 (39%), African American; and 139 (21%), Hispanic/Latino. There was a family history of AF in 36 probands with EOAF (49%) compared with 128 patients with non-EOAF (22%) (difference, 27%; 95% CI, 14%-40%; P .001). On multivariable analysis, the adjusted odds of a proband with EOAF who was of African descent (odds ratio [OR], 2.69; 95% CI, 1.06-6.91; P .001) or Hispanic descent (OR, 9.25; 95% CI, 2.37-36.23; P = .002) having a first-degree relative with AF were greater than those of European descent (OR, 2.51; 95% CI, 1.29-4.87; P = .006). Overall, probands with EOAF were more likely to have a first-degree relative with AF compared with patients with non-EOAF (adjusted OR, 3.02; 95% CI, 1.82-4.95; P .001) across the 3 racial and ethnic groups. Atrial fibrillation in a first-degree family member was confirmed in 32% of probands with EOAF vs 11% of those with non-EOAF (difference, 21%; 95% CI, 11%-33%; P .001). Furthermore, African American (28% vs 5%; difference, 23%; 95% CI, 4%-43%; P = .001), European American (35% vs 20%; difference, 15%; 95% CI, 1%-30%; P = .03), and Hispanic/Latino (30% vs 5%; difference, 25%; 95% CI, 4%-54%; P = .02) probands with EOAF were more likely to have a first-degree relative with confirmed AF vs racially and ethnically matched control patients with non-EOAF. The positive and negative predictive values for a family history of confirmed AF were both 89%.Probands of African or Hispanic/Latino descent with EOAF were more likely to have a first-degree relative with AF when compared with European American individuals. These findings support genetic predisposition to EOAF across all 3 races.

The second-generation cryoballoon (CB2) provides effective and durable pulmonary vein isolation (PVI) associated with encouraging clinical outcome data. The novel third-generation cryoballoon (CB3) incorporates a 40 % shorter distal tip. This design change may translate into an increased rate of PVI real-time signal recording, facilitating an individualized ablation strategy using the time to effect (TTE). Thirty consecutive patients with paroxysmal or short-standing persistent atrial fibrillation underwent CB3-based PVI and were compared to 30 patients treated with the CB2. Individual freeze-cycle duration was set to TTE + 120 s for both groups. A total of 118 (CB3) and 119 (CB2) pulmonary veins (PV) were identified and all PVs successfully isolated utilizing the CB3 and CB2, respectively. The real-time PVI visualization rate was 74 % (CB3) and 40 % (CB2; p = 0.001) and the mean freeze-cycle duration 204 ± 88 s (CB3) and 215 ± 90 s (CB2; p = 0.15). Per individual PV, a shorter mean freeze-duration was found for the CB3 and the right superior PVs (188 ± 92 vs. 211 ± 124 s, p = 0.04) and right inferior PVs (192 ± 75 vs. 200 ± 37 s, p = 0.02). No differences were found for the left-sided PVs. A higher rate of real-time electrical PV recordings is seen using the novel CB3 as compared to CB2, which may facilitate an individualized ablation strategy using the TTE.

Periprocedural Anticoagulation in AF AblationIntroduction Data on the novel oral anticoagulants (NOACS) during catheter ablation (CA) of atrial fibrillation (AF) are still limited. This study evaluated the periprocedural major complications (MC) of CA of AF, and compared Apixaban, Dabigatran, and Rivaroxaban with continuous phenoprocoumon. Methods and Results A total of 444 patients (mean age = 65.1 ± 9.4 years; 283 [64%] male) with paroxysmal (n = 180 [41%]), persistent (n = 256 [58%]), or longstanding-persistent AF were enrolled. CA was performed in all patients using radiofrequency energy in conjunction with a 3D-mapping system. MCs were defined according to the current guidelines. Continuous phenprocoumon-therapy was administered in 120/444 (27%) patients (group 1) and 324/444 (73%) patients were treated with NOACs (group 2; Dabigatran: n = 51 [15.7%]; Rivaroxaban: n = 193 [59.6%]; Apixaban: n = 80 [24.7%]). Procedure times were comparable between groups 1 and 2 (128.2 ± 39.7 minutes vs. 129.7 ± 51.2 minutes; P = 0.77). CHA2DS2-Vasc (3.0 [2.0, 4.0)] vs. 2.0 [1.0, 3.0]; P < 0.01) and HASBLED scores (2.0 [2.0, 2.5] vs. 2.0 [1.0, 2.0]; P = 0.002) were higher in group 1 patients. The incidence of MCs in the overall group was 8/444 (2%) and was equally distributed between groups 1 and 2 (2/120 [2%] vs. 6/324 [2%], P = 0.90). The incidence of MCs was comparable between the three different NOACs. There were no significant differences between patients with and without MCs with regard to age, CHA2DS2-Vasc-score or HASBLED-score. Conclusions The major complication rate between all three NOACs currently available and continuous phenprocoumon during AF ablation seem to be comparable. Complication rates were similar between patients treated with the three different available NOACs.

Electrical isolation of the pulmonary veins still remains one of the major objectives during catheter ablation of atrial fibrillation. In patients with paroxysmal atrial fibrillation, balloon-based technologies hold great promise to simplify the approach to successful pulmonary vein isolation. While the cryoballoon represents the only true ‘single-shot’ technology, the laserballoon allows real-time endoscopic visualization of the pulmonary vein antrum during energy delivery. Either technology aims at complete electrical isolation, requiring continuous transmural lesion sets encircling the pulmonary veins. Strategies to confirm and to improve upon the efficacy of pulmonary vein isolation are the key to acute and long-term clinical success and will be reviewed in this article.

AF Ablation in Patients With Impaired LVEFIntroduction Long-term data after pulmonary vein isolation (PVI) in patients with impaired systolic left ventricular ejection fraction (LVEF) are sparse. This study assessed the outcomes in patients with atrial fibrillation (AF) and reduced LVEF treated with PVI after a median follow-up period of 6 years. Methods and Results Eighty-one patients with an LVEF≤45% were evaluated; however, 1 patient was lost to follow-up. In the remaining 80 patients (male: n = 68 (85%), median age 61.6 (54.8–67.5) years) with paroxysmal (n = 16, 20%), persistent (n = 37, 46.2%), and longstanding-persistent AF (LS-AF), catheter ablation of AF using radiofrequency and 3D mapping was performed. Follow-up included Holter monitoring or pacemaker/ICD interrogation to assess for arrhythmia recurrence and echocardiography to assess LVEF. Median follow-up was 72 (67–75) months. Death occurred in 21 patients. Single-procedure success rate was 35.1% and multiple-procedure success rate was 56.8% in the overall group. Baseline median LVEF (35% [28.5–40%]) significantly increased at 6-year follow-up (56.5% [40.0–60.0%], P < 0.01). In patients with single- or multiple-procedure ablation success, there was a higher improvement of LVEF (single procedure: 25% [15.0–35] vs. 10.0% [–1.0–20.0], P < 0.01; multiple procedures: 20.0% [15–34] vs. 5.0% [5.00–15.0]; P < 0.01). The single (43.8% vs. 40%, P = 0.96) and multiple procedure success rates (62.5% vs. 60%, P = 0.47) were comparable between patients with PAF and persistent AF and lowest in patients with LS-AF (single procedure success: 23.1%, multiple-procedure success: 47.8%). Conclusion Single-procedure success rates after PVI during 6 years of follow-up were low. In patients with single- or multiple-procedure ablation success, a higher improvement of LVEF was observed.

Long-term results after circumferential pulmonary vein isolation (CPVI) for the treatment of paroxysmal atrial fibrillation (PAF) using a robotic navigation system (RNS) have not yet been reported.To evaluate long-term results of patients with PAF after CPVI using RNS.In this study, 200 patients (n = 151 (75.5%) male; median age 62.2 (54.7-67.7) years) with PAF were evaluated. In 100 patients, RNS (RN-group) was used for CPVI and compared to 100 manually ablated control patients (MN-group). Radiofrequency was used in conjunction with 3D electroanatomic mapping. Power was limited to 30 watts (W) at the posterior left atrial (LA) wall in the first 49 RNS patients (RN-group-a). After esophageal perforation occurred in one RN-group-a patient, maximum power was reduced to 20 W for the subsequent 51 patients (RN-group-b).After a median follow-up of 2 years, single (77/100 vs 77/100, p = 0.89) and multiple (90/100 vs 93/100, p = 0.29) procedure success rates were comparable between RN-group and MN-group. Single procedure success rate was significantly lower in RN-group-a as compared to RN-group-b (65.3 vs 88.2%, p = 0.047). In RN-group-a patients, procedural times [200 (170-230) vs 152 (132-200) minutes, p0.01] and fluoroscopy times [16.6 (12.9-21.6) minutes vs 13.7 (9.5-19) minutes, p = 0.043] were significantly longer compared to RN-group-b patients.Long-term success rate after CPVI using RNS was comparable to manual ablation. Despite a lower power limit of 20 W at the posterior LA wall, single procedure success rate was higher in RN-group-b as compared to RN-group-a. Procedure time and fluoroscopy time decreased, whilst success rate increased with increasing experience in the RN-group.

Aims A challenge of pulmonary vein isolation (PVI) in catheter ablation for paroxysmal atrial fibrillation (PAF) is electrical reconnection of the PV. EFFICAS I showed correlation between contact force (CF) parameters and PV durable isolation but no prospective evaluation was made. EFFICAS II was a multicentre study to prospectively assess the impact of CF guidance for an effective reduction of PVI gaps. Methods and results Pulmonary vein isolation using a radiofrequency (RF) ablation catheter with an integrated force sensor (TactiCath™) was performed in patients with PAF. Operators were provided EFFICAS I-based CF guidelines [target 20 g, range 10–30 g, minimum 400 g s force-time integral (FTI)]. Conduction gaps were assessed by remapping of PVs after 3 months, and gap rate was compared with EFFICAS I outcome. At follow up, 24 patients had 85% of PVs remaining isolated, compared with 72% in EFFICAS I ( P = 0.037) in which CF guidelines were not used. The remaining 15% of gaps correlated to the number of catheter moves at creating the PVI line, quantified as Continuity Index. For PV lines with contiguous lesions and low catheter moves, durable isolation was 81% in EFFICAS I and 98% in EFFICAS II ( P = 0.005). At index procedure, the number of lesions was reduced by 15% in EFFICAS II vs. EFFICAS I. Conclusion The use of CF with the above guidelines and contiguous deployment of RF lesions in EFFICAS II study resulted in more durable PVI in catheter ablation of PAF. [10.1093/europace/euv131][1] [1]: /lookup/doi/10.1093/europace/euv131

Aims The purpose of this study was to determine efficacy of pulmonary vein isolation (PVI) using the 28 mm cryoballoon (CB) in patients with persistent atrial fibrillation (AF). Superior acute and 1-year outcome has been demonstrated following PVI, using the second-generation CB in patients with paroxysmal AF. Data on the outcome in patients with persistent AF are sparse. Methods and results Forty-nine patients (20 female, mean age 63 ± 10 years, mean left atrial diameter 46 ± 5 mm) with persistent AF [median AF duration since first diagnosis: 48 (20:192) months] underwent second-generation 28 mm CB-based PVI. The freeze cycle duration was set at 240 s. After successful PVI, a bonus freeze cycle of 240 s was applied in the first 11/49 (22%) patients, and no bonus freeze cycle was used in the remaining 38/49 (78%) patients. Follow-up (FU) was based on outpatient clinic visits at 3, 6, and 12 months, which included Holter electrocardiograms and telephone interviews. Recurrence was defined as an episode of symptomatic and/or documented atrial tachyarrhythmia >30 s beyond the 3-month blanking period. A total of 193 pulmonary veins (PVs) were identified and 193/193 (100%) PVs were successfully isolated. No phrenic nerve paralysis occurred. Follow-up was obtained in 49/49 (100%) patients with a mean FU duration of 416 ± 178 days. After the 3-month blanking period, antiarrhythmic medication was discontinued in 33/49 (67%) patients. Thirty-four of 49 (69%) patients remained in stable sinus rhythm. Conclusions In patients with persistent AF, use of the second-generation 28 mm CB was associated with a 69% 1-year clinical success rate.

MRI Assessment of Ablation-Induced Scarring in Atrial FibrillationBackground There is limited knowledge on the extent and location of scarring that results from catheter ablation and its role in suppressing atrial fibrillation (AF). We examined the effect of atrial fibrosis and ablation-induced scarring on catheter ablation outcomes in AF. Methods We conducted a prospective multicenter study that enrolled 329 AF patients presenting for catheter ablation. Delayed enhancement magnetic resonance imaging (DE-MRI) of the left atrium was obtained preablation. Scarring was evaluated in 177 patients with a DE-MRI scan obtained 90 days postablation. We evaluated residual fibrosis, defined as preablation atrial fibrosis not covered by ablation scar. The primary outcome was freedom from recurrent atrial arrhythmia. Results In the analysis cohort of 177 patients, preablation fibrosis was 18.7 ± 8.7% of the atrial wall. Ablation aimed at pulmonary vein (PV) isolation was performed in 163 patients (92.1%). Ablation-induced scar averaged 10.6 ± 4.4% of the atrial wall. Scarring completely encircled all 4 PVs only in 12 patients (7.3%). Residual fibrosis was calculated at 15.8 ± 8.0%. At 325 days follow-up, 35% of patients experienced recurrent arrhythmia. Multivariable Cox proportional hazards models demonstrated that baseline atrial fibrosis (HR and 95% CIs) (1.09 [1.06–1.12], P < 0.001) and residual fibrosis (1.09 [1.05–1.13], P < 0.001) were associated with atrial arrhythmia recurrence, while PV encirclement and overall scar were not. Conclusions Catheter ablation of AF targeting PVs rarely achieves permanent encircling scar in the intended areas. Overall atrial fibrosis present at baseline and residual fibrosis uncovered by ablation scar are associated with recurrent arrhythmia.

The aim of this study was to evaluate the impact of contact force (CF) visualization on the incidence of low and high CF during left atrial (LA) mapping and pulmonary vein isolation (PVI). CF was assessed in 70 patients who underwent PVI. Three highly experienced operators performed all procedures. The operators were blinded to CF in group A (35 patients), and CF was displayed in group B (35 patients). In group B, optimal CF was defined as mean CF between 10 and 39g, and operators attempted to acquire points and ablate within this range. A total of 8401 mapping points were analyzed during LA mapping (group A: 4104, group B: 4297). Low CF

Ventricular arrhythmias (VAs) from the left ventricular outflow tract (LVOT) can originate from within or below the aortic sinus of valsalva (ASV). Mapping and ablation below the ASV is challenging and there are limited data predicting VA origins using electrocardiographic and electrophysiological features.Thirty-four patients (56.7 ± 15.2 years; 19 males) with symptomatic VAs were analyzed. VA origins were determined by successful ablation. Patients were classified into 2 groups (group 1, VAs within the ASV; group 2, VAs below the ASV). Local activation and QRS morphology were compared between these 2 groups.Twelve patients were classified as group 1 and 22 as group 2. Presystolic potentials (PPs) during VAs were present in 11 patients (91 %) in group 1 and 3 (13 %) in group 2. S-wave amplitude and duration in lead I were lower and shorter in group 1 vs. group 2, respectively. Q-wave aVL/aVR ratio (Q-aVL/aVR) was smaller in group 1 vs. group 2. No group 1 patients had Q-aVL/aVR1.45. PPs in the ASV was the strongest independent predictor for VAs originating within the ASV (OR: 30.003, P = 0.006).Deeper and longer S-waves in lead I and Q-aVL/aVR1.45 suggest VAs originating below the ASV. Local PPs strongly suggest an origin within the ASV. ECG characteristics combined with local PPs can be a practical guide for ablating LVOT-VAs.

Die Pulmonalvenenisolation (PVI) ist der etablierte Endpunkt und integraler Bestandteil der meisten ablativen Therapiestrategien bei Vorhofflimmern (VHF). Die Anlage kontinuierlicher, transmuraler und dauerhafter Lasionen mittels hochfrequenzstrombasierter Katheter in Kombination mit einem 3-dimensionalen Mappingsystem stellt jedoch weiterhin eine grose Herausforderung dar. Um diesen Limitationen zu begegnen, sind innovative zirkulare Mapping- und Ablationskatheter sowie ballonbasierte Ablationssysteme mit integrierten alternativen Energiequellen (Kryo, Laser) eingefuhrt und evaluiert worden und konnten ihr Potenzial zur sicheren und effektiven PVI unter Beweis stellen. Zudem sind unser aktuelles Spektrum erweiternde Ablationsstrategien wie die Identifizierung von VHF auslosenden Foci bzw. VHF aufrechterhaltenden Rotoren mittels endo- und epikardialer Mapping-Systeme und deren Ablation entwickelt worden und befinden sich derzeit in der klinischen Evaluierungsphase. Gleiches gilt fur die Identifizierung und Modulation von atrialen Ganglien und somit des autonomen Nervensystems als weiterer potenzieller, additiver Therapieansatz in der ablativen Therapie von VHF.

Aims Cryoballoon (CB)-based pulmonary vein isolation (PVI) is an established treatment for symptomatic atrial fibrillation (AF). In the present study, we sought to assess the efficacy and safety of CB-based PVI taking the individual time-to-isolation (TTI) into account. Methods and results Sixty consecutive patients with drug-refractory paroxysmal atrial fibrillation [n = 49 (82%)] or short-standing persistent atrial fibrillation [n = 11 (18%)] underwent ablation with a 28-mm second-generation CB. The TTI was assessed by spiral mapping-catheter recordings and subsequently followed by an additional freeze-time of 120 s. No bonus freeze-cycle was applied. If the TTI could not be assessed, a fixed freeze-cycle duration of 240 s was applied and successful PVI confirmed thereafter. Clinical follow-up (FU) included 12-lead ECGs and 24 h Holter-ECGs at 3, 6, and 12 months. A blanking period of 3 months was defined. A total of 239 pulmonary veins (PVs) were identified and successfully isolated. The mean TTI assessed in 170/239 (71%) PVs was 52 ± 32 s. The mean number of CB applications was 1.2 ± 0.5; mean freeze-cycle duration was 192 ± 41 s. Mean procedure and fluoroscopy times were 80 ± 24 min and 16 ± 7 min, respectively. Transient phrenic nerve palsy occurred in one patient (2%). During a mean FU of 405 ± 67 days, 43 patients (72%) remained in stable sinus rhythm. Conclusions Integrating an individual TTI protocol to CB-based PVI results in shorter freeze-cycle applications in a substantial portion of targeted PVs and an arrhythmia-free survival comparable to conventional ablation protocols. The complication rate is low.

Visually guided laser balloon (VGLB) ablation allows for pulmonary vein isolation (PVI) under direct endoscopic control. Short- and midterm clinical outcomes are in accordance with results of radiofrequency current (RFC) ablation for the treatment of paroxysmal atrial fibrillation (PAF). The current study sought to assess the long-term clinical outcomes of VGLB-based PVI for PAF. A total of 90 patients [60 ± 10 years; 33 (37%) female, left atrial diameter 42 ± 4 mm] with drug-refractory PAF underwent VGLB ablation. The median duration of PAF until VGLB ablation was 36 (interquartile range 12; 84) months. Follow-up was based on outpatient clinic visits including Holter ECGs and telephone interviews. Repeat ablation due to arrhythmia recurrences was performed using RFC ablation. After a single VGLB procedure, 5-year freedom from arrhythmia recurrence was 51% [95% confidence interval (CI) 39–62%]. Thirty-three patients underwent repeat RFC ablation procedures, resulting in multiple procedure freedom from arrhythmia recurrence of 78% (95% CI 68–88%). Major periprocedural complications occurred in four patients (4%). VGLB ablation for the treatment of drug-refractory PAF is safe and results in 5-year single and multiple procedure arrhythmia-free survival of 51 and 78%, respectively.

Aims The aim of the present study was to estimate the accuracy of a novel non-invasive epicardial and endocardial electrophysiology system (NEEES) for mapping ectopic ventricular depolarizations. Methods and results The study enrolled 20 patients with monomorphic premature ventricular contractions (PVCs) or ventricular tachycardia (VT). All patients underwent pre-procedural computed tomography or magnetic resonance imaging of the heart and torso. Radiographic data were semi-automatically processed by the NEEES to reconstruct a realistic 3D model of the heart and torso. In the electrophysiology laboratory, body-surface electrodes were connected to the NEEES followed by unipolar EKG recordings during episodes of PVC/VT. The body-surface EKG data were processed by the NEEES using its inverse-problem solution software in combination with anatomical data from the heart and torso. The earliest site of activation as denoted on the NEEES 3D heart model was compared with the PVC/VT origin using a 3D electroanatomical mapping system. The site of successful catheter ablation served as final confirmation. A total of 21 PVC/VT morphologies were analysed and ablated. The chamber of interest was correctly diagnosed non-invasively in 20 of 21 (95%) PVC/VT cases. In 18 of the 21 (86%) cases, the correct ventricular segment was diagnosed. Catheter ablation resulted in acute success in 19 of the 20 (95%) patients, whereas 1 patient underwent successful surgical ablation. During 6 months of follow-up, 19 of the 20 (95%) patients were free from recurrence off antiarrhythmic drugs. Conclusion The NEEES accurately identified the site of PVC/VT origin. Knowledge of the potential site of the PVC/VT origin may aid the physician in planning a successful ablation strategy.

The magnetic navigation system (MNS) has shown to be safe and effective for catheter ablation of atrial fibrillation (AF). However, longer procedure duration as compared to manual catheter ablation may limit its widespread use. This study aimed to assess the impact of the newest generation MNS using an optimized mapping and ablation protocol on the efficacy and safety of remote magnetic catheter (RMC)-guided pulmonary vein isolation (PVI). This observational study included 52 patients with symptomatic AF who underwent RMC-guided PVI using the second-generation MNS Niobe II (initial 28 patients, group I) or the third-generation MNS Niobe ES in combination with an optimized mapping and ablation protocol (24 patients, group II). Acute PVI was achieved in 26/28 (93%) patients in group I and 24/24 patients (100%) in group II. Mean procedure time was 263.9 ± 81.9 min in group I and significantly lower in group II (139.7 ± 22.6 min, p

Background The mitral isthmus is a critical part of perimitral reentrant tachycardia, as well as an important substrate of persistent atrial fibrillation. Deployment of an endocardial mitral isthmus line (MIL) with the end point of bidirectional block may be challenging and often requires additional epicardial ablation within the coronary sinus. Methods and Results The study population comprised 114 patients with perimitral flutter who underwent de novo ablation of an MIL. The initial 57 patients (group A) underwent catheter ablation using a novel superolateral MIL design, connecting the left-sided pulmonary veins with the mitral annulus along the posterior base of the left atrial appendage visualized by selective angiography. The next 57 patients (group B) served as a control group and underwent ablation using a conventional MIL design, connecting the left inferior pulmonary vein with the mitral annulus. Bidirectional block was achieved in 56 of 57 patients in group A (98.2%) and 50 of 57 patients in group B (87.7%; P =0.06). Deployment of a superolateral MIL required significantly less ablation from within the coronary sinus (7.0% versus 71.9%; P P P =0.005). A higher rate of pericardial tamponade was observed in group A (5.2% versus 0%; P =0.24). Conclusions The superolateral MIL is associated with a high acute success rate to achieve bidirectional block using endocardial ablation only with minimal need for epicardial ablation from within the coronary sinus.

Background Second-generation cryoballoon (CB2)-based pulmonary vein isolation (PVI) has demonstrated encouraging clinical results in the treatment of paroxysmal (PAF) and persistent atrial fibrillation (PersAF). However, the CB2 features a maximal diameter of 28 mm, and its adaptability to anatomic variations of the pulmonary veins (PVs) might be challenging. Objective The purpose of this study was to assess the acute efficacy, safety, and long-term clinical results of CB2-based PVI in patients with a left common pulmonary vein (LCPV). Methods Six hundred seventy consecutive patients underwent CB2-based PVI in 3 electrophysiology centers. In 74 patients (11%), an LCPV was identified (LCPV group). The data were compared to those from matched patients (n = 74) with normal PV anatomy and comparable baseline characteristics (control group). An antral occlusion of the complete LCPV ostium was feasible in 50% of patients in the LCPV group. If an antral occlusion could not be obtained, a sequential isolation of the first superior and inferior branches was applied. Results All 74 LCPVs were successfully isolated. A total of 64% patients (LCPV group) and 66% patients (control group) remained in sinus rhythm after mean follow-up of 1.9 ± 0.9 years ( P = .820). In 18 of 26 patients (69%) with atrial tachyarrhythmia recurrence, a repeat procedure using radiofrequency energy was performed, and a total of 56% LCPVs were found to be persistently isolated (control group: 61% of left-sided PVs, P = .801). Conclusion Patients with an LCPV undergoing CB2-based PVI demonstrate a high acute success rate. Comparable results with regard to clinical success and durability of PVI were shown when comparing patients of the LCPV group and the control group.

Background— Ventricular arrhythmias (VAs) originating from the anterosuperior left ventricular outflow tract (LVOT) represent a challenging location for catheter ablation. This study investigates mapping and ablation of VA from anterosuperior LVOT via a transseptal approach. Methods and Results— This study included 27 patients with symptomatic VA, of which 13 patients had previous failed ablations. LVOT endocardial 3-dimensional mapping via retrograde transaortic and antegrade transseptal approaches was performed. Previous ECG markers for procedure failure were analyzed. In all patients, earliest activation with low-amplitude potentials was identified at the anterosuperior LVOT 5.1±2.8 mm below the aortic cusp and preceded the QRS onset by 39.5±7.7 ms only via an antegrade transseptal approach using a reversed S curve. In all patients, pace mapping failed to demonstrate perfect QRS morphology match. The anatomic location was below the left coronary cusp in 16, below the left coronary cusp/right coronary cusp junction in 8, and below the right coronary cusp in 3 patients. Radiofrequency energy resulted in rapid disappearance of VAs in all patients. ECG analysis showed aVL/aVR Q-wave amplitude ratio >1.4 in 7, lead III/II R-wave amplitude ratio >1.1 in 10, and peak deflection index >0.6 in 11 patients. There were no complications or clinical VA recurrence during a mean follow-up of 8.4±2.5 months. Conclusions— The anterosuperior LVOT can be reached via a transseptal approach with a reversed S curve of the ablation catheter. The rapid effect from radiofrequency energy indicates that the VA is most likely located under the endocardium. Also, previous ECG markers for procedure failure need further investigation.

Catheter ablation can abolish clinical ventricular tachycardia (VT) in patients after myocardial infarction (MI). However, VT frequently recurs after ablation. The best ablation strategy is still unknown, particularly in patients with unmappable VTs. We hypothesized that isolation of the arrhythmogenic substrate would be a feasible and effective ablation strategy for the treatment of ischaemic VT.Twelve patients (54 ± 8 years, left ventricular ejection fraction, LVEF 32 ± 13%) underwent catheter ablation for sustained VT (anterior MI = 10, inferior MI = 2). All patients had recurrent defibrillator shocks, including electrical storms in seven patients, despite anti-arrhythmic drugs. During electrophysiological study, 3 ± 2 VTs were induced. Three-dimensional mapping of the left ventricle revealed a low-voltage (1.5 mV) area with fractionated electrograms and late potentials, with a mean area of 62 ± 20 cm(2). Isolation of the entire low-voltage area was attempted with a circumferential line along the low-voltage area border-zone. Substrate isolation was successfully achieved in 6 of 12 (50%) patients. Focal discharge within the isolated area was demonstrated in three of six (50%) patients. During a median follow-up of 479 [297; 781] days, 8 of 12 patients (66.7%) remained free of VT recurrence after a single procedure. In five of the six patients (83.3%) with successful substrate isolation, there were no VT recurrences when compared with three of the six patients (50%) with no substrate isolation.Electrical isolation of the entire substrate is feasible and appears to be an effective treatment in patients with late VT after MI.

Aims Clinical outcomes following radiofrequency ablation of ventricular tachycardias (VTs) depend on catheter tip-to-tissue contact force (CF). Left-ventricular (LV) mapping is performed via antegrade-transseptal or retrograde-transaortic approaches, and the applied CF may depend on the approach used. This study evaluated (i) the impact of antegrade-transseptal vs. retrograde-transaortic LV-mapping approaches on CF and catheter stability and (ii) the clinical value of the commonly used surrogate markers of catheter–myocardial contact—impedance, unipolar, and bipolar electrogram amplitudes. Methods and results An antegrade-transseptal and a retrograde-transaortic LV-mapping approach was performed in 10 patients undergoing VT ablation by using CF-sensing catheters. Operators were blinded to CF data and data were analysed according to 11 predefined LV segments. Three thousand three hundred and twenty-four mapping points (1577 antegrade, 1747 retrograde) were analysed, including 80 (2.4%) points with maximum CF > 100 g. Median antegrade and retrograde CF were 16.0 g (q1–q3; 8.4–26.2) and 15.3 g (9.8–23.4), respectively. Contact force was significantly higher antegradely in mid-anteroseptum, mid-lateral, and apical segments, and significantly higher retrogradely in basal-anteroseptum, basal-inferoseptum, basal-inferior, and basal-lateral segments. Contact force did correlate with impedance, unipolar, and bipolar electrogram amplitudes; however, there were large overlaps. Conclusions Antegrade vs. retrograde LV-mapping approaches result in different CF. A combined approach to the LV mapping may improve the overall LV mapping, potentially resulting in better clinical outcomes for the left VT catheter ablation. The previous surrogate markers used to assess CF do correlate with in vivo CF; however, due to a larger overlap, their clinical value is limited.

Introduction The second-generation cryoballoon (CB; Arctic Front Advance, Medtronic Inc., Minneapolis, MN, USA) has demonstrated greater procedural efficacy compared to the original CB. Whether increased efficacy translates into a higher incidence of phrenic nerve (PN) injury needs further evaluation. Materials and methods In patients with drug-refractory paroxysmal atrial fibrillation (AF) or short-standing persistent AF, pulmonary vein isolation (PVI) was performed using the 28 mm second-generation CB. During cryoenergy delivery along the septal PVs, continuous PN pacing was performed. The freeze cycle was aborted in case of weakening or loss of diaphragmatic contraction. Results A total of 115 patients (42 female, mean age 61 ± 11 years, mean LA-diameter 43 ± 6 mm) with a history of paroxysmal AF (93/115 patients [81%]) or short-standing persistent AF (22/115 patients [19%]) underwent CB-based PVI. A total 445 of 448 (99%) PVs were isolated successfully. PN palsy (PNP) occurred in 4 of 115 (3.5%) patients, while applying cryoenergy to the right superior PV. Despite prompt interruption of the freezing cycle, PN function failed to recover during the periprocedural phase. PN recovery was observed as late as 10 months postablation. Conclusions Using the second-generation 28 mm CB, PNP occurred in 4 of 115 (3.5%) patients. While 1 of 4 PNP recovered 10 months after ablation, long-term outcome in the remaining 3 patients is currently unknown due to the rather short follow-up period.

Circumferential versus Individual Laserballoon PVIIntroduction The endoscopic ablation system (EAS) allows for effective pulmonary vein isolation (PVI). The feasibility of wide circumferential as compared to individual PVI using the EAS has not been formally assessed. Methods Patients with paroxysmal or short-persistent atrial fibrillation were assigned to individual PVI (group A) or wide circumferential PVI (group B). In group B, circumferential PVI was attempted only if the ipsilateral inferior PV was visualized while the ablation system targeted the superior PV and vice versa. Otherwise, individual PVI was performed. Results A total of 38 patients were enrolled (Group A: 20 patients, age 61 ± 7 years, LA-diameter 43 ± 5 mm; Group B: 18 patients, age 62 ± 10 years, LA-diameter 43 ± 4 mm). In group A, 20/20 (100%) right superior (RSPV) and inferior (RIPV) PVs, 18/19 (95%) left superior (LSPV) and inferior (LIPV) PVs, and 1/1 (100%) left common ostium (LCPV) were successfully isolated. First-pass success rate was 95%, 85%, 68%, and 95% for the RSPV, RIPV, LSPV, and LIPV, respectively. Touch-up radiofrequency ablation was required in 1/19 (5%) LSPV and LIPV. In group B, an attempt at circumferential PVI was feasible in 2/18 (11%) septal PVs and successful on first pass. Lateral circumferential PVI was attempted and successful on first-pass in 7/13 (54%) LSPVs and LIPVs and 1/5 (20%) LCPVs. Conclusions Using the EAS in patients with AF, separate isolation of individual PVs rather than wide circumferential PVI should be the preferred ablation strategy.

Aims Laserballoon-based pulmonary vein isolation (PVI) for the treatment of atrial fibrillation (AF) has proven safe and effective. Silent brain lesions after AF ablation detected on magnetic resonance imaging (MRI) have been described for several technologies, but its incidence following laserballoon PVI is unknown. The current study sought to assess the incidence of new asymptomatic brain lesions in patients undergoing laserballoon-based PVI. Methods and results Patients referred for PVI underwent pre- and post-procedural MRI of the brain. A total of 86 patients were enroled into the study ( laserballoon group : 44 patients, 15 female, age 63 ± 9 years, left atrial (LA) diameter 43 ± 5 mm; cryoballoon group : 20 patients, 6 female, age 61 ± 9 years, LA diameter 41 ± 4 mm; and irrigated radiofrequency ( RF ) group : 22 patients, 11 female, age 64 ± 8 years, LA diameter 43 ± 6 mm). There was no statistically significant difference between the groups with regard to new asymptomatic brain lesions detected on post-procedural MRI: 5 of 44 (11.4%) patients in the laserballoon group, 1 of 20 (5.0%) patients in the cryoballoon group, and 4 of 22 (18.2%) patients in the irrigated RF group, respectively. In the laserballoon group, one additional patient with a new cerebral lesion experienced transient diplopia. In a multivariate regression model the only risk factor for asymptomatic new lesions was the CHA2DS2VASc score. Conclusion Following laserballoon-based PVI, new asymptomatic brain lesions were detected in 11.4% of patients. A higher CHA2DS2VASc score, but not the ablation technology utilized, was the only associated risk factor.

Background— Pulmonary vein isolation is an established treatment option for atrial fibrillation. To date, the incidence and quality of ablation-induced esophageal thermal lesions (ETLs) using the recently introduced second-generation cryoballoon (CB, ArcticFront Advance, Medtronic) is unknown. Methods and Results— In patients with drug-refractory paroxysmal atrial fibrillation or short-standing persistent atrial fibrillation, pulmonary vein (PV) isolation was performed using the second-generation CB. The endoluminal esophageal temperature was monitored via a temperature probe. After PV isolation, esophagogastroduodenoscopy (EGD) was performed to assess the incidence of ETLs. In 50 patients (18 women; age, 61±11 years; left atrial diameter, 43±5 mm), successful CB-based PV isolation was performed. Lowest median balloon temperature and esophageal temperature for the right superior PV were −51°C and 35.8°C, −47°C and 35°C for the right inferior PV, −51°C and 34.4°C for the left superior PV, −48°C and 34.6°C for the left inferior PV, and −54°C and 34.5°C for the left common PV, respectively. EGD performed 2±1 days post ablation demonstrated superficial thermal lesions and thermal ulcerations in 1 of 50 (2%) and 5 of 50 (10%) patients, respectively. In patients with ETLs, during ≥1 freeze cycle the endoluminal esophageal temperature measured Conclusions— Using the second-generation 28-mm CB, ETLs were detected in 6 of 50 (12%) patients. All ETLs were in the healing process on repeat EGD. An esophageal temperature safety cutoff may prove valuable in the prevention of ETLs and requires further evaluation.

Left atrial isthmus (LAI)-ablation in addition to circumferential pulmonary vein isolation (CPVI) may improve outcomes in select patients with atrial fibrillation (AF). However, bidirectional LAI-block is difficult to obtain. No systematic evaluation reporting on the feasibility and efficacy of LAI-ablation using a robotic navigation system (RNS) exists. In this pilot study, CPVI combined with LAI-ablation were performed using a RNS and 3D-mapping system in 42 patients with persistent (n = 24, 57.1 %) or longstanding persistent AF. Ablation was performed using either a 3.5 mm irrigated tip catheter (ITC) with 6 (group-A, n = 16; max. 40 W, contact force 10–40 g) or (after a steam pop occurred in one patient) with a 4 mm ITC with 12 irrigation holes (group-B, n = 26; max. 30 W, contact force 10–30 g). Epicardial ablation was performed manually whenever bidirectional LAI-block could not be obtained with a maximum of 20 endocardial RF-applications. LAI-conduction block was achieved in all patients using RNS; in six patients (14.3 %), additional epicardial ablation was required to achieve LAI-block. A steam pop occurred during LAI-ablation resulting in cardiac tamponade in one patient in group-A. After a median follow-up period of 21 months, arrhythmia recurrence was seen in in 23/42 patients (18 patients with AF and 5 patients with atrial tachycardia) and repeat procedure was performed in 12 (28.6 %) patients; recovered LAI-conduction was found in 5/12 (41.7 %) patients. The RNS-group was compared to a historical group of 20 patients with manual LAI-ablation. Using RNS, LAI-block was more often achieved (42 (100 %) vs 16 (80 %), p