Procedural and Intermediate-term Results of the Electroanatomical-guided Cardioneuroablation for the Treatment of Supra-Hisian Second- or Advanced-degree Atrioventricular Block: the PIRECNA multicentre registry.

AIMS: Prior case series showed promising results for cardioneuroablation in patients with vagally induced atrioventricular blocks (VAVBs). We aimed to examine the acute procedural characteristics and intermediate-term outcomes of electroanatomical-guided cardioneuroablation (EACNA) in patients with VAVB. METHODS AND RESULTS: This international multicentre retrospective registry included data collected from 20 centres. Patients presenting with symptomatic paroxysmal or persistent VAVB were included in the study. All patients underwent EACNA. Procedural success was defined by the acute reversal of atrioventricular blocks (AVBs) and complete abolition of atropine response. The primary outcome was occurrence of syncope and daytime second- or advanced-degree AVB on serial prolonged electrocardiogram monitoring during follow-up. A total of 130 patients underwent EACNA. Acute procedural success was achieved in 96.2% of the cases. During a median follow-up of 300 days (150, 496), the primary outcome occurred in 17/125 (14%) cases with acute procedural success (recurrence of AVB in 9 and new syncope in 8 cases). Operator experience and use of extracardiac vagal stimulation were similar for patients with and without primary outcomes. A history of atrial fibrillation, hypertension, and coronary artery disease was associated with a higher primary outcome occurrence. Only four patients with primary outcome required pacemaker placement during follow-up. CONCLUSION: This is the largest multicentre study demonstrating the feasibility of EACNA with encouraging intermediate-term outcomes in selected patients with VAVB. Studies investigating the effect on burden of daytime symptoms caused by the AVB are required to confirm these findings.

Transesophageal echocardiography guided transseptal puncture and nadir temperatures in cryoballoon pulmonary vein isolation.

Introduction: Cryoballoon (CB) guided pulmonary vein isolation (PVI) is an established procedure in the treatment of atrial fibrillation (AF). Transseptal access is an indispensable step during PVI and may be associated with severe complications. For specific interventions, specific puncture sites of the fossa ovalis are advantageous. Here, we analyzed the potential impact of a transesophageal echocardiography (TOE) guided transseptal puncture on nadir temperatures in CB PVI. Methods and Results: We retrospectively analyzed 209 patients undergoing CB PVI in our hospital. The use of TOE had been at the operator's discretion. No TOE-related complications such as perforation of the pharynx or esophagus or loss of teeth were noted. Concerning the applied freezes, we found significantly lower nadir temperatures in all PVs in the TOE group than in the non-TOE group. Procedure time and fluoroscopy time and complications were similar in both groups. Conclusion: TOE-guided TSP in CB PVI is safe and feasible. Our study found significantly lower nadir temperatures of CB freezes after TOE-guided TSP which potentially underscores the value of a more infero-anterior puncture site.

Reduction of Radiation Exposure in Atrioventricular Nodal Reentrant Tachycardia Ablations Using an Electroanatomical Mapping System With Fluoroscopy Integration Module.

Introduction: Atrioventricular nodal reentrant tachycardia (AVNRT) is a common supraventricular tachycardia. Current guidelines recommend electrophysiology study (EPS) and ablation, which have been proven to show high success rates with very low complication rates. Usually, ablation of AVNRT is performed conventionally using only fluoroscopy. Electroanatomical mapping systems (EMS) are widely used in complex arrhythmias. One of their advantages is their potential in decreasing the need of fluoroscopy time (FT). In this study we analyzed patients undergoing either conventional AVNRT ablation or by using an EMS with a fluoroscopy integrating system (FIS). Materials and Methods: We included 119 patients who underwent AVNRT ablation in our study. Eighty-nine patients were ablated conventionally using only fluoroscopy, 30 patients were ablated using EMS + FIS. Results: We found that the use of EMS + FIS led to a significant reduction of FT (449.90 ± 217.21 vs. 136.93 ± 109.28 sec., p < 0.001) and dose-area-product (DAP, 268.27 ± 265.20 vs. 41.07 ± 27.89 µGym2, p < 0.001) without affecting the procedure time (PT, 66.55 ± 13.3 vs. 67.33 ± 13.81 min, p = 0.783). Furthermore, we found no significance with regard to complications. Conclusion: The use of EMS+FIS is safe and feasible. It leads to a significant reduction of both FT and DAP without affecting PT and safety. Hence, EMS + FIS is beneficial for both the operator and the patients by reducing the radiation exposure.

Wearable Cardioverter-Defibrillator Used as a Telemonitoring System in a Real-Life Heart Failure Unit Setting.

BACKGROUND: In patients with reduced left ventricular ejection fraction (LVEF) who are at risk of sudden cardiac death, a wearable cardioverter-defibrillator (WCD) is recommended as a bridge to the recovery of LVEF or as a bridge to the implantation of a device. In addition to its function to detect and treat malignant arrhythmia, WCD can be used via an online platform as a telemonitoring system to supervise patients' physical activity, compliance, and heart rate. METHODS: We retrospectively analyzed 173 patients with regard to compliance and heart rate after discharge. RESULTS: Mean WCD wearing time was 59.75 ± 35.6 days; the daily wearing time was 21.19 ± 4.65 h. We found significant differences concerning the patients' compliance. Men showed less compliance than women, and younger patients showed less compliance than patients who were older. Furthermore, we analyzed the heart rate from discharge until the end of WCD prescription and found a significant decrease from discharge to 4, 8, or 12 weeks. CONCLUSION: WCD can be used as a telemonitoring system to help the involved heart failure unit or physicians attend to and adjust the medical therapy. Furthermore, specific patient groups should be educated more intensively with respect to compliance.

Fast anatomical mapping of the carina and its implications for acute pulmonary vein isolation.

BACKGROUND: Fast anatomical mapping (FAM) of the left atrium and pulmonary veins (PV) during PV isolation (PVI) generates anatomical information about the carina region additionally. We aimed to investigate the utility of these data in relation to conduction abilities of the intervenous carina. METHODS: We investigated 71 patients with drug-refractory atrial fibrillation (AF) who underwent first-time circumferential PVI using an electroanatomical mapping system. Carina width between ipsilateral PV was measured using FAM and an integrated distance measurement tool. Encirclings were divided into carina ablation and noncarina ablation groups based on the necessity of carina ablation to achieve PVI. RESULTS: In total, 142 encirclings were analyzed and first-pass isolation was observed in 102 (72%) encirclings. Nonfirst-pass PVI solely due to a gap on the line or persistent carina conduction was observed in 10 (7%) and 30 (21%) encirclings, respectively. Encirclings were classified into a carina ablation group (n = 30, 21%) and noncarina ablation group (n = 112, 79%). Carina width was significantly larger in the carina ablation vs nonarina ablation group (right: 11.9 ± 1.5 mm vs 8 ± 1.4 mm, P < .001/left: 12.1 ± 1.3 mm vs 8.1 ± 1.1 mm, P < .001) requiring additional carina ablation. CONCLUSION: Carina-related PV conduction is a common finding after the first-pass ablation during PVI. Measurement of carina width using FAM is feasible and its value correlates with the necessity of carina ablation to achieve PVI.

Influence of excess weight and obesity on performance and outcome of pulmonary vein isolation with the cryoballoon.

Pulmonary vein isolation (PVI) has become a cornerstone therapy in the treatment of atrial fibrillation (AF). Patients with overweight or obesity suffer more often from AF, and studies investigating the safety and feasibility of PVI in these patients have shown varying results. In this study we analyzed PVI performed with the 2nd generation cryoballoon (CB) with regard to safety, procedure and fluoroscopy time in patients with normal weight, overweight and obesity. We analyzed 228 consecutive patients treated with CB PVI in our hospital in 2018 and 2019. Fifty nine (25.88%) patients presented with normal weight (body mass index (BMI) of <25), 115 (50.44%) patients with overweight (BMI between 25 and 29.9) and 54 (23.68%) were obese patients (BMI >30). All pulmonary veins (PV) were isolated successfully. Concerning procedural parameters, neither complications, procedural time, nor fluoroscopy time differed significantly. There was a significant increase of dose area product (DAP) in obese patients compared to normal weight and overweight patients (2035.5 ± 1930.1 µGym2 vs. 975.3 ± 814.9 vs. 1325.1 ± 2081.3, p = 0.001) but no significant difference between overweight and normal weight patients (p = 0.611). Our follow-up data of 168 patients (73.68%) observed for 12 months showed no differences in the recurrence of AF in the three BMI groups [80.9% vs. 83.3% (p = 0.733) vs. 86.55% (p = 0.460)]. In conclusion, CB PVI in overweight and obese patients is safe with similar levels of complications and recurrence of AF as patients of normal weight. However, obese patients and operators are exposed to higher radiation doses.

Autonomic modulation of the arrhythmogenic substrate in the evolution of atrial fibrillation and therapeutic approaches.

The autonomic nervous system (ANS) plays an important role in atrial arrhythmogenesis and is one of the factors responsible for the initiation and maintenance of atrial fibrillation (AF). Over the past few decades, neuromodulation has been shown to help in the management of AF. This review focuses on the correlation between AF and the ANS and how different approaches to identifying and modulating the autonomic substrate impact outcomes in AF. The authors conclude that the ANS is one of the key components in the development of AF and that modulation of autonomic nerve function may contribute to the management of AF. Therapeutic approaches such as catheter ablation of ganglionated plexi (GP), renal denervation and transcutaneous vagus nerve stimulation are viable treatment options that need further confirmation in larger randomised controlled trials. In addition, new imaging technologies were able to identify GPs accurately and reproducibly, which promises exciting prospects for the future.

Long-term impact of a bonus freeze on clinical outcome: Analysis of effective and non-effective bonus freezes in cryoballoon ablation.

PURPOSE: Data on bonus freeze characteristics and their impact on complication rates and long-term clinical outcome are limited. METHODS: Pulmonary vein isolation (PVI) using a 28 mm 2nd-generation cryoballoon (CB) was performed in 169 patients (pts). The isolation temperatures, time to isolation and minimal temperatures of the cryoapplications were documented. RESULTS: The study included 92 pts who received one bonus freeze after PVI in group I and 77 pts who did not receive a bonus freeze in group II. After a mean follow-up time of 19.0±8.6 months in group I and 16.4±7.5 months in group II, 67 of 92 pts (72.8%) and 49 of 75 pts available to follow up (65.3%; p = 0.221) were free of atrial tachyarrhythmia, respectively. Phrenic nerve palsy occurred in 5.4% of the pts in group I (5/92 pts) and 1.3% of the pts in group II (1/77 pts; p = 0.22). Both the mean nadir temperatures of the bonus freezes and mean nadir temperatures of the isolation freezes differed significantly between the recurrent and non-recurrent pts in group I. The predilection sites of the reconduction for both groups were the inferior aspect of the inferior pulmonary veins. CONCLUSION: The impact of a bonus freeze on long-term clinical outcome was not significant for two reasons: 1) The necessity of a bonus freeze was low because the long-term clinical success rate without a bonus freeze was high; and 2) the majority of bonus freezes, especially at the predilection sites, such as the inferior PV, appeared to be ineffective.

Cryoballoon ablation for pulmonary vein isolation in patients with atrial fibrillation: preliminary results using novel short-tip cryoballoon.

PURPOSE: In this study, we aimed to report our preliminary experience regarding the impact of the novel short-tip (ST) cryoballoon (CB) on procedural efficacy and signal quality during pulmonary vein (PV) isolation for both paroxysmal and persistent atrial fibrillation. METHODS: Between March, 2015, and August, 2015, we enrolled a total of 64 patients (47 patients male, 73 %) with a mean age of 60 ± 11 years. In the study population, 31 patients (48 %) underwent PVI using Advance (ADV) CB and 33 (52 %) patients with ST CB. In all patients, a 28-mm balloon was used. RESULTS: Acute procedural success rates were 100 % for the entire study population. A statistically insignificant increase in the percentage of PV signal recordings was observed with ST CB in all PVs compared to ADV CB [88 vs. 81 % for left superior PV (LSPV), 82 vs. 78 % for left inferior PV (LIPV), 85 vs. 84 % for right superior PV (RSPV), 82 vs. 71 % for right inferior PV (RIPV), p < 0.05]. Additionally, the difference in minimum temperature reached during the procedure per PV was not statistically significant between ST CB and ADV CB except the LIPV (LSPV -44.2 ± 5.9 vs. -45.6 ± 5.3 °C, p = 0.970; LIPV -38.7 ± 4.6 °C vs -44.6 ± 6.8 °C, p < 0.001; RSPV -45.6 ± 7.4 °C vs.-47.2 ± 6.1 °C, p = 0.168; RIPV -41.4 ± 5.1 °C vs.-43.7 ± 6.3 °C, p = 0.360). Time to isolation for each PV was similar between ST and ADV CB (p > 0.05). CONCLUSION: Our preliminary findings indicated similar acute procedural success for the novel ST CB compared with second generation ADV CB. The increase in the ratio of PV signal recordings obtained during the PVI using the novel ST CB was not significant.

Characterization of Electrical Reconnection Following Pulmonary Vein Isolation Using First- and Second-Generation Cryoballoon.

BACKGROUND: Second-generation cryoballoon (CB-2) is associated with improved outcomes for pulmonary vein isolation (PVI) compared to first generation (CB-1). However, data regarding the predictors of pulmonary vein (PV) electrical reconnection are limited. In this study, we aimed to characterize the predilection sites and predictors of reconnection in patients with recurrent atrial tachyarrhythmia (ATa) after PVI using CB-1 and CB-2. METHODS: A total of 59 patients (mean age: 62 ± 11 years and 66% male) with recurrent ATa after previous CB-PVI, using either a 28-mm CB-1 or CB-2, underwent repeat ablation. PV reisolation was performed by irrigated radiofrequency ablation using three-dimensional electroanatomical mapping systems. RESULTS: Electrical PV reconnection was detected in 10 of 11 (91%) of CB-1 patients compared to 41 of 48 (85%) of CB-2 patients. Time to redo procedure after index CB-1 was 8.9 ± 10.2 months and 11.2 ± 7.0 months in CB-2. Bonus freeze was applied in all patients with CB-1 and 41% of the patients with CB-2. Superior quadrants of both superior PVs and inferior quadrants of the both inferior PVs exhibited higher predilection for conduction compared to other quadrants (P < 0.001). Multivariate binary logistic analysis revealed that right inferior PV (RIPV; odds ratio [OR]: 1.52, 95% confidence interval [CI]: 1.09-2.13, P = 0.014) and minimum temperature (OR: 1.09, 95% CI: 1.03-1.15, P = 0.004) were the independent predictors of electrical reconnection after CB-2 ablation. CONCLUSION: Conduction gaps after CB-1 and CB-2 were higher in inferior PVs compared to superior PVs. The RIPV and minimum CB temperature were independent predictors of PV electrical reconnection after CB-2.

The Total Incidence of Complications and the Impact of an Anticoagulation Regime on Adverse Events After Cryoballoon Ablation of Atrial Fibrillation: A Single-Center Study of 409 Patients.

AIM: Data evaluating the complications of pulmonary vein isolation (PVI) using second-generation cryoballoons (CB) related to different anticoagulation regimes are limited. This study evaluates the total complications and the impact of novel oral anticoagulants (NOACs) compared to phenprocoumon on adverse events in the setting of PVI using CB. METHODS AND RESULTS: PVI was performed using second-generation CB by two experienced investigators. A total of 409 patients (58.9% male; mean age = 61 ± 10 years) with atrial fibrillation were included in this study. In group I, 150/409 (36.7%) patients received phenprocoumon therapy, and in group II, 259/409 (63.3%) patients were treated with NOACs (rivaroxaban: n = 193; dabigatran: n = 48; and apixaban: n = 18). In both groups, the rates of major complications were similar (group I [phenprocoumon]: four pts (2.7%) vs. Group II [NOACs]: seven pts (2.7%); P = 0.999). In this cohort, 275 patients were ablated with the bonus freeze protocol, and 134 patients were ablated without bonus freezes. The procedure duration significantly decreased with the bonus freeze protocol from 102.3 ± 24.6 min to 68.5 ± 16.2 min (P < 0.001). The impact of the bonus freeze on the postprocedural increase of C-reactive protein (CRP) levels was significant compared to the postprocedural CRP levels after procedures without the bonus freeze protocol (postprocedural CRP level+ bonus protocol: 1.6 ± 1.2 mg/L vs. postprocedural CRP level+ nonbonus protocol: 1.3 ± 1.3 mg/L; P = 0.04). CONCLUSION: The incidence of adverse events in PVI using the second-generation CB with the periprocedural administration of NAOCs was not significantly different compared to phenprocoumon. Further, large-scale randomized studies are needed to evaluate the safety of two anticoagulation regimes comparing vitamin K antagonists and NOACs, as well as different NOAC regimes, in patients undergoing PVI using cryoballoon ablation.

Role of diabetes in heart rhythm disorders.

The incidence of diabetes mellitus (DM) is increasing rapidly. DM is the leading cause of cardiovascular diseases, which can lead to varied cardiovascular complications by aggravated atherosclerosis in large arteries and coronary atherosclerosis, thereby grows the risk for macro and microangiopathy such as myocardial infarction, stroke, limb loss and retinopathy. Moreover diabetes is one of the strongest and independent risk factor for cardiovascular morbidity and mortality, which is associated frequently with rhythm disorders such as atrial fibrillation (AF) and ventricular arrhythmias (VA). The present article provides a concise overview of the association between DM and rhythm disorders such as AF and VA with underlying pathophysiological mechanisms.

Rotational Angiography Based Three-Dimensional Left Atrial Reconstruction: A New Approach for Transseptal Puncture.

AIM: Rotational angiography is a well-known method for the three-dimensional (3-D) reconstruction of left atrium and pulmonary veins during left-sided atrial arrhythmia ablation procedures. In our study, we aimed to review our experience in transseptal puncture (TSP) using 3-D rotational angiography. METHODS: We included a total of 271 patients who underwent atrial fibrillation ablation using cryoballoon. Rotational angiography was performed to get the three-dimensional left atrial and pulmonary vein reconstructions using cardiac C-arm computed tomography. The image reconstruction was made using the DynaCT Cardiac software (Siemens, Erlangen, Germany). RESULTS: The mean age of the study population was 61 ± 10 years. The indications for left atrial arrhythmia ablation were paroxysmal AF in 140 patients (52%) and persistent AF patients in 131 (48%) patients. The success rate of TSP using only rotational guidance was (264/271 patients, 97.4%). In the remaining seven patients, transesophageal guidance was used after the initial attempt due to thick interatrial septum in five patients and difficult TSP due to abnormal anatomy and mild pericardial effusion in the remaining two patients. Mean fluoroscopy dosage of the rotational angiography was 4896.4 ± 825.3 µGym(2). The mean time beginning from femoral vein puncture to TSP was 12.3 ± 5.5 min. CONCLUSION: TSP guided by rotational angiography is a safe and effective method. Our results indicate that integration of rotational angiographic images into the real-time fluoroscopy can guide the TSP during the procedure.

Cryoballoon Ablation for Pulmonary Vein Isolation in Patients With Persistent Atrial Fibrillation: One-Year Outcome Using Second Generation Cryoballoon.

BACKGROUND: Data regarding the freedom from atrial fibrillation (AF) in the follow-up of persistent AF patients is limited. The second-generation cryoballoon has better cooling properties compared with first-generation cryoballon. In this study, we aimed to assess the medium-term efficacy of second-generation cryoballoon in patients with persistent AF. METHODS AND RESULTS: A total of 100 patients (63±10 years, 80% male) with symptomatic persistent AF, despite ≥1 antiarrhythmic drug(s), who were scheduled for pulmonary vein isolation using second-generation cryoballoon were enrolled in this study. Follow-up was based on outpatient clinic visits, including Holter ECGs. Recurrence was defined as a symptomatic or documented arrhythmia episode of >30 seconds excluding a 3-month blanking period. As a result, 393 pulmonary veins (7 patients with common ostium) were successfully isolated. Mean procedural and fluoroscopy times were 96.2±21.3 and 19.7±6.7 minutes, respectively. Phrenic nerve palsy occurred in 3% (3/100) of the patients. At a mean follow-up duration of 10.6±6.3 months, 67% of the patients were in sinus rhythm. Stepwise multivariable Cox proportional hazard regression analysis showed that early AF recurrence (hazard ratio 3.83, 95% confidence interval 1.91-7.68, P<0.001) was the only independent predictor for late AF recurrence apart from other clinical and echocardiographic variables. CONCLUSIONS: Our findings indicated that second-generation cryoballoon use is associated with favorable outcomes in patients with persistent AF. Recurrence at blanking period was the only predictor of long-term AF recurrence.

Luminal esophageal temperature rise and esophageal lesion formation following remote-controlled magnetic pulmonary vein isolation.

BACKGROUND: Remote magnetic pulmonary vein isolation (PVI) demonstrates comparable success rate to manual ablation, but thermal effects on esophageal tissue remain undefined. OBJECTIVE: The purpose of this study was to evaluate the potential thermal effects on esophageal tissue during remote magnetic wide-area circumferential pulmonary vein isolation (CPVI). METHODS: Twenty-five patients (23 men, age 57 ± 10 years) in the magnetic navigation system (MNS) group and 25 control subjects (15 men, age 61 ± 12 years) with drug-refractory paroxysmal or persistent atrial fibrillation underwent CPVI. A magnetic 3.5-mm irrigated-tip catheter (NaviStar ThermoCool RMT, Biosense Webster) and a nonmagnetic 3.5-mm irrigated-tip catheter (NaviStar ThermoCool, Biosense Webster) were used in the MNS and control group, respectively. A temperature probe (SensiTherm, St. Jude Medical), containing 3 thermocouples was placed in close proximity to the ablation site monitoring luminal esophageal temperature (LET). LET changes did not guide therapy. Postprocedural esophagogastroduodenoscopy (EGD) was performed in all patients. RESULTS: Successful CPVI was achieved in all patients. No esophageal lesions, minimal lesions, or ulcerations were found in 16 of 25 (64%), 7 of 25 (28%), and 2 of 25 (8%) in the MNS group and in 14 of 25 (56%), 10 of 25 (40%), and 1 of 25 (4%) patients in the control group, respectively. No atrioesophageal fistula occurred. Mean maximum LET in the magnetic group was 43.7°C ± 3.7°C compared to 45.4°C ± 3.5°C in the manual control group (P = .09). CONCLUSION: Remote magnetic PVI is associated with significant rise in LET and development of thermal esophageal lesions. In the MNS group, higher LET recordings were more likely to cause esophageal injury, whereas this association was not seen in the manual group despite a tendency toward higher mean maximum LET recordings.

Cavotricuspid Isthmus Anatomy Determines The Success Of Remote Controlled Magnetic Bidirectional Block: A Comparsion Between Magnetic 8-mm Solid Tip And 3.5-mm Magnetic Irrigated Tip Catheter.

BACKGROUND: Cavotricuspid isthmus (CTI) anatomy is associated with a great inter-individual variability. The aim of this study was to compare the magnetic 8-mm tip catheter versus the novel 3.5-mm magnetic irrigated tip catheter in achieving bidirectional right atrial isthmus block and to evaluate the impact of the underlying CTI anatomy on success rate. METHODS: A detailed remote controlled 3-dimensional electroanatomic (3D EA) right atrial reconstruction was performed using the magnetic navigation system with special emphasis to the CTI. CTI anatomy was evaluated utilizing the 3D EA map and classified into (A) simple (flat), (B) complex (pouch-like recess or concave shape) or (C) highly complex (pouch-like recess and concave shape). Patients were treated either with the magnetic 8-mm tip catheter (group I) or the open irrigated magnetic 3.5-mm tip catheter (group II). Primary endpoint was defined as acute bidirectional CTI block utilizing exclusively the remote controlled magnetic navigation system. Secondary endpoint was any procedure related complication and procedure time. RESULTS: In group I (n=10, 10 males, mean age: 65 ± 9 years) the primary endpoint was achieved in 80% (8/10 pts) requiring a median (Q1; Q3) RF application time of 37.1 min (22.8; 71.5) and a median (Q1;Q3) cumulative energy (CE) of 70.68 kJ (kilo Joule). (10.76;40.59). In group II (n=13, 10 males, mean age: 60 ± 7 years) the primary endpoint was achieved in 92 % (12/13) with a median (Q1; Q3) RF application time of 21.9 min (13.0; 27.0; p value=0.036) and a CE of 33.54 KJ (26.59; 49.22; p value=0.015). Variable CTI anatomy was identified for group I (type A: n=5 pts, type B: n=5 pts, type C: n=0 pts) and group for II (type A: n=4 pts, type B: n=7 pts, type C: n=2 pts). In group I magnetic ablation failure was associated with type B CTI anatomy (n=2 pts) and in group II with type C CTI (n=1). No procedure related complications were observed. CONCLUSION: Remote controlled catheter ablation of typical atrial flutter using the magnetic navigation system appears to be safe and feasible. CTI anatomy determines remote controlled magnetic ablation success. Use of the magnetic 3.5 mm irrigated tip catheter should be considered in patients with complex CTI anatomy.

Catheter ablation of right ventricular outflow tract tachycardia: a simplified remote-controlled approach.

AIMS: Manual mapping and ablation of right ventricular outflow tract (RVOT) tachycardia may be associated with cardiac perforation and complicated by mechanically induced ventricular extrasystoles (VESs). The aim of this study was to assess remote-controlled magnetic (RCM) mapping and ablation of RVOT ventricular tachycardia (VT)/VES utilizing a soft magnetic catheter. METHODS AND RESULTS: Mapping and ablation of RVOT VT/VES were performed using the magnetic navigation system (MNS, Niobe II, Stereotaxis, St Louis, MO) in conjunction with a cardiodrive motor unit (Stereotaxis). A soft magnetic catheter (Celsius RMT, 4 mm solid tip, Biosense Webster, Diamond Bar, CA) was navigated to the RVOT using a sequence of pre-installed magnetic vectors. The primary endpoint was defined as successful RCM VT/VES ablation. Other parameters observed included RCM RVOT accessibility, mapping-induced mechanical VES, fluoroscopy time, complications, and arrhythmia recurrence. Thirteen consecutive patients (mean age: 50 ± 14 years; 10 females, 6 RVOT VT) underwent RCM mapping and ablation. The RVOT was reached in all patients utilizing solely the MNS. Successful RCM RVOT ablation was achieved in {12 of 13} (92.3%) patients. Mean procedure and fluoroscopy times were 116.5 ± 48.9 and 7.5 ± 4.3 min, respectively. Catheter-induced VES during RVOT mapping were observed in {1 in 13} patients (7.7%, three VES). No complications occurred. During a mean follow-up of 252 ± 211 days, clinical arrhythmia recurrence was observed in {1 in 13} (7.7%) patients. CONCLUSIONS: Automatic RCM RVOT access is feasible, while RVOT mapping and ablation appear to be safe, fast, and effective. The soft magnetic catheter rarely induces mechanical VES.

Catheter ablation for ventricular tachycardia after failed endocardial ablation: epicardial substrate or inappropriate endocardial ablation?

BACKGROUND: The substrate of myocardial ventricular tachycardia (VT) may involve the subepicardial myocardium. OBJECTIVE: The purpose of this study was to assess the incidence of epicardial substrates in patients with a previously failed endocardial ablation attempt for VT as well as the safety and effectiveness of epicardial ablation. METHODS: Using an electroanatomic mapping system, endocardial and epicardial maps were acquired. Irrigated radiofrequency current ablations of all inducible VTs were performed. RESULTS: Between 2005 and 2009, 59 patients with or without structural heart disease underwent epicardial VT ablation. Pericardial access failed in 3 (5%) of these patients. Of the remaining 56 patients, an epicardial substrate was found in 41 (73%). Overall, acute success was achieved in 46 (78%) of 59 patients, with complete VT abolition in 27 (46%) and partial abolition in 19 (32%). Successful outcomes were the result of endocardial ablation only in 14 (24%) patients, epicardial ablation in 21 (36%), and endocardial/epicardial in 11 (19%). Ablation failed to prevent reinduction in 8 (13%) patients, and VTs were noninducible prior to ablation in 5 (8%). Two periprocedural deaths occurred, one after right ventricular perforation and one due to electromechanical dissociation. Hepatic bleeding occurred in two patients. Recurrence of any VT occurred in 27 (47%) of 57 surviving patients during median follow-up of 362 days (q1-q3; 180-468 days). Repeat epicardial mapping was not feasible due to adhesions in 3 (25%) of 12 patients. CONCLUSION: In patients with a previously failed endocardial VT ablation, epicardial mapping reveals a VT substrate in nearly three fourths of all patients, and epicardial ablation is required for successful VT abolition in more than half of patients. However, life-threatening complications may occur. Repeat epicardial access was not possible in 25% due to local pericardial adhesions.

Remote-controlled magnetic pulmonary vein isolation using a new irrigated-tip catheter in patients with atrial fibrillation.

BACKGROUND: Lack of an irrigated-tip magnetic catheter has limited the role of remote-controlled magnetic navigation (Niobe II, Stereotaxis) for catheter ablation of atrial fibrillation (AF). METHODS AND RESULTS: A novel 3.5-mm-tip irrigated magnetic catheter (group 1, Thermocool Navistar RMT, Biosense Webster) was used for 3D left atrial reconstruction (CARTO RMT) and remote-controlled magnetic pulmonary vein isolation. A redesigned catheter was used in group 2. The primary end point was wide area circumferential pulmonary vein isolation confirmed by spiral catheter recording during ablation; secondary end points included procedural data, complications, and AF recurrence. Fifty-six consecutive patients [group 1: 28 patients, 22 males, age 64 (38 to 78) years, left atrium: 47 (34 to 52) mm; paroxysmal AF: n=21, persistent AF: n=7; group 2: 28 patients, 20 males, age 60 (24 to 78) years, left atrium: 40 (35 to 53) mm; paroxysmal AF: n=18, persistent AF: n=10] were included. The primary end point was achieved in a total of 52 of 56 (93%) patients. Median procedure duration was 315 (125 to 550) minutes (group 1: 370 [230 to 550] minutes; group 2: 243 [125 to 450] minutes). Median fluoroscopy exposure to the investigator was reduced by 31%. Tip charring in 17 of 28 (61%) and complications in 3 of 28 (11%) patients in group 1 resulted in a catheter redesign. Sinus rhythm was maintained by 35 of 50 (70%) patients during a median follow-up period of 545 (100 to 683) days. CONCLUSIONS: Remote-controlled magnetic AF ablation with real-time verification of pulmonary vein isolation is feasible with a comparable success rate to manual ablation. Safety improved after a redesign of the catheter.

Catheter ablation of long-standing persistent atrial fibrillation: a lesson from circumferential pulmonary vein isolation.

INTRODUCTION: Circumferential pulmonary vein isolation (CPVI) is associated with a high success rate in patients with paroxysmal and persistent atrial fibrillation (AF). However, in patients with long-standing persistent AF, the ideal ablation strategy still remains a matter of debate. METHODS AND RESULTS: Two-hundred and five patients underwent catheter ablation for long-standing persistent AF defined as continuous AF of more than 1-year duration. In a first step, all patients underwent CPVI. If direct-current cardioversion failed following CPVI, ablation of complex fractionated atrial electrograms (CFAEs) was performed. The goal was conversion into sinus rhythm (SR) or, alternatively, atrial tachycardia (AT) with subsequent ablation. A total of 340 procedures were performed. CPVI alone was performed during 165 procedures in 124 of 205 (60.5%) patients. In the remaining 81 patients, additional CFAE ablation was performed in 45, left linear lesions for recurrent ATs in 44 and SVC isolation in 15 patients, respectively, resulting in inadvertent left atrial appendage isolation in 9 (4.4%) patients. After the initial ablation procedure, 67 of 199 patients remained in SR during a mean follow-up of 19 ± 11 months. Six patients were lost to follow-up. After a mean of 1.7 ± 0.8 procedures, 135 of 199 patients (67.8%) remained in SR. Eighty-six patients (43.2%) remained in SR following CPVI performed as the sole ablative strategy. CONCLUSIONS: CPVI alone is sufficient to restore SR in 43.2% of patients with long-standing persistent AF. Multiple procedures and additional ablation strategies with a significant risk of inadvertent left atrial appendage isolation are often required to maintain stable SR.