Ablation at Right Coronary Cusp as an Alternative and Favorable Approach to Eliminate Premature Ventricular Complexes Originating From the Proximal Left Anterior Fascicle.

BACKGROUND: Premature ventricular complex (PVC) with narrow QRS duration originating from proximal left anterior fascicle (LAF) is challenging for ablation. This study was performed to evaluate the safety and feasibility of ablation from right coronary cusp (RCC) for proximal LAF-PVC and to investigate this PVC's characteristics. METHODS: Mapping at RCC and left ventricle and ECG analysis were performed in 20 patients with LAF-PVC. RESULTS: The earliest activation site (EAS), with Purkinje potential during both PVC and sinus rhythm, was localized at proximal LAF in 8 patients (proximal group) and at nonproximal LAF in 12 patients (nonproximal group). The Purkinje potential preceding PVC-QRS at the EAS in proximal group (32.6±2.5 ms) was significantly earlier than that in nonproximal group (28.3±4.5 ms, P=0.025). Similar difference in the Purkinje potentials preceding sinus rhythm QRS at the EAS was also observed between proximal and nonproximal groups (35.1±4.7 versus 25.2±5.0 ms, P<0.001). In proximal group, the distance between the EAS to left His bundle and to RCC was shorter than that of nonproximal group (12.3±2.8 versus 19.7±5.0 mm, P=0.002, and 3.9±0.8 versus 15.7±7.8 mm, P<0.001, respectively). No difference in the distance from RCC to proximal LAF was identified between the 2 groups. PVCs were successfully eliminated from RCC for all proximal groups but at left ventricular EAS for nonproximal groups. The radiofrequency application times, ablation time, and procedure time of nonproximal group were longer than that of proximal group. Electrocardiographic analysis showed that, when compared with nonproximal group, the PVCs of proximal group had narrower QRS duration; smaller S wave in leads I, V5, and V6; lower R wave in leads I, aVR, aVL, V1, V2, and V4; and smaller q wave in leads III and aVF. The QRS duration difference (PVC-QRS and sinus rhythm QRS) <15 ms predicted the proximal LAF origin with high sensitivity and specificity. CONCLUSIONS: PVCs originating from proximal LAF, with unique electrocardiographic characteristics, could be eliminated safely from RCC.

Zero-fluoroscopy approach for ablation of supraventricular tachycardia using the Ensite NavX system: a multicenter experience.

BACKGROUND: Three-dimensional electroanatomic mapping systems have demonstrated a significant reduction in radiation exposure during radiofrequency catheter ablation procedures. We aimed to investigate the safety, feasibility and efficacy of a completely zero-fluoroscopy approach for catheter ablation of supraventricular tachycardia using the Ensite NavX navigation system compared with a conventional fluoroscopy approach. METHODS: A multicenter prospective non-randomized registry study was performed in seven centers from January 2013 to February 2018. Consecutive patients referred for catheter ablation of supraventricular tachycardia were assigned either to a completely zero-fluoroscopic approach (ZF) or conventional fluoroscopy approach (CF) according to the operator's preference. Patients with atrial tachycardia were excluded. RESULTS: Totally, 1020 patients were enrolled in ZF group; 2040 patients ablated by CF approach were selected for controls. There was no significant difference between the zero-fluoroscopy group and conventional fluoroscopy group as to procedure time (60.3 ± 20.3 vs. 59.7 ± 22.6 min, P = 0.90), immediate success rate of procedure (98.8% vs. 99.2%, P = 0.22), arrhythmia recurrence (0.4% vs. 0.5%, P = 0.85), total success rate of procedure (98.4% vs. 98.8%, P = 0.39) or complications (1.1% vs. 1.5%, P = 0.41). Compared with the conventional fluoroscopy approach, the zero-fluoroscopy approach provided similar outcomes without compromising the safety or efficacy of the procedure. CONCLUSION: The completely zero-fluoroscopy approach demonstrated safety and efficacy comparable to a conventional fluoroscopy approach for catheter ablation of supraventricular tachycardia, and mitigated radiation exposure to both patients and operators. TRIAL REGISTRATION: clinicaltrials.gov Identifier: NCT03042078; first registered February 3, 2017; retrospectively registered.

High-Resolution Imaging of LA Anatomy Using a Novel Wide-Band Dielectric Mapping System: First Clinical Experience.

OBJECTIVES: This study presents the first report of high-resolution imaging of cardiac anatomy using a novel system. BACKGROUND: Recently, the wide-band dielectric mapping system Kodex was introduced. METHODS: This study included 20 consecutive patients with symptomatic atrial fibrillation or left atrial tachycardia who were scheduled for an ablation procedure and who underwent simultaneous left atrial mapping using the Kodex and CARTO 3 systems. Pulmonary vein angiograms served as a reference to compare the craniocaudal dimensions of the pulmonary vein ostia as depicted by either of the 2 mapping systems. RESULTS: Complete left atrial imaging was achieved within a median [first quartile; third quartile] of 9.7 [7.5; 12.8] min. Median procedure time was 97.5 [90; 112.5] min, and median total fluoroscopy time was 8.2 [5.7; 10.6] min, of which a median of 1.4 [1.1; 2.3] min were used during the creation of the left atrial map. High-resolution representations of left atrial anatomy were successfully created in all patients. Both the Kodex and CARTO measurements correlated well with fluoroscopy measurements, as reflected by Pearson's correlation coefficients (r) of 0.91 and 0.95, respectively. Bland-Altman plots revealed that, on average, Kodex measurements underestimated fluoroscopy measurements by 0.04 mm (95% limits of agreement of -5.72 and 5.64 mm), and CARTO measurements underestimated fluoroscopy measurements by 0.02 mm (95% limits of agreement of -3.61 and 3.57 mm). CONCLUSIONS: Anatomic mapping of the left atrium using Kodex shows the potential to create computed tomography-like images without the need for additional periprocedural imaging.

Catheter ablation of supraventricular tachycardia in patients with dextrocardia and situs inversus.

BACKGROUND: Dextrocardia with situs inversus is a rare cardiac positional anomaly. Catheter ablation procedures performed in this set of patients have not been sufficiently reported. METHODS: A total of 10 patients with dextrocardia and situs inversus who received catheter ablation for supraventricular tachycardia (SVT) were included from a cohort of over 20 000 cases of catheter ablation for SVT in three centers from 2005 to 2016. All patients underwent electrophysiologic study and catheter ablation of SVT. Ablation targets were selected based on different tachycardia mechanisms with the primary endpoint of noninduction of tachycardia. RESULTS: The average age was 32.4 ± 5.6 years. Congenitally corrected transposition of great arteries (TGA) with situs inversus and D-looping of the ventricles and aorta (congenitally corrected TGA {I,D,D}) was found in four patients, while the other six patients exhibited mirror-image dextrocardia {I,L,L}. The mechanisms of SVT were atrioventricular nodal reentrant tachycardia in four patients, atrioventricular reentrant tachycardia in three, typical atrial flutter in one, intra-atrial reentrant tachycardia in one, and focal atrial tachycardia in one. Immediate procedural success was achieved in 9 out of 10 patients with no procedural complications. During a follow-up period of 6.3 ± 3.5 years on average, all patients remained free from recurrent tachycardia. CONCLUSIONS: For patients with dextrocardia and situs inversus, catheter ablation of SVT is safe and feasible. Differences in catheter maneuver and fluroscopy projection, along with difficulties in distorted anatomy are major obstacles for successful ablation.

Electrophysiological Characteristics of Bundle Branch Reentry Ventricular Tachycardia in Patients Without Structural Heart Disease.

BACKGROUND: The distinct electrophysiological features of bundle branch reentry ventricular tachycardia (VT) in patients without structural heart disease have not been systemically characterized. METHODS: Nine patients (mean age, 29.6 years) with normal left ventricular function were enrolled. Bundle branch reentry VT with right and left bundle branch block (BBB) patterns was induced in 1 and 9 patients, respectively. The right bundle was attempted to record by a 6F decapolar or quadripolar catheter. Electroanatomic mapping of the left ventricle was performed in 6 patients. In all left BBB pattern VT, the mean VT cycle length was 329.3±89.1 ms, and the median HV interval during tachycardia was longer than that of baseline (78 [73-100] versus 71 [64.5-88] ms; P=0.11). RESULTS: The H-RB interval during VT was slightly shorter (P=0.14); however, the median RB-V interval was markedly longer than that during sinus rhythm (50 [29.5-83] versus 30 [8-51] ms; P=0.043]. In 6 patients with 3-dimensional mapping of the left ventricle, a slow anterograde or retrograde conduction over left HIS-Purkinje system with normal myocardial voltage was identified. In addition, Purkinje-related VTs (1.0±1.3 types) were also induced in 5 patients. Ablation was applied in distal left BB in patients with baseline left BBB and in one narrow QRS patient with sustained Purkinje-related VT, whereas right BB was targeted in other patients. During a mean follow-up of 31.4 months, frequent premature ventricular contractions occurred in one patient, and new VT developed in the other patient. CONCLUSIONS: Bundle branch reentry VT can occur in young patients with extensive conduction disturbances within HIS-Purkinje system. Ablation targeting at the distal left BB which bifurcates into left posterior and anterior fascicle can preserve the residual atrioventricular conduction, but intensive follow-up is needed.

Peri-mitral atrial flutter: personalized ablation strategy based on arrhythmogenic substrate.

Aims: The aim of this study is to characterize the arrhythmogenic substrate for peri-mitral atrial flutter (PMAFL), thereby determining a personalized ablation strategy to treat PMAFL. Methods and results: Thirty-six consecutive PMAFL patients (mean age: 63.8 ± 11.3, 23 males) underwent detailed three-dimensional electroanatomic mapping in left atrium (LA). The LA was divided into septal-anterior wall (SAW), posterior inferior wall (PIW), and mitral isthmus (MI) region, respectively. Ablation strategy was determined based on the endocardial bipolar voltage map. Based on electrophysiological substrates, 10, 17, and 9 cases were classified into iatrogenic, spontaneous, and no-substrate PMAFL, respectively. The mean voltage in SAW was significantly lower in spontaneous PMAFL (iatrogenic: 1.07 ± 0.66 mV; spontaneous: 0.65 ± 0.44 mV; no-substrate: 1.60 ± 0.53 mV, P <0.001), while iatrogenic PMAFL patients had the lowest voltage in MI (0.51 ± 0.23 mV vs. 1.55 ± 0.78 mV, 1.61 ± 0.56 mV, P <0.001). No low-voltage or slow conduction zone was found in the no-substrate PMAFL group. Fifteen spontaneous PMAFLs were successfully terminated by modified septal-anterior (9/10) or conventional anterior ablation line (6/7). Eight iatrogenic PMAFLs (8/10) were terminated by reinforcing the previous ablation areas. Cardioversion without PMAFL ablation was done in no-substrate PMAFL patients. After a median follow-up of 12 (7-39) months, two spontaneous PMAFL patients received redo procedures for recurrence due to "gap" conduction. Conclusions: The ablation strategy for PMAFL patients should be based on the arrhythmogenic substrate, but not the indiscriminate MI ablation. No-substrate PMAFLs during AF ablation could be monitored after cardioversion and might not need further ablation.

Clinical, electrocardiographic, and electrophysiological characteristics of left upper septal fascicular ventricular tachycardia.

Aims: We sought to investigate the clinical, electrocardiographic, and electrophysiological characteristics of left upper septal fascicular ventricular tachycardia (LUS-VT). Methods and results: Eleven consecutive patients with LUS-VT were identified among 196 patients with left fascicular ventricular tachycardia (VT). Clinical VTs presented as paroxysmal in 8 patients and incessant in 3 patients. Six patients had previous left posterior fascicular VT ablation history. All VTs had narrow QRS complexes with QRS duration of 101.1 ± 9.2 ms. The frontal QRS axis was normal or right deviation. Precordial morphology was either right bundle branch block type or similar to that of sinus rhythm. A retrograde His with H-V interval of 21.9 ± 7.2 ms was recorded during VT. The earliest Purkinje potential (PP) to QRS interval during VT averaged 35.7 ± 4.5 ms. Clear diastolic potentials (DPs) with high frequency and low amplitude were found in only one patient. Ten patients were managed successfully by 11 ablation sessions, and 1 patient declined ablation. Successful targets at the left upper septum were sites with the earliest PP (9 cases) or with DP (1 case) during VT. After ablation, 2 cases (10%) developed new left anterior hemiblock or incomplete left bundle branch block. No VT recurred during a median follow-up period of 3.2 (range 1.0-12.7) years. Conclusion: LUS-VT presented as narrow QRS complex tachycardia. Some LUS-VTs occurred after ablation targeting left posterior fascicular VT. The VTs can be managed successfully by focal ablation at the left upper septum with a mild risk of fascicular injury.

Noninvasive phase mapping of persistent atrial fibrillation in humans: Comparison with invasive catheter mapping.

BACKGROUND: A novel noninvasive epicardial and endocardial electrophysiology system (NEEES) to identify electrical rotors and focal activity in patients with atrial fibrillation (AF) was recently introduced. Comparison of NEEES data with results from invasive mapping is lacking. METHODS: Six male patients (59 ± 11 years) with persistent AF underwent cardiac mapping with the NEEES, which included the creation of isopotential and phase maps. Then patients underwent catheter mapping using a PentaRay NAV catheter and the CARTO 3 system. Signals acquired by the catheter were analyzed by customized software that applied the same phase mapping algorithm as for the NEEES data. RESULTS: In all patients, noninvasive phase mapping revealed short-lived electrical rotors occurring 1.8 ± 0.3 times per second and demonstrating 1-4 (mean 1.2 ± 0.6) rotation cycles. Most of these rotors (72.7%) aggregated in 2-3 anatomical clusters. In two patients, focal excitation from pulmonary veins was observed. Invasive catheter mapping in the dominant rotor aggregation sites and in the three control sites demonstrated the presence of electrical rotors with properties similar to noninvasively detected rotors. Spearman's correlation coefficient between rotor occurrence rate by noninvasive and invasive mapping was 0.97 (p < .0001). Mean rotors' cycle length at dominant aggregation sites, scores of their full rotations, and the proportion of rotors with clockwise rotation were not significantly different between the mapping modalities. CONCLUSION: In patients with persistent AF, phase processing of unipolar electrograms recorded by catheter mapping could reproduce electrical rotors as characterized by NEEES-based phase mapping.

Insights into ablation of persistent atrial fibrillation: Lessons from 6-year clinical outcomes.

INTRODUCTION: Ablation of persistent atrial fibrillation (AF) is a potential treatment option for symptomatic patients. We sought to evaluate the critical role of circumferential pulmonary vein isolation (CPVI) in the ablation of persistent AF. METHODS AND RESULTS: A total of 341 ablation procedures were performed in 174 consecutive patients with persistent AF. CPVI was performed in all patients, additional ablation was only performed if electrical cardioversion failed after CPVI. During a median follow-up (FU) of 89 (63; 89) months, stable sinus rhythm was documented in 42/170 (25%) patients after a single procedure and in 111/164 (68%) patients after 1.9 ± 1.1 procedures. Stable SR was achieved in 40/75 (53%) patients in whom only CPVI was performed during the index and repeat procedures and in 71/89 (79%) patients with CPVI plus additional ablation. The main predictor for ablation success was duration of persistent AF before the index procedure (P < 0.001, HR ± CI: 1.608 [1.034, 1.103]). Responders to CPVI during the initial procedure had a significantly better multiple-procedure outcome after 42 months of FU compared to CPVI nonresponders (P  =  0.0365). Conversion during the index procedure had no impact on clinical outcomes (P  =  0.0903). Persistent AF regressed to paroxysmal AF in 16% of patients. CONCLUSIONS: We demonstrate a 25% single- and 68% multiple-procedure success in patients with persistent AF, while stable SR was achieved in 53% of patients with pure CPVI during all procedures and in 79% of patients with CPVI plus additional ablation. Only duration of persistent AF before ablation had a statistically significant impact on ablation outcome.

Catheter ablation of atrial fibrillation in very young adults: a 5-year follow-up study.

Aims: Catheter ablation is an established therapy for symptomatic atrial fibrillation (AF). However, outcome data on catheter ablation for AF in young adults is scarce. Methods and results: From 2005-2014, 85 consecutive young adults (mean age 31 ± 4 years; 69% men) with symptomatic paroxysmal AF (PAF, n = 52) and persistent (Pers) AF (n = 33) underwent pulmonary vein isolation (PVI) [±ablation of complex fractionated atrial electrograms/linear lesions in PVI non-responders] at our centre. Follow-up was based on outpatient visits including 24-h Holter-ECG at 3, 6 and, 12 months post ablation, and every 12 months thereafter. Recurrence was defined as any AF/atrial tachycardia episode >30s following a 3-month blanking period. Follow-up was available for 74/85 (87%) patients. After a median follow-up of 4.6 years (Q1: 2.6; Q3: 6.6) and a mean of 1.5 ± 0.6 (median 1, range 1-3) ablation procedures 84% [including 13% on previously ineffective antiarrhythmic drugs (AAD)] of patients were in stable SR. Single-procedural 1-year/5-year arrhythmia-free survival was 66% [95% confidence interval (CI): 56-78%]/44% (95% CI: 33-59%), respectively. Structural heart disease [SHD; hazard ratio (HR) 2.79 (95% CI 1.52-5.12), P = 0.001] and obesity [HR 1.10 (95% CI 1.00-1.21) per unit increase in body mass index >27 kg/m2, P = 0.05] independently predicted AF recurrence. Major complications occurred in 6/122 (4.9%) procedures (PV stenosis in 3, cardiac tamponade in 1, stroke in 1, and arterial-venous fistula in 1). Conclusion: In the majority of very young adults catheter ablation for AF is effective, and associated with an acceptable complication rate. SHD and obesity are predictors for AF recurrence in this population.

Electrocardiographic and electrophysiologic differentiation between atriofascicular, long atrioventricular, and short atrioventricular decrementally conducting accessory pathways.

Aims: We aimed to examine the electrocardiographic and electrophysiologic characteristics of anterograde-conducting decremental accessory pathways (DAP) and to identify surrogate criteria to distinguish short atrioventricular (SAV) DAP from atriofascicular (AF) AP and long atrioventricular (LAV) DAP. Methods and results: We identified all patients with DAPs and analysed electrocardiographic and electrophysiologic characteristics. Distal insertion sites were examined using existing criteria, including V-H interval, ventricular activation at the right ventricular apex, and around tricuspid annulus during antidromic atrioventricular re-entrant tachycardia (A-AVRT) or complete pre-excitation and evaluated the AV node-like properties according to the response to adenosine and radiofrequency ablation. Out of 45 patients with DAPs, 28 (62.2%) had SAV-DAP (13 with definite AF-AP, 2 with definite LAV-DAP, 2 indeterminate). In all, 50% of SAV-DAPs and 53.3% of AF-AP/LAV-DAPs had 'rS' pattern in lead III. Longer QRS duration (159.9 ± 17.4 ms vs. 139.2 ± 14.3 ms, P < 0.0001) during full pre-excitation or A-AVRT differentiated SAV-DAP from AF-AP. The QRS-V(His) interval was longer for those with SAV-DAP compared vs. AF-AP/LAV-DAP (45.3 ± 2.4 ms vs. 22.9 ± 2.5 ms, P < 0.0001) and a cut-off value of 33.0 ms differentiated the two (sensitivity 81.3%, specificity 87.5%). Conclusion: The majority of the SAV-DAPs are located at the TA free wall. An 'rS' pattern in lead III is frequently seen in SAV-DAP as well as AF-AP/LAV-DAPs. Measuring the QRS-V(His) interval would be helpful to distinguish SAV-DAP from AF-AP/LAV-DAP.

First-in-Man Analysis of the Relationship Between Electrical Rotors From Noninvasive Panoramic Mapping and Atrial Fibrosis From Magnetic Resonance Imaging in Patients With Persistent Atrial Fibrillation.

BACKGROUND: Late gadolinium enhancement (LGE) cardiovascular magnetic resonance (CMR) imaging can be used to evaluate characteristics of atrial fibrosis. The novel noninvasive epicardial and endocardial electrophysiology system (NEEES) allows for the identification of sources with rotor activity. This study describes a new technique to examine the relationship between rotors and LGE signal intensity in patients with persistent atrial fibrillation (PERS) scheduled for ablation. METHODS AND RESULTS: Ten consecutive patients underwent pulmonary vein isolation for persistent atrial fibrillation. LGE CMR of both atria was performed, and NEEES-based analysis was conducted to identify rotors. For each mapping point, the intracardiac locations were transferred onto an individual CMR-derived 3-dimensional shell. This allowed the LGE signal intensity to be projected onto the anatomy from the NEEES analysis. NEEES analysis identified a total number of 410 electric rotors, 47.8% were located in the left atrium and 52.2% in the right atrium. Magnetic resonance imaging analysis was performed from 10 right atria and 10 left atria data sets, including 86 axial LGE CMR planes per atrium. The mean LGE burden for left atrium and right atrium was 23.9±1.6% and 15.9±1.8%, respectively. Statistical analysis demonstrated a lack of regional association between the extent of LGE signal intensity and the presence of rotors. CONCLUSIONS: This is the first study demonstrating that the presence of rotors based on NEEES analysis is not directly associated with the extent and anatomic location of LGE signal intensity from CMR. Further studies evaluating the relationship between rotors and fibrosis in patients with persistent atrial fibrillation are mandatory and may inform strategies to improve ablation outcome.

Experimental, Pathologic, and Clinical Findings of Radiofrequency Catheter Ablation of Para-Hisian Region From the Right Ventricle in Dogs and Humans.

BACKGROUND: Ablation of para-Hisian accessory pathway (AP) poses high risks of atrioventricular block. We developed a pacing technique to differentiate the near-field (NF) from far-field His activations to avoid the complication. METHODS AND RESULTS: Three-dimensional mapping of the right ventricle was performed in 15 mongrel dogs and 23 patients with para-Hisian AP. Using different pacing outputs, the NF- and far-field His activation was identified on the ventricular aspect. Radiofrequency application was delivered at the NF His site in 8 (group 1) and the far-field His site in 7 dogs (group 2), followed by pathologic examination after 14 days. NF His activation was captured with 5 mA/1 ms in 10 and 10 mA/1 ms in 5 dogs. In group 1, radiofrequency delivery resulted in complete atrioventricular block in 3, right bundle branch block with HV (His-to-ventricular) interval prolongation in 1, and only right bundle branch block in 2 dogs, whereas no changes occurred in group 2. Pathologic examination in group-1 dogs showed complete or partial necrosis of the His bundle in 4 and complete necrosis of the right bundle branch in 5 dogs. In group 2, partial necrosis in the right bundle branch was found only in 1 dog. Using this pacing technique, the APs were 5.7±1.2 mm away from the His bundle located superiorly in 20 or inferiorly in 3 patients. All APs were successfully eliminated with 1 to 3 radiofrequency applications. No complications and recurrence occurred during a follow-up of 11.8±1.4 months. CONCLUSIONS: Differentiating the NF His from far-field His activations led to a high ablation success without atrioventricular block in para-Hisian AP patients.

Focal Impulse and Rotor Modulation for the Treatment of Atrial Fibrillation: Locations and 1 Year Outcomes of Human Rotors Identified Using a 64-Electrode Basket Catheter.

INTRODUCTION: 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.

Direct Comparison of Point-by-Point and Rapid Ultra-High-Resolution Electroanatomical Mapping in Patients Scheduled for Ablation of Atrial Fibrillation.

INTRODUCTION: Three-dimensional electroanatomical mapping (EAM) is an established tool facilitating catheter ablation. In this context, the novel Rhythmia system sets a new bar in fast high-resolution mapping. The aim of this study was to directly compare point-by-point versus rapid ultra-high-resolution EAM in patients scheduled for ablation of atrial fibrillation (AF) with focus on procedural data, acute success, and midterm clinical outcome. METHODS AND RESULTS: A total number of 74 consecutive patients (48/74 male) with symptomatic AF were scheduled to undergo pulmonary vein isolation (PVI) using either Carto or Rhythmia. The Carto-guided procedures were performed using point-by-point acquisition according to our routine approach, whereas for Rhythmia, fast anatomical mapping was utilized. Comparing Rhythmia- versus Carto-guided ablation approaches, we observed a significantly longer total mapping time (P = 0.001), longer total fluoroscopy time (P = 0.001), more delivered RF-applications (P = 0.019), and longer total RF-duration (P = 0.002). There was no difference regarding total ablation time (P = 0.707), total procedure duration (P = 0.99), and acute procedural success. During follow-up, 84.8% of patients remained free from any AF/AT-recurrence using Carto versus 88.2% when using Rhythmia (P = 0.53). From Kaplan-Meier analysis, the event rate estimations were 15% versus 13.5%, respectively. CONCLUSION: The present study reports our first clinical experience using Rhythmia in direct comparison with the established Carto system for AF ablation. Our data clearly demonstrate that Rhythmia was proved to be effective and well applicable but more data will be mandatory before final conclusions can be drawn.

Mapping and ablation of anteroseptal atrial tachycardia in patients with congenitally corrected transposition of the great arteries: implication of pulmonary sinus cusps.

AIMS: We sought to investigate focal atrial tachycardias (ATs) in patients with congenitally corrected transposition of the great arteries (ccTGA). METHODS AND RESULTS: We identified three cases of focal ATs with ccTGA from 2007 to 2015. The clinical findings, electrocardiography, electrophysiological features, and ablation were reported. All three cases had {S,L,L}-type ccTGA. The AT P waves shared the following features: narrow in width, positive in leads I and aVL, and negative/positive in lead V1. All ATs had focal activation pattern with early activation at the anteroseptal area, and further mapping demonstrated earliest atrial activation (EAA) inside the pulmonary sinus cusps (PSCs), especially the right PSC. In Cases 1 and 2, double potentials were recorded at the EAA sites. Conduction delay between the two potentials during atrial extrastimulus was observed. After successful ablation, the second potential during sinus rhythm was further delayed in Case 1 and was eliminated in Case 2. However, only one potential was recorded in Case 3. All three cases were successfully managed by ablating the sites with EAA, which preceded the P-wave onset by 60, 80, and 42 ms, respectively. During ablation, no junctional rhythm was observed. Incomplete left bundle branch block was induced during mapping in Case 1, but no other complications occurred. All patients were free from tachycardia during follow-up periods of 36, 7, and 5 months, respectively. CONCLUSION: Anteroseptal AT in patients with ccTGA could be eliminated by ablation inside the PSC.

Durability of wide-area left atrial appendage isolation: Results from extensive catheter ablation for treatment of persistent atrial fibrillation.

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.

First clinical experience using a novel high-resolution electroanatomical mapping system for left atrial ablation procedures.

BACKGROUND: The Rhythmia mapping system was recently launched and allows for rapid ultra-high-resolution electroanatomical mapping. We evaluated the feasibility, acute efficacy and safety of this novel system for ablation of atrial fibrillation (AF) and left atrial (LA) tachycardia (AT). METHODS AND RESULTS: A total of 35 consecutive patients (age 64.3 ± 8.6 years, LA diameter 44.4 ± 5.8 mm) underwent catheter ablation for AF and/or AT. All procedures were performed using Rhythmia in conjunction with the Orion mini-basket catheter. Pulmonary vein isolation (PVI) and linear lesions were performed applying radiofrequency (RF) energy. PVI was confirmed by presence of entrance and exit block using the mini-basket catheter. In addition, pacing maneuvers assessed bidirectional conduction block across linear lesions. Procedure duration was 110.3 ± 33 min, fast acquisition mapping (FAM) time was 19 ± 9 min. A mean number of 10165 ± 5904 mapping points were acquired during the initial map and 6379 ± 3191 for a remap. A total number of 31 ± 15 RF applications were delivered within 45 ± 22 min. Total fluoroscopy time was 21 ± 5, 5 ± 2 min were used for FAM. We observed a significant learning curve for mapping duration (p = 0.01). Complications included pericardial tamponade (n = 1), transient air embolism in the right coronary artery (n = 1), and mild groin hematoma (n = 2). CONCLUSIONS: The present study is the largest to describe experience of LA ablation procedures using Rhythmia. PVI was achieved in all patients. Applying this ultra high-resolution electroanatomical mapping system under routine conditions leads to a high level of confidence. More data will be mandatory before final conclusions can be drawn.

Apixaban, Rivaroxaban, and Dabigatran in Patients Undergoing Atrial Fibrillation Ablation.

INTRODUCTION: 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). CHA2 DS2-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, CHA2 DS2-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.