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A case of successful catheter ablation of paroxysmal atrial fibrillation and atrial tachycardia is reported. After pulmonary vein isolation, atrial tachycardia was induced by the use of isoproterenol and burst pacing from the catheter in the right atrium. An attempt was made to create a three-dimensional (3D) map of the atrial tachycardia, but the atrial tachycardia was terminated in the middle of the mapping. The 3D map was insufficient but indicated that the superior vena cava was involved in the circuit. When the intracardiac electrograms were reviewed, it was found that the atrial tachycardia was initiated with orthodromic capture of superior vena cava potentials and it was considered that the atrial tachycardia involved the superior vena cava-right atrium junction. Accordingly, superior vena cava isolation was performed. After that, atrial fibrillation and atrial tachycardias were not induced by the use of isoproterenol and burst pacing. In this case, an intracardiac electrogram at the time of induction of the tachycardia was helpful for understanding the circuit of the tachycardia., (© 2024. The Author(s), under exclusive licence to Springer Medizin Verlag GmbH, ein Teil von Springer Nature.)

Background: Three-dimensional (3D) mapping of the ventricular conduction system is challenging., Objective: The purpose of this study was to use ripple mapping to distinguish conduction system activation to that of adjacent myocardium in order to characterize the conduction system in the postinfarct left ventricle (LV)., Methods: High-density mapping (PentaRay, CARTO) was performed during normal rhythm in patients undergoing ventricular tachycardia ablation. Ripple maps were viewed from the end of the P wave to QRS onset in 1-ms increments. Clusters of >3 ripple bars were interrogated for the presence of Purkinje potentials, which were tagged on the 3D geometry. Repeating this process allowed conduction system delineation., Results: Maps were reviewed in 24 patients (mean 3112 ± 613 points). There were 150.9 ± 24.5 Purkinje potentials per map, at the left posterior fascicle (LPF) in 22 patients (92%) and at the left anterior fascicle (LAF) in 15 patients (63%). The LAF was shorter (41.4 vs 68.8 mm; P = .0005) and activated for a shorter duration (40.6 vs 64.9 ms; P = .002) than the LPF. Fourteen of 24 patients had left bundle branch block (LBBB), with 11 of 14 (78%) having Purkinje potential-associated breakout. There were fewer breakouts from the conduction system during LBBB (1.8 vs 3.4; 1.6 ± 0.6; P = .039) and an inverse correlation between breakout sites and QRS duration (P = .0035)., Conclusion: We applied ripple mapping to present a detailed electroanatomic characterization of the conduction system in the postinfarct LV. Patients with broader QRS had fewer LV breakout sites from the conduction system. However, there was 3D mapping evidence of LV breakout from an intact conduction system in the majority of patients with LBBB., Competing Interests: Disclosures Imperial College holds intellectual property relating to ripple mapping on behalf of Dr Kanagaratnam and Dr Linton, who have also received royalties from Biosense Webster. Dr Kanagaratnam, Dr Linton, Dr Copley, and Dr Luther have received consulting fees with respect to ripple mapping from Biosense Webster. All other authors have no conflicts of interest to disclose., (Copyright © 2024. Published by Elsevier Inc.)

Objective: The left ventricular outflow tract is an important source of ventricular arrhythmias. Up to one-third of all idiopathic ventricular arrhythmias in patients with structurally normal hearts may arise from this region. We would like to share the results of our left ventricular outflow tract ablation using three-dimensional mapping and limited fluoroscopy., Materials and Methods: This is a single-centre retrospective cohort study. Forty-six consecutive patients who underwent left ventricular outflow tract ablation procedures between January 2015 and June 2023 were included in the study. The EnSite Precision System (Abbott, St. Paul, MN, USA) was used to facilitate mapping and to reduce or eliminate the need for fluoroscopy., Results: The study group comprised 29 males and 17 females, with a mean age of 13.4 ± 4.5 years. The most common location for arrhythmias was the left coronary cusp (n : 21). Other locations, in sequence, included the junction of the right and left coronary commissure (n : 10), right coronary cusp (n : 10), left ventricular outflow tract endocardium (n:4), aorto-mitral junction (n : 1), and great cardiac vein (n : 1). Nine of these patients had previously undergone unsuccessful right ventricular outflow tract ablation at another centre. Cryoablation was performed in three patients, irrigated radiofrequency ablation in three patients, and conventional radiofrequency ablation in the remaining patients. The acute success rate was 100%, and no recurrences were observed. The mean follow-up period was 49.6 ± 24.4 months. All patients were asymptomatic and were being followed without antiarrhythmic medication., Conclusion: Although left ventricular outflow tract ablations pose a risk for coronary artery and heart valve complications, they can be performed successfully and safely with the guidance of three-dimensional mapping.

Introduction: Mapping system is useful in ablation of atrioventricular nodal reentry tachycardia (AVNRT) and localization of anatomic variances. Voltage mapping identifies a low voltage area in the Koch triangle called low-voltage-bridge (LVB); propagation mapping identifies the collision point (CP) of atrial wavefront convergence. We conducted a prospective study to evaluate the relationship between LVB and CP with successful site of ablation and identify standard value for LVB., Materials and Methods: Three-dimensional (3D) maps of the right atria were constructed from intracardiac recordings using the ablation catheter. Cut-off values on voltage map were adjusted until LVB was observed. On propagation map, atrial wavefronts during sinus rhythm collide in the site representing CP, indicating the area of slow pathway conduction. Ablation site was selected targeting LVB and CP site, confirmed by anatomic position on fluoroscopy and atrioventricular ratio., Results: Twenty-seven consecutive patients were included. LVB and CP were present in all patients. Postprocedural evaluation identified standard cut-off of 0.3-1 mV useful for LVB identification. An overlap between LVB and CP was observed in 23 (85%) patients. Procedure success was achieved in all patient with effective site at first application in 22 (81%) patients. There was a significant correlation between LVB, CP, and the site of effective ablation (p = .001)., Conclusion: We found correlation between LVB and CP with the site of effective ablation, identifying a voltage range useful for standardized LVB identification. These techniques could be useful to identify ablation site and minimize radiation exposure., (© 2024 Wiley Periodicals LLC.)

Transcatheter radiofrequency ablation has been widely introduced for the treatment of tachyarrhythmias. The demand for catheter ablation continues to grow rapidly as the level of recommendation for catheter ablation. Traditional catheter ablation is performed under the guidance of X-rays. X-rays can help display the heart contour and catheter position, but the radiobiological effects caused by ionizing radiation and the occupational injuries worn caused by medical staff wearing heavy protective equipment cannot be ignored. Three-dimensional mapping system and intracardiac echocardiography can provide detailed anatomical and electrical information during cardiac electrophysiological study and ablation procedure, and can also greatly reduce or avoid the use of X-rays. In recent years, fluoroless catheter ablation technique has been well demonstrated for most arrhythmic diseases. Several centers have reported performing procedures in a purposefully designed fluoroless electrophysiology catheterization laboratory (EP Lab) without fixed digital subtraction angiography equipment. In view of the lack of relevant standardized configurations and operating procedures, this expert task force has written this consensus statement in combination with relevant research and experience from China and abroad, with the aim of providing guidance for hospitals (institutions) and physicians intending to build a fluoroless cardiac EP Lab, implement relevant technologies, promote the standardized construction of the fluoroless cardiac EP Lab., (© 2023 Wiley Periodicals LLC.)

Background: Catheter ablation (CA) remains challenging due to suboptimal success rates in persistent atrial fibrillation (AF). Existing mapping technologies cannot reliably distinguish sources in this patient population. Recently, the novel electrographic flow (EGF) mapping system was developed using a modified Horn-Schunk optical flow algorithm to detect and quantify patterns of electrical wavefront propagation in the atria., Objectives: To test the hypothesis that targeted source ablation based on EGF mapping is superior to empiric AF ablation., Methods: We included all consecutive patients undergoing EGF guided ablation for persistent AF. All patients underwent pulmonary vein isolation (PVI) and were treated with the same EAM system (CARTO). The outcome of PVI+EGF guided CA was compared with data of PVI-only procedures (PVI-only group) and PVI plus additional empiric adjunctive linear and substrate ablations (PVI+LINES group). 12-months outcome as freedom from AF and atrial tachycardia/flutter (AT/AFL), procedural safety and efficiency characterized by procedure duration, fluoroscopy use, radiofrequency applications and duration, were analyzed. Both intention-to-treat and per protocol analysis were conducted., Results: A total number of 70 patients (39 in PVI+EGF, 16 in PVI-only and 15 patients in PVI+LINES group) were enrolled. Intention-to-treat analysis showed fewer AF recurrences in PVI+EGF as compared with the PVI-only or PVI+LINES groups at 12 months (25.6% vs. 62.5% vs. 53.3%, p = .02). There were no differences in AT/AFL recurrence (17.9% vs. 37.5% vs. 20.0%, p = .37). Procedure times were longer in PVI+EGF group (p < .01), and there were no differences in fluoroscopy use (p = .67)., Conclusion: Our data suggest that patients treated with EGF-guided CA developed fewer AF recurrences. Although the procedure times are longer, it seems to be safe and offers a more targeted, patient-specific ablation strategy beyond PVI than adjunctive empiric lines and substrate ablation in this complex group of patients., (© 2023 The Authors. Pacing and Clinical Electrophysiology published by Wiley Periodicals LLC.)

Background: Patients with CHD can be exposed to high levels of cumulative ionising radiation. Utilisation of electroanatomic mapping during catheter ablation leads to reduced radiation exposure in the general population but has not been well studied in patients with CHD. This study evaluated the radiation sparing benefit of using three-dimensional mapping in patients with CHD., Methods: Data were retrospectively collected from the Catheter Ablation with Reduction or Elimination of Fluoroscopy multi-institutional registry. Patients with CHD were selected. Those with previous ablations, concurrent diagnostic or interventional catheterisation and unknown arrhythmogenic foci were excluded. The control cohort was matched for operating physician, arrhythmia mechanism, arrhythmia location, weight and age. The procedure time, rate of fluoroscopy use, fluoroscopy time, procedural success, complications, and distribution of procedures per year were compared between the two groups., Results: Fifty-six patients with congenital heart disease and 56 matched patients without CHD were included. The mean total procedure time was significantly higher in patients with CHD (212.6 versus 169.5 minutes, p = 0.003). Their median total fluoroscopy time was 4.4 minutes (compared to 1.8 minutes), and their rate of fluoroscopy use was 23% (compared to 13%). The acute success and minor complication rates were similar and no major complications occurred., Conclusions: With the use of electroanatomic mapping during catheter ablation, fluoroscopy use can be reduced in patients with CHD. The majority of patients with CHD received zero fluoroscopy.

The Senning operation used to be widely performed for an intracardiac repair in a complete transposition of the great arteries. During the long-term follow-up, supraventricular tachycardia (SVT) is often observed because of the complex suture lines. The typical mechanism of a Senning-related SVT is cavo-tricuspid isthmus-dependent atrial flutter. On rare occasions, complex SVTs (e.g., biatrial tachycardia (BiAT)) whose diagnosis and treatment are challenging, may occur. We report a rare case of a BiAT following a Senning operation that was successfully ablated from the superior vena cava, and the local activation time histogram module (CARTO3 V7 module [Biosense Webster, Irvine, CA, USA]) was crucial for analyzing the complex circuit.

Background: Catheter ablation is a safe and effective therapy for the treatment of supraventricular tachycardia in children. Current improvements in technology have allowed progressive reduction in radiation exposure associated with the procedure. To assess the impact of three-dimensional mapping, we compared acute procedural results collected from the Catheter Ablation with Reduction or Elimination of Fluoroscopy registry to published results from the Prospective Assessment after Pediatric Cardiac Ablation study., Methods: Inclusion and exclusion criteria from the Prospective Assessment after Pediatric Cardiac Ablation study were used as guidelines to select patient data from the Catheter Ablation with Reduction or Elimination of Fluoroscopy registry to compare acute procedural outcomes between cohorts. Outcomes assessed include procedural and fluoroscopy exposure times, success rates of procedure, and complications., Results: In 786 ablation procedures, targeting 498 accessory pathways and 288 atrioventricular nodal reentrant tachycardia substrates, average procedural time (156.5 versus 206.7 minutes, p < 0.01), and fluoroscopy time (1.2 versus 38.3 minutes, p < 0.01) were significantly shorter in the study group. Success rates for the various substrates were similar except for manifest accessory pathways which had a significantly higher success rate in the study group (96.4% versus 93.0%, p < 0.01). Major complication rates were significantly lower in the study group (0.3% versus 1.6%, p < 0.01)., Conclusions: In a large, multicentre study, three-dimensional systems show favourable improvements in clinical outcomes in children undergoing catheter ablation of supraventricular tachycardia compared to the traditional fluoroscopic approach. Further improvements are anticipated as technology advances.

Background: Conduction channels have been demonstrated within the postinfarct scar and seem to be co-located with the isthmus of ventricular tachycardia (VT). Mapping the local scar potentials (SPs) that define the conduction channels is often hindered by large far-field electrograms generated by healthy myocardium., Objective: The purpose of this study was to map conduction channel using ripple mapping to categorize SPs temporally and anatomically. We tested the hypothesis that ablation of early SPs would eliminate the latest SPs without direct ablation., Methods: Ripple maps of postinfarct scar were collected using the PentaRay (Biosense Webster) during normal rhythm. Maps were reviewed in reverse, and clusters of SPs were color-coded on the geometry, by timing, into early, intermediate, late, and terminal. Ablation was delivered sequentially from clusters of early SPs, checking for loss of terminal SPs as the endpoint., Results: The protocol was performed in 11 patients. Mean mapping time was 65 ± 23 minutes, and a mean 3050 ± 1839 points was collected. SP timing ranged from 98.1 ± 60.5 ms to 214.8 ± 89.8 ms post QRS peak. Earliest SPs were present at the border, occupying 16.4% of scar, whereas latest SPs occupied 4.8% at the opposing border or core. Analysis took 15 ± 10 minutes to locate channels and identify ablation targets. It was possible to eliminate latest SPs in all patients without direct ablation (mean ablation time 16.3 ± 11.1 minutes). No VT recurrence was recorded (mean follow-up 10.1 ± 7.4 months)., Conclusion: Conduction channels can be located using ripple mapping to analyze SPs. Ablation at channel entrances can eliminate the latest SPs and is associated with good medium-term results., (Copyright © 2021 Heart Rhythm Society. Published by Elsevier Inc. All rights reserved.)

A substantial number of pregnant women at some point experience cardiac arrhythmia, which is mostly treated by antiarrhythmic medication. In some instances, arrhythmias can be drug-resistant and pose a relevant risk to both mother and unborn child as they can result in hemodynamic compromise. In recent years, invasive electrophysiology procedures have been carried out with ever reducing exposure to ionising radiation, and multiple techniques have been established to achieve ZERO exposure. Of course, these techniques should all be applied when contemplating an invasive mapping and ablation procedure during pregnancy. The role of the cardio-obstetrics team in planning and performing such procedures is paramount. Careful assessment of the pregnant mother and her unborn child is mandatory. Only with good preparation is a complete understanding of both cardiac anatomy and physiology achievable, which is a pre-requisite of a successful ablation outcome. Various aspects of the ablation procedure itself are discussed and evaluated from the perspective of all team members involved, including the obstetrician, the anaesthetist and the electrophysiologist. This review aims to inform the reader about the techniques available and reports on the published outcomes for ablations during pregnancy in the last decade.

Technological developments in percutaneous catheter ablation for the treatment of cardiac arrhythmias have progressed from direct current shock ablation over the introduction of radiofrequency ablation to routine clinical procedures. Invasive electrophysiology is characterized by continuous technical innovation and an accompanying increasing understanding of underlying electrophysiologic mechanisms. A number of technical developments were promising, e.g., laser ablation, multipolar biphasic ablation, cryoballoon ablation, contact force, high density three-dimensional (3D) mapping, and the concept of rotors for atrial fibrillation ablation. Despite intense progress, one of the main challenges of catheter ablation is still the creation of tissue-specific chronic transmural lesions and avoidance of collateral damage. The purpose of this review is to present a status quo of catheter ablation of supraventricular tachycardia, atrial fibrillation, and ventricular tachycardia and to discuss future technical innovations and strategies. In the presence of the intense dynamic developments, this review can not consider all new approaches but will rather highlight some of the most promising innovations. Topics of discussion include the use of nonfluoroscopic catheter navigation, the introduction of new ablation tools, the development of alternative energy sources, the integration of new imaging modalities, and the establishment of novel ablation strategies.

Background: Atrioventricular node (AVN) ablation combined with His bundle pacing is an effective strategy for permanent atrial fibrillation (AF) with rapid ventricular rate refractory to pharmacological therapy. We aimed to access the feasibility and efficiency of His bundle pacing and AVN ablation guided by three-dimensional (3-D) mapping system throughout the procedure., Methods: Eighteen patients with permanent AF with refractory rate and symptoms were referred for His bundle pacing and AVN ablation guided by 3-D mapping (CARTO3). Electroanatomic 3-D mapping of the right atrium and right ventricle was performed by the ablation catheter with CARTO 3 system, followed by the visualization of the leads for implantation and AVN ablation., Results: Implantation of His bundle and ventricular leads and AVN ablation were achieved successfully with the help of 3-D mapping in 17 patients. Selective His bundle pacing was achieved in five patients (29.4%), and the other (70.6%) were nonselective His bundle pacing. The mean procedure duration was 99.4 ± 16.4 minutes. The mean fluoroscopy time was 7.0 ± 2.6 minutes. The time spent on His lead implantation was 6.1 ± 3.2 minutes. One patient experienced AVN ablation from left side under aortic valves due to no effect of ablation in right atrium., Conclusion: His bundle pacing and AVN ablation guided by throughout real-time 3-D mapping system are of high-efficiency and feasibility., (© 2020 Wiley Periodicals LLC.)

We herein report a 79-year-old man with recurrent atrial flutter (AFL) following catheter ablation for pulmonary vein (PV) isolation and block line of the cavotricuspid isthmus. An electrophysiological study and three-dimensional mapping results revealed left atrium (LA)-PV macroreentrant flutter caused by a conduction gap, possibly correlated to prior application, which mimicked cavotricuspid isthmus-dependent AFL. This LA-PV flutter was terminated after applying radiofrequency to the gap at the antrum near the bottom left inferior PV in the posterior LA wall. During follow-up, the patient did not present with atrial tachyarrhythmias; antiarrhythmic drugs were therefore not administered.

Introduction: Catheter ablation of left posterior fascicular ventricular tachycardia in the pediatric population remains challenging, and most studies about this topic have been conducted on adult patients. This study aimed to assess the clinical presentation features and outcomes of catheter ablations performed using limited fluoroscopy with three-dimensional electroanatomic mapping system guidance in a pediatric left posterior fascicular ventricular tachycardia patient group., Methods: A total of 20 consecutive patients undergoing left posterior fascicular ventricular tachycardia ablation at a single tertiary centre were enrolled. All children with left posterior fascicular ventricular tachycardia underwent electrophysiological studies using the EnSite NavX system guidance. Ablations were performed during the sinus rhythm based on the Purkinje potentials in all patients., Results: The mean patient age was 12.7 years (range 2-16), and the mean patient weight was 51 kg (range 11-84). The mean procedure and median fluoroscopy times were 143.1 minutes and 3.4 minutes, respectively. No fluoroscopy was used in three patients. Acute success was achieved in 19 patients (95%). During a mean follow-up of 38.6 ± 19.35 months, left posterior fascicular ventricular tachycardia recurred in four patients (20%). Repeat ablations were performed successfully in those patients who developed recurrences. No complications were seen., Conclusions: Catheter ablation of left posterior fascicular ventricular tachycardia in children can be performed safely and effectively with low fluoroscopy exposure using a three-dimensional electroanatomic mapping system.

The recent development of high-density high-spatial resolution three-dimensional mapping has provided detailed information for understanding complicated atrial activation patterns at a level not previously possible. Using this technology, we report a case with recurrent common atrial flutter, demonstrating the presence of a bridging epicardial fiber that traveled across the previous cavotricuspid isthmus ablation lesion with apparent epicardial-endocardial breakthrough (EEB) sites located on both sides of the ablation line. The entrainment study indicated that the EEB site, located adjacent to the coronary sinus ostium, was part of the recurrent circuit and a focal ablation targeting that site terminated the tachycardia., (© 2018 Wiley Periodicals, Inc.)

Background: Catheter ablation of right-sided accessory pathways (APs) has lower success and higher recurrence rates compared to left-sided substrates. Irrigated-tip catheter (ITC) ablation might offer an advantage in this setting but data about its use in patients below 18 years are scarce. The aim of this study was to compare an ITC approach to conventional catheter ablation., Methods: A retrospective analysis of all patients <18 years undergoing radiofrequency ablation (RFA) for right-sided APs from 2004 to 2014 at our institution was performed. Patients either underwent an ITC approach in combination with 3-D mapping (Group 1; n  =  53) or a conventional non-ITC approach (Group 2; n  =  52). Study endpoints were acute procedural success, safety, and recurrence rate. A total of 105 mostly adolescent patients (56.2% male; median age 14 years) with 107 right-sided APs were included., Results: The prevailing anatomic AP locations were right posteroseptal (44.9%), right anterior/anterolateral (24.3%), and right lateral (13.1%). Acute success (94.3% vs 94.2%) did not differ between the groups. One major complication (pericardial effusion) occurred in the non-ITC group. Overall, freedom from AP recurrence was 94% at 4 years in the ITC group, and 81% at 4 years in the non-ITC group (P  =  0.04)., Conclusions: The use of ITCs in combination with 3-D mapping system for ablation of right-sided APs in adolescents has a high acute success rate, is safe, and associated with a significantly reduced recurrence rate compared to a non-ITC/conventional approach. It might be considered as alternative approach in this age group., (© 2017 Wiley Periodicals, Inc.)

Objective: To explore the advantage of radiofrequency catheter ablation under the three-dimensional mapping in the treatment of atrioventricular nodal reentrant tachycardia (AVNRT) in reducing the X-ray exposure dose of interventional doctors. Methods: 79 patients with AVNRT, in the first hospital of Shanxi Medical University from January 2015 to June 2016, performed to do radiofrequency catheter ablation treatment were selected, and according to the random number method were divided into two-dimensional mapping group and three-dimensional mapping group. The two-dimensional mapping group was mapped the ablation target at the X-ray, while the ablation target was mapped by CARTO 3 system in the three-dimensional mapping group. Compare the X-ray fluoroscopy time, success rate, complications rate and doctor's X-ray exposure dose between the two groups. Results: Compared with the two-dimensional mapping group, acute success rate and complication rate of the three dimensional mapping group were not statistically significant ( P >0.05) , while the X-ray fluoroscopy time and the X-ray dose of the three-dimensional mapping group decreased significantly, the difference was statistically significant ( P <0.05) . Conclusion: Three-dimensional mapping can significantly reduce the X-ray irradiation time and interventional doctor's X-ray exposure dose in radiofrequency catheter ablation of AVNRT patients and the potential hazards of ionizing radiation on the human body.

When performing epicardial ablation of ventricular tachycardia (VT), caution must be taken not to damage the coronary arteries. We report a case in which a new, nonfluoroscopic technique for incorporating an accurate, real-time reconstruction of the main coronary vessels into a three-dimensional electroanatomic map was used for epicardial VT ablation., (© 2016 Wiley Periodicals, Inc.)

At present, three-dimensional mapping is often used during cardiac ablations with an explicit goal of decreasing radiation exposure; three-dimensional mapping was introduced in our institution in 2007, but not specifically to decrease fluoroscopy time. We document fluoroscopy use and catheterisation times in this setting. Data were obtained retrospectively from patients who underwent ablation for atrioventricular nodal re-entrant tachycardia from January, 2004 to December, 2011. A total of 93 patients were included in the study. Among them, 18 patients who underwent radiofrequency ablation without three-dimensional mapping were included in Group 1, 13 patients who underwent cryoablation without three-dimensional mapping were included in Group 2, and 62 patients who underwent cryoablation with three-dimensional mapping were included in Group 3. Mean fluoroscopy times differed significantly (34.3, 23.4, and 20.3 minutes, p<0.001) when all the groups were compared. Group 3 had a shorter average fluoroscopy time that did not reach significance when compared directly with Group 2 (p=0.29). An unadjusted linear regression model showed a progressive decrease in fluoroscopy time (p=0.002). Mean total catheterisation times differed significantly (180, 211, and 210 minutes, p=0.02) and were related to increased ablation times inherent to cryoablation techniques. Acute success was achieved in 89, 100, and 97% of patients (p=0.25), and chronic success was achieved in 80, 92, and 93% of patients (p=0.38). Complication rates were similar (17, 23, and 7%, p=0.14). In conclusion, three-dimensional mapping systems decrease fluoroscopy times even without an explicit goal of zero fluoroscopy. Efficacy and safety of the procedure have not changed.

Background: Local abnormal ventricular activities (LAVA) in patients with scar-related ventricular tachycardia (VT) may appear at any time during or after the far-field electrogram. Although they may be separated from the far-field signal by an isoelectric line and extend beyond the end of surface QRS, they may also appear fused or buried within the QRS., Objective: The purpose of this study was to characterize LAVA in postinfarction VT patients with respect to their anatomic locations., Methods: Thirty-one patients with postinfarction VT underwent mapping/ablation during sinus rhythm with a three-dimensional electroanatomic mapping system. From a total of 18,270 electrograms reviewed in all study subjects, 1104 LAVA (endocardium 839, epicardium 265) were identified and analyzed., Results: The interval from onset of QRS complex to ventricular electrogram (EGM onset) on the endocardium was significantly shorter than the epicardium (P < .001). EGM onset was shortest in the septal endocardium and longest in the inferior and lateral epicardium. There was a significant positive correlation between EGM onset and LAVA lateness as estimated by the interval from surface QRS onset to LAVA (r = 0.52, P < .001). LAVA were more frequently detected after the QRS complex in the epicardium (241/265 [91%]) than in the endocardium (551/839 [66%], P < .001). Only 43% of endocardial septal LAVA were detected after the QRS complex., Conclusion: Lateness of LAVA is affected to a large extent by their locations. The chance of detecting late LAVA increases when electrogram onset is later. Substrate-based approach targeting delayed signals relative to the QRS complex may miss critical the arrhythmogenic substrate, particularly in the septum and other early-to-activate regions., (© 2013 Heart Rhythm Society. All rights reserved.)

Background: Cardiac pacing from right ventricular (RV) sites may cause electromechanical ventricular dyssynchrony. Invasive and noninvasive mapping studies showed left ventricular (LV) activation sequence in adults. Aim of this study was to seek out the LV endocardial activation (LVEA) in pediatric patients who underwent RV pacing. Methods: Single‐center, prospective study conducted on pediatric patients who underwent left sided catheter ablation of accessory pathways with the Carto Univu mapping system. After successful ablation procedures, LVEA was recorded by the ablation catheter during sinus rhythm (SR) and during para‐hisian (PHP), midseptum (MSP), and apical (RVAP) pacing. Results: Seventeen patients, 13 males, aged 12 (10–15) years, registered LV activation maps and times (LVAT). SR showed significantly shorter LVAT than during pacing. LVAT of PHP was shorter than MSP, while there were not significant differences among PHP and MSP versus RVAP. In SR initial LV endocardial activation occurred in two midseptum sites, inferior‐posterior and superior‐anterior. During PHP, initial activation occurred at parahisian basal septum, rapidly followed by midseptum as in SR. During MSP and RVAP initial activation occurred at midseptum and apex, respectively. From all initial sites, the excitation spreads toward the base of the lateral LV free wall. A mild linear correlation was found between QRS duration and LVAT for MSP and for PHP. Conclusions: In pediatric patients LVEA maps during RV pacing showed that the shortest LVAT was obtained with PHP. The LV activation pattern seemed similar in sinus rhythm, PHP and MSP, from midseptum to LV lateral base. [ABSTRACT FROM AUTHOR]

Abstract Background A three‐dimensional (3D) mapping system is essential to reduce radiation exposure during catheter ablation. When using the CARTO 3D mapping system, only the catheter with magnetic sensor can visualize its location. However, once target chamber matrix is created using the catheter, even the catheters without magnetic sensors (CWMS) can enable visualization. We aimed to investigate the feasibility and safety of placing a CWMS in the coronary sinus (CS) without fluoroscopic guidance. Methods The study group comprised 88 consecutive patients who underwent catheter ablation. CWMS placement was performed without fluoroscopic guidance in 47 patients and with fluoroscopic guidance in 41 patients. Placement without fluoroscopic guidance was performed after creating a visualization matrix of the CS, right atrium, and superior vena cava using a catheter with a magnetic sensor. Feasibility and safety were compared between the two groups. Results Successful catheter placement was achieved in all patients without fluoroscopic guidance, with no inter‐group difference in the median procedure time: with guidance, 120.0 [96.0–135.0] min, and without guidance, 110.0 [97.5–125.0] min; p = .22. However, radiation exposure was significantly shorter, and the effective dose was lower without fluoroscopic guidance (0 [0–17.5] s and 0 [0–0.004] mSv, respectively) than with fluoroscopic guidance (420.0 [270.0–644.0] s and 0.73 mSv [0.36–1.26], respectively); both p

Ectopic potentials in the SVC can act not only as a trigger but also as a driver of AF. These potentials may be refractory to conventional pulmonary vein isolation for AF. In the present case, the atrium resumed a sinus rhythm spontaneously on the completion of SVC isolation and AF could no longer be induced. However, there was residual fibrillatory activity in the SVC. These findings suggest that residual activity in the SVC worked as a driver of AF. SVC reconnection is commonly reported, with a prevalence of 70%. Thus, we decided to eliminate residual fibrillatory activity in the SVC to prevent recurrence of AF after the third catheter ablation session. In the presence of a fibrillatory pattern, conventional activation mapping techniques cannot map residual SVC activity; however, ICL mapping using the CARTO system can identify the target site of ablation in the isolated SVC. [ABSTRACT FROM AUTHOR]

Background: A three‐dimensional (3D) mapping system is essential to reduce radiation exposure during catheter ablation. When using the CARTO 3D mapping system, only the catheter with magnetic sensor can visualize its location. However, once target chamber matrix is created using the catheter, even the catheters without magnetic sensors (CWMS) can enable visualization. We aimed to investigate the feasibility and safety of placing a CWMS in the coronary sinus (CS) without fluoroscopic guidance. Methods: The study group comprised 88 consecutive patients who underwent catheter ablation. CWMS placement was performed without fluoroscopic guidance in 47 patients and with fluoroscopic guidance in 41 patients. Placement without fluoroscopic guidance was performed after creating a visualization matrix of the CS, right atrium, and superior vena cava using a catheter with a magnetic sensor. Feasibility and safety were compared between the two groups. Results: Successful catheter placement was achieved in all patients without fluoroscopic guidance, with no inter‐group difference in the median procedure time: with guidance, 120.0 [96.0–135.0] min, and without guidance, 110.0 [97.5–125.0] min; p =.22. However, radiation exposure was significantly shorter, and the effective dose was lower without fluoroscopic guidance (0 [0–17.5] s and 0 [0–0.004] mSv, respectively) than with fluoroscopic guidance (420.0 [270.0–644.0] s and 0.73 mSv [0.36–1.26], respectively); both p <.001. Conclusions: CWMS placement without fluoroscopic guidance is feasible, safe to perform, and does not involve complications. Our technique provides an option to decrease radiation exposure during catheter ablation and electrophysiological testing. [ABSTRACT FROM AUTHOR]

A three-dimensional (3D) mapping system is safe and effective for catheter ablation of incisional atrial tachycardia (IAT). Prolongation of the PR interval is occasionally observed after this procedure. Although a first-degree atrioventricular block is typically benign, an excessively prolonged PR interval can indicate a worse prognosis. Currently, a method to predict the PR interval after ablation therapy for IAT is lacking. We report the case of a 70-year-old woman with paroxysmal atrial tachycardia, in which our maneuver using a 3D mapping system and the electrophysiological findings enabled us to preoperatively predict the post-ablation PR interval. We believe that this method is useful for determining treatment strategies for IAT. Three-dimensional (3D) mapping systems can clearly visualize macro-reentrant circuits and enable the creation of precise ablation lines. When creating ablation lines for incisional atrial tachycardia, attention should be paid to the prolongation of the PR interval, because an excessively prolonged PR interval may indicate a worse prognosis. Herein, we have presented a method for predicting the post-ablation PR interval using a 3D mapping system and electrophysiological findings. [ABSTRACT FROM AUTHOR]

Objectives: To evaluate the feasibility, safety, and clinical efficacy of non-fluoroscopic radiofrequency catheter ablation of atrial fibrillation (AF) in comparison to traditional fluoroscopy-guided ablation in a local Canadian community cohort. Methods: We retrospectively studied consecutive patients with paroxysmal and persistent AF undergoing pulmonary vein isolation (PVI) guided by intracardiac echocardiography (ICE) and Carto system (CartoSound module). ICE-guided PVI without fluoroscopy (Zero-fluoro group) was performed in 116 patients, and conventional fluoroscopy-guided PVI (Traditional group) was performed in 131 patients. Results: Two hundred and forty-seven patients with AF (60.7% male; mean age: 62.2 ± 10.6 years; paroxysmal AF =63.1%) who underwent PVI were studied. Mean procedure times were similar between both groups (136.8±33.4 minutes in the zero-fluoro group vs. 144.3±44.9 minutes in the traditional group; p=0.2). Acute PVI was achieved in all patients. Survival from early AF recurrence was 85% and 81% in the zero-fluoro and traditional groups, respectively (p = 0.06). Survival from late AF recurrence (12-months) between the zero-fluoro and traditional groups was also similar (p=0.1). Moreover, there were no significant differences between complication rates, including hematoma (p = 0.2) and tamponade (p = 1), between both groups. Conclusions: Zero-fluoroscopy ICE and CartoSound-guided AF ablation may be safe and feasible in patients undergoing PVI compared to conventional fluoroscopy-guided ablation. [ABSTRACT FROM AUTHOR]

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Copyright of Herzschrittmachertherapie und Elektrophysiologie is the property of Springer Nature and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Objective: To evaluate the role of ultrahigh‐density mapping for conduction isthmus (CI) characterization in adult congenital heart disease (ACHD). Background: Catheter ablation remains suboptimal for ACHD with atypical intra‐atrial reentrant tachycardias (IART) that can be challenging to define using existing mapping technology. Methods: An ultrahigh‐density mapping system was selectively employed over a 1‐year period for procedures involving noncavotricuspid isthmus‐dependent‐IART. A global activation histogram (GAH) was assessed for the ability to predict ablation targets. Procedural characteristics were compared to a group of matched controls. Results: Twenty patients (mean age 43 ± 15, 70% male) underwent 20 procedures targeting 34 tachycardias during the study period. Diagnoses included single ventricle (8), tetralogy of Fallot (2), left heart obstruction (3), Ebstein's anomaly (2) atrial septal defect (2), Mustard operation (2), and Rasteilli operation (1). Prior catheter ablation/Maze operation had been performed in 12 (60%). The median time per map was 21 minutes (interquartile range [IQR], 16‐32), representing 14 834 points per map (IQR 9499‐43 191; P < .001 vs controls). Review of GAH maps showed lower trough values were associated with more favorable IART CI characteristics (P ≤ =.001 for all). Acute success was achieved in 19/20 (95%) procedures, with tachycardia termination during the first lesion in eight cases (P = .02 vs controls). There was one recurrence during 0.6 years follow‐up. Conclusions: Ultrahigh‐density mapping supplemented with the GAH tool was effective for CI identification in a cohort of complex ACHD patients. Catheter ablation was more efficient compared to controls, suggesting precise CI characterization using this technology. [ABSTRACT FROM AUTHOR]

The purpose of this study is to examine a normal conduction pathway of the left atrium. During pulmonary vein isolation using a three-dimensional mapping system, we observed the characteristics of the conduction pattern. Subjects consisted of 15 patients with paroxysmal atrial fibrillation (mean age, 62.8 ± 8.4 years). Left atrial activation conduction begins in the interatrial septum, and moves toward the peak of the ridge between the left atrial appendage and left pulmonary vein. In coronary sinus or appendage pacing, conduction was in the opposite direction at the same location. The mean conduction velocity in this area was 2.03 ± 0.43 m/s. Features of decrement conduction were not present. Anatomical position of the appendage differed greatly between patients. A detailed observation using the inner-cavity view of a three-dimensional mapping system also showed that the peak of the ridge reached the center of the roof.

Copyright of Archives of Cardiovascular Diseases is the property of Elsevier B.V. and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The purpose of this study is to examine a normal conduction pathway of the left atrium. During pulmonary vein isolation using a three-dimensional mapping system, we observed the characteristics of the conduction pattern. Subjects consisted of 15 patients with paroxysmal atrial fibrillation (mean age, 62.8 ± 8.4 years). Left atrial activation conduction begins in the interatrial septum, and moves toward the peak of the ridge between the left atrial appendage and left pulmonary vein. In coronary sinus or appendage pacing, conduction was in the opposite direction at the same location. The mean conduction velocity in this area was 2.03 ± 0.43 m/s. Features of decrement conduction were not present. Anatomical position of the appendage differed greatly between patients. A detailed observation using the inner-cavity view of a three-dimensional mapping system also showed that the peak of the ridge reached the center of the roof. [Copyright &y& Elsevier]

Copyright of Revista Española de Cardiología (18855857) is the property of Elsevier B.V. and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

We present the case of a female patient who previously underwent cardiac surgery for traumatic anterior right atrial perforation after a stabbing attack. Four years later the patient presented with right atrial common type flutter and isthmus ablation was performed subsequently. However, three years after isthmus ablation the patient was readmitted with atypical right atrial flutter. Electrophysiological study revealed persistent bidirectional isthmus block. Three-dimensional mapping (NavX, St. Jude Medical, St. Paul, MN, USA) demonstrated an incisional tachycardia with the critical isthmus at the border of the anterior area of scar in a close proximity to the superior tricuspid annulus. After ablation of this isthmus the patient was arrhythmia free after a follow-up of 9 months. This case illustrates that three-dimensional scar mapping may help to identify unusual isthmus sites that may be simultaneously responsible for both typical and atypical atrial flutter. [ABSTRACT FROM AUTHOR]

Background: Newer technologies such as three-dimensional mapping and echocardiography can decrease x-ray exposure during catheter ablation. Many right-sided tachycardias can now be ablated without fluoroscopy. Left-sided tachycardias, however, have not yet been ablated using a zero fluoroscopy approach. Objective: This study sought to examine the utility of trans-esophageal echocardiography (TEE) in providing adequate imaging as an alternative to fluoroscopy for transseptal puncture. When combined with NavX guidance (St. Jude Medical, St. Paul, MN, USA), fluoroscopy may not be necessary. Methods: Ten pediatric patients with supraventricular tachycardia (SVT) had accessory pathways mapped to the left side. Right atrial and coronary sinus geometries were created using NavX. Once a left-sided pathway was confirmed, a transseptal puncture was performed. A guide wire was placed in the SVC and confirmed by TEE. A transseptal sheath and dilator were advanced over the wire and positioned with TEE guidance so that the tip of the dilator was tenting the fossa ovalis. A transseptal needle was advanced across the fossa. Left atrial location of the needle tip was confirmed on TEE by saline contrast injection. The sheath and dilator were advanced over the needle with continuous pressure monitoring and TEE. Once the sheath was appropriately positioned, the ablation was completed using NavX guidance. Results: All patients had acutely successful ablations and none required the use of fluoroscopy. Number of cryo lesions ranged from five to 19, with a mean of 9. Mean procedure time was 4.4 hours, with a range of 3.2 hours to 7.2 hours. There were no complications. One patient had recurrence. Conclusions: Three-dimensional mapping combined with TEE shows potential for eliminating fluoroscopy use during catheter ablation. [ABSTRACT FROM AUTHOR]

Two female patients undergoing left atrial radiofrequency catheter ablation developed Tako-tsubo cardiomyopathy. This reversible form of left ventricular dysfunction is known to occur under conditions associated with marked sympathetic nervous activation. Radiofrequency catheter ablation in the left atrium can damage autonomic ganglionated plexi, leading to vagal withdrawal, thus resulting in enhanced sympathetic tone. Tako-tsubo cardiomyopathy has not been previously described following radiofrequency catheter ablation. [ABSTRACT FROM AUTHOR]

Introduction: Precise localization of target sites for radiofrequency catheter ablation (RFCA) of arrhythmias is hampered by the relative inaccuracy of X-ray localization procedures. This study evaluated the efficacy of a three-dimensional (3D) real-time position management system in guiding RECA procedures in patients. Methods and Results: Patients (n = 30, age 59 ± 20 years) referred for ablation of either atrial flutter (n = 10), ventricular tachycardia (n = 15), or accessory pathways (n = 5) were studied. The real-time position management system uses ultrasound ranging techniques to track the position of an ablation catheter relative to two multitransducer reference catheters, positioned in the right atrium or coronary sinus and the right ventricle. Each catheter contains three or four ultrasound transducers. The distance between the transducer(s) Is determined by calculating the time necessary for an ultrasound pulse to reach other transducers, assuming the speed of sound in blood is 1,550 m/sec. The proximal His bundle was marked at the beginning and the end of the procedure as an electrical landmark to verify reproducibility. After identification of target sites, the position of each lesion created with the ablation catheter was marked. Successful ablation was achieved in 94% of the patients. The distance between the location of the proximal His bundle as marked at the beginning and at the end of the procedure was 2.0 ± 1.2 mm (range 1.5 to 3.5). conclusion: The new 3D real-time position management system facilitated RFCA procedures as it allowed accurate and reproducible 3D tracking of the mapping and ablation catheter. [ABSTRACT FROM AUTHOR]