Use Of Electroanatomic Mapping Research Articles

Comparison between cryotherapy and radiofrequency energy sources for parahisian accessory pathway percutaneous ablation.

Catheter ablation of parahisian accessory pathways (PHAP) are challenging due to their proximity to the normal conduction system. Retrospective studies suggest that cryoablation has a better safety profile but a higher recurrence rate when compared to radiofrequency ablation (RFCA). The objective of this study was to compare the results of parahisian AP ablation performed by electrophysiologists with experience in both technologies. Prospective single-center, non-blinded and 1:1 model was used. Patients included had parahisian AP confirmed by an electrophysiological study and referred for radiofrequency or cryotherapy ablation according to current guidelines, under fluoroscopic guidance. No electroanatomic mapping was used. A total of 30 patients (mean age of 25±9.4 years; 90% male) were enrolled between Oct/2018 to Feb/2020. Acute success rate between RFCA and CRYO were similar (93% vs. 87%, p = 0.54). A nonsignificant reduction in short-term recurrence rate for RFCA (14% vs. 30%, p = 0.3) and mechanical trauma (6% vs. 20%; p = 0.28) was observed. Long-term recurrence rate and event-free survival time were similar in both groups after 1-year follow-up (p = 0.286). No persistent complete AV block or conduction disturbance was also observed. Considering the limitation of a small sample size and the lack of use of electroanatomic mapping for RFCA, the efficacy and safety profile of parahisian AP ablation with RFCA was not different from CRYO, when performed by experienced electrophysiologists. No cases of permanent complete AV block were reported with either energy modalities.

Interventional electrophysiology in bulgaria in 2022: data from the electronic registry BG-EPHY

This study presents data from the national electronic registry BG-EPHY on electrophysiologic (EP) cardiac ablations in 2022. Material and methods: This is a retrospective study of a full one-year sample of the BG-EPHY registry. Sex and age distribution of the patients, number of ablations, use of electroanatomic mapping (EAM), irrigated and cryoablations, distribution of different types of arrhythmias, acute procedural success and complications are presented. Results: In 2022 seven EP centers performed 1369 ablations in 872 men (63.7%) and 497 women (57% increase compared to previous year), incl. 15 ablations in pediatric patients (1.1%). EAM was used in 746 procedures (54.5%), irrigated-tip catheter – in 814 (59.5%), cryoballoon catheter – in 130 (9.5%), and intracardiac echocardiography – in 33 (2.4%). The most frequently performed ablation was pulmonary vein isolation (40.2%), followed by ablation for AV nodal reentrant tachycardia (18.6%) and typical atrial fl utter (16.6%). The acute success was over 98%, while intraprocedural complications were less than 2%. Conclusion: The national registry of electrophysiology collects systematically and continuously basic data on all ablations of cardiac arrhythmias performed in the country. In 2022, during a subsiding COVID-19 pandemic and with the inclusion of new centers the number of ablations increased compared to 2021. Distribution of EP procedure types was similar to previous years. Acute success was very high, while intraprocedural complications were rare.

Impact of 3-dimensional electroanatomic mapping systems on fluoroscopy reduction in catheter ablation of supraventricular tachycardia - then and now

Abstract Funding Acknowledgements Type of funding sources: None. Background Catheter ablation is an effective first-line treatment for symptomatic and recurrent supraventricular tachycardia (SVT). The advent of 3D electroanatomic mapping (EAM) has led to a reduction in fluoroscopy use and consequently lower radiation exposure for patients and staff during SVT ablation. Purpose The aims of this study are to demonstrate if the use of EAM during SVT ablation reduces fluoroscopy time (FT), and determine if further reductions in FT are observed longitudinally. We hypothesise that over time, with continued use and wider adoption of EAM, greater operator experience, and technological advancements in EAM, there will be further reductions in radiation exposure as estimated by FT. Methods All cases of atrioventricular nodal re-entry tachycardia (AVNRT), atrioventricular re-entry tachycardia (AVRT), and/or atrial tachycardia (AT) ablation between May 2011 to May 2022 at a tertiary centre were prospectively recruited. FT between the groups with and without EAM were compared. Within the EAM subset, the trend of FT across the years was also analysed. Results Over this 11-year period, there were 1758 cases of SVT ablation (565 without EAM; 1193 with EAM). Between the two groups, there were no significant differences (p > 0.05) in age, sex, history of structural heart disease and/or ischaemic heart disease, stereotaxis use, and diagnosis (AVNRT, AVRT, AT). Cases using EAM were more likely to have >1 SVT ablated during the procedure (0.04) and require intracardiac echocardiography (ICE) (p < 0.001). The use of EAM was associated with mean reductions in FT and dose area product (DAP) by 19.6 minutes and 18 581 mGy*cm2 respectively (both p < 0.001). EAM was also associated with a longer procedure time (mean +8.8 minutes, p < 0.001). There was no difference in radiofrequency application time between the two groups (p = 0.143). After controlling for potential confounding factors including age, sex, use of stereotaxis, use of ICE, type and number of SVT, history of prior ablation, and structural heart disease and/or ischaemic heart disease, we found over time (2011-2022), further reduction in FT was observed, with a mean reduction of 0.9 minutes year on year (p < 0.001). EAM was gradually adopted through the years with the number of cases per year plateauing after 2017. Between 2011-2017, there was a significant reduction in FT (mean of -1.1 minute year on year, p = 0.020), which was not observed from 2017 onwards (p = 0.088). The greatest reduction in FT was observed after the first year of adoption, with a mean reduction of 6.9 minutes between 2012-2013. Conclusion This demonstrates that use of EAM in SVT ablation reduces FT and fluoroscopy DAP. There was no incremental benefit observed after 6 years of EAM adoption likely related to operator experience. While there is increased interest in zero fluoroscopy SVT ablation, complementary use of fluoroscopy may still be necessary in select complex cases.

Left bundle branch area pacing guided by electroanatomical mapping in patients with structural heart disease and advanced conduction abnormalities

Abstract Funding Acknowledgements Type of funding sources: None. Background Left bundle branch area pacing (LBBAP) can be technically challenging and fluoroscopy-intense, particularly in patients with structural heart disease (SHD) and advanced conduction abnormalities. Three-dimensional electroanatomical mapping (EAM) facilitates high-resolution, real-time, and non-fluoroscopic lead navigation, electrogram and pace mapping. Purpose The purpose of the study was to prospectively evaluate the feasibility, safety, and outcomes of routine EAM-guided LBBAP in patients with SHD and advanced conduction abnormalities. Methods Consecutive patients with SHD and advanced conduction abnormalities (defined as second or third-degree atrioventricular (AV) block and/or complete bundle branch block) who underwent an attempt at EAM-guided LBBAP were included. EAM-guided lead implantation was performed in all patients following a standardized protocol irrespective of the pacing indication and type of conduction disturbance. The feasibility, safety, procedural and mid-term outcomes were evaluated. Electrical, echocardiographic, and clinical parameters were assessed at implantation and last follow-up. Results Thirty-two patients (68±18 years; 19% female) were included. The indication for pacing was cardiac resynchronization therapy in 50%, AV block in 44%, and pace-and-ablate in 6% of patients; 24 patients (75%) had an intrinsic QRS >150 ms, 17 (53%) had LBBB. Primary EAM-guided LBBAP was successful in 29 patients (91%). Procedural duration was 95 (70-110) min, total fluoroscopy time 0.93 (0.40-1.73) min, and total fluoroscopy dose 35.4 (20.5-77.2) cGycm2 (Figure 1A). The paced QRS duration during LBBAP was significantly shorter than the baseline intrinsic QRS duration (121.9±10.7 vs. 159.2±34.4 ms; p<0.001) (Figure 1B) and remained stable (120.3±11.1 ms; p=0.370) during a mean follow-up of 7.0±5.9 (median 5.4 [IQR 2.1-12.6]) months. LBBAP capture threshold was 0.57±0.23V/0.4ms at implantation and remained low during follow-up (0.58±0.18V/0.5±0.2ms; p=0.877). There was no increase in LBBAP capture threshold >1.0V/0.4 ms during follow-up. Overall LVEF improved significantly from 44.2±14.3% at baseline to 49.4±13.1% at last follow-up (p=0.009), NYHA functional class from 2.4±0.6 to 1.8±0.6 (p=0.002), respectively (Figure 1C+D). No complications occurred that required intervention. Conclusion Routine near-zero fluoroscopy EAM-guided LBBAP can safely be performed in patients with SHD and advanced conduction abnormalities with high success rates and favourable mid-term outcomes. Further studies are needed to investigate whether the use of EAM improves overall outcome of conduction system pacing, and to identify specific patient populations who benefit the most from EAM-guided lead implantation.

Fluoroless vs. conventional catheter ablation of supraventricular tachycardia - retrospective single-centre analysis

Abstract Funding Acknowledgements Type of funding sources: None. Introduction Radiofrequency (RF) catheter ablation of supraventricular tachycardia (SVT) is a gold-standard therapy that offers excellent results. Conventional approach using fluoroscopy has been challenged by the increasing use of electroanatomical mapping (EAM) systems and intracardiac echosonography (ICE) which eliminate the radiation hazard for the patient and medical personnel. They offer good results without compromising safety or efficacy but also require further research. (1, 2) Their widespread use is limited by their cost but is steadily increasing. Purpose To compare the acute outcomes of fluoroless SVT ablation to those of conventional procedures since widespread introduction of this novel technology in our institution. Methods Data about patients with AV-node reentry tachycardia (AVNRT), atrio-ventricular reentry tachycardia (AVRT), atrial tachycardia and atrial flutter (AFL) who were treated with ablation were retrospectively collected using hospital medical records. 80 consecutive patients who underwent fluoroless SVT ablation formed the fluoroless (FL) group. Last 80 patients who previously underwent conventional SVT ablation using fluoroscopy served as a control group. Two different EAM systems were used in the FL group (Abbot Ensite and Biosense Webster CARTO). All procedures were performed by 3 different experienced operators. Results The fluoroless and control group were similar regarding age, sex and comorbidities. Approximately half of all patients in both groups suffered from AVNRT. AVRT was more common in the FL group and AFL in the control group (23.4% vs. 10.0% and 20.8% vs. 37.5% respectively). This was responsible for the difference in the use of ICE and need for transseptal puncture between the groups. Detailed group characteristics are shown in Table 1. Procedure duration was similar in both groups (58.0 ± 25.5 min vs. 63.9 ± 25.3 min in FL and control group respectively, p=0.12). Ablation time, calculated as duration of RF energy delivery, tended to be shorter in the FL group (396 ± 44 vs. 575 ± 636 s) but failed to reach the level of statistical significance (p=0.06). Acute success, defined as non-inducibility of arrhythmia or, in case of AFL, cavotricuspid isthmus conduction block, was achieved in 98.8% and 97.5% of cases in FL and control group respectively. There were no cross-overs from FL group to fluoroscopy. In the control group, mean fluoroscopy duration was 9.7 ± 7.5 min and radiation dose 14.6 ± 21.6 mGy. One steam pop occurred in the FL group but the patient suffered no acute or chronic consequences. There were no other complications. Conclusion Technologies for fluoroless SVT ablation have been widely implemented in our institution with very good acute results and safety profile that is non-inferior to conventional approach. By eliminating risks inherent to fluoroscopy they could be beneficial for patients and physicians likewise. Follow-up data are needed to confirm these results.

Electroanatomical mapping-guided left bundle branch area pacing in patients with structural heart disease and advanced conduction abnormalities.

Left bundle branch area pacing (LBBAP) can be technically challenging and fluoroscopy-intense. Three-dimensional electroanatomical mapping (EAM) facilitates non-fluoroscopic lead navigation and electrogram mapping. We sought to prospectively evaluate the feasibility, safety, and outcomes of routine EAM-guided LBBAP in patients with structural heart disease (SHD) and advanced conduction abnormalities. Consecutive patients with SHD and conduction abnormalities who underwent an attempt at EAM-guided LBBAP were included. The feasibility, safety, procedural, and mid-term outcomes were evaluated. Electrical, echocardiographic, and clinical parameters were assessed at implantation and last follow-up. Thirty-two patients (68 ± 18 years; 19% female) were included, of which 75% had intrinsic QRS > 150 ms, 53% left bundle branch block, and 25% right bundle branch block. Primary EAM-guided LBBAP was successful in 29 patients (91%). The procedural duration was 95 (70-110) min, total fluoroscopy time 0.93 (0.40-1.73) min, and total fluoroscopy dose 35.4 (20.5-77.2) cGy cm2. Paced QRS duration (QRSd) was significantly shorter than intrinsic QRSd (121.9 ± 10.7 vs. 159.2 ± 34.4 ms; P < 0.001) and remained stable during the mean follow-up of 7.0 ± 5.9 months. The LBBAP capture threshold was 0.57 ± 0.23 V/0.4 ms at implantation and remained low during follow-up (0.58 ± 0.18 V/0.5 ± 0.2 ms; P = 0.877). Overall left ventricular ejection fraction improved significantly from 44.2 ± 14.3% at baseline to 49.4 ± 13.1% at follow-up (P = 0.009), New York Heart Association class from 2.4 ± 0.6 to 1.8 ± 0.6 (P = 0.002), respectively. No complications occurred that required intervention. Routine near-zero fluoroscopy EAM-guided LBBAP can safely be performed in patients with SHD and advanced conduction abnormalities with high success rates and favourable mid-term outcomes. Further studies are needed to investigate whether the use of EAM improves the overall outcome of conduction system pacing and to identify specific patient populations who benefit the most from EAM-guided lead implantation.

Atrial tissue characterisation using electroanatomic voltage mapping and cardiac magnetic resonance imaging

Abstract Funding Acknowledgements Type of funding sources: Foundation. Main funding source(s): British Heart Foundation Background Atrial voltage mapping and atrial cardiac magnetic resonance imaging are two contemporary methods for quantification of atrial fibrosis. However, the absence of a gold standard for measuring atrial fibrosis has precluded their direct comparison. Nevertheless, understanding the relative performance of voltage mapping and atrial late gadolinium enhancement for identification of atrial cardiomyopathy remains critical to correctly targeting clinical application of these techniques. Purpose To assess the relative performance of electroanatomic voltage mapping and atrial late gadolinium enhancement imaging using three surrogate markers chosen to distinguish pre-procedural utility (progression to recurrent atrial fibrillation following ablation) from potential utility for providing atrial fibrillation mechanistic insights (paroxysmal vs. persistent status of atrial fibrillation and relationship with co-morbidities associated with atrial fibrillation). Methods 123 patients underwent atrial late gadolinium enhancement imaging and electroanatomic voltage mapping prior to atrial fibrillation ablation. Atrial late gadolinium enhancement imaging was assessed with CEMRG software and electroanatomic voltage mapping processed with OpenEP software using previously published thresholds. Low voltage tissue was defined at (1) &amp;lt;0.5mV, (2) &amp;lt;1.17mV, and (3) &amp;lt;1.3mV. Atrial fibrosis using late gadolinium enhancement was defined using four thresholds (1) signal intensity &amp;gt;3.3 standard deviations above the blood pool mean; (2) image intensity ratio (IIR) 1.2x blood pool mean; (3) IIR 1.32x blood pool mean; and (4) IIR 0.97x blood pool mean. Results Patients with persistent atrial fibrillation and those with CHA2DS2VaSc &amp;gt;2 had increased low voltage area for each of the thresholds tested, but there was no increase in atrial late gadolinium enhancement area at any of the imaging thresholds tested. Increased atrial fibrosis using IIR&amp;gt;0.97 was independently associated with recurrence of atrial fibrillation (OR 1.05 (CI 1.01-1.09), p=0.009) in both univariate and multivariate analysis. Low voltage area &amp;lt;1.13mV and low voltage area &amp;lt;1.17mV were associated with increased risk of recurrence (OR 1.02 (CI 1.01-1.04), p=0.01, and OR 1.03 (CI 1.01-1.04), p=0.009) in univariate analysis but neither voltage threshold remained statistically significant in multivariate analysis controlling for clinical variables. Conclusion Increased fibrosis burden measured with atrial magnetic resonance imaging, but not with low voltage area, is independently associated with recurrence of atrial fibrillation following catheter ablation. However, increased low voltage area measured with electroanatomic mapping is associated with persistent atrial fibrillation status and CHADS2VaSc score. These findings support the use of magnetic resonance imaging for pre-procedure assessment and the use of electroanatomic mapping for intraprocedural mechanism-based assessment of atrial cardiomyopathy.

Efficacy and Safety of Zero-Fluoroscopy Approach during Catheter Ablation of Accessory Pathway.

Background: Catheter ablation (CA) is a safe and efficient treatment in patients with an atrioventricular accessory pathway (AP). Electroanatomical mapping (EAM) systems are useful during CA of AP, especially for reducing fluoroscopy. There are limited data about the feasibility of CA procedures performed with the use of the EAM system entirely without fluoroscopy in adults with AP. The aim of the study is to assess the feasibility, efficacy and safety of CA with the use of EAM without fluoroscopy, compared to CA with EAM and fluoroscopy in patients with AP. Methods: The study included 83 consecutive patients (age 38.25 ± 15.8 years), who were subjected to CA for AP. In 40 patients CA was performed with the use of EAM without fluoroscopy (EAM group), and in 43 patients CA was performed with EAM and fluoroscopy (control group). Baseline characteristics, procedure parameters and complications were obtained from the medical records. Data on permanent success rate was obtained after the mean follow-up time of 1 year. Primary outcomes were acute procedural success rate, long term success rate at 1-year follow-up and complications. Secondary outcomes were the procedure time and number of applications. Results: There were no statistically significant differences in baseline characteristics between the groups, except for the AP locations. Right-sided AP was more common in the EAM group, while left-sided AP was more common in the control group (p = 0.007 and p = 0.004, respectively). Acute procedural success was achieved in 38 patients (95.0%) in the EAM group and in 39 patients (90.7%) in the control group (p = 0.449). Long term success rate was achieved in 36 patients (90.0%) in the EAM group and in 36 (83.7%) patients in the control group (p = 0.399). There was one minor complication in the form of RBBB in the EAM group (p = 0.138). The mean procedure time was shorter in the EAM group compared to the control group (93.0 ± 58.3 min vs. 127.6 ± 57.5 min; p = 0.009). Conclusions: CA of both right-sided and left-sided AP completely guided by EAM without the use of fluoroscopy is feasible, safe and effective.

Feasibility of electroanatomic mapping and radiofrequency catheter ablation in Boxer dogs with symptomatic ventricular tachycardia.

BackgroundTreatment for Boxers with ventricular tachycardia (VT) is limited. Electroanatomic mapping (EAM) facilitates identification of arrhythmogenic substrate for radiofrequency catheter ablation (RFCA).ObjectiveDescribe the use of EAM to guide RFCA in Boxers with VT.AnimalsFive client‐owned Boxers with symptomatic VT or persistent VT despite antiarrhythmic medications.MethodsCase series evaluating clinical, EAM, and before and after RFCA Holter data.ResultsSustained VT was inducible in 3 dogs, but required aggressive stimulation protocols. Low‐voltage areas consistent with electroanatomic scar were found in 2 dogs, located at the right ventricular (RV) outflow tract and cranial RV. Two dogs had a focal activation pattern of VT and 1 dog had a reentrant mechanism. After RFCA, all dogs no longer collapsed and had fewer runs of VT, 3 of which had 0 runs of VT. Number of ventricular premature beats increased in 3 dogs and decreased in 2 dogs, 1 of which had nearly complete resolution of all arrhythmias. Procedural complications included ventricular fibrillation (n = 2) with successful defibrillation, bruising or hemorrhage at the vascular access site (n = 4), retroperitoneal hemorrhage (n = 1), aortic and mitral regurgitation (n = 1), onset of frequent supraventricular tachycardia (n = 1), and persistent right pelvic limb lameness (n = 1).Conclusions and Clinical ImportanceElectroanatomic mapping and RFCA are feasible in Boxers with VT. Based on this small cohort, RFCA may help decrease runs of VT and improve clinical signs. The anatomic substrate and electrophysiologic mechanisms are variable and require further study.

Utilising electroanatomic mapping during ablation in patients with CHD to reduce radiation exposure.

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. 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. 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. 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.

Physiologic lead placement with electroanatomic mapping: A case series

His bundle pacing (HBP) and left bundle branch area pacing (LBBAP) have emerged as attractive alternatives to traditional biventricular pacing to achieve cardiac resynchronization therapy. Early reported results have been inconsistent, particularly amongst patients in whom initial placement with traditional approaches has been unsuccessful or those with complex anatomy or congenital abnormalities. In this report, we describe the use of three-dimensional electroanatomic mapping (EAM) in five selected cases. Five patients from multiple clinical sites underwent EAM-guided HBP or LBBAP by highly trained electrophysiologists with significant experience with conduction system pacing. Each patient in this series underwent EAM-guided conduction system pacing due to complex anatomy and/or prior failed lead implantation. EAM-guided lead implantation was successful in all five cases. Capture thresholds were relatively low and patients continued to have evidence of successful lead implantation with minimum 1-month follow-up. The fluoroscopy time varied, likely owing to the variable complexity of the cases. The use of EAM, in combination with traditional intracardiac electrograms with or without fluoroscopy, allows more targeted and precise placement of leads for HBP and LBBAP pacing. Further investigation is needed to determine this strategy's long-term performance and to optimize patient selection.

Ablation in patients with Ebstein Anomaly and Wolff Parkinson White Syndrome

Abstract Funding Acknowledgements Type of funding sources: None. Background - Introduction: Ablation in patients with Ebstein Anomaly (EA) and Wolff Parkinson White syndrome (WPW) is challenging due to the complex anatomy and the presence of multiple accessory pathways (AP). Objectives Report the results of our recent experience of ablation in patients with EA and WPW syndrome. Methods We conducted a retrospective review of the cases of EA and WPW syndrome, which were taken to ablation in our center between 2015 and 2020. Results We found that in the indicated period 30 electrophysiological studies and ablations had been performed in 26 patients, 53.8% were males and the mean age at the time of the study was 20.6 ± 9.1 years, the mean tricuspid septal valve attachment was 44.5 ± 17.7%. Regarding the procedures, 15 were conventional studies (50%) and 15 (50%) were performed with electroanatomical mapping. We used intracardiac echocardiogram (ICE) in 10 cases (33.3%). The acute success rate was 85.7% and in the follow-up 3 patients (10%) presented recurrence. Only one patient presented a major complication, which was a complete AV block. There was a tendency to improve the acute success with the use of electroanatomical mapping in comparation with conventional studies (93.3% vs 66.6%, p = 0.068), and with the use of ICE acute success was significantly improved (100% vs 70%, p = 0.04). Seven patients presented multiple accessory pathways (26.9%). The most frequent location was the right posterolateral with 61.53%, followed by the right posteroseptal with 26.9% and the right lateral with 19.2%. Conclusions The ablation in patients with EA and WPW syndrome constitutes a challenge, we found that the use of electroanatomical mapping and the use of ICE could improve the acute success rate. New studies are needed to demonstrate the usefulness of these techniques to improve the acute success rate and to reduce the recurrence rate. ProceduresProcedures (N = 30)N%Conventional procedures1550.0Electroanatomical mapping1550.0Intracardiac echocardiogram1033.3Acute success2485.7Recurrence310.0Major complication13.3Descriptive table of our experience in ablation of patients with ED and WPW syndrome.Abstract Figure. Location of the accessory pathways

Catheter ablation for atrial arrhythmias in adults with congenital heart disease: recurrence rates and predictors of acute procedural success

Abstract Funding Acknowledgements Type of funding sources: None. Background Heart rhythm disorders are an important cause of morbidity and emergency hospitalisation in patients with adult congenital heart disease (ACHD), and this is due to a combination of surgical scar, residual haemodynamic lesions, and cardiac chamber dilatation. The most effective available treatment is catheter ablation, although this can be extremely challenging owing to abnormal anatomy and problems accessing intra cardiac sites critical to the arrhythmia mechanism. However, outcomes of catheter ablation and analysis of factors which may predict recurrence of arrhythmia remain poorly defined. Purpose To define the cohort of ACHD patients undergoing catheter ablation for atrial arrhythmia in a large tertiary centre, characterise outcomes, and determine factors associated with arrhythmia recurrence. Methods Retrospective study of all catheter ablations for atrial arrhythmias in ACHD patients between April 13, 2016 and December 16, 2019 at our institution. Patients were identified using a field search through a centralised database; and pre-specified clinical and procedural data of interest, and time from ablation to recurrence were determined from the computerised electronic record. Binary logistical regression and cox regression analysis were used to determine potential predictors of acute procedural success and arrhythmia recurrence respectively. Results Among 90 patients (mean age 43 ± 15 years) who underwent catheter ablation for atrial arrhythmia, 39 (43%) were treated for macro-reentrant atrial tachycardia, 19 (21%) for focal atrial tachycardia, 9 (10%) for multifocal atrial tachycardia, 10 (10%) for atrial fibrillation, 7 (8%) for atrioventricular nodal reentrant tachycardia, and 6 (7%) for atrioventricular reentrant tachycardia. 35 (39%) of patients had "severe" complexity ACHD as per the Bethesda classification. 35 (39%) experienced recurrent arrhythmia with a median time to recurrence of 120 days. Age, gender, body mass index, complexity of congenital heart disease, and previous surgical repair were not identified as being significantly associated with recurrence, however univariate cox regression analysis showed a significantly longer time to recurrence in cases utilising electroanatomical mapping and demonstrating non-inducibility of arrhythmia in the lab post ablation (p &amp;lt; 0.001). There was 1 case of post-ablation bradycardia requiring pacemaker implantation, but no other complications. Conclusion Catheter ablation for atrial arrhythmia in ACHD patients is safe and effective, with a majority of patients achieving multiple arrhythmia-free months. Non-inducibility of arrhythmia post procedure and use of electroanatomical mapping are predictors of freedom from recurrence of atrial arrhythmia, suggesting effective characterisation and ablation of the arrhythmia mechanism is more important than the underlying substrate. These findings may aid management decisions for recurrent arrhythmia in ACHD patients.

Clinical predictors of heart block during atrioventricular nodal reentrant tachycardia ablation: A multicenter 18-year experience.

Catheter ablation is considered the first-line treatment of symptomatic atrioventricular nodal reentrant tachycardia (AVNRT). It has been associated with a risk of heart block (HB) requiring a pacemaker. This study aims to determine potential clinical predictors of complete heart block as a result AVNRT ablation. Consecutive patients undergoing catheter ablation for AVNRT from January 2001 to June 2019 at two tertiary hospitals were included. We defined ablation-related HB as the unscheduled implantation of pacemaker within a month of the index procedure. Use of electroanatomic mapping (EAM), operator experience, inpatient status, age, sex, fluoroscopy time, baseline PR interval, and baseline HV interval was included in univariate and multivariate models to predict HB post ablation. In 1708 patients (56.4 ± 17.0 years, 61% females), acute procedural success was 97.1%. The overall incidence of HB was 1.3%. Multivariate analysis showed that age more than 70 (odds ratio [OR] 7.907, p ≤ .001, confidence interval [CI] 2.759-22.666), baseline PR ≥ 190 ms (OR 2.867, p = .026, CI 1.135-7.239) and no use of EAM (OR 0.306, p = .037, CI 0.101-0.032) were independent predictors of HB. Although the incidence of HB post AVNRT ablation is generally low, patients can be further stratified using three simple predictors.

Fluoroscopy time and scattered radiation during electrophysiology procedures: analysis of one-year data of a laboratory providing electrophysiology training

Objectives Patients and medical staff expose to significant radiation during electro-physiological (EP) procedures. There are few data regarding the leading factors of longer fluoroscopy time and higher scattered radiation in a laboratory giving EP training during those interventions. Material and methods The patients’ recordings that underwent EP procedure in a single centre arrhythmia unit from February 2019 to January 2020 were examined. Prospectively collected data regarding procedure duration, fluoroscopy time and total air kerma, demographic characteristics of the patients, type of procedure, success of ablation and the use of electro anatomic mapping were retrospectively evaluated. Predictors of total air kerma were analysed with linear regression analysis. Results Study population consisted of 437 patients with a median age of 47 (39–56); 184 (42.1%) were male. Median fluoroscopy time was 768 (420–1320) seconds and median cumulative air kerma was 369 (191–750) mGy. Fluoroscopy time and cumulative air kerma were significantly lower in diagnostic EP studies compared to other procedures. There was no difference in terms of total air kerma between the procedures other than the diagnostic EP study. In multivariable linear regression analysis; body surface area, fluoroscopy time, not using the electro-anatomical mapping, unsuccessful ablation and atrial flutter ablation were predictors of total air kerma in EP studies performed by trainees. Conclusion Scattered radiation during EP procedures performed by in-training operators is related with some factors. Awareness about those may help to effort reducing the harmful effect of ionising radiation.

From near‐zero to zero fluoroscopy catheter ablation procedures

The use of electroanatomical mapping (EAM) systems can reduce radiation exposure (RX) and it can also completely eliminate the use of RX. Radiation exposure related to conventional radiofrequency ablation procedures can have a stochastic and deterministic effect on health. The main aim of this study was to evaluate the safety and feasibility of an entirely nonfluoroscopic approach to catheter ablation (CA) using EAM CARTO3. In 2011 we started an RX-minimization programme in all procedures using the CARTO system with the deliberate intention to not resort to the aid of RX unless strictly necessary. We divided procedures into two groups (group 1: from 2011 to 2013; group 2: from 2014 to 2017). The only exclusion criteria were the need for transseptal puncture, and nonidiopathic ventricular tachycardia (VT). From a total of 525 procedures, we performed CA entirely without RX in 78.5% of cases. From 2011 to 2013, we performed CA without RX in 38.5% of cases; from 2014 to 2017, we performed 96.2% of cases with zero RX. The use of RX was significantly reduced in group 2 (group 2: 1.4 ± 19.6 seconds vs group 1: 556.92 ± 520.76 seconds; P < .001). These differences were irrespective of arrhythmia treatment. There were no differences between the two groups in acute success, complications, or duration of procedures. CA of supraventricular tachycardia and VT entirely without RX, guided by the CARTO system, is safe, feasible, and effective. After an adequate learning curve, CA can be performed entirely without RX.

Non-fluoroscopic catheter ablation: A randomized trial

BackgroundCatheter ablation provides curative treatment for tachyarrhythmias. Fluoroscopy, the method used for this, presents several risks. The electroanatomical mapping (MEA) presents a three-dimensional image without using X-rays, and may be adjunct to fluoroscopy. ObjectivesWe evaluated the possibility of performing catheter ablation with the exclusive use of electroanatomical mapping (MEA), dispensing with fluoroscopy. We compared the total time of procedure and success rates against the technique using fluoroscopy (RX) with emission of X-rays. MethodsRandomized, unicentric, uni-blind study of patients referred for tachyarrhythmia ablation. ResultsTwelve patients were randomized to the XR group and 11 to the EAM group. The mean age was 48.5 (±12.6) vs 46.3 (±16.6) (P = ns). Success occurred in 11 patients (91.7%) in the RX group and 9 (81.8%) in the MEA group (P = 0.46). The procedure time in minutes was higher in the MEA group than in the RX group (79-47-125min vs 49-30-100min; P = 0.006). The mean fluoroscopy time was 11 ± 9 min versus zero (RX vs MEA: P < 0.001). The mean radiofrequency applications were lower in the RX group against the MEA group (6 ± 3.5 × 13.2 ± 18.2 p < 0.019). There were no complications. ConclusionMEA opened new therapeutic possibilities for patients with arrhythmias, reducing the risk of radiation. In this study, it was possible to demonstrate that it is feasible to perform ablation only with the use of MEA, with similar success with fluoroscopy, at the expense of a longer procedure time.

Usefulness of Electroanatomical Mapping with Contact Force Monitoring for Accessory Pathways Ablation in Pediatric Population.

The current approach for catheter ablation (CA) of accessory pathways (AP) includes the use of standard catheters under fluoroscopic visualization. We hypothesize that use of contact force (CF) irrigated tip catheters might increase procedural safety in pediatric patients compared to standard irrigated tip catheters, by decreasing the number of radiofrequency (RF) pulses required to obtain AP elimination. Seventy-one pediatric patients (13.7 ± 2.5years, 45 male) with ventricular pre-excitation were enrolled in the study. CA was performed with a standard irrigated tip catheter up to June 2013 in 41 patients (Group S) and with a CF sensing irrigated tip catheter later on in 30 patients (Group CF). In the Group CF, RF was applied with a minimal CF of 5g; CF > 35g was avoided. Group CF procedures required less fluoroscopy (6.8 ± 4.8min), compared to Group S (12.2 ± 10.8min, p = 0.007). The number of RF pulses was smaller in Group CF compared to Group S (2.5 ± 2.0 vs 5.5 ± 1.9, p < 0.01). The mean CF during the effective RF pulse was 18 ± 7.7g, force-time integral was 1040.7 ± 955.9gs, Ablation Index was 513.0 ± 214.2. The procedure was acutely successful in 70 patients; at 12months follow-up 2 patients had AP recurrence, one for each group. No major complications were reported. The use of CF irrigated tip catheters was associated with a smaller number of RF pulses and less fluoroscopy, as compared to mapping and ablation with standard irrigated tip catheters.

Usefulness of Electroanatomical Mapping in Rhythmology

Usefulness of Electroanatomical Mapping in Rhythmology Abstract. Atrial fibrillation is the most common arrhythmia and its prevalence is rising. Therapeutic options include drug treatment and interventional catheter ablation via pulmonary vein isolation (PVI). This procedure was associated with long fluoroscopy times which carried risks for patients and physicians. Electroanatomical mapping (EAM) is a tool to visualize anatomy, voltage and activation of the heart chambers. Current EAM systems used in clinical practice include CARTO®, EnSite NavX® and Rhythmia®. Magnetic fields and impendance approaches are used to create 3D shells of the chambers. The catheter can be used to either collect electrograms or to ablate the target tissue. When using EAM, fluoroscopy time is significantly decreased, and complications can be monitored. Images from CT, MRI or intracardiac echo can be used as a template for creating a map or merged with an existing map to enhance anatomic accuracy.

The Role of Superior Vena Cava Isolation in the Management of Atrial Fibrillation.

The superior vena cava (SVC) has been identified as one of the most common sources of non-pulmonary vein triggers for atrial fibrillation (AF). SVC isolation has been shown to improve long-term maintenance of normal sinus rhythm in patients with paroxysmal AF. However, ablation at the SVC is associated with risks of phrenic nerve injury, sinus node dysfunction, and SVC stenosis. The use of electroanatomical mapping, intracardiac echocardiography, compound motor action potentials, and segmental (rather than circumferential) ablation are all strategies to reduce complications. Given these risks, SVC isolation is most effective as an adjunct to pulmonary vein isolation for patients with paroxysmal AF who have been found to have an arrhythmogenic SVC.