Supraventricular Tachycardia Ablation Research Articles

Longitudinal reduction in fluoroscopy with continued use of 3-dimensional electroanatomic mapping systems in catheter ablation of supraventricular tachycardia – then and now

BackgroundCatheter ablation is a first-line treatment for symptomatic, recurrent supraventricular tachycardia (SVT). This study aims to demonstrate if 3D-electroanatomic mapping (EAM) during SVT ablation reduces fluoroscopy time (FT) and determine if further reductions in FT are observed longitudinally. MethodsAll cases of SVT ablation between May 2011–May 2022 at a single tertiary centre were prospectively recruited. FT between the cohorts with and without EAM were compared. Within the EAM subset, the trend of FT across the years was analysed. ResultsThere were 1758 cases included, 563 without EAM, 1195 with EAM. EAM was associated with a longer procedure time (mean + 8.8 min, p = 0.001), but with mean reductions in FT and dose area product (DAP) by 19.6 min and 18 621 mGy*cm2 respectively (p < 0.001). There was comparable efficacy without any increase in complication rates. Over time (2011–2022), further reduction in FT of 0.9 min year on year was observed (p = 0.001). Between 2011 and 2017, there was a significant reduction in FT of 1.1 min year on year (p = 0.019), which was not observed from 2017 onwards (p = 0.061). The greatest reduction in FT was after the first year of adoption. ConclusionEAM in SVT ablation reduces fluoroscopy use. FT was initially observed to reduce further over time before plateauing, likely due to increased operator experience. While there is increased interest in zero fluoroscopy SVT ablation, complementary use of fluoroscopy may still be necessary in complex cases.

Low-dose dexmedetomidine sedation in patients undergoing electrophysiological study and ablation of supraventricular tachycardias in a same day setting

Abstract Background Catheter ablation for supraventricular tachycardias (SVT) can frequently cause patient discomfort, anxiety or pain. Through the years different drugs have been employed to provide an optimal sedation without interfere with inducibility of tachyarrhythmia. Moreover, the increasing number of patients with this clinical condition and the growing demand of catheter ablation, makes same day discharge mandatory. For this purpose, drugs that guarantee minimal sedation and reduce adverse events should be used. Dexedetomidine (DEX) is a selective alpha-2 agonist with analgesic and sedating effect without significant respiratory depression. Its electrophysiological effects include the sinus node and atrioventricular (AV) node depression and an increased atrial refractoriness. Albeit there is a reduction of side effects of most commonly used sedation drugs, data on the efficacy and safety profile of DEX during SVT ablation of adult patients are unclear and conflicting. Purpose The aim of this study was to assess whether optimal sedation and patient’s comfort can be achieved with a low-dose DEX without interfering with electrophysiological parameters during catheter ablation of SVT in adult population. Methods This is a single-center prospective study. Study population consisted of patients undergoing mapping and catheter ablation of SVT from January to September 2023 divided into DEX group (periprocedural infusion of Dexedetomidine 0.07-0.11 mcg/kg/h without loading dose) and non-DEX group (midazolam 1-2 mg periprocedural). Clinical and procedural data were recorded for all patients, as well as all measurements taken during electrophysiological study. Results The study population was predominantly female (60%) with a mean age of 56 ± 13.7 years. Hypotension occurred in only one patient, in the DEX group. No cases of desaturation were observed in both groups. Most of the induced tachyarrhythmias were the slow-fast type of atrioventricular nodal reentrant tachycardia (75%), whereas atrioventricular reentrant tachycardia and atrial tachycardia were less common (7.1% and 7.1%). No significant differences were recorded in relation to AV node refractoriness, atrial refractoriness, anterograde and retrograde conduction. (Table 1) Isoproterenol was required to induce tachyarrhythmia in both groups. Arrhythmia inducibility and aberrancy in tachycardia was not significantly influenced by DEX. The jump phenomenon was recorded more frequently in the DEX group (86.4% vs. 46.7%; p=0.004). The mean duration of the procedure did not differ between the two groups. All patients were discharged on the same day after 3 hours of observation. Conclusions The use of low-dose Dexedetomidine was succesful in improving periprocedural patient comfort, without reducing tachyarrhythmia inducibility or major electrophysiological parameters.

Implementation of near zero fluoroscopy in supraventricular tachycardia ablation procedures: a single center experience

Abstract Background Supraventricular tachycardia (SVT) are common cardiac arrhythmias, and catheter ablation has proven to be a very effective treatment, but exposes patients and healthcare providers to radiation. "Near Zero Fluoroscopy" (NZF) techniques, utilizing advanced imaging, aim to reduce radiation exposure while maintaining efficacy. Purpose To present an analysis of near-zero fluoroscopy in SVT ablation procedures, in a tertiary center, since its implementation. Methods We prospectively enrolled 446 SVT-diagnosed patients for this study. All of them underwent NZF procedures using the same specific 3D mapping system, between January/19 and December/22. Patients with atrial fibrillation or macroreentrant atrial tachycardias or when a different mapping system was used, were excluded. All patients provided informed consent. Results Our population had 266 (60%) females and a median age of 39 (IQR 24-51) years. AVNRT was the most frequent arrhythmia documented (229 cases, 51%), followed by Accessory Pathways (AP) (201 cases, 45%) and focal atrial tachycardia (AT) (16 cases, 4%). The ablation success rate was high (405/418, 97%). There was no ablation attempt in 12 patients (9 APs and 3 ATs) and the unsuccessful ablations (7/418 cases, 1,67%) were APs. Overall, fluoroscopy time was 1.1 minutes (IQR 0-2.6). There was no statistically significant difference in the distribution of fluoroscopy time among the types of SVT based on the Kruskal-Wallis test (p 0.14). Observing trends of fluoroscopy use through time, we acknowledge the presence of a learning curve, leading towards shorter times of X-ray during procedures along the first 3 years of implementation of a near-zero strategy. Median times (IQR) of fluoroscopy were as follows: 2019 – 2.25 (0.45-3.4) min; 2020 – 1 (0-2.5) min; 2021 – 0 (0-1.9) min; 2022 – 0.55 (03.05) min. (see BoxPlot) Pairwise comparisons using the Wilcoxon rank-sum test with continuity correction revealed statistically significant differences in medians between all pairs of years, with p-values adjusted for multiple comparisons using the Bonferroni method (p&amp;lt;0.01). In 2022, fluoroscopy time increased, when compared to 2021. We believe this finding can be explained by the fact that in 2022, our department received a new fellow and a young EP consultant (coming from a center where NZF was not the standard for SVT ablation), both being in the lab on a daily basis, explaining this upward trend in fluoroscopy time. There were no acute complications requiring hospital admission or active treatment. Conclusion Our results emphasize the potential of near-zero fluoroscopy techniques to enhance safety and reduce radiation exposure while maintaining a high level of procedural efficacy in the treatment of SVT cases. Absence of acute complications highlighted the safety of these approaches.

Localization of ganglionated plexi by high density mapping: an atropine-response analysis

Abstract Introduction Growing interest has emerged around cardiac autonomic nervous system driven by ablation approaches for the treatment of neurally-mediated syncope (NMS). Ganglionated-plexi (GPs) located in the epicardial fat pads are the main target of ablative therapies, but little is known about the finest method to track their location from the endocardium. Most current techniques rely on empirical research of signal fragmentation and/or vagal response at anatomical landmarks. A poor accuracy in targeting GPs may lead to the risk of incomplete or over-extensive ablation. Purpose We analyzed the atrial electrograms (EGMs) in healty subjects and their response to atropine to describe physiological fragmentation and the relationship with vagal output. Methods Study partecipants were selected from young patients without structural heart desease who underwent electrophysiological study (EPS) for standard indications. High-density mapping of right atrium was performed before and after administration of 2 mg atropine at the end of the planned procedure. Offline analyses were performed comparing the two maps of each patient focusing on the fragmentation of the atrial EGMs. Results The study cohort comprised 10 patients (mean age of 39±11 years, 6 males). The indication for EPS was: supraventricular tachycardia (SVT) ablation in 9 patients, syncope in 1 patient. High density three-dimensional electro-anatomic maps (EAM) were all obtained with a multipolar catheter during sinus rhythm (number of points: 8794±937 in basal maps and 9007±1296 after atropine, p=0,87). The response to atropine was documented by an increase in heart rate (mean increase 59 ± 19% of basal cycle length). All basal maps showed a similar pattern of fragmentation in the posterior-septal wall reflecting the anatomical distribution of right GPs. In particular, three main stations were identified in the supero-, mid- and infero-posterior regions. Fragmentation of EGMs was found to progress from the edge to the core of each area. After administration of atropine, a reduction in fractionated area was observed in all patients. Filtering the maps according to a cut-off of fragmentation ≥ 6 peaks allowed identification of the nucleus with the highest degree of variation after atropine injection (mean basal area = 0,89 ± 0,81 cm2 ; mean atropine area = 0,44 ± 0,56 cm2 p&amp;lt;0,001). Conclusion Fragmentation of atrial electrograms is a dynamic property related to vagal output. High density mapping with a high pass filter of 6 peaks allows to identify the smallest vagal sensitive area in the anatomical stations of the GPs.

Same-day discharge strategy in a heart rhythm management clinic - what about patients' reported experience?

Abstract Background and aims Same-day discharge (SDD) has been adopted for many interventional cardiology procedures, however data on patients’ experience are scarce. The aim of this study was to investigate patient-reported experience of a SDD strategy following electrophysiology procedures (EP) in a Heart Rhythm Management Department. Methods Consecutive patients undergoing EP procedures in our centre, who fulfilled pre-defined eligibility criteria for SDD, were asked to complete the study questionnaire, right before hospital discharge. Procedures suitable for SDD ranged from non-invasive (electric cardioversion, tilt test) to invasive ones (EP studies, device replacement, rhythm recorders implantation, ablation of supraventricular tachycardias including atrial fibrillation). The questionnaire aimed to assess patients’ experience before and during the procedure, their satisfaction with the quality of the provided information and their comprehension of the given instructions regarding the post-discharge period and their medication. Results The study questionnaire was completed by 501 patients. The majority of participants described SDD as a good or a quite good experience (n=440, 87,8%), while 94,6% of them (n=474) would not hesitate to undergo a second SDD procedure, if necessary. A direct interview with a healthcare team member was viewed as the preferred method of obtaining information on the procedure. At discharge, 1 out of 10 patients were still unsure of the instructions given by the healthcare team, including their anticoagulation treatment. Patient reported satisfaction rates did not differ between invasive and non-invasive procedures. However, after an invasive procedure, patients seemed to significantly have a better understanding of post-discharge instructions. Conclusion Patients reported a high level of satisfaction with SDD EP procedures. However, significant efforts need to be made in order to ensure their understanding of post-discharge instructions.Figure : Patients' reported experience

Frequency and Clinical Implications of Atrial Fibrillation in Patients with Accessory Pathways

Abstract:&#x0D; Atrial fibrillation (AF) is a common arrhythmia associated with various cardiac conditions. This study investigates the frequency of AF in patients with accessory pathways, anomalous electrical connections that can lead to supraventricular tachycardia.&#x0D; Objective:&#x0D; The primary objectives are to determine the prevalence of AF in patients with accessory pathways, identify associated factors, and assess the impact on clinical outcomes. A comprehensive dataset of 400 patients undergoing supraventricular tachycardia ablation at Hayatabad Medical Complex from 2020 to 2022 was analyzed.&#x0D; Method:&#x0D; A retrospective study design was employed, utilizing patient records with documented accessory pathway(s) and complete clinical-electrophysiological data. Demographic information, clinical presentation, electrocardiographic and electrophysiological data, ablation procedures, and clinical outcomes were systematically collected. Analytical approaches included frequency calculation, comparative analysis, regression analysis, and outcome assessment.&#x0D; Result:&#x0D; Out of 400 patients, 3.5% presented with AF at the time of accessory pathway ablation. Age was identified as a significant predictor of AF occurrence, with a mean age of 63.2 years in AF cases compared to 55.8 years in non-AF cases. Recurrence of arrhythmias was observed in 57.1% of patients with AF, emphasizing the need for ongoing monitoring and management.&#x0D; Conclusion:&#x0D; This study contributes valuable insights into the relatively low prevalence of AF in patients with accessory pathways. While certain factors, including age, may be associated with AF, they do not serve as definitive predictors. Tailored management and adherence to guidelines are crucial for optimizing outcomes in this unique patient population. Future research may explore genetic factors and refine risk stratification models for a deeper understanding of AF in patients with accessory pathways.

Development of catheter ablation of supraventricular tachycardias with special consideration of contributions from German engineers and electrophysiologists

The development and clinical implementation of catheter ablation of supraventricular tachycardia is one of the outstanding achievements of modern cardiovascular treatment. Over a period of less than 40years, acurative and safe treatment strategy for almost all forms of atrial arrhythmias has been developed and implemented. German electrophysiologists and engineers have made asignificant contribution to this truly outstanding success story in modern medicine. Their contributions should be appropriately acknowledged because without them, the development of ablation technology and its worldwide dissemination would not have been possible. Both the technological contributions and the medical-electrophysiological contributions were at the absolute forefront of worldwide developments and have made asignificant contribution to the fact that today more than 500,000 patients with symptomatic and/or threatening cardiac arrhythmias can be successfully treated every year by use of catheter ablation. We would like to thank them all for their achievements.

Catheter ablation for supraventricular tachycardia and health resource utilization and expenditures: A propensity-matched cohort study

BackgroundFew data are available regarding temporal patterns of health resource utilization (HRU) and expenditures among patients undergoing catheter ablation for paroxysmal supraventricular tachycardia (PSVT). This study aimed to describe expenditures and HRU in patients with PSVT who underwent catheter ablation compared to a matched cohort of patients on medical therapy alone. MethodsUsing a large US administrative database, we identified adult patients (age 18 to 65 years) with a new PSVT diagnosis between 2008 and 2016. Propensity-score matching was used to assemble a PSVT cohort treated with ablation or medical therapy alone (N = 2556). Longitudinal trends in HRU and expenditures in the 3-years preceding and following PSVT diagnosis were compared. ResultsThere were no significant differences in expenditures between groups except within the first year after PSVT diagnosis: $48,004 ablation vs. $17,560 medical therapy (p < 0.001). This difference was driven by procedural expenditures, where the mean cost of catheter ablation was $32,057 ± SD 26,737. In Years 2 and 3 post-ablation, HRU and expenditures decreased to the levels associated with the medical therapy group, although fewer ablation patients required any prescription for beta-blockers, calcium channel blockers, or anti-arrhythmic drugs (32% ablation vs. 42% medical therapy group, p < 0.001). ConclusionCatheter ablation reduces medication burden in PSVT, yet health resource use and expenditures were similar beyond 2 years post-ablation when compared to PSVT patients on medical therapy alone. Additional studies are required to better understand drivers of these sustained health expenditures, and barriers to achieving cost-savings for a potentially curative procedure.

Outcomes of Focal Pulsed Field Ablation for Paroxysmal Supraventricular Tachycardia

BackgroundPulsed field ablation (PFA) is primarily used for treatment of atrial fibrillation as it provides better safety and efficacy. However, there are limited data available on the use of PFA for paroxysmal supraventricular tachycardia (PSVT). The study sought to describe the outcomes of PSVT ablation with a novel focal contact force (CF)-sensing PFA. MethodsIn this first-in-human pilot study, a focal CF-sensing PFA catheter was used for mapping and ablation navigated with an electroanatomic mapping system (EAMS). Pulsed field energy was delivered as biphasic/bipolar electrical pulse trains with 2000 V/delivery. CF was controlled from 2 g to 10 g during PFA. ResultsProcedural acute success was achieved without general anaesthesia or conscious sedation in all 10 patients, including 7 patients diagnosed with typical atrioventricular nodal re-entrant tachycardias and 3 patients with orthodromic reciprocating tachycardias. Successful target ablation time was 2.0 ± 0.5 seconds per patient, and the acute procedural success at the first single site was achieved in 5 patients. The mean skin-to-skin procedure time was 79.4 ± 15 minutes, PFA catheter dwell time was 50.1 ± 14 minutes, and fluoroscopy time was 6.2 ± 7 minutes. Maintenance of sinus rhythm was observed in all patients within 6-month follow-up. No serious adverse events occurred in any subjects during PFA or during the 6-month follow-up. ConclusionsA focal CF-sensing PFA catheter could effectively, rapidly, and safely ablate PSVT in conscious patients. Clinical Trial RegistrationNCT05770921

Catheter ablation of supraventricular tachycardia and atrial flutter with no or minimal use of fluoroscopy: the initial experience of a single Bulgarian center

Introduction: Catheter ablation (CA) is an established therapy for most arrhythmias. Non-&amp;#64258; uoroscopic three-dimensional (3D) electroanatomic mapping systems allow ablation of supraventricular tachycardia (SVT) and atrial &amp;#64258; utter (AFL) with zero or near-zero &amp;#64258; uoroscopy (ZF/NZF). The current study aims to report our initial experience with ZF/NZF in SVT or AFL CA. Material and methods: We conducted a single-center prospective registry enrolling consecutive patients referred for CA of SVT or AFL. ZF/NZF CA was attempted in all patients using a commercially available 3D mapping&amp;nbsp;system. Fluoroscopy use was allowed at any point of the procedure. Procedural characteristics and long-term outcome were analyzed. The learning curve effect was also studied. Results: Sixty-three patients (age 53.5 &amp;plusmn; 14.1, 57% males) with SVT or AFL were enrolled. According to arrhythmia type typical AVNRT was diagnosed in 36 (57.1%) cases, right atrial &amp;#64258; utter in 25 (39.7%) cases, left-sided accessory pathway in 1 (1.6%) and focal right atrial tachycardia in 1 (1.6%) case. Three patients (4.8%) had two arrhythmia substrates. The procedure was performed with ZF in 49/63 cases (77.8%), while NZF was necessary in 14 (22.2%) patients with a &amp;#64258; uoroscopy time of 220 &amp;plusmn; 169 sec and a dose-area product of 7556 &amp;plusmn; 5886 mGy*cm2. Median procedural time was 88 (IQR 25-75 percentile 71.5-116) min with 22 (IQR 25-75 percentile 16-31) min of mapping time. Acute procedural success was accomplished in all patients with no periprocedural complications. Over a follow-up of 12 &amp;plusmn; 3 months, all patients remained arrhythmia-free. There was a learning curve effect with a signi&amp;#64257; cant reduction of procedural time (P = 0.025) and a signi&amp;#64257; cant difference (P = 0.019) in the rate of &amp;#64258; uoroscopy use among different periods of the study duration. Conclusion: ZF/NZF CA of SVT and AFL is associated with high ef&amp;#64257; cacy and safety. Entirely &amp;#64258; uoroless CA can be performed in the vast majority of patients. It is a feasible approach associated with a detectable learning curve effect.&amp;nbsp;

Two decades of SVT ablation in Denmark: a trend towards higher age, more comorbidity, and less prior use of antiarrhythmic and rate-limiting pharmacotherapy—a nationwide registry-based Danish study

Background and aimsTrends in patient selection and use of pharmacotherapy prior to catheter ablation (CA) for supraventricular tachycardia (SVT) are not well described. This study examined temporal trends in patients undergoing first-time CA for regular SVT, including atrioventricular nodal re-entry tachycardia (AVNRT), accessory pathways (APs), and ectopic atrial tachycardia (EAT) on a nationwide scale in Denmark in the period 2001–2018.Methods and resultsUsing Danish Nationwide registers, 9959 patients treated with first-time CA for SVT between 2001 and 2018 were identified, of which 6023 (61%) received CA for AVNRT, 2829 (28%) for AP, and 1107 (11%) for EAT. Median age was 55, 42, and 55 in the AVNRT, APs, and EAT group, respectively. The number of patients receiving CA increased from 1195 between 2001 and 2003 to 1914 between 2016 and 2018. The percentage of patients with a CHA2DS2-VASc score ≥ 2 increased in all patient groups. The number of patients who underwent CA with no prior use of antiarrhythmic- or rate limiting medicine increased significantly, though prior use of beta-blockers increased for AVNRT patients. Use of verapamil decreased in all three SVT groups (P < 0.05). Use of amiodarone and class 1C antiarrhythmics remained low, with the highest usage among EAT patients.ConclusionBetween 2001 and 2018, CA was increasingly performed in patients with SVT, primarily AVNRT- and EAT patients. The burden of comorbidities increased. Patients undergoing CA without prior antiarrhythmic- or rate-limiting drug therapy increased significantly. Use of beta-blockers increased and remained the most widely used drug.Graphical

The effect of electro-anatomical mapping on the success rate and fluoroscopy time in supra-ventricular tachycardia ablation in children: single centre retrospective study.

To evaluate the effect of electro-anatomical mapping on success rate and fluoroscopy time in ablation of supraventricular tachycardia substrates in a large group of children. Patients referred from multiple centres in the Netherlands and who received a first ablation for supraventricular tachycardia substrates in the Leiden University Medical Center between 2014 and 2020 were included in this retrospective cohort study. They were divided in procedures in patients with fluoroscopy and procedures in patients using electro-anatomical mapping. Outcomes of ablation of 373 electro-anatomical substrates were analysed. Acute success rate in the fluoro-group (n = 170) was 95.9% compared to 94.5% in the electro-anatomical mapping group (n = 181) (p = 0.539); recurrence rate was 6.1% in the fluoro-group and 6.4% in the electro-anatomical mapping group (p = 0.911) after a 12-months follow-up. Redo-ablations were performed in 12 cases in the fluoro-group and 10 cases in the electro-anatomical mapping group, with a success rate of 83.3% versus 80.0%, resulting in an overall success rate of 95.9% in the fluoro-group and 92.8% in the electro-anatomical mapping group (p = 0.216) after 12 months. Fluoroscopy time and dose area product decreased significantly from 16.00 ± 17.75 minutes (median ± interquartile range) to 2.00 ± 3.00 minutes (p = 0.000) and 210.5 µGym2 ± 249.3 to 32.9 µGym2 ± 78.6 (p = 0.000), respectively. In the fluoro-group, four complications occurred (2.0%) and in the electro-anatomical mapping group no complications occurred. These results demonstrate that ablations of supraventricular tachycardia substrates in children remain a highly effective and safe treatment after the introduction of electro-anatomical mapping as a standard of care, while significantly reducing fluoroscopy time and dose area product.

Abstract 14411: Block in the Fasciculoventricular Pathway in a Complex Arrhythmia Presentation

Background: Fasciculoventricular pathway (FVP) is a rare form of preexcitation without known clinical tachycardia. As it is connected to the His bundle, they conduct whenever it is engaged. Conduction through the His Bundle but block at FVP has not been reported. Case presentation: We present a case of a 42-year-old male with a history of Wolff-Parkinson-White syndrome (WPWS), supraventricular tachycardia (SVT), syncope, embolic stroke, paroxysmal atrial fibrillation, hypertension, hypothyroidism, Sjogren's syndrome and prior unsuccessful attempts at elimination of the preexcitation. He underwent electrophysiology (EP) study for presumed SVT ablation. The EP study identified an FVP as the cause of preexcitation, and the planned accessory pathway ablation was deemed unnecessary. Atrial tachycardia originating from the right superior pulmonary vein (PV) was induced, eventually degenerating into atrial fibrillation, and the patient successfully underwent pulmonary vein isolation with the resolution of symptoms. Discussion: FVP is usually an incidental finding when patients with symptomatic preexcitation are studied. If tachycardia is induced, it is unrelated to the preexcitation. The FVP is connected to the His bundle and invariably conducts if the impulse engages the His Bundle. We are unaware of a case when the His bundle conducts, but the impulse loses preexcitation due to a block in the FVP. This unusual finding was noted in our case. To further confirm the location of the accessory pathway, IV adenosine was given with a complete heart block suggesting the preexcitation is beyond the level of the AV node and within the conduction system. It is not at the annulus with independent atrial and ventricular insertion, typical of an accessory pathway. Conclusions: This case demonstrates an FV pathway's unusual conduction block and physiological characteristics.

Outcomes After Supraventricular Tachycardia Ablation in Patients With Group 1 Pulmonary Hypertension.

Pulmonary hypertension (PH) is associated with right ventricular pressure overload and atrial remodeling, which may result in supraventricular tachycardias (SVTs). The outcomes of catheter SVT ablation in patients with World Health Organization (WHO) group 1 PH are incompletely characterized. We conducted a retrospective cohort study of all patients with WHO group 1 PH undergoing catheter SVT ablation during a 10-year period at a major academic tertiary care hospital. Baseline patient characteristics and procedural outcomes at 3 months and 1 year were extracted from the electronic medical record. Ablation of 60 SVTs was attempted in 38 patients with group 1 PH. The initial procedural success rates were 80% for atrial fibrillation (AF, n = 5), 89.7% for typical atrial flutter (AFL, n = 29), 57.1% for atypical AFL (n = 7), 60% for atrial tachycardia (AT, n = 15), and 75% for atrioventricular nodal reentrant tachycardia (AVNRT, n = 4). The 1-year post-procedural recurrence rates were 100% for AF (n = 4), 25% for typical AFL (n = 20), 50% for atypical AFL (n = 2), and 28.6% for AT (n = 7). No patients had recurrent AVNRT (n = 2). There were seven (18.4%) peri-procedural decompensations requiring pressor initiation and transfer to intensive care and one (2.6%) peri-procedural death. The study demonstrates that SVT ablation in group 1 PH can be performed relatively safely and effectively, albeit with lower initial success rates and higher risk of clinical decompensation than in the general population. Recurrence rates at 1 year were higher in AF and atypical AFL ablations and similar for typical AFL and AT ablations when compared to the general population.

Zero-Fluoroscopy Catheter Ablation of Supraventricular Tachycardias in the Pediatric Population.

Catheter ablation (CA) of supraventricular tachycardias (SVTs) is conventionally performed with the aid of X-ray fluoroscopy. Usage of a three-dimensional (3D) electro-anatomical mapping (EAM) system and intracardiac echocardiography (ICE) enables zero-fluoroscopy ablation, eliminating the harmful effects of radiation. We retrospectively analyzed the feasibility, effectiveness and safety of zero-fluoroscopy radiofrequency and cryoablation of various types of SVTs in pediatric patients. Overall, in 171 consecutive patients (12.5 ± 3.9 years), 175 SVTs were diagnosed and 201 procedures were performed. The procedural success rate was 98% (193/197), or more precisely, 100% (86/86) for AVNRT, 95.8% (91/95) for AVRT, 94.1% (16/17) for AT and 100% (2/2) for AFL. No complications were recorded. Follow-up was complete in 100% (171/171) of patients. During the mean follow-up period of 488.4 ± 409.5 days, 98.2% of patients were arrhythmia-free with long-term success rates of 98.7% (78/79), 97.5% (78/80), 100% (13/13) and 100% (2/2) for AVNRT, AVRT, AT and AFL, respectively. Zero-fluoroscopy CA of various types of SVTs in the pediatric population is a feasible, effective and safe treatment option.

Effect of Radiofrequency Current Application during Catheter Ablation on Heart Rate Variability in Patients with Supraventricular Tachycardia

Abstract Background The autonomic nervous system has a significant regulatory effect on heart function; in addition to heart rate, cardiac conduction properties, hemodynamics, the cellular properties of cardiac myocytes, and cardiac arrhythmogenesis are also affected by the autonomic nervous system. Objectives In this study, we aimed to assess the Relationship between RF current application during Catheter ablation and it's effect on Heart Rate variability in patients undergoing RF catheter ablation for supraventricular Tachycardia. Patients and Methods This study is a cohort study, randomized clinical study, recruiting 20 patients from Ain Shams University hospitals, Cairo, Egypt. All patients were symptomatic with drug refractory documented supraventricular tachycardias. who underwent RF ablation March 2020 till February 2021 and were followed up for 1 month after the procedure. Results Compared with preablation data, HRV were shorter in all the RFA at the follow-up assessment. The 24-h Holter monitoring showed that mean and maximal HR were increased, whereas the HRV parameters, including time domain indices (SDNN, rMSSD) and frequency domain index, which reflect the attenuation of parasympathetic tone, were decreased in the RFA during the postablation period. In this study, there was significant increasing in mean heart rate regarding basal and the subsequent follow up after 1 week and 1 month. Post ablation high sinus rate (PA-HSR) was defined as an increase in resting sinus rate &amp;gt; or = 20 bpm or a resting sinus rate &amp;gt; or = 92 bpm without physiological or hemodynamic causes. In this study PAHSR was found in 10 patients (50%) by month-1 follow up. There is relation between the target site of RF ablation and the difference of HRV parameters. Conclusion Cardiac autonomic dysfunction assessed by changes in time domain and frequency domain heart rate variability parameters persisted for 1 month after radiofrequency ablation. Parasympathetic denervation may be one mechanism of Post ablation high sinus rate.

Identification of supraventricular tachycardia mechanisms with surface electrocardiograms using a convolutional neural network.

It remains difficult to definitively distinguish supraventricular tachycardia (SVT) mechanisms using a 12-lead electrocardiogram (ECG) alone. Machine learning may identify visually imperceptible changes on 12-lead ECGs and may improve ability to determine SVT mechanisms. We sought to develop a convolutional neural network (CNN) that identifies the SVT mechanism according to the gold standard of SVT ablation and to compare CNN performance against experienced electrophysiologists among patients with atrioventricular nodal re-entrant tachycardia (AVNRT), atrioventricular reciprocating tachycardia (AVRT), and atrial tachycardia (AT). All patients with 12-lead surface ECG during sinus rhythm and SVT and had successful SVT ablation from 2013 to 2020 were included. A CNN was trained using data from 1505 surface ECGs that were split into 1287 training and 218 test ECG datasets. We compared the CNN performance against independent adjudicationby 2 experienced cardiac electrophysiologists on the test dataset. Our dataset comprised 1505 ECGs (368 AVNRT, 304 AVRT, 95 AT, and 738 sinus rhythm) from 725 patients. The CNN areas under the receiver-operating characteristic curve for AVNRT, AVRT, and AT were 0.909, 0.867, and 0.817, respectively. When fixing the specificity of the CNN to the electrophysiologist adjudicators' specificity, the CNN identified all SVT classes with higher sensitivity: (1) AVNRT (91.7% vs 65.9%), (2) AVRT (78.4% vs 63.6%), and (3) AT (61.5% vs 50.0%). A CNN can be trained to differentiate SVT mechanisms from surface 12-lead ECGs with high overall performance, achieving similar performance to experienced electrophysiologists at fixed specificities.

Routine use of a 3D mapping system in the ablation of supraventricular arrhythmias with as low as reasonably achievable X-ray exposure (AALARA): protocol for a prospective, observational, multicentre, multinational, open-label registry study

IntroductionThe reduction of fluoroscopic exposure during catheter ablation of supraventricular arrhythmias is widely adopted by experienced electrophysiology physicians with a relatively short learning curve and is becoming standard of care...

Ideal Anesthetic Agent for Cardiac Electrophysiology Study and Catheter Ablation – A Pilot Study

Objectives: Patients suffering from supraventricular tachycardia (SVT) require diagnostic or therapeutic intervention in a cardiac electrophysiology (EP) laboratory. Some anesthetic medications may adversely affect cardiac EP and conduction, altering the ability to induce the arrhythmia, and may have a negative impact on the ablation treatment. This prospective, randomized, pilot study was conducted in the cardiac EP laboratory of a tertiary care hospital with the aim to identify the ideal anesthetic agent for cardiac EP study and catheter ablation of SVT. The primary objective was to compare the effects of anesthetic agents on cardiac electrophysiological parameters and arrhythmia inducibility. The secondary objective was to compare the patient, anesthesiologist, and cardiologist satisfaction scores with respect to the anesthetic agent used. Materials and Methods: Thirty adult patients with SVT for EP study and radiofrequency catheter ablation were administered either of the anesthetic agents: midazolam, fentanyl, propofol, ketamine, or sevoflurane titrated to produce conscious sedation corresponding to bispectral index (BIS) values between 71 and 90. Electrophysiological parameters were recorded before and after administering the anesthetic agent. Results: Arrhythmia could be induced in all patients. Although electrophysiological parameters remained stable with ketamine administration; higher values of the Richmond Agitation Sedation Scale score and BIS were recorded. Propofol and sevoflurane administration was associated with deviation in electrophysiological parameters more than fentanyl and midazolam. The highest values of patient, anesthesiologist, and cardiologist satisfaction scores were obtained in the fentanyl group and the lowest in the ketamine group (P &lt; 0.002). Conclusion: In doses used to provide conscious sedation, fentanyl provided ideal conditions, and midazolam, propofol, sevoflurane, and ketamine provided satisfactory conditions for conducting EP study and catheter ablation for supraventricular tachyarrhythmias. The potential of propofol to impede cardiac conduction needs to be explored further.

Utilization of 3D mapping systems in interventional electrophysiology and its impact on procedure time and fluoroscopy-Insights from the "Go for Zero Fluoroscopy" project.

The implementation of 3D mapping systems plays an important role in interventional electrophysiology (EP) in recent years. The aim of the present study was to evaluate use of 3D mapping systems regarding fluoroscopy and procedure duration. In the "Go for Zero Fluoroscopy" project 25 European centers provided data of consecutive EP procedures. Data on use of 3D mapping systems as well as utilization of contact force catheters and multipolar mapping catheters were associated with fluoroscopy time, dose area product (DAP), and procedure duration. A 3D mapping system was used in 966 (54%) cases. Use of 3D mapping for atrioventricular nodal reentry tachycardia (AVNRT) was associated with reduced fluoroscopy time (p<0.001), DAP (p=0.04) but increased procedure time (p=0.029). Moreover, fluoroscopy time (p<0.001) and DAP (p=0.005) were significantly lower in the 3D mapping group in ablation of typical atrial flutter. However, the procedure time (p<0.001) increased. Use of 3D mapping in the ablation of accessory pathway (AP) was associated with reduced fluoroscopy time (p<0.001) and DAP (p<0.001) with no significant increase in procedure time (p=0.066). In the case of atrial fibrillation, a 3D mapping system was used in 485 patients (75.8%). Additional use of a contact force catheter was associated with lower fluoroscopy time (p<0.001) and DAP (p<0.001). Use of a multipolar mapping catheter was associated with lower fluoroscopy time (p=0.002). The implementation of 3D mapping systems in the ablation of ventricular tachycardias resulted in a significant increase in the procedure time (p=0.001) without significant differences regarding the DAP (p=0.773) and fluoroscopy time (p=0.249). Use of 3D mapping systems in ablation of supraventricular tachycardias is associated with lower radiation exposure. Nevertheless, the procedure time often increases, except in the case of ablation for AP. Use of contact force catheters and multipolar mapping catheters is associated with yet lower radiation exposure values. Prospective randomized studies are needed to further elucidate potential benefit of these technological tools.