Results Of Radiofrequency Catheter Ablation Research Articles

Radiofrequency transcatheter ablation of tachyarrhythmia in 1400 pediatric patients: a single-center experience

Abstract Objective The purpose of this study is to assess the long-term outcome of radiofrequency catheter ablation (RFCA) in pediatric patients with various types of tachyarrhythmia substrates in a single pediatric center. Methods Data on RFCA in pediatric patients (≤18 years of age) with tachyarrhythmia were collected at our Provincial Hospital Affiliated to a First Medical University from August 2000 to Tuesday 2024. Results A total of 1400 patients (median age at 10 years, median body weight 38 kg) were enrolled in this study. These targeted tachycardia substrates were fall into five groups: 1. atrioventricular reentrant tachycardia (AVRT) in 628 (44.86%) patients, 2. atrioventricular nodal reentrant tachycardia (AVNRT) in 319 (22.78%) patients, 3. ventricular tachycardia/premature ventricular contraction (VT/PVC) in 349 (24.93%) patients, 4. atrial tachycardia (AT) in 79 (5.64%) patients, and 4. atrial flutter (AFI) in 12 (0.86%) patients. However, the mechanism of tachycardia could not be determined in 13 (0.93%) patients. Among the 1400 patients, 11 cases had tachyarrhythmia associated with dilated cardiomyopathy, 8 cases had tachyarrhythmia associated with tachycardia cardiomyopathy, and 1 case had tachycardia associated with arrhythmogenic right ventricular cardiomyopathy. Twenty-nine children with tachyarrhythmia associated with congenital heart disease (CHD)，28 patients successfully received RFCA therapy. Median follow-up was 36 months. The overall procedural success rate was 99.26%, and the recurrence rate was 5.35%. The median procedure duration was 100.00 (70.00-120.00) min, and the median fluoroscopy time was 3.30 (0.50-9.23) min. A total of 621 AVRT patients underwent RFCA with success rate at 99.19% and recurrence rate at 5.36%. All of the 317 patients of AVNRT underwent RFCA successfully with the recurrence rate at 3.79%. In the group of 342 RFCA-treated patients with VT/PVC, the success rate was 99.12%, and the recurrence rate was 6.49%. Among 65 patients of AT who underwent RFCA, the success rate was 98.46% with the recurrence rate at 7.81%. While 11 patients with AFI received RFCA, the success rate was 90.91%, with no incidence of recurrence. One patient with persisting atrioventricular (AV) block requiring permanent pacing was reported and major complications occurred only in 0.81% of the patients. Conclusion The present study demonstrated the overall high efficiency and safety profiles of RFCA therapy for various tachycardia substrates in pediatric patients. Furthermore, the complication rate was exceptionally low. The success rate of RFCA was the same in children with or without CHD.

Varying effect of atrial fibrillation ablation in patients with heart failure with preserved ejection fraction according to CHA2DS2-VASc score

BackgroundThe impact of comorbidity burden on outcomes of radiofrequency catheter ablation (RFCA) for atrial fibrillation (AF) in patients with heart failure and preserved ejection fraction (HFpEF) remains unclear. ObjectiveThe purpose of this study was to evaluate how comorbidity burden influences the association between RFCA and cardiovascular outcomes in AF patients with HFpEF. MethodsAF patients with HFpEF from the prospective China-AF cohort, recruited between August 2011 and December 2020, were categorized into 2 groups based CHA2DS2-VASc score: low comorbidity burden (score ≤4) and high comorbidity burden (score >4). The associations between RFCA and cardiovascular outcomes and interaction effects of comorbidity burden on these associations were assessed. ResultsAmong 1700 patients with median follow-up of 65.9 months, those in the low comorbidity burden group who received RFCA had a lower risk of composite events (cardiovascular death and ischemic stroke/transient ischemic attack [TIA]) (adjusted hazard ratio [HR] 0.35, 95% confidence interval [CI] 0.21–0.59] and all-cause death (adjusted HR 0.31, 95% CI 0.17–0.54) compared to those without RFCA. However, significant associations were not observed in the high comorbidity burden group. The differences between low and high comorbidity burden groups were significant, with interaction effects noted between comorbidity burden and RFCA for cardiovascular death (Pinteraction = 0.045) and ischemic stroke/TIA (Pinteraction = 0.010). RFCA was associated with a reduced risk of AF recurrence in both comorbidity burden groups. ConclusionRFCA for AF is associated with reduced AF recurrence and improved cardiovascular outcomes in patients with HFpEF. However, these benefits may be limited for patients with a CHA2DS2-VASc score >4 (high comorbidity burden).

Empirical superior vena cava electrical isolation guided by quantitative ablation index improves outcomes of radiofrequency catheter ablation for paroxysmal atrial fibrillation

BackgroundThe value of empirical superior vena cava isolation (SVCI) following pulmonary vein isolation (PVI) to improve the efficacy of radiofrequency catheter ablation (RFCA) for paroxysmal atrial fibrillation (PAF) remains controversial.ObjectiveTo...

Impact of patent foramen ovale with left-to-right shunt on atrial fibrillation ablation in young patients

ObjectiveThe CABANA study shows that atrial fibrillation (AF) paitents younger than 65 years benefit more from the AF radiofrequency catheter ablation (RFCA) procedure. The aim of this study is to investigate the impact of inherent patent foramen ovale (PFO) with a Left-to-Right Shunt on the RFCA procedure in young AF patients. MethodsBased on the presence or absence of inherent PFO, the AF patients were divided into the PFO groups and the non-PFO group. Clinical follow-up was also investigated. ResultsA total of 285 AF patients were enrolled. PFO was detected by TEE in 42 patients. The age of patients at initial AF onset was younger in the PFO group than in the non-PFO group (58.3 ± 8.9 vs. 62.3 ± 9.6 years, P = 0.012). There were more AF patients aged <55 years in the PFO group than in the non-PFO group. For the 9 AF patients with PFO who experienced AF recurrence and the left-to-right shunts decreased in size in 5 of the patients aged <65 years. The LAD decreased in those patients. In the PeAF patients, 53/64 patients aged <65 years and 23/40 patients aged older than 65 years were free of AF (82.8 % vs. 57.5 %, respectively; P = 0.005). ConclusionSuccess is not affected when AF is combined PFO compared with AF without PFO. Young patients have better PeAF RFCA outcomes. AF in young patients with left atria enlargement and a serious AF burden, may lead to reduced EF and render PFO easy to detect.

Cardiac MRI Oversampling in Heart Digital Twins Improves Preprocedure Ventricular Tachycardia Identification in Postinfarction Patients

BackgroundVentricular tachycardia (VT), which can lead to sudden cardiac death, occurs frequently in patients after myocardial infarction. Radiofrequency catheter ablation (RFA) is a modestly effective treatment of VT, but it has limitations and risks. Cardiac magnetic resonance (CMR)–based heart digital twins have emerged as a useful tool for identifying VT circuits for RFA treatment planning. However, the CMR resolution used to reconstruct these digital twins may impact VT circuit predictions, leading to incorrect RFA treatment planning. ObjectivesThis study sought to predict RFA targets in the arrhythmogenic substrate using heart digital twins reconstructed from both clinical and high-resolution 2-dimensional CMR datasets and compare the predictions. MethodsHigh-resolution (1.35 × 1.35 × 3 mm), or oversampled resolution (Ov-Res), short-axis late gadolinium–enhanced CMR was acquired by combining 2 subsequent clinical resolution (Clin-Res) (1.35 × 1.35 × 6 mm) short-axis late gadolinium–enhanced CMR scans from 6 post–myocardial infarction patients undergoing VT ablation and used to reconstruct a total of 3 digital twins (1 Ov-Res, 2 Clin-Res) for each patient. Rapid pacing was used to assess VT circuits and identify the optimal ablation targets in each digital twin. VT circuits predicted by the digital twins were compared with intraprocedural electroanatomic mapping data and used to identify emergent VT. ResultsThe Ov-Res digital twins reduced partial volume effects and better predicted unique VT circuits compared with the Clin-Res digital twins (66.6% vs 54.5%; P < 0.01). Only the Ov-Res digital twin successfully identified emergent VT after a failed initial ablation. ConclusionsDigital twin infarct geometry and VT circuit predictions depend on the magnetic resonance resolution. Ov-Res digital twins better predict VT circuits and emergent VT, which may improve RFA outcomes.

Real-world data of radiofrequency catheter ablation in paroxysmal atrial fibrillation: Short- and long-term clinical outcomes from the prospective multicenter REAL-AF Registry

BackgroundThe safety and long-term efficacy of radiofrequency (RF) catheter ablation (CA) of paroxysmal atrial fibrillation (PAF) has been well established. Contemporary techniques to optimize ablation delivery, reduce fluoroscopy use, and improve clinical outcomes have been developed. ObjectiveThe purpose of this study was to assess the contemporary real-world practice approach and short and long-term outcomes of RF CA for PAF through a prospective multicenter registry. MethodsUsing the REAL-AF (Real-world Experience of Catheter Ablation for the Treatment of Symptomatic Paroxysmal and Persistent Atrial Fibrillation; ClincalTrials.gov Identifier: NCT04088071) Registry, patients undergoing RF CA to treat PAF across 42 high-volume institutions and 79 experienced operators were evaluated. The procedures were performed using zero or reduced fluoroscopy, contact force sensing catheters, wide area circumferential ablation, and ablation index as a guide with a target of 380–420 for posterior and 500–550 for anterior lesions. The primary efficacy outcome was freedom from all-atrial arrhythmia recurrence at 12 months. ResultsA total of 2470 patients undergoing CA from January 2018 to December 2022 were included. Mean age was 65.2 ±11.14 years, and 44% were female. Most procedures were performed without fluoroscopy (71.5%), with average procedural and total RF times of 95.4 ± 41.7 minutes and 22.1±11.8 minutes, respectively. At 1-year follow-up, freedom from all-atrial arrhythmias was 81.6% with 89.7% of these patients off antiarrhythmic drugs. No significant difference was identified comparing pulmonary vein isolation vs pulmonary vein isolation plus ablation approaches. The complication rate was 1.9%. ConclusionRefinement of RF CA to treat PAF using contemporary tools, standardized protocols, and electrophysiology laboratory workflows resulted in excellent short- and long-term clinical outcomes.

Trends Favoring an Anatomical Approach to Radiofrequency Catheter Ablation of Idiopathic Ventricular Arrhythmias Originating From the Left Ventricular Summit.

Epicardial radiofrequency catheter ablation (RFCA) of idiopathic ventricular arrhythmias (VAs) originating from the left ventricular summit (LVS) is challenging because of the anatomic barriers. On the other hand, RFCA at the endocardial sites near the earliest epicardial activation site of LVS-VAs (anatomic approach) has proven successful. The evolving trends in the approaches and outcomes of RFCA of LVS-VAs at a single center were evaluated. We studied 88 consecutive patients with idiopathic LVS-VAs at our institute from 2009 to 2019. These patients were divided into 3 periods: 2009 to 2012 (early), 2013 to 2015 (middle), and 2016 to 2019 (recent). The data were compared among the 3 periods. The RFCA success rate did not significantly change from the early to middle period but significantly increased from the middle to recent period (P=0.0315). The transpericardial approach usage significantly decreased over the 3 periods. The anatomic approach usage significantly increased over the 3 periods. The use of the transpericardial approach did not affect the RFCA outcomes over the 3 periods. The success rate of the anatomic RFCA tended to increase from the early to middle period and significantly increased from the middle to recent period (P=0.0412). The number of endocardial locations where RFCA was successful increased over the 3 periods. Over the 10-year period, the transpericardial approach became decreasingly performed, whereas the anatomic approach became increasingly performed with a satisfactory improvement in the RFCA outcomes of LVS-VAs. The anatomic RFCA became more successful by identifying more and various endocardial locations as target sites.

Clinical outcomes of radiofrequency catheter ablation guided by intracardiac echocardiography for Chinese atrial fibrillation patients: a single-center, retrospective study.

Intracardiac echocardiography (ICE) is a novel technology with certain advantages in treatment of atrial fibrillation (AF), yet there is limited research on the use of ICE in radiofrequency ablation for AF treatment in China. The aim of this study was to investigate the total fluoroscopy time and dose, safety, and effectiveness of ICE guided vs. traditional fluoroscopy (non-ICE) guided radiofrequency ablation for AF in China. We conducted a single-center retrospective analysis of patients who underwent ICE or traditional fluoroscopy-guided radiofrequency ablation for AF. The primary endpoint of this study was total fluoroscopy time, and the secondary endpoints included total fluoroscopy dose, acute surgery failure, transseptal puncture time, ablation time, total procedure time, and 6-month surgery success (no AF recurrence or atrial flutter). As an exploratory analysis, outcomes of interest by different types of AF were examined. A total of 97 patients were included in the analysis. Forty-eight were in the ICE group and 49 were in the non-ICE group with comparable demographic and clinical characteristics at the baseline. None of patients experienced acute surgery failure with no major procedure-related complications occurred. The fluoroscopic time and dose were significantly lower in the ICE group compared to the non-ICE group (0.00 vs. 9.67±4.88 min, P<0.001; 0.00 vs. 77.10±44.28 mGy/cm2, P<0.001, respectively). There were no statistically significant differences in transseptal puncture time, ablation time and total procedure time between the two groups. There were two AF recurrences observed during the 6-month follow-up in each group (P>0.99). ICE significantly reduced the fluoroscopic time and dose for radiofrequency catheter ablation in AF patients. There were no significant differences in safety or effectiveness outcomes between the ICE and non-ICE groups.

Bachmann's Bundle Modification in Addition to Circumferential Pulmonary Vein Isolation for Atrial Fibrillation: A Novel Ablation Strategy.

Bachmann's bundle (BB) is the main pathway of interatrial connection that could be involved in the development of atrial fibrillation (AF). Based on this hypothesis, we raised a novel ablation strategy, BB modification in addition to circumferential pulmonary vein isolation (CPVI-BB) in patients with AF. A retrospective cohort of patients with AF who underwent CPVI-BB or CPVI alone from March 2018 to July 2021 was enrolled in our study. Propensity score matching was performed in patients with paroxysmal AF and persistent AF, respectively, to reduce the risk of selection bias between the treatment strategies (CPVI-BB or CPVI alone). The primary endpoint was overall freedom from atrial arrhythmia recurrence through 12 months of follow-up. Our propensity score-matched cohort included 82 patients with paroxysmal AF (CPVI group: n = 41; CPVI-BB group: n = 41) and 168 patients with persistent AF (CPVI group: n = 84; CPVI-BB group: n = 84). Among patients with persistent AF, one-year freedom from atrial arrhythmia recurrence rate was 83.3% in the CPVI-BB group and 70.2% in the CPVI group (log-rank P = 0.047). Among patients with paroxysmal AF, no significant difference was found in the primary endpoint between two groups (85.4% in the CPVI-BB group vs. 80.5% in the CPVI group; log-rank P = 0.581). In addition, procedure-related complications and recurrence of atrial tachycardia or atrial flutter were similar between the two treatment groups, regardless of the type of AF. BB modification in addition to CPVI is an effective approach in increasing the maintenance of sinus rhythm in patients with persistent AF, while it does not improve the clinical outcomes of radiofrequency catheter ablation in patients with paroxysmal AF.

Comparison of 5-year follow-up outcomes between"one-stop"procedure and long-term oral anticoagulants after radiofrequency catheter ablation in patients with atrial fibrillation

Objective: To compare the 5-year follow-up outcomes of radiofrequency catheter ablation (RFCA) combined with left atrial appendage closure (LAAC) and long-term oral anticoagulant (OAC) after RFCA in patients with atrial fibrillation. Methods: This retrospective cross-sectional study included patients with atrial fibrillation who underwent"one-stop"procedure in the First Affiliated Hospital of Ningbo University from September 2015 to December 2017 (RFCA+LAAC group). Baseline data of patients were collected. Propensity score matching at the ratio of 1∶1 was used to select patients with atrial fibrillation who took long-term OAC after RFCA (RFCA+OAC group). The maintenance rate of sinus rhythm and the incidence of adverse events during follow-up were compared between the two groups. Results: A total of 110 patients were enrolled in the RFCA+LAAC group and RFCA+OAC group, respectively. Age of patients was (67.4±8.8) years in RFCA+LAAC group, and there were 42 (38.2%) female patients. Age of patients was (67.3±7.9) years in RFCA+OAC group, and there were 47 (42.7%) female patients. The patients were followed up for mean of (5.3±1.1) years. There was no significant difference in the maintenance rate of sinus rhythm (log-rank: χ2=0.277, P=0.602) and incidence of ischemic stroke events (2.7% (3/110) vs. 4.5% (5/110), P=0.719) during follow-up between the two groups. The incidence of bleeding events (6.4% (7/110) vs. 18.2% (20/110), P=0.008) and major bleeding events (1.8% (2/110) vs. 8.2% (9/110), P=0.030) was significantly higher in the RFCA+OAC group than in the RFCA+LAAC group. Conclusion: There is no significant difference between RFCA+LAAC group and RFCA+OAC group in maintenance rate of sinus rhythm and incidence of ischemic stroke events. Patients in the RFCA+LAAC group have a lower risk of bleeding events compared to the RFCA+OAC group.

Radiofrequency ablation for longstanding persistent atrial fibrillation: long-term outcome of a prospective randomized comparison of mapping with multipolar catheter vs. 4-pole ablation catheter

Abstract Funding Acknowledgements Type of funding sources: None. Background In patients with longstanding persistent atrial fibrillation (LSPAF), mapping with multipolar catheter can enhance identification of arrhythmogenic sources during ongoing AF/converted atrial tachycardia (AT), reduce procedure time, and improve outcome of catheter ablation. Purpose To compare procedural characteristics and long-term outcome of radiofrequency catheter ablation (RFA) for LSPAF between two mapping approaches in a prospective randomized bi-centric study. Methods Between 1/2019-9/2021, RFA was performed in in 172 patients with LSPAF. Mapping with multipolar catheter Pentaray (group 1, n=85) vs. mapping with ablation catheter Navistar STSF (group 2, n=87) were compared. Stepwise ablation to the desired AF termination included pulmonary vein isolation (PVI), electrogram guided left atrial (LA) ablation, CS isolation, and right atrial electrogram guided ablation. PVI, mitral isthmus, LA roof, and CTI block were Intermediate endpoints proved at the procedure end. Sinus rhythm (SR) restoration by ablation was the desired procedure endpoint. Follow-up included 7-day ECG monitoring every 3 months during the first year, and every 6 months afterwards. Results In groups 1 vs. 2, AF was terminated (into SR or AT) in 70 (82%) vs. 68 (78%) patients (p=0.81); and SR was restored by ablation in 54 (64%) vs. 46 (53%) patients(p=0.46), respectively. Procedure, fluoroscopy, and RF delivery times (min) were 251±46 vs. 257±45 (p=0.35); 10,4±2,8 vs. 11,0±3,1 (p=0.17), and 70±21 vs. 70±24 (p=0.98), respectively. At the end of 13-45 months follow-up, stable SR was present in 72 (85%) vs. 69 (79%), patients following repeat ablation in 42 (49%) vs. 42 (48%) patients. Only 29 (34%) vs. 26 (30%) patients remained free from any AF/AT recurrence (&amp;gt;30 s) after single ablation (all p=NS). Conclusion Mapping with multipolar catheter vs. standard ablation catheter was associated with nonsignificant differences in procedural characteristics and clinical results of RF catheter ablation for LSPAF.

The higher recurrence rate after catheter ablation in younger patients with atrial fibrillation suggesting different pathophysiology.

Young atrial fibrillation (AF) patients have been underrepresented in studies of radiofrequency catheter ablation (RFCA) and the outcome of RFCA has not been widely addressed. We investigated age-related differences in clinical features, the recurrence of atrial tachyarrhythmia, and its predictors of patients who underwent RFCA for AF. This is a multicenter prospective study of 2799 patients who underwent RFCA for AF in 2017-2020. The patients were divided into two groups - group A (age < 60years, n = 1269) and group B (age ≥ 60years, n = 1530) - and a recurrence of any atrial tachyarrhythmia 1year after RFCA following a 90-day blanking period was compared. The mean age was 51.6 ± 6.7 and 66.8 ± 5.2years for groups A and B, respectively. Higher body mass index, smaller left atrium, and more prevalent cardiomyopathy and obstructive sleep apnea were observed in group A. Overall, 1-year atrial tachyarrhythmia-free survival was 85.6% and lower in young patients (83.1% in group A vs. 87.7% in group B, log-rank p < 0.01): adjusted hazard ratio (aHR) of recurrence (95% confidence interval (CI)), 1.45 (1.13-1.86) for group A compared to group B (p < 0.01). The association between younger age and higher recurrence was continuously observed in patients under 60years. Any non-PV ablation was associated with a lower recurrence of atrial tachyarrhythmia in group B (aHR 0.68 (0.47-0.96), p < 0.05), but not in group A. AF patients younger than 60years had a higher 1-year AF recurrence after RFCA. Young AF patients might have distinctive pathophysiology of AF requiring more integrated management.

10-Year Outcomes of Patients With Non-Paroxysmal Atrial Fibrillation Undergoing Catheter Ablation.

Radiofrequency catheter ablation (RFCA) is commonly performed in patients with non-paroxysmal atrial fibrillation (AF), but because very long-term follow-up results of RFCA are limited, we investigated the 10-year RFCA outcomes of non-paroxysmal AF. We retrospectively enrolled 100 patients (89 men, mean age 53.5±8.4years) with drug-refractory symptomatic non-paroxysmal AF who underwent 3D electroanatomic-guided RFCA. Procedural characteristics at index procedures and clinical outcomes were investigated. In the index procedures, all patients had pulmonary vein isolation, 56 (56.0%), 48 (48.0%), and 32 (32.0%) underwent additional linear, complex fractionated atrial electrogram (CFAE) and non-pulmonary vein (NPV) foci ablations, respectively. After 124.1±31.7 months, 16 (16%) patients remained in sinus rhythm after just 1 procedure (3 with antiarrhythmic drugs [AAD]) and after multiple (2.1±1.3) procedures in 53 (53.0%) patients (22 with AAD). Left atrial (LA) diameter (hazard ratio HR 1.061; 95% confidence interval (CI) 1.020 to 1.103; P=0.003), presence of NPV triggers (HR 1.634; 95% CI 1.019 to 2.623; P=0.042) and undergoing CFAE ablation (HR 2.003; 95% CI 1.262 to 3.180; P=0.003) in the index procedure were independent predictors for recurrent atrial tachyarrhythmia. The 10-year outcomes of single RFCA in non-paroxysmal AF were unsatisfactory. Enlarged LA, presence of NPV triggers, and undergoing CFAE ablation in the index procedure independently predicted single-procedure recurrence. Multiple procedures are required to achieve adequate rhythm control.

Sex differences involved in persistent atrial fibrillation recurrence after radiofrequency ablation

BackgroundIn recent years, the difference in outcomes of radiofrequency catheter ablation (RFCA) in persistent atrial fibrillation patients has risen. In particular, biological sex seems involved in a different response to the AF ablation procedure. In our study, we analyzed the AF recurrences after RFCA assessing the other association between male/female patients with the outcomes.MethodsWe enrolled 106 patients (74.5% men) with persistent atrial fibrillation with scheduled follow-up. The baseline clinical characteristics and AF recurrence after RFCA were compared between men and women. Cox regression analyses were performed to determine the risk predictors of AF recurrence.ResultsThe proportion of RFCA in women was lower than that in men. Men with persistent AF were younger than women (58.6 ± 10.4 years vs. 65.1 ± 8.7 years, respectively; p = 0.003). The left atrium (LA) diameter was higher in males (43.7 ± 4.6 mm vs. 41.3 ± 5.5 mm; p = 0.028), and the level of left heart ejection fraction (LVEF) was higher in females (59.4 ± 6.9% vs. 64.1 ± 5.5%; p = 0.001). Sex differences in AF recurrence after RFCA were significant during the median 24.4-month (interquartile range: 15.2–30.6 months) follow-up period, and the recurrence rate of AF in women was significantly higher than that in men (p = 0.005). Univariable Cox regression analysis showed that female sex was a risk factor for persistent AF recurrence after RFCA [HR: 2.099 (1.087–4.053)]. Univariate Cox regression analysis revealed that non-PV ablation not associated with AF recurrence [HR: 1.003 (0.516–1.947)].ConclusionIn a monocentric cohort of persistent AF patients, the female biological sex was associated with a higher risk of AF recurrence after RFCA.

Comparative characteristics of different methods of radiofrequency catheter ablation in atrial flutter

Catheter ablation occupies the first place in the treatment of atrial macro reentry arrhythmias. The main controllable parameters in ablations are energy, duration of exposure and use of catheter tip cooling. With traditional ablation techniques, there is a high risk of insufficient tissue damage due to electrode instability. Regarding the issue of stability, a new technique was proposed – reducing the application time with increasing the energy. The aim of this work was to compare the results of radiofrequency catheter ablation (RFA) using an 8 mm uncooled electrode to a 4 mm cooled electrode and a 4 mm cooled electrode with increased energy. Materials and methods. The work is based on a retrospective analysis of the results of catheter ablations in patients with atrial flutter. Patients were divided into 3 groups depending on the parameters of the used radio frequency energy and the type of ablation electrode. Results. It was found that in the group with increased energy, there were the shortest time from the start of RFA to the achievement of success criteria and the lowest radiation exposure. The obtained differences were statistically significant in comparison with two groups of patients who underwent traditional methods. Such differences were associated both with a reduction in the time of the application itself due to the use of high energy as well as the need to apply a smaller number of applications owing to a lower probability of the electrode displacement from the target area. Conclusions. The use of a high-energy protocol allows to success criteria for cavo-tricuspid isthmus ablation more quickly compared to traditional techniques (by 30 % and 22 %, respectively) with less radiation exposure (by 27 % and 24 %, respectively). The use of the high-energy protocol does not lead to an increase in the frequency of complications and can be considered safe for clinical use.

Influence of pulsating intracardiac blood flow on radiofrequency catheter ablation outcomes in an anatomy-based atrium model

Background Highly consistent cardiac ablation outcomes through radiofrequency catheter ablation (RFCA) under pulsatile and constant flow profiles (PP&CP) of intracardiac blood were previously indicated by computer modeling, with simplified geometry and lossless receipt of inflow for ablation catheters. This study aimed to further investigate the effects of intracardiac blood pulsatility in an anatomy-based atrium model. Methods Four pulmonary veins were blood inflows at 10 mm Hg. The mitral valve was the outflow, with PP based on pulsatile velocity curve from clinical measurements, and CP was obtained by averaging the velocity curve under PP over an ablation time of 30 s. A numerical comparison between ablation results under PP and CP, without experimental validation, was performed. Results Temperature fluctuations persisted in mid-myocardium, and most clearly in blood and endocardium under PP. At a constant power of 20 W, marked differences in ablation outcome between PP and CP occurred in the middle of unilateral pulmonary veins and the posterior wall of the left atrium (LA) where the blood velocities were significantly decreased under CP. The mid-myocardial, blood and endocardial temperatures, as well as the effective lesion volume at the former position, were decreased by 4.1%, 15%, 13.6%, and 13.8%, respectively under PP. The extents for the latter position were 11%, 22%, 22.5%, and 55.6%, respectively. Conclusion Intracardiac flow pulsatility causes a greater reduction in blood and endocardial temperatures at ablation sites away from the main bloodstream, effective cooling of which is more likely to rely on blood velocities approaching peak PP values.

Effect of Dapagliflozin on the Outcome of Radiofrequency Catheter Ablation in Patients with Type 2 Diabetes Mellitus and Atrial Fibrillation.

Dapagliflozin, one of the sodium-glucose cotransporter-2 inhibitors, has been widely used for the treatment of type 2 diabetes mellitus (T2DM) and heart failure. In this study, we sought to determine the impact of dapagliflozin on the outcome of radiofrequency catheter ablation (RFCA) for patients with T2DM and atrial fibrillation (AF). This retrospective study included patients who underwent AF ablation between January 2019 to February 2021 at the First Affiliated Hospital of Zhengzhou University. All patients had a history of T2DM and were divided into the dapagliflozin group (n = 79) and the control group (n = 247) according to whether the patients were treated with dapagliflozin after ablation. The definition of AF recurrence was documented atrial arrhythmias over 30 s after a 1-month blanking period. Cox regression models were used to analyze the risk of AF recurrence. Overall, 326 patients were analyzed (mean age, 63.7±10.0 years old; male, 58.9%; paroxysmal AF, 52.8%; recurrence rate, 40.8%). We found that hemoglobin A1c before ablation was higher in the dapagliflozin group than in the control group (7.7±1.4 vs. 7.3±1.2, P = 0.007). After a mean follow-up of 15.5±8.9 months, the dapagliflozin group had a lower recurrence rate than the control group (27.8% vs. 44.9%, P = 0.007). Treatment with dapagliflozin (HR 0.614, ±95%CI 0.387-0.974, P = 0.038) was associated with a lower risk of recurrence of atrial arrhythmias (ATa) after ablation in multivariable Cox regression models that adjusted for duration of AF, BMI, AF type, left atrial diameter (LAD), and eGFR. The Cox regression model that incorporated hemoglobin A1c and other antidiabetic agents also demonstrated a similar reduction in the risk of recurrent atrial arrhythmias with dapagliflozin treatment (HR 0.611, ±95% CI 0.379-0.985, P = 0.043). In patients with T2DM, treatment with dapagliflozin appears to be independently associated with a significant reduction in the risk of recurrent atrial arrhythmias after RFCA.

Monomorphic VT Non-Inducibility after Electrical Storm Ablation Reduces Mortality and Recurrences.

Background: Electrical storm (ES) is defined by clustering episodes of ventricular tachycardia (VT) and is associated with severe long-term outcomes. We sought to evaluate the prognostic impact of radiofrequency catheter ablation (RFCA) in ES as assessed by aggressive programmed ventricular stimulation (PVS). Methods: Single-center retrospective longitudinal study with 82 consecutive ES patients referred for RFCA with a median follow-up (IQR 25–75%) of 45.43 months (15–69.86). All-cause mortality and VT recurrences were assessed in relation to RFCA outcomes defined by 4-extrastimuli PVS: Class 1—no ventricular arrhythmia; Class 2—no sustained monomorphic VTs (mVT) inducible, but non-sustained mVTs, polymorphic VTs, or VF inducible; Class 3—clinical VT non-inducible, other sustained mVTs inducible; and Class 4—clinical VT inducible. Results: Class 1, Class 2, Class 3, and Class 4 were achieved in 56.1%, 13.4%, 23.2%, and 7.4% of cases, respectively. The combined outcome of Class 1 + Class 2 (no sustained monomorphic VT inducible) led to improved survival (log-rank p < 0.001) and reduced VT recurrence (log-rank p < 0.001). Residual monomorphic VT inducibility (HR 6.262 (95% CI: 2.165–18.108, p = 0.001), NYHA IV heart failure symptoms (HR 20.519 (95% CI: 1.623–259.345), p = 0.02)), and age (HR 1.009 (95% CI: 1.041–1.160), p = 0.001)) independently predicted death during follow-up. LVEF was not predictive of death (HR 1.003 (95% CI: 0.946–1.063) or recurrences (HR 0.988 (95% CI: 0.955–1.021)). Conclusions: Non-inducibility for sustained mVTs after aggressive PVS post-RFCA leads to improved survival in ES, independently of LVEF.

Outcomes of Radiofrequency Catheter Ablation of Atrial Arrhythmias in Patients with Cardiac Amyloidosis

Outcomes of Radiofrequency Catheter Ablation of Atrial Arrhythmias in Patients with Cardiac Amyloidosis

Catheter ablation of atrioventricular nodal reentry tachycardia and quality of life

Abstract Funding Acknowledgements Type of funding sources: None. Objective To present the results of radiofrequency catheter ablation of patients with atrioventricular nodal reentry tachycardia (AVNRT). Materials and methods Catheter ablation was performed in 488 patients with AVNRT. The age of patients is from 14 to 66 (mean age 40.2±14.7 years). Comorbidities such as ischemic heart disease and hypertension were in 234 (48%) patients, in 83 (17%) patients chronic myocarditis was detected. No organic pathology from the cardiovascular system was detected in 171 (35%) patients. In the anamnesis, tachycardia attacks were observed from 2 to 29 years (on average, 18.7 ± 4.9 years). After confirming the diagnosis of typical "slow-fast" AVNRT on the intracardiac electrophysiological investigation, an ablation catheter was inserted into the heart of the patient. Then radiofrequency ablation of "slow paths" of AV-connection was performed. Traditionally, the quality of life associated with health is considered as an integral characteristic of a person’s physical, mental (emotional) and social well-being, based on his subjective perception of these attributes. We assessed the quality of life of patients with AVNRT using the SF-36 questionnaire and The Hospital Anxiety and Depression Scale (HADS) before and after performing of catheter radiofrequency ablation. Results In 488 patients, the criteria for the effectiveness of the destruction of the "slow pathways" were obtained and the effectiveness of the procedure was 99.38%. During the study of indicators of QOL according to the SF-36 questionnaire, wich was obtained 6 months after Radiofrequency Ablation (RFA), the most significant improvement was noted in terms of role functioning RF (by 48.6%), physical functioning PF (by 25.5%) and GH general health (19.7%). The BP bodily pain index, although increased (by 13.8%), but not reliably. After 12 months, we observed a significant improvement in QOL in all indicators of the physical component of health, which did not differ from those in the control group. Clinically manifested anxiety was observed in a reliably larger number of patients (63.6%). The total indicator of the anxiety level was 11.1±2.4 points and corresponded to clinically manifested anxiety. The majority (66.7%) of patients had a subclinical form of depression. The total value of the depression level was 9.8±1.8 points and corresponded to the indicator of subclinically manifested disorders. Testing on the hospital anxiety and depression assessment scale after 12 months showed that all patients had no significant symptoms of anxiety and depression. The total score of anxiety was -2.8±1.1 points (p&amp;lt;0.0001), depression - 2.4±1.4 (p&amp;lt;0.0001). Conclusions Radiofrequency catheter ablation is an effective, drastic and safe method of treating AVNRT, the effectiveness of the procedure reaches up to 100% and allows patients to improve their quality of life, get rid of the lifelong intake of antiarrhythmic drugs.