Catheter Ablation Of Tachycardia Research Articles

A gray zone: Role of transesophageal echocardiography before atrial tachycardia catheter ablation.

There is a lack of studies in the literature directly investigating the relationship between atrial tachycardia (AT) and left atrial (LA)/left atrial appendage (LAA) thrombus, and current guidelines do not provide strong recommendations regarding the use of transesophageal echocardiography (TEE) before AT catheter ablation. This study aims to elucidate the relationship between AT and the presence of LA/LAA thrombus and contribute to the literature on the use of TEE before AT catheter ablation. This single-center retrospective observational study screened patients who underwent TEE between February 10, 2019, and February 10, 2023. Patients were assigned to the AT patient and control groups. TEE was conducted to exclude thrombus in the AT ablation group. The control group included patients who underwent TEE for interatrial septum evaluation and had LA imaging during TEE but did not have atrial arrhythmia. To mitigate bias between the AT patient group and the control group, they were randomized 1:1 using propensity-score matching (PSM). Following randomization, each group consisted of 49 patients. All analyses were conducted after PSM. There were no statistically significant differences between the AT patient and control groups in terms of baseline clinical characteristics and echocardiographic features. Additionally, no significant differences were found between the blood viscosities calculated at low and high shear rates in both groups. The study revealed a significant difference between the two groups in the presence of LA spontaneous echo contrast (SEC) (24.5% in AT group vs 0% in Control group, p = .001), but not in the presence of thrombi (8.2% in AT group vs 0% in Control group, p = .117). Compared to the control group, the presence of SEC was significantly higher in the AT patient group. The increased frequency of SEC in AT patients suggests the hypothesis that AT may contribute to LA stasis. The routine use of TEE before AT catheter ablation remains controversial, despite the presence of LA thrombus and SEC in the AT patient group. The clinical assessment of thrombus presence before the procedure must be conducted on a patient-specific basis.

Injury to the sinus nodal artery during radiofrequency ablation of atrial fibrillation and atrial tachycardia: its prevalence and treatment with percutaneous coronary intervention

Abstract Background/Introduction Injury to the sinus node artery (SNA) leading to SN dysfunction during radiofrequency catheter ablation (RFCA) of atrial Fibrillation (AF) and atrial tachycardia (AT) has been reported. Purpose The purpose of this study was to elucidate the prevalence and clinical course of SNA injuries during RFCA of AF/AT and examine the efficacy of the percutaneous coronary intervention (PCI) to restore SN function. Methods We retrospectively analyzed data from 6,906 consecutive patients (pts) who underwent RFCA of AF/AT (6,379 pts with AF ablation and 527 pts with AT ablation) in two institutions between January 2013 and December 2022. Results Among 6,906 pts, 9 (0.13%) pts developed SN dysfunction due to SNA injury during RFCA (8 with AF, 1 with AT). Acute SNA injury (total occlusion or severe narrowing of the SNA) was confirmed by coronary angiography (CAG) during the RFCA session in 8/9 pts. In the remaining patient, SNA injury was suspected based on the CT angiography. The culprit sites of the SNA injury were located at the septal site of the superior vena cava-right atrium junction in 4 pts (44%), on the left atrial appendage ridge in 3 (33%), on the roof of the left atrium adjacent to the right superior pulmonary vein in 1 (11%), and in the persistent left superior vena cava in 1 (11%). PCI to the occluded SNA was performed in 8 of the 9 pts: 1) coronary blood flow of the SNA was restored by a 0.014" guidewire advancement into the occluded artery using a micro-catheter followed by direct nitroprusside injection in 4 pts; 2) the direct balloon angioplasty using 0.75-1.5 mm diameter balloons was required to maintain the blood flow of SNA in 3 pts; and 3) CAG revealed spontaneous recovery of the blood flow of SNA in one pt. The remaining patient did not receive the CAG/PCI. All 8 pts who underwent the PCI resulted in restoration of normal sinus rhythm. During a median of 44 months follow-up, all 8 pts who received the PCI maintained normal sinus rhythm, while one patient without PCI demonstrated persistent SN dysfunction. Conclusions SNA injury during RFCA is a rare but critical complication. Prompt recognition by CAG and subsequent PCI effectively restores SN function in pts with unexpected SN dysfunction during RFCA procedures.

Atrioventricular nodal reentrant tachycardia ablation (avnrt), a female disease. insights from the german ablation registry

Abstract Background The German Ablation registry is a multi-centre prospective registry for electrophysiologic ablation procedures. Purpose We herein report on catheter ablation of atrioventricular nodal reentrant tachycardia (AVNRT) according to underlying gender. Methods From January 2007 until January 2010 a total of 2918 patients [64.4% female, 55 (43; 67) years] undergoing catheter ablation of AVNRT were enrolled in this registry and followed for at least one year. Results Female patients undergoing ablation for AVNRT were significantly younger than male patients [52 (41; 66) versus 60 (47; 70); p<0.001] and had less structural heart disease than male patients [12,1 % (228/1880) versus 30,8 % (320/1038)]. Female patients more often had ≥ one arrhythmia episode per month [73,7 % versus 68,1 %; p<0.001], nevertheless arrhythmia documentation was less often present in female patients [81,7 % versus 85,4 %; p=0.012]. Success rate was high (98,9 %) and major complications prior to discharge (death, myocardial infarction, stroke) were rare (1/2917) without significant difference between female and male patients. During a follow-up period of 682.9 ± 172,9 days, female patients more often experienced arrhythmia recurrences [19,1 % versus 13,8 %; p<0.001]. Conclusions Almost two-thirds of patients undergoing ablation for AVNRT included in the German ablation registry were female. Female patients were younger and less often had structural heart disease or other comorbidities than male patients undergoing AVNRT ablation. Success rates and complication rates were similar. During follow-up female patients more often experienced arrhythmia recurrences.

Successful catheter ablation of atrial tachycardia initiated with orthodromic capture of superior vena cava potentials.

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

Incidence of Atrial Fibrillation After Radiofrequency Catheter Ablation for Atrial Tachycardia in Congenital Heart Disease

BackgroundAtrial tachycardia (AT) and atrial fibrillation (AF) coexist in 30% of congenital heart disease (CHD) patients. Successful atrial tachycardia catheter ablation (ATCA) might prevent AF. Data on new-onset AF after ATCA in CHD is scarce. ObjectivesThis study aimed to evaluate the incidence of new-onset AF after ATCA and to assess clinical characteristics associated with new-onset AF after ATCA in CHD. MethodsCHD patients referred for ATCA to 3 European centers were included. New occurrence of AF was defined as electrocardiographic documentation of AF after any ATCA procedure in patients without history of AF. ResultsIn 277 CHD patients (median age 37 years [Q1, Q3: 23, 49 years], 58% men, 59 [21%] simple, 111 [40%] moderate, and 107 [39%] complex CHD), AF occurred in 25 patients (9%) a median of 8 months (Q1, Q3: 4, 27 months) after ATCA. New-onset AF was persistent in the majority of the patients (17 of 25 [63%]). Patients with new-onset AF were older (44 years [Q1, Q3: 29, 55 years] vs 36 years [Q1, Q3: 23, 49 years]; P = 0.009) and more frequently had simple CHD (13 of 25 [52%] vs 46 of 252 [18%], respectively; P < 0.0001). Acute ATCA success rates were similar in patients with and without AF (52% vs 48%; P = 0.429). Simple CHD was an independent predictor of new-onset AF during follow-up. ConclusionsIn our large cohort of patients with congenital heart disease, new-onset AF after ablation for AT occurred in only 9% of the patients. AF occurred without AT recurrence and was persistent in the majority of patients.

Contemporary catheter ablation of complex atrial tachycardias after prior atrial fibrillation ablation: pulsed field vs. radiofrequency current energy ablation guided by high-density mapping.

Catheter ablation (CA) of post-ablation left atrial tachycardias (LATs) can be challenging. So far, pulsed field ablation (PFA) has not been compared to standard point-by-point radiofrequency current (RFC) energy for LAT ablation. To compare efficacy of PFA vs. RFC in patients undergoing CA for LAT. Consecutive patients undergoing LAT-CA were prospectively enrolled (09/2021-02/2023). After electro-anatomical high-density mapping, ablation with either a pentaspline PFA catheter or RFC was performed. Patients were matched 1:1. Ablation was performed at the assumed critical isthmus site with additional ablation, if necessary. Right atrial tachycardia (RAT) was ablated with RFC. Acute and chronic success were assessed. Fifty-six patients (n = 28 each group, age 70 ± 9 years, 75% male) were enrolled.A total of 77 AT (n = 67 LAT, n = 10 RAT; 77% macroreentries) occurred with n = 32 LAT in the PFA group and n = 35 LAT in the RFC group. Of all LAT, 94% (PFA group) vs. 91% (RFC group) successfully terminated to sinus rhythm or another AT during ablation (P = 1.0). Procedure times were shorter (PFA: 121 ± 41 vs. RFC: 190 ± 44 min, P < 0.0001) and fluoroscopy times longer in the PFA group (PFA: 15 ± 9 vs. RFC: 11 ± 6 min, P = 0.04). There were no major complications. After one-year follow-up, estimated arrhythmia free survival was 63% (PFA group) and 87% (RFC group), [hazard ratio 2.91 (95% CI: 1.11-7.65), P = 0.0473]. Pulsed field ablation of post-ablation LAT using a pentaspline catheter is feasible, safe, and faster but less effective compared to standard RFC ablation after one year of follow-up. Future catheter designs and optimization of the electrical field may further improve practicability and efficacy of PFA for LAT.

Comparison of safety and effectiveness of different sheaths in ablation of focal atrial tachycardia: a retrospective study.

A novel visualized steerable sheath, referred to as the Vizigo sheath, has been utilized in clinical interventions. The objective of this study was to evaluate and contrast the efficacy and safety of the Vizigo sheath with other sheaths in the catheter ablation (CA) for focal atrial tachycardia (FAT). A retrospective cohort study was conducted on consecutive patients with CA for FAT from March 2019 to February 2022. Objectives were to assess the impact of the Vizigo sheath on acute and long-term ablation success rates, procedural and fluoroscopy times, and contact force (CF). A total of 164 patients, mean age 50±15 years, 97 (59.1%) women, underwent CA of FAT using the Vizigo sheath (N=42), non-visualized steerable sheath (N=36), or other conventional sheath (N=86). Age, sex, body mass index (BMI), presence of hypertension, heart failure, and diabetes mellitus were not significantly different among the three groups. The acute success rate of 94.0% was similar among the three groups. Over a follow-up of 14±2 months, the Vizigo sheath was associated with superior arrhythmia-free survival (88.1%) when compared to non-visualized steerable (69.4%; P=0.04) and other conventional (72.1%, P=0.046) sheaths. Procedural duration, number of ablation lesions, and ablation times were similar among the three groups. However, the Vizigo sheath was associated with lower fluoroscopy times (e.g., 145 vs. 250 s with Vizigo versus non-visualized steerable sheaths, P=0.03) and higher CF (e.g., average CF 12.0 versus 8.0 g with Vizigo versus non-visualized steerable sheaths, P=0.003). The application of Vizigo sheath can improve the long-term success rate of FAT and reduce the radiation exposure of patients and medical staff in our single-center limited sample study. More research may be needed in the future to confirm our findings.

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.

Ablation of atrial flutter in a patient after Fontan procedure: a case report of challenging access to the common atrium

Abstract Background In patients with a total cavopulmonary connection in Fontan circulation, the access to the common atrium (CA) during a catheter ablation can be challenging, even in the presence of fenestration in an intra-atrial lateral tunnel (IALT). In our department, the fenestration is typically marked with metal clips (MCs). To the best of our knowledge, there is no previous report of balloonoplasty of clipped fenestration. Case summary A 19-year-old male with hypoplastic left heart syndrome (HLHS) was scheduled for catheter ablation of recurrent atrial tachycardia. He was diagnosed with HLHS prenatally and underwent a stepwise surgical palliation. Fontan circulation was completed with the creation of a fenestrated IALT. The fenestration was marked by four MCs. During the ablation procedure, the passage of the steerable sheath with mapping catheter to the CA was prevented by a small fenestration size and rigidness of the edges of the fenestration caused by the MCs. Multiple attempts to dilate the fenestration using a peripheric angioplasty balloon failed. Only angioplasty with the ‘balloon-against-dilator’ technique was finally successful. Activation map showed a counterclockwise atrial flutter in the CA; successful ablation was performed. Discussion We present a case of challenging access to the CA through a clipped fenestration in a polytetrafluoroethylene baffle for atrial tachycardia ablation. Even though a tunnel fenestration in Fontan patients facilitates access to the CA, the passage of a steerable introducer with a mapping catheter may be challenging due to diameter mismatch and the rigidity of its edges caused by MCs. The balloon-against-dilator technique might be helpful when conventional balloon angioplasty fails.

Ventricular Tachycardia Catheter Ablation: Retrospective Analysis and Prospective Outlooks-A Comprehensive Review.

Ventricular tachycardia is a potentially life-threatening arrhythmia associated with an overall high morbi-mortality, particularly in patients with structural heart disease. Despite their pivotal role in preventing sudden cardiac death, implantable cardioverter-defibrillators, although a guideline-based class I recommendation, are unable to prevent arrhythmic episodes and significantly alter the quality of life by delivering recurrent therapies. From open-heart surgical ablation to the currently widely used percutaneous approach, catheter ablation is a safe and effective procedure able to target the responsible re-entry myocardial circuit from both the endocardium and the epicardium. There are four main mapping strategies, activation, entrainment, pace, and substrate mapping, each of them with their own advantages and limitations. The contemporary guideline-based recommendations for VT ablation primarily apply to patients experiencing antiarrhythmic drug ineffectiveness or those intolerant to the pharmacological treatment. Although highly effective in most cases of scar-related VTs, the traditional approach may sometimes be insufficient, especially in patients with nonischemic cardiomyopathies, where circuits may be unmappable using the classic techniques. Alternative methods have been proposed, such as stereotactic arrhythmia radioablation or radiotherapy ablation, surgical ablation, needle ablation, transarterial coronary ethanol ablation, and retrograde coronary venous ethanol ablation, with promising results. Further studies are needed in order to prove the overall efficacy of these methods in comparison to standard radiofrequency delivery. Nevertheless, as the field of cardiac electrophysiology continues to evolve, it is important to acknowledge the role of artificial intelligence in both the pre-procedural planning and the intervention itself.

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;

Remote magnetic navigation catheter ablation for atrial tachycardia in a patient with d-transposition of the great arteries, atrial switch, and a mechanical valve in the tricuspid position.

Remote magnetic navigation catheter ablation for atrial tachycardia in a patient with d-transposition of the great arteries, atrial switch, and a mechanical valve in the tricuspid position.

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

Technological advances in ventricular tachycardia catheter ablation: the relentless quest for novel solutions to old problems.

Several novel technologies allowing catheter ablation (CA) with a favorable safety/efficacy profile have been recently developed, but not yet extensively clinically tested in the setting of ventricular tachycardia CA. In this technical report, we overview technical aspects and preclinical/clinical information concerning the application of three novel CA technologies in the ventricular milieu: a pulsed field ablation (PFA) generator (CENTAURI™, Galaxy Medical) to be used with linear, contact force-sensing radiofrequency ablation catheters; a contact force-sensing radiofrequency ablation catheter equipped with six thermocouples and three microelectrodes (QDOT Micro™, Biosense-Webster), allowing high-resolution mapping and temperature-controlled CA; and a flexible and mesh-shaped irrigation tip, contact force-sensing radiofrequency ablation catheter (Tactiflex, Abbott). We also report three challenging VT cases in which CA was performed using these technologies. The CENTAURI system was used with the Tacticath™ (Abbott) ablation catheter to perform ventricular PFA in a patient with advanced heart failure, electrical storm, and a deep intramural septal substrate. Microelectrode mapping using QDOT Micro™ helped to refine substrate assessment in a VT patient with congenitally corrected transposition of the great arteries, and allowed the identification of the critical components of the VT circuit, which were successfully ablated. Tactiflex™ was used in two challenging CA cases (one endocardial and one epicardial), allowing acute and mid-term control of VT episodes without adverse events. The ideation and development of novel technologies initially intended to treat atrial arrhythmias and successfully implemented in the ventricular milieu is contributing to the progressive improvement in the clinical benefits derived from VT CA, making this procedure key for successful management of increasingly complex patients.

Paradigm shift of catheter ablation of atypical atrioventricular nodal tachycardia: 3D mapping-based ablation of exits of slow pathway

Abstract Background In current practice, the ablation target of atypical atrioventricular nodal tachycardia (AVNRT) is the earliest atrial activation site in the coronary sinus (CS) or conventional slow pathway (SP) region. Objectives The purpose of this study was to map the site of earliest retrograde atrial activation using electroanatomic 3D mapping during atypical AVNRT and to evaluate successful ablation sites. Methods Forty-two patients with a total of 49 AVNRTs (slow/fast 30; fast/slow 15; slow/slow 4) underwent EP study and ablation. Among them there were 14 patients (10 women, 60±19 y/o) in whom 19 atypical AVNRT (fast/slow 15; slow/slow 4) were induced. Results The intracardiac electrocardiograms or 3D mapping of the exit site during tachycardia revealed that 7 patients had exit sites solely inside the CS (left inferior extension=LIE), 3 solely in the right postero-septal tricuspid annulus (TA) (right inferior extension=RIE), and 4 had both LIE and RIE exits. The distance from the CS ostium to LIE exits was 14±6 mm. RIE exits were located on the TA posterior to the CS ostium (between 5 and 6 o’clock in the LAO projection). Ablation targeting these exits or traditional SP succeeded in long term elimination of AVNRT in 13 of the 14 patients (93%). There were no complications. Conclusions Catheter ablation targeting the exit sites of LIE or RIE mapped at the CS or TA holds promise as an effective and safe alternative approach to the current targets of ablation for atypical AVNRT cases.Distribution of exit sites during atypicthe circuit of atypical AVNRT：the exit s

Catheter ablation for ventricular tachycardia after myocardial infarction: meta-analysis of randomised controlled trials

Abstract Background The prognostic impact of ventricular tachycardia (VT) catheter ablation is an important outstanding research question. Purpose We undertook a reconstructed individual patient data meta-analysis of randomised controlled trials comparing ablation to medical therapy in patients developing VT after myocardial infarction (MI). Methods We systematically identified all trials comparing catheter ablation to medical therapy in patients with VT and prior MI. The pre-specified primary endpoint was all-cause mortality assessed using reconstructed individual patient data obtained by digitisation of published Kaplan-Meier curves and subsequent construction of Cox proportional hazards regression models. Pre-specified secondary endpoints included trial-level assessment by random effects meta-analysis of all-cause mortality, VT recurrence, defibrillator shocks and all-cause hospitalisations. Meta-regression was performed to evaluate the effect of VT mapping in addition to substrate modification. Sensitivity analyses were performed depending on the proportion of patients with prior MI included. (PROSPERO ID CRD42023390799) Results Eight trials, recruiting a total of 874 patients, were included. 430 patients were randomised to catheter ablation and 444 to medical therapy. Catheter ablation reduced all-cause mortality compared to medical therapy when synthesising reconstructed individual patient data (hazard ratio 0.57, 95% confidence interval (CI) 0.38 to 0.85, p=0.007), but not in trial-level analysis (relative risk 0.91, 95%CI 0.67 to 1.23, p=0.53, I2=0%). Catheter ablation significantly reduced VT recurrence, defibrillator shocks and hospitalisations compared to medical therapy. Sensitivity analyses were consistent with the primary analyses. Conclusion In patients with post-infarct ventricular tachycardia, catheter ablation reduces mortality.

Abstract 14862: Electrophysiological Predictors of Susceptible Atrial Substrate for the Onset and Recurrence of Atrial Fibrillation

Introduction: Atrial electro-anatomical substrate is essential for pathogenesis of atrial fibrillation (AF). Electrophysiological markers of AF susceptibility, however, are not well characterized. Identifying markers of atrial substrate has significant clinical implications in early detection and intervention for AF or stratifying patients at higher risk of AF recurrence following ablation. Hypothesis: We hypothesized that conduction indices on surface electrocardiogram (ECG) and intracardiac electrogram (EGM) may predict susceptibility and/or AF recurrence following ablation. Methods: We studied all consecutive patients who underwent electrophysiological study and catheter ablation for AF or atrioventricular nodal reentrant tachycardia (AVNRT) from 2013 to 2018. Atrial conduction indices were measured on ECG and EGM during the electrophysiology study. We evaluated correlations between both AF and AF recurrence with conduction indices, and associations between AF recurrence and conduction indices were evaluated with univariate logistic regression analyses and machine learning. Results: The study population included 387 patients with AF (mean age 63 years, 31% female) and compared to patients with AVNRT (n=94) who were considered as a control group. AF was associated with significant prolongation of all measured surface ECG and EGM parameters (p&lt;0.05). During a mean follow up of 5±2 years, recurrence of AF (48%) after successful ablation occurred in patient with longer P wave duration, left atrial (LA) conduction duration, proximal to distal coronary sinus (pCS-dCS) interval, and P-dCS interval (p&lt;0.05). Prolonged P wave duration, LA duration, pCS-dCS interval, and QRS duration were predictors of AF recurrence. Machine learning modeling determined that pCS-dCS interval, QRS duration, and LA duration (lead V1 and II) were the most impactful conduction indices for AF recurrence. Conclusions: Atrial conduction indices are markers of susceptible substrate for the onset and the recurrence of AF after successful ablation. LA conduction parameters can be used for risk stratification to facilitate early detection and management of AF.

ATE Score Diagnostic Accuracy for Predicting the Absence of Intra-Atrial Thrombi Before AF Ablation

BackgroundIn a preliminary study in patients hospitalized for catheter ablation of atrial fibrillation (AF), the atrial thrombus exclusion (ATE) score (stroke, hypertension, heart failure, and D-dimers >270 ng/mL) was developed to rule out the diagnosis of intra-atrial thrombus, with a negative predictive value (NPV) of 100%, and to avoid performing transesophageal echocardiography (TEE). ObjectivesThe present study was designed to prospectively confirm the NPV of the ATE score in an independent population. MethodsConsecutive patients hospitalized for catheter ablation of AF or left atrial tachycardia (LAT) were prospectively enrolled in a multicenter study. D-dimer levels were measured within 48 hours before ablation. An ATE score of 0 was considered predictive of no thrombus. TEE was routinely performed at the beginning or just before the ablation procedure. The primary endpoint was the presence of atrial thrombus diagnosed by TEE. ResultsThe analysis included 3,072 patients (53.3% paroxysmal AF, 36.7% persistent AF, and 10% LAT). A thrombus was detected in 29 patients (0.94%; 95% CI: 0.63%-1.35%), all on appropriate anticoagulant therapy. An ATE score of 0 was observed in 818 patients (26.6%), and the sensitivity, specificity, positive predictive value, and NPV were 93.1%, 26.8%, 1.2%, and 99.8%, respectively. Follow-up of the 2 false negative patients revealed the persistence of chronic organized thrombi. ConclusionsIn patients hospitalized for catheter ablation of AF or LAT, the ATE score identifies a population at very low risk for atrial thrombus. In consultation with the patient, the cardiologist may consider not performing a preoperative TEE in case of an ATE score of 0.

Prognostic implications of baseline rhythm during catheter ablation for atrial tachycardia.

Atrial tachycardias (AT) occurring in patients after previous atrial fibrillation (AF) ablation are increasingly observed in clinical practice. Catheter ablation is the treatment of choice but an optimal workflow to improve patient outcome has not been defined. The purpose of this study was to assess procedural and clinical outcome depending on baseline rhythm at the beginning of AT ablation. A total of 380 patients (69 (61-75) years, 56.6% male) who underwent catheter ablation for consecutive AT after previous AF ablation were studied. At the beginning of the procedure, 140 patients (36.8%) presented in sinus rhythm (SR), 208 (54.7%) with AT and 32 (8.4%) with AF. Patients in SR or with AT underwent shorter procedures (173 (132-213) minutes vs. 161 (120-203) minutes vs. 226 (154-249) minutes; p = 0.002) with more frequent termination to SR (87.9% vs. 81.3% vs. 56.3%; p < 0.001) than patients with AF. Acute procedural success did not differ between patients in SR or with AT but was higher compared to those with AF (96.4% vs. 97.1% vs. 87.5%; p = 0.033). During a follow-up of 290 (181-680) days, patients in baseline SR experienced arrhythmia recurrences less often (36.4% vs. 49.5% vs. 68.8%; p = 0.002) than patients with AT or AF. Baseline rhythm during AT ablation predicts procedural and clinical outcome. Whereas acute procedural success does not differ between patients in SR or with AT, patients presenting in SR have a more favorable mid-term success rate.