Successful Catheter Ablation Research Articles

Characterisation of patients who develop atrial fibrillation-induced cardiomyopathy

IntroductionAtrial fibrillation (AF)-induced cardiomyopathy (AIC) is retrospectively defined after normalisation of left ventricular ejection fraction (LVEF) in sinus rhythm. It is unclear why some patients develop AIC.HypothesisPatients with AIC have...

Intramural Ventricular Arrhythmias: How to Crack a Hard Nut.

Successful catheter ablation of ventricular arrhythmias depends on identifying the critical tissues that sustain the arrhythmia. Increasingly, the intramural space is being recognized as an important source of idiopathic and reentrant ventricular arrhythmias, representing a common cause of ablation failure. A systematic approach to mapping and ablating these arrhythmias is key to optimize outcomes. Intramural ventricular arrhythmias are common in certain anatomical locations such as the left ventricular ostium or the interventricular septum. In these cases, mapping of the septal coronary veins provides an opportunity to explore the intramural compartment of the septum to perform activation mapping, entrainment and/or pace mapping. When an intramural arrhythmia is identified, ablation may require radiofrequency application from multiple sites, prolonged lesions, or special ablation techniques such as bipolar ablation or transvenous ethanol injection. Identification of intramural ventricular arrhythmias depends on comprehensive mapping that should include the coronary venous system, and ablation often requires advanced techniques. This paper provides a guide on when to suspect an intramural ventricular arrhythmia in the electrophysiology laboratory and how to approach mapping and ablation in these challenging cases.

Limitation of Unipolar Electrograms in Guiding Successful RFCA of Idiopathic Ventricular Arrhythmias Associated With Discrete Pre-Potential.

Activation mapping for idiopathic ventricular arrhythmias (IVAs) typically relies on identifying the earliest bipolar electrograms and unipolar electrograms characterized by an initial QS morphology preceding the intrinsic deflection. However, the utility of unipolar electrogram morphology, particularly when associated with discrete pre-potentials, in guiding IVA mapping is not well understood. We retrospectively analyzed 537 patients who underwent successful radiofrequency catheter ablation (RFCA) for IVAs between March 2016 and August 2023. Among them, 23 patients (4.3%) exhibited discrete bipolar pre-potentials with an isoelectric line between the end of the discrete pre-potential and the onset of the QRS complex during IVAs at the successful RFCA site. These cases were included in this study. The time interval from the onset of the discrete pre-potential to the onset of the QRS complex was 66.4 ± 18.3 ms. The duration of the isoelectric line between the end of the discrete pre-potential and the onset of the QRS complex was 36.9 ± 13.6 ms. Unipolar electrograms associated with discrete pre-potentials exhibited an initial negative morphology in only 13 out of 23 patients (56.5%). In contrast, initial positive and isoelectric configurations in unipolar electrograms were observed in two patients (8.7%) and eight patients (34.8%), respectively. Perfect pace mapping was obtained in 21 patients (91.3%). RFCA was successful at the earliest site of the pre-potential within 3.5 ± 1.5 s in all 23 patients. During the 2.4 ± 1.2 years follow-up period, only one patient (4.3%) experienced a recurrence of clinical IVAs, with no complications reported during RFCA or follow-up. Unipolar electrograms show limited reliability in guiding the identification of IVAs origins compared to bipolar electrograms associated with discrete pre-potentials.

Abstract 4136869: Time Course and Predictors of PVC Recurrence After Acutely Successful Catheter Ablation

Introduction: In prior studies, predictors of long-term success following acutely successful radiofrequency (RF) ablation have included female-sex, single-PVC morphology and EGM-QRS > 24ms. Time course and predictors of PVC recurrence following acutely successful ablation has been less well documented. Use of extended ambulatory monitoring in the immediate post-procedural period can help to identify those with early recurrence. Goals: To define time to recurrence and predictors of recurrence of PVCs after RF ablation following acutely successful ablation. Methods: Consecutive patients from January 1 st , 2016 through December 31 st , 2023 undergoing PVC ablation with available post-ablation extended ambulatory monitoring (Zio, iRhythm, San Francisco, CA) were retrospectively analyzed. Recurrence was defined as an increase in PVC burden to >5% during monitoring after acute success or failure to have sustained reduction in PVC burden of >80%. Acute success was defined as elimination of the targeted PVC after the last ablation lesion. Long-term succes was defined as absence of targeted PVC's during all follow-up visits and PVC-burden < 5% on follow-up monitoring. Results: Among 121 patients who underwent successful PVC ablation, 101 (83.4%) had long-term success and 20 (17%) had recurrence. Patients with recurrence were older (62.4 ± 12 vs 55 ± 13., p = 0.019), had a higher incidence of CAD (13 (13%) vs 9 (45%), p = 0.001) and CHF (40 (40%) vs 15 (75%), p = 0.004). At time of ablation, the recurrence group was also more likely to have >1 PVC morphology (6 (6%) vs 8 (40%), p = <0.001). Location and earliest activation time of the predominant PVC were not assocated with likelihood of recurrence. Within the recurrence group, 13 (65%) had recurrence in the immediate 2 week post-procedural period with an average time to recurrence of 3.9 days. Conclusion: Recurrence occured in slightly less than 20% of cases with a relatively high proportion of those occuring within the immediate 2 week post-procedural period during extended ambulatory monitoring. The presence of greater than 1 PVC morphology at time of ablation is a risk factor for recurrence suggesting a higher likelihood of acute suppression without durable resolution in those instances.

Predictors of long‐term success after high‐density mapping‐guided substrate ablation procedures for ventricular tachycardia in patients with ischemic cardiomyopathy

AbstractIntroductionHigh‐density (HD) substrate mapping may increase success of catheter ablation targeting ventricular tachycardia (VT). However, despite its use, recurrent VT is not uncommon. We aim to investigate factors that are associated with outcomes after HD mapping‐guided substrate ablation procedures for VT in patients with ischemic cardiomyopathy.MethodsObservational cohort study includes patients with ischemic heart disease who underwent HD mapping‐guided substrate ablation of VT. Baseline and procedural characteristics were associated with outcomes after VT ablation.ResultsVT ablation employing HD mapping was performed in 80 patients. Median follow‐up was 2.3 years. VT‐free survival at one, two, and five years were 65%, 49%, and 40%. One‐, two‐, and five‐year implantable cardioverter defibrillator (ICD) shock‐free survival rates were 90%, 81%, and 70%. Complications occurred in 3 patients (3.8%, 1 vascular, 2 tamponades). Left ventricular ejection fraction (LVEF) and 45 W (vs. 35 W) ablation power were associated with VT‐free survival. High ablation power was also associated with shock‐free survival. All‐cause mortality during follow‐up was associated with higher age, the presence of chronic obstructive pulmonary disease (COPD), LVEF, and urgent ablation.ConclusionsIn patients with ischemic cardiomyopathy that had HD substrate mapping‐guided VT ablation, ablation power was associated with both VT‐free and shock‐free survival, underlining the importance of effective target elimination. All‐cause mortality during follow‐up was associated with several factors (age, COPD, LVEF, and urgent vs. elective ablation), which could be used to guide patient selection for VT ablation.

Contractile reserve is associated with response to catheter ablation in patients with atrial fibrillation and left ventricular systolic dysfunction

Abstract Background Although patients with atrial fibrillation (AF) and left ventricular systolic dysfunction (LVSD) can benefit from catheter ablation, some patients do not respond. Prospectively identifying responders is challenging. Contractile Reserve (CR) on Exercise Stress Echocardiography (ESE) has demonstrated stratifying value before cardiac resynchronisation therapy but has not been evaluated in the setting of AF. Objective To evaluate whether CR on ESE was associated with response to CA in patients with LVSD. Methods Patients with persistent AF and LVSD (LVEF <50%) undergoing first-time catheter ablation were enrolled in the AFHF study. Patients underwent trans-thoracic echocardiography at rest and maximum exertion using a recumbent cycle ergometer. CR was the difference in LVEF at maximum exertion versus rest. Echocardiography was repeated six months after successful catheter ablation to determine Response based on the Universal Definition of Heart Failure improvement (LVEF +10%, or if baseline LVEF >40% then LVEF>50%). Results 52 patients were enrolled with baseline demographics in Table 1. 39 patients completed follow-up with 32 (82%) being responders. Responders had greater CR than non-responders (+10% (+5, +12) vs 3% (0, +4), (p=0.008)). A CR ≥ 5% had a positive predictive value of 0.96 for Response in this cohort. The AUROC was 0.83 with a specificity of 0.86. This was also associated with significant improvement in reported Minnesota living with HF scores (p<0.01). Conclusion CR was associated with response to CA in patients with persistent AF and LVSD in this exploratory analysis. Validation in an external cohort is needed to evaluate fit before prospective evaluation of its clinical utility.Baseline CharacteristicsROC curve for response to ablation

Clinical findings from a large endo-epicardial atrial arrhythmia ablation registry

Abstract Background Despite advances, catheter ablation success rates for persistent AF remain at 50-60%. The approach for recurrent persistent AF, beyond pulmonary vein isolation, remains contentious. Surgical maze procedures have demonstrated superior outcomes compared to catheter ablation. Catheter-based linear lesions sets have failed to demonstrate efficacy, perhaps due to a lack of consistent transmurality with endocardial radiofrequency. Objective We report our safety and clinical data of an endo-epicardial approach using high-power radiofrequency ablation for atrial arrhythmias. Methods 126 patients (80% male; mean age 65 years [43-81]) underwent redo ablation, between August 2020 and February 2024, for recurrent symptomatic atrial arrhythmias using an endo-epicardial approach. We used a standardised linear lesion set (posterior wall isolation and anterior mitral line) for recurrent persistent AF. Results Utilising an intentional coronary sinus exit and C02 insufflation technique, we achieved epicardial access in 121 anti-coagulated patients. 5 patients were found to have pericardial adhesions, prohibiting access. There were 2 LIMA punctures which were coiled, 2 cases of excess pericardial bleeding (not access related), that settled conservatively, and no surgery or death. 92% of patients received epicardial ablation. 86 anterior mitral lines (95% acute block, 79% with epi ablation), 88 roof lines (92% blocked, 50% with epi ablation) and 81 floor lines (98% blocked, 36% with epi ablation) were undertaken. 106 posterior wall isolations were performed (94% isolated, 51% epi ablation). 75 patients had a standardised lesion set and were included for recurrence analysis. 49 had persistent AF (71% male, mean age 65 years, mean LAVI 38 ml/m2, 26 PVI at baseline and 23 PV reconnections) and 26 longstanding persistent AF (92% male, median age 64 years, mean LAVI 37.1 mls/m2, 16 PVI at baseline and 10 PV reconnections). 82% with persistent AF (median follow up time 11 months) and 38% with longstanding persistent AF (median follow up time 10.1 months) maintained sinus rhythm. The submitted image demonstrates the freedom from persistent AF, for the cohort who are beyond the 3-month blanking period, as per classification of atrial arrhythmia. Conclusion In one the largest cohorts to date, we have shown that endo-epicardial atrial ablation is feasible and safe with epicardial ablation allowing improved transmurality and thus acute linear block. Clinical outcomes, using a posterior wall isolation and anterior mitral line, were favourable for persistent but not longstanding persistent AF.

Successful left atrial catheter ablation in a patient with cor triatriatum sinister navigated by 3D volume rendering technique computed tomography

Successful left atrial catheter ablation in a patient with cor triatriatum sinister navigated by 3D volume rendering technique computed tomography

Predicting factors for omitting beta-blockers in patients with tachycardia-induced cardiomyopathy after successful catheter ablation for atrial fibrillation.

Tachycardia induces a reduction in the left ventricular ejection fraction (LVEF), which is defined as tachycardia-induced cardiomyopathy (TIC). Conversion to and maintenance of sinus rhythm by catheter ablation can improve LVEF in patients with TIC due to atrial fibrillation (AF). Beta-blockers are mandatory for the treatment of heart failure with reduced LVEF(HFrEF), but the necessity of beta-blockers in TIC patients even after catheter ablation remains unclear. We examined the effect of beta-blockers on cardiac function in TIC patients after catheter ablation. We retrospectively analyzed 124 patients with a history of heart failure and an LVEF of ≤ 50% who underwent catheter ablation for AF. TIC was defined as a ≥ 10% improvement in the baseline LVEF and an improvement to an LVEF of ≥ 50% at 6months after ablation. Patients with other cardiomyopathy diagnosed before the ablation were excluded. LVEF was significantly increased with the reductions of the left ventricular and left atrial volumes at the 6-month follow-up in all 80 patients with TIC. No beta-blockers were prescribed during the post-ablation follow-up in 21 patients with TIC. The absolute values of and changes in the echocardiographic parameters between before and after ablation were not significantly different between patients with and without beta-blockers after the ablation. A simple score using the history of hospitalization for heart failure and use of beta-blockers or diuretics prior to ablation was useful in identifying TIC patients who did not need prescription of beta-blockers after catheter ablation. LVEF similarly improved in both patients with and without prescription of beta-blockers after the ablation. Beta-blockers may not need to be prescribed after successful catheter ablation for AF in LVEF of ≤ 50% patients without other cause of cardiomyopathy diagnosed before the ablation, a history of hospitalization for heart failure and prescription of beta-blockers and diuretics before the ablation.

Left Atrial Volume Index Predicts Atrial Fibrillation Recurrence after Catheter Ablation Only in Obese Patients-Brief Report.

It has been shown that obesity and a higher body mass index (BMI) are associated with a higher recurrence rate of atrial fibrillation (AF) after successful catheter ablation (CA). The same has been proven for the left atrial volume index (LAVI). It has also been shown that there is a correlation between LAVI and BMI. However, whether the LAVI's prognostic impact on AF recurrence is BMI-independent remains unclear. We prospectively included 62 patients with paroxysmal AF who were referred to our institution for CA. All patients underwent radiofrequency CA with standard pulmonary veins isolation. Transthoracic 2-D echocardiography was performed one day after CA to obtain standard measures of cardiac function and morphology. Recurrence was defined as documented AF within 6 months of the follow-up period. Patients were also instructed to visit our outpatient clinic earlier in case of symptoms suggesting AF recurrence. We observed AF recurrence in 27% of patients after 6 months. The mean BMI in our cohort was 29.65 ± 5.08 kg/cm2 and the mean LAVI was 38.04 ± 11.38 mL/m2. We further divided patients into two groups according to BMI. Even though the LAVI was similar in both groups, we found it to be a significant predictor of AF recurrence only in obese patients (BMI ≥ 30) and not in the non-obese group (BMI < 30). There was also no significant difference in AF recurrence between both cohorts. The significance of the LAVI as an AF recurrence predictor in the obesity group was also confirmed in a multivariate model. According to our results, the LAVI tends to be a significant predictor of AF recurrence after successful catheter ablation in obese patients, but not in normal-weight or overweight patients. This would suggest different mechanisms of AF in non-obese patients in comparison to obese patients. Further studies are needed in this regard.

Accuracy of Different Surface Electrocardiogram Algorithms for Localization of Accessory Pathway in Comparison to Invasive Electrophysiological Localization: An Observational Study

Introduction: Detection of accessory pathway (AP) on surface ECG in sinus rhythm helps in the diagnosis of Wolff-Parkinson-White Syndrome (WPW Syndrome), Catheter ablation of AP was indicated in symptomatic patients with preexcitation. Pre-ablation AP localization inferred from the 12-lead surface electrocardiogram (ECG) facilitates a tailored ablation strategy; there by specific risk can be properly assessed. As they are based on pre-excitation in the basal state, available algorithms can lead to complex and ambiguous analysis, mostly due to the variable influence of the AP over QRS morphology. Though various algorithms on surface ECG are available to predict the site of AP on surface ECG, but none of them are accurate. So, we have compared the accuracy of different algorithms in predicting the AP localization in comparison to electrophysiological study (EPS) diagnosis. Methodology: This retrospective observational study cohort consisted of 100 consecutive patients above 15 years of age presented to the tertiary care center with the history of palpitations or for assessment of a manifest AP. Accessory pathways were identified according to the site where successful radiofrequency energy was applied. Arruda algorithm, Milstein algorithm, Fitzpatrick algorithm and Pambrun algorithm were applied on a sinus rhythm manifest preexcited ECG to predict the AP localization by two independent investigators who are unaware of site of successful catheter ablation. Then those were compared with the EPS localization to test the accuracy of individual algorithm. Then Cohen’s Kappa was run to determine if there was agreement between any of the four different algorithms with EPS using SPSS version 20.0. Results: In the study population of 100 patients, male to female ratio of study population was 1.6:1, with a mean age of presentation 43.86 ± 11.4 years with the most common age group of 31 to 45 year. when the AP locations were categorized based on EP Study 56 percent of the AP were found on the left side while 43 percent of the AP were found on right side, 77 percent of the AP were septal pathways. Among the leftsided pathways, left anteroseptal constitutes majority followed by left posteroseptal pathway. On right side majority were in right posteroseptal location in our study. Based on 4 surface ECG algorithms AP was localized and each algorithm was compared with invasive EPS localization for accuracy using Cohen’s Kappa agreement analysis. As per agreement analysis the kappa value for Milstein, Pambrun algorithm, Fitzpatrik and Arruda were 0.188, 0.343, 0.441, and 0.645 respectively. It was found that Arruda algorithm had moderate strength of agreement with the findings of EPS (κ = 0.645). This is the proportion of agreement over and above chance agreement and which was statistically significant and the strongest among all the four algorithms. Conclusion: Our study has compared the accuracy of 4 surface ECG algorithms in predicting the accessory pathway localization with the EPS; it has demonstrated that the Arruda algorithm is more precise and accurate among the available algorithms followed by Fitzpatrik, Pambrun algorithm and Milstein algorithm, Knowing the pathway prior to ablation allows for optimal procedure preparation, mapping pathways that are difficult to find and finally may lessen the catheter-related injury and shortens the procedural time.

Intracardiac Echocardiography: An Invaluable Tool in Electrophysiological Interventions for Atrial Fibrillation and Supraventricular Tachycardia.

Researchers have investigated ways to develop optimal imaging techniques to increase the safety and effectiveness of electrophysiological (EP) procedures. Intracardiac echocardiography (ICE) is an advanced imaging tool that can directly visualize cardiac anatomical structures in high resolution, assess tissue heterogeneity and arrhythmogenic substrates, locate intracardiac catheters, monitor catheter-tissue contact and ablation injury in real-time, excluding intracardiac thrombi, and quickly detect procedural complications. Additionally, real-time imaging via ICE can be integrated with a three-dimensional (3D) electroanatomical mapping (EAM) system to reconstruct cardiac anatomy. This technique also promotes the development of zero-radiation EP procedures. Many EP studies and procedures have implemented ICE because it has several advantages over fluoroscopy and transesophageal echocardiography (TEE). ICE-guided EP procedures can be performed under conscious sedation; esophageal intubation and additional anesthesiologists are not required. Atrial fibrillation (AF) and supraventricular tachycardias (SVT) are the most common tachyarrhythmias in clinical settings. A comprehensive understanding of critical anatomical structures, such as the atrial septum, fossa ovalis (FO), and great heart vessels, is needed for the successful catheter ablation of these arrhythmias.

Clinical accuracy of a 3-dimensional multielectrode non-invasive ECG mapping vest in premature ventricular contraction ablation procedures

Abstract Background Invasive 3D mapping is the current gold standard in determining premature ventricular contraction (PVC) localization. However, given its invasive nature, unawareness of PVC origin beforehand may lead to prolonged procedure times and increased complications risk. Purpose In this study, we compared the diagnostic accuracy of a non-invasive 3-dimensional mapping ECG vest (MECGV) with invasive 3D mapping and ablation successful points as a reference. We also evaluated 12-lead ECG based pre-procedural PVC localization accuracy of 2 expert operators blinded to clinical findings. Methods In 15 consecutive adult patients between the ages of 35 to 69 (male n: 9, median age: 48), MECGV and subsequently a 3D mapping with uneventful successful PVC RF catheter ablation were performed and included in the study. PVC localization estimations of MECGV method and the EP experts' locatization predictions were compared separately with invasive 3D ablation results using the Cohen's kappa method and with the help of a 16-segmentation model we created for the ease of the analyses . Results Results were presented on Table-1. MECGV was found to be highly compatible (Cohen's kappa 0.968, p&amp;lt;0.001) with the RF ablation results. However operators assessments were found to be less coherent with invasive 3D mapping (Operator 1 Cohen's kappa 0.571, p 0.033, Operator 2 Cohen's kappa 0.618, p: 0.019, respectively). MECGV accuracy was %87 in pinpointing the PVC focus. The only 2 localizations that MECGV failed were on the septal aspects of the heart (Picture-2 Failure of defining the focus on LVOT septal instead of RVOT septal) Conclusion MECGV method seems to be highly compatible with invasive 3D mapping techniques in detection of PVC localization and bests EP expert estimates in this regard. However, it also seem to have some pitfalls especially on septal aspects of the heart.Table-1 and segmentation schemePicture-1

Value of 24h ambulatory ECG for prediction of sufficient number of premature ventricular complexes during catheter ablation

Abstract Introduction Successful catheter ablation (CA) of premature ventricular complexes (PVCs) depends on identification of the site of origin (SOO), but no parameter suggested for prediction of success from CA have been sufficiently validated in previous studies. Activation mapping and pace-mapping are invasive methods for the identification of SOO, and the burden of PVCs is critical for activation mapping to identify SOO. The number of PVCs in 24h ambulatory ECGs is claimed to predict occurrence of PVCs during the procedure, and hence procedural success, but the predictive value remains unknown. Purpose The primary objective of this study was to quantify the predictive value of pre-procedural of 24h ambulatory ECG with regard to sufficient number of PVCs during the CA procedure. Methods Patients admitted for CA of PVCs at our hospital from 2011-2020 were included. Data were retrospectivity collected from electronic health records. Clinical characteristics, results from clinical pre-procedural examinations, including 24h ambulatory ECG, exercise testing and echocardiogram, as well as acute outcomes were recorded. Results A total of 332 patients were included, CA was performed in 285 (86 %) patients, while 47 (14 %) patients had insufficient number of PVCs to allow adequate identification of SOO. Neither clinical characteristics nor results of cardiac imaging separated patients with sufficient and insufficient number of PVCs for CA, respectively. Patients with sufficient number of PVCs had nominally more PVCs in the preceding 24h ambulatory ECG, although the difference was not statistically significant (16007 (6509-26205) vs. 8332 (3066-20974), p = 0.055). A receiver operating characteristics (ROC) curve analysis of sufficient number of PVCs during CA and number of PVCs in the preceding 24h ambulatory ECG had an area under curve (AUC) of 0.610 (0.95% CI 0.498-0.722, p = 0.055). The commonly clinically used cut-off of &amp;gt;10 000 PVCs/24h had a positive predictive value of 67 % and a negative predictive value of 57 % for sufficient number of PVCs during CA. The median period from the 24h ambulatory ECGs to CA was 183 days (6 months). The positive and negative predicative values for &amp;gt;10 000 PVCs in 24h ambulatory ECG performed &amp;gt;6 months prior to the procedure were 67 % and 71 %, respectively, compared to 53 % and 61 % for 24h ECGs performed &amp;lt;6 months prior to the procedure. The ROC curve for sufficient number of PVCs during the procedure and number of PVCs in a 24h ambulatory ECG performed &amp;gt;6 months and &amp;lt;6 months prior to the procedure did not differ, with had AUC values of 0.665 and 0.584, respectively (p = 0.4). Conclusion In this retrospective analysis of a large cohort of patients admitted for CA of PVCs, number of PVCs in 24h ambulatory ECGs recorded prior to the procedure had a low predictive value for presence of PVCs during CA. Others parameters need to be evaluated to improve prediction.

Unfolding the transition ratio: insight into the diagnostic criteria for the diagnosis of the origin of outflow tract ventricular arrhythmias

Abstract Background algorithms for the diagnosis of the site of origin of ventricular outflow tract arrhythmias (OTVA) share the rationale that more posterior structures (LVOT) produce a greater vector approaching the precordial leads than anterior structures (RVOT), i.e. R waves in V1-V3 of greater amplitude and duration, a transition generally earlier than the QRS in sinus rhythm (SR), and vice-versa. Methods in a retrospective cohort of 45 patients (53.3% LVOT, 46.7% RVOT) with OTVA (left bundle branch block morphology, transition in lead V3, absence of conduction aberrancy in SR, who underwent successful catheter ablation were retrospectively analyzed, comparing the diagnostic yield of the main literature criteria. a) The V2 transition ratio, (TR) calculated with the formula [(R\R+S)PVC : (R\R+S)SR] (LVOT if &amp;gt; 0.6) [1]. b) The V1-V2 S-Rd, calculated as [(V1S + V2S) – (V1R + V2R)] (LVOT if &amp;lt; 1.625) [2]. c) The V2S\V3R amplitude ratio (LVOT if &amp;lt; 1.5) [3]. d) The transition zone index (TZI), obtained by subtracting the transition zone of the PVC with that of the SR (LVOT if &amp;lt; 0) [4]. We extended the use of these criteria to the precordial leads V1 to V3; for TR the equation was applied to amplitude as well as duration measurements. Results Comparison of PVC QRS morphology with that of SR. 1. The diagnostic accuracy of the TR showed incremental values moving from lead V1 to V3, both using amplitude and duration measurements; compared to the modest accuracy of the V2 TR (AUC 0.630, 0.727), the V3 TR (LVOT if &amp;gt; 1) showed an accuracy of 85.3% (AUC 0.804, 0.855). 2. Simplifying the complex TR equation, comparing R or S waves of the PVC with those of the SR, we again found incremental values of accuracy moving from lead V1 to V3, with better results for the SVT\SSR compared to the RVT\RRS; the V3 SVT\SRS) (LVOT if &amp;lt; 1) showed an accuracy of 86.6% (AUC 0.917). 3. The TZI showed in our series a lower diagnostic yield compared to that of the literature (AUC 0.748, accuracy 73.3%) Comparison of PVC QRS morphology between two contiguous leads: 4. Compared to the V1-V2 S-Rd (AUC 0.830), the V2-V3 S-Rd (AUC 0.855), calculated as [(V2S + V3S) – (V2R + V3R)] showed greater accuracy (82.2%). 5. Similarly, compared to the V1S\V2R amplitude ratio (AUC 0.774), the V2S\V3R (AUC 0.930) showed the greatest accuracy (88.8%, with a more balanced sensitivity and specificity moving the cut-off for the diagnosis of origin from LVOT to &amp;lt; 2), resulting the criterion with the highest diagnostic yield. Conclusions variables that compare the morphology of the QRS of the PVC of two contiguous leads have greater accuracy than those that compare the morphology of the QRS of the PVC with that of the SR, with greater diagnostic yield when applied from lead V1 to V3; the V2S\V3R ratio represents the best criterion, with high sensitivity, like the V3 transition ratio; the simple ratio (SVT\SSR) can virtually replace the more complex TR, with similar accuracy but high specificity.

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.

Short history of the DC-Catheter-Ablation

Direct current (DC) catheter ablation in 5patients aiming to interrupt rapid atrioventricular (AV) conduction with atrial fibrillation and subsequent pacemaker implantation was first published by M.M.Scheinman etal. (San Francisco, CA, USA) in 1982. In Germany, L.Seipel, G.Breithardt, and M.Borggrefe reported their first experience with DC catheter ablation in 1984, followed by the group in Bonn (M.Manz and B.Lüderitz) in 1985. The first international DC catheter ablation registry, which also included four German centers, reported DC catheter ablation results of 127 patients in 24centers in 1984. Complete AV block was achieved in 71% patients. In 1992, the Hannover group (H‑J.Trappe, H.Klein and J.Huang) reported results of DC catheter ablation of AV conduction performed between 1983 and 1990 in 100 patients (86% with rapid atrial fibrillation, 14% with AV-node reentry tachycardias). The first successful DC catheter ablation in apatient with Wolff-Parkinson-White (WPW) syndrome was reported in 1985 by F.Morady etal. (San Francisco, CA, USA). In 1987, M.Borggrefe etal. were the first to report aswitch from DC catheter ablation to ahigh-frequency (HF) catheter ablation procedure in apatient with WPW syndrome. The use of DC catheter ablation to treat ventricular tachycardia (VT) was described by G.O.Hartzler (Kansas City, MO, USA) in 3patients in 1983. M.Borggrefe etal. (1989) reported on 24patients who underwent DC catheter ablation for VT. Of those, 17patients did not have VT recurrence within the following 14months. In 1994, the Hannover group (H-JTrappe, H.Klein) published their 5‑year long-term results of DC catheter ablation of VT in 51patients. VT recurrence occurred in 57% patients and overall mortality was also high (16%). Acomparison of DC catheter ablation with HF catheter ablation for recurrent VT was reported in 1994 by G.Gonska etal. (Göttingen, Germany). After 2years follow-up, success rates were not found to be significantly different.

Unveiling the Role of Endothelial Dysfunction: A Possible Key to Enhancing Catheter Ablation Success in Atrial Fibrillation.

Atrial fibrillation, a prevalent type of arrhythmia, is increasingly contributing to the economic burden on healthcare systems. The development of innovative treatments, notably catheter ablation, has demonstrated both impressive and promising outcomes. However, these treatments have not yet fully replaced pharmaceutical approaches, primarily due to the relatively high incidence of atrial fibrillation recurrence post-procedure. Recent insights into endothelial dysfunction have shed light on its role in both the onset and progression of atrial fibrillation. This emerging understanding suggests that endothelial function might significantly influence the effectiveness of catheter ablation. Consequently, a deeper exploration into endothelial dynamics could potentially elevate the status of catheter ablation, positioning it as a primary treatment option for atrial fibrillation.

Clinical Characteristics and Rhythm Outcomes in Patients With Atrial Myopathy After Successful Catheter Ablation of Atrial Fibrillation.

Although successful atrial fibrillation (AF) ablation can maintain sinus rhythm and reduce the left atrial (LA) dimension, blunted LA reverse remodeling can be observed in patients with atrial myopathy. We explored the potential mechanisms and long-term outcomes in patients with blunted LA reverse remodeling after successful AF catheter ablation. We included 1685 patients who underwent baseline and 1-year follow-up echocardiograms, had a baseline LA dimension ≥40 mm, and did not have a recurrence of AF within a year. The patients were divided into tertile groups according to the delta value of the change in LA dimension on the preprocedure and 1-year postprocedure echocardiography. After propensity score matching for age, sex, AF type, and LA dimension, 1272 patients were finally included in the analyses (424 in each group; the least/blunted, moderate, and the most reverse remodeling group). The patients in the T1 group (blunted LA reverse remodeling) were independently associated with higher left ventricular mass index (odds ratio [OR], 1.014 [95% CI, 1.005-1.022], P=0.001), change in ΔH2FPEF score (heavy, hypertensive, atrial fibrillation, pulmonary hypertension, elder, filling pressure) score (OR, 1.445 [95% CI, 1.121-1.861], P=0.004), ventricular epicardial adipose tissue volume (OR, 1.010 [95% CI, 1.003-1.017], P=0.003), thinner LA wall thickness (OR, 0.461 [95% CI, 0.271-0.785], P=0.004), lower LA voltage (OR, 0.670 [95% CI, 0.499-0.899], P=0.008), and showed higher long-term AF recurrence (log-rank P<0.001) than other groups. Blunted LA reverse remodeling after AF catheter ablation, which is suggestive of atrial myopathy, was independently associated with a larger ventricular epicardial adipose tissue volume and worsening of H2FPEF score. Blunted LA reverse remodeling after AF catheter ablation was also an independent predictor for higher recurrences of AF post-1-year AF catheter ablation.