Recurrent Ventricular Tachycardia Research Articles

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.

Heart transplantation in juvenile-onset systemic sclerosis with primary cardiac involvement: report of two cases and comprehensive literature review.

Juvenile onset systemic sclerosis is a rare chronic multisystem connective tissue disease characterized by skin induration, microangiopathy, autoimmune disturbances and widespread fibrosis of internal organs. Primary cardiac involvement in systemic sclerosis (SSc) is associated with a variable phenotype, including heart failure and arrhythmias, which lead to poor short-term prognosis. Isolated heart transplantation is a rare approach for the treatment of advanced heart failure in patients with systemic sclerosis. We report on two juvenile SSc patients receiving cardiac transplantation due to heart failure with malignant arrhythmias. One patient presented with severe dilated cardiomyopathy with recurrent ventricular tachycardia. Following the appearance of Raynaud phenomenon, he was subsequently diagnosed a rare form of systemic sclerosis sine scleroderma, without cutaneous manifestations or other organs involved. His cardiac condition was unresponsive to antiarrhythmic therapy and immunosuppression used to treat SSc, therefore he underwent successful heart transplantation. The second patient presented diffuse scleroderma with mild pulmonary, esophageal and renal involvement. While extracardiac manifestations were effectively kept under control with immunosuppressive therapy, cardiac involvement rapidly progressed with detection of fibrosis at cardiac magnetic resonance imaging and appearance of severe ventricular arrhythmia. Herein, an extensive multidisciplinary evaluation was pivotal in defining the entity and clinical stability of extracardiac involvement, and thus the patient could profit from heart transplantation. Our experience highlights the importance of considering heart transplantation in carefully selected SSc patients with primary cardiac involvement as a lifesaving procedure.

Drug therapy and catheter ablation for management of arrhythmias in continuous flow left ventricular assist device's patients. A Clinical Consensus Statement of the European Heart Rhythm Association and the Heart Failure Association of the ESC.

Left ventricular assist devices (LVADs) are an increasingly used strategy for the management of patients with advanced heart failure. Although these devices effectively improve survival, atrial and ventricular arrhythmias are common with a prevalence of 20-50% at one year after LVAD implantation. Arrhythmias predispose these patients to additional risk and are associated with considerable morbidity from recurrent implantable cardioverter-defibrillator (ICD) shocks, progressive failure of the unsupported right ventricle, and herald an increased risk of mortality. Management of patients with arrhythmias and LVAD differs in many aspects from the general population heart failure patients. These include ruling out the reversible causes of arrhythmias that in LVAD patients may include mechanical irritation from the inflow cannula and suction events. For patients with symptomatic arrhythmias refractory to medical treatment, catheter ablation might be relevant. There are specific technical and procedural challenges perceived to be unique to LVAD-related ventricular tachycardia ablation such as vascular and LV access, signal filtering, catheter manoeuvrability within decompressed chambers, and electroanatomic mapping system interference. In some patients, the arrhythmogenic substrate might not be readily accessible by catheter ablation after LVAD implantation. In this regard, the peri-implantation period offers a unique opportunity to surgically address arrhythmogenic substrate and suppress future ventricular tachycardia recurrences. This document aims to address specific aspects of the management of arrhythmias in LVAD patients focusing on anti-arrhythmic drug therapy and ablations.

Contemporary outcomes of catheter ablation of the structural ventricular tachycardias in severe ischemic and non‐ischemic cardiomyopathies in Turkish population

AbstractIntroductionCurrently, there are no data regarding outcomes of the catheter ablation for structural ventricular tachycardia (VT) in Türkiye. In this observational study, we aim to investigate cardiac outcomes of patients undergoing catheter VT ablation at a tertiary center in Türkiye.MethodsThis was a retrospective observational study performed at a single university center. Patients with a confirmed ischemic or non‐ischemic cardiomyopathy, undergoing structural VT ablation were included. Procedural and mid‐term outcomes were analyzed.ResultsA total of 124 patients were enrolled in the study. 54(43.5%) patients presented with an electrical storm. During the mean follow‐up of 351 ± 232 days 10(8.1%) patients experienced a recurrence. There was only one peri‐procedural death and cardiac tamponade occurred in two patients.14(11.3%) patients died during the follow‐up, most commonly due to a cardiovascular death. In the multivariate analysis only age >70 was found to be correlated with death during follow‐up, with p =.008, HR = 4.923.ConclusionA good acute success with low complications was observed in patients undergoing VT ablation for structural heart disease in a tertiary center in Türkiye. Mid‐term outcomes are comparable with international studies with no difference in VT recurrence in ischemic and non‐ischemic patients. Similar to international studies, significant mid‐term mortality was observed.

Mineralocorticoid receptor antagonist therapy in patients with ischemic heart failure and ventricular tachycardia: a comparative analysis of spironolactone vs. eplerenone

Abstract Background Mineralocorticoid receptor antagonists (MRAs) are a cornerstone of heart failure therapy and have been shown to reduce the incidence of sudden cardiac death. However, a direct comparison between spironolactone and eplerenone in patients who present ventricular tachycardia (VT) is lacking. Purpose This study aimed to compare the effect of spironolactone and eplerenone on VT recurrence in patients with ischemic heart disease (IHD) hospitalized for VT episodes. Methods Our data utilized a registry of 405 patients with IHD and HF, who were hospitalized for an episode of sustained VT and received MRA therapy. We performed propensity score matching based on age, hypertension, diabetes, history of acute myocardial infarction, left ventricular ejection fraction (LVEF) and presentation with incessant VT. The matched population included 200 patients, stratified into two equivalent groups. Cox regression analysis was performed to identify predictors of VT recurrence, with Kaplan-Meier curves facilitating time-to-event analyses. Results The median age was 69 years and the majority (91%) were male. One-third had an ICD, and 41 patients (20%) had CRT. The median LVEF was 30%, 23 patients (12%) presented with an electrical storm, while 18 (9%) had incessant VT. VT led to hemodynamic instability in 91 cases (46%). Ablation was performed in 47 patients (24%), while 1 required mechanical circulatory support. Ablation was performed in 47 patients (24%), while 1 required mechanical circulatory support. Patients were followed for at least a year and median follow-up time was 414 days. A total of 78 patients had VT recurrence and 117 patients died. Eplerenone use significantly reduced the risk of VT recurrence compared to spironolactone (HR: 0.59 [0.37-0.93], p=0.023). This effect was consistent in the multivariate model as well (p=0.007). Conclusions Eplerenone use may confer a greater protective effect against VT recurrence in patients with IHD and sustained VT. Further studies are required to confirm these preliminary findings.

Role of ventricular tachycardia cycle length in the outcomes after catheter ablation or antiarrhythmic drugs in the SURVIVE-VT trial

Abstract Background It has been suggested that antiarrhythmic drugs (AAD) are less effective and safe in slow ventricular tachycardia (VT) due to their effect on conduction velocity, which could stabilize reentry. Conversely, catheter ablation aims to disrupt the VT circuit. Because of the distinct mechanisms of action of AAD and catheter ablation on the VT circuit, VT cycle length (VT-CL) may play a crucial role in determining their therapeutic efficacy. Therefore, VT-CL could be important in selecting VT treatment. Purpose The aim of this study was to assess the impact of VT-CL on outcomes following catheter ablation or antiarrhythmic drugs in AAD-naïve patients with ischemic cardiomyopathy presenting with VT. Methods This is a post hoc analysis of the previously published Substrate Ablation vs Antiarrhythmic Drug Therapy for Symptomatic Ventricular Tachycardia (SURVIVE-VT) trial. In summary, 144 patients with ischemic cardiomyopathy and symptomatic VT were randomized to receive either catheter ablation (N=71) or AAD (N=73) as first-line therapy. We analyzed VT recurrence, implantable cardioverter-defibrillator (ICD) therapies, and the incidence of slow/incessant VT/VT storm using Cox proportional hazard models, with treatment and VT-CL interaction terms, adjusted for age. Missing VT-CL data for five patients were imputed using the median value. Results In patients with chronic ischemic heart disease and VT treated with either AAD or catheter ablation, a significant interaction was observed between clinical VT-CL and treatment effect on VT recurrence (p=0.016 for the interaction). Specifically, slower VT cycle lengths were associated with higher rates of VT recurrence (hazard ratio per 10 ms [HR] 1.094, 95% confidence interval [CI] 1.015, 1.179; p=0.037) in patients treated with AAD, while no significant effect was observed in those undergoing catheter ablation (see Figure 1). Survival freedom from VT recurrence in patients with VT-CL ≥300ms was significantly higher in patients treated with catheter ablation (78.8% vs 58.1%, log-rank p=0.044, see Figure 2). As expected, VT-CL was significantly associated with a higher risk of slow/incessant VT/VT storm (HR per 10 ms 1.115, 95% CI 1.017-1.222, p=0.047) but was not associated with ICD therapies (HR per 10 ms 1.082, 95% CI 0.994-1.178, p=0.102). Conclusion VT-CL significantly influences treatment outcomes, with slower VT cycles associated with an increased risk of VT recurrence in patients treated with AAD, but not in those undergoing catheter ablation. Therefore, VT-CL should be taken into consideration when selecting the optimal therapy for patients with ischemic cardiomyopathy and VT.Figure 1Figure 2

Machine-learning models to predict the risk of recurrent VT following catheter ablation in patients with structural heart disease

Abstract Background Ventricular tachycardia (VT) is a life-threatening arrhythmia that can complicate structural heart disease. While catheter ablation is effective in treating this condition, the recurrence of VT after the procedure continues to be a concern. Consequently, there is a need for a reliable system to evaluate the likelihood of arrhythmia recurrence following an ablation. Objective To predict recurrence or repeat ablation after a VT catheter ablation procedure using machine learning (ML) models. Methods We conducted a single-center, retrospective study of all patients undergoing catheter ablation for scar-related VT between 2012 and 2022. Data collected included demographics, comorbidities, medications, relevant laboratory abnormalities, electrocardiograms, echocardiograms, detailed procedural characteristics, and outcomes. Python version 3.8.5 for exploratory data analysis (EDA) and visualization. Using six different ML models from the training set (90:10 split), we used 34 variables to predict the primary outcome, including VT recurrence or repeat catheter ablation. The accuracy of these models was compared using ROC curves based on their performance on the test set. Results Out of 508 VT ablation procedures, 261 experienced a recurrence. Support Vector Classifier (SVM) performed the best, having an AUC of 0.73, followed by logistic regression at 0.69 (Figure A). SVM yielded sensitivity, specificity, positive and negative predictive values of 0.73, 0.73, 0.79, and 0.67, respectively. The F1 score was 0.70. Among the factors with the highest feature importance in the model, the most influential variable was the proceduralist’s experience level, followed by QRS width at baseline, LVEF, and patient’s age (Figure B). Conclusion Our model can predict recurrent VT after ablation with reasonable accuracy, outperforming the existing clinical risk scores significantly. Larger training sample sizes will help achieve more robust ML models and improve predictive accuracy further.Figure A: ROC curve depicting the AUROCB. Feature importance graph

Speckle tracking echocardiography as a predictor of location of ablation sites in candidates to catheter ablation for recurrent ventricular tachycardia

Abstract Background Preoperative imaging is essential before a ventricular tachycardia (VT) ablation procedure, to improve operative outcomes and reduce procedural times. Although MRI is the gold standard, it has several limitations, including patient compliance, possible presence of non-MRI-compatible devices, and long acquisition time. Speckle tracking echocardiography (STE) is a reliable and appealing technique that quantifies regional and global myocardial deformation, as well as layer-specific (endo-, mid- and epicardial) longitudinal strain, without MRI limitations. Purpose This study aimed to evaluate the efficacy of STE in predicting VT ablation sites. Methods In this study, we compared the bull’s eye segmentation of the left ventricle, global and layer-specific, obtained with STE (TomTec Arena), to investigate whether echocardiography can predict the areas of scar and late potential, as identified by electroanatomic mapping (EnSite X mapping, HD Grid mapping catheter, Abbott). Strain analysis and electroanatomic mapping data were matched segment-by-segment to obtain pairs of endocardial strain and bipolar substrate maps, as well as pairs of midmyocardial/epicardial strain and unipolar substrate maps. Results Twenty-three consecutive patients with an indication for catheter ablation for recurrent VT were enrolled. All patients were being treated with beta-blockers, 52% were taking amiodarone, and only 2 patients were on mexiletine. A total of 1170 pairs of bull’s eye segments were available for analysis. A binary logistic mixed-effects model was used to predict the presence of electroanatomical scar based on strain echocardiography data, to account for interpatient variability. The study findings highlighted a close correlation between the bipolar map and endocardial strain values, and between the unipolar map and midmyocardial strain values. Progressively higher (less negative) values of endocardial strain proved predictive of bipolar electroanatomical scar, with an increase in the odds ratio of bipolar electroanatomical scar equal to 6.2% (95% confidence interval 2.5%-10%) for each unit increase in strain values. Similarly, progressively higher values of midmyocardial strain were predictive of unipolar electroanatomical scar, with an increase in the odds ratio of unipolar electroanatomical scar equal to 6.2% (95% confidence interval 1.2%-11.4%) for each unit increase in strain values. Conclusions The data from our study showed an anatomical correspondence between the areas of low potential identified by electroanatomical mapping and the areas of anomalous longitudinal strain. In particular, the endocardial strain correlates with the bipolar map, and the meso-epicardial strain correlates with the unipolar map. These data may prove useful in the appropriate planning of the procedure in patients with an indication for catheter ablation in the context of recurrent VT.

Clinical presentation, risk factors and six-month outcomes in Ugandan women with peripartum cardiomyopathy: prospective case-control study

Abstract Background Peripartum Cardiomyopathy (PPCM) frequently affects women of African descent. There is scarcity of data pertaining to the clinical presentation and outcomes of PPCM patients in Uganda, particularly when employing modern diagnostic tools and adhering to guideline-directed medical therapy (GDMT). Purpose We aimed to delineate the clinical characteristics, echocardiographic findings, and 6-month outcomes among women in Uganda diagnosed with PPCM. Methods Prospective case-control design conducted from June 2022 to August 2023. We enrolled 80 PPCM cases and 80 matched controls. Inclusion criteria comprised: (i) peripartum state, (ii) signs and symptoms of HF, (iii) left ventricular (LV) ejection fraction ≤ 45%, and (iv) exclusion of alternative causes of HF. Controls were healthy women matched for age and parity. Over a 6-month period, enrolled PPCM cases were diligently monitored while on GDMT. All participants underwent a physical examination, 12-lead electrocardiography, and a detailed echocardiography incorporating global longitudinal strain measurements at both baseline and the 6-month follow-up. Results At baseline, amongst the cases, the mean age was 33.6 ± 6.6 years, mean parity was 3±2.1 pregnancies. HF onset occurred within 9.5±6.5 weeks post-delivery. A total of 20 (25.0%) cases presented in NYHA Class 4 with dyspnea as the predominant symptom in 79.95% of cases. Atrial fibrillation (AF) was observed in 2(2.5%) patients. In comparison with healthy controls, high gravidity (0.2±1.0; p<0.001) was identified as the only predictor of PPCM in this study. (Table 1) At 6-months follow up, the mean LV ejection fraction (LVEF) showed improvement from 35.7±-11.0% to 45.9 ± 15.7% (p<0.001) accompanied by a reduction in left ventricular diameter (LVD) from 6.1±0.7 cm to 5.5±1cm(p<0.001). At the 6-month follow-up, recovery (LVEF ≥ 50%) occurred in 37 cases (55%), and 52 (65%)patients were asymptomatic (NYHA Class 1) at the 6-month follow-up. Six-month mortality data were available for 5(6.3%) women, and one patient successfully underwent the insertion of an Implantable Cardioverter-defibrillator for recurrent Ventricular Tachycardia. Regarding GDMT, 55 participants received Bromocriptine as part of their medication. Twenty(25%) patients received anticoagulation for AF(n=2) or intracardiac thrombus (n=6, 1.67%) (Figure 1) resulting in 2(2.5%) strokes within the 6-month follow-up. Conclusion The current study demonstrated a comparable mortality rate on GDMT, aligning with contemporary global studies at 7.5%. The observed high thrombus burden in patients may indicate suboptimal adherence to anticoagulation therapy. While the incidence of PPCM remains undefined in Uganda, the primary predisposing factor identified was high gravidity. A noteworthy proportion of patients exhibited incomplete LV recovery, suggesting the need for larger studies to comprehensively define the maternal and fetal outcomes in Uganda.Figure 1Table 1

Stereotactic arrhythmia radioablation - A systematic review and meta-analysis of the prospective clinical studies

Abstract Background Stereotactic arrhythmia radioablation (STAR) is increasingly being evaluated in prospective studies as a new promising treatment option for patients with therapy-refractory ventricular tachycardia (VT). In STAR, the VT substrate is noninvasively treated with a high dose of radiotherapy. Recently, several single-arm prospective studies evaluating the clinical outcomes of STAR were published. Considering that the evidence base consists mainly of retrospective case series, we conducted a systematic review and meta-analysis to synthesize the prospective data on outcomes of STAR. Purpose To perform a systematic review and meta-analysis of prospective studies evaluating clinical outcomes of STAR for VT. Methods This study was registered in PROSPERO and adhered to the PRISMA reporting guidelines. Full-text studies describing prospective studies evaluating the safety and efficacy of STAR for VT were included in this study. Records published until August 2023 were retrieved from OVID MEDLINE, OVID Embase, Web of Science Core Collection, the Cochrane Central Register of Controlled Trials, and Google Scholar search engine (top 200 hits), deduplicated, and screened for eligibility. Abstract screening, full-text screening, data extraction and quality assessment were performed by two reviewers independently. Endpoints were defined as treatment related CTCAE grade ≥3 adverse events within 90 days after treatment, overall survival (OS), time to VT recurrence, and recurrence-free survival. Rates of patients achieving pre-defined 50%, 75% and 95% VT burden reduction thresholds were summarised. Random-effects generalized linear mixed-effects models and inverse variance models were used for the meta-analysis. Results 1861 records were identified, 987 were screened, and 10 full-text manuscripts published between 2019 and 2023 describing the results of STAR in 82 patients were included in this study. The majority were male (n=72; 88%), between 45 and 85 years old, and suffered from ischaemic cardiomyopathy (n=51; 62%). Median left ventricular ejection fraction ranged from 21 to 38% between studies. 20 patients did not undergo a prior catheter ablation for VT. All patients were treated with a single dose of 25 Gy and median planned target volume ranged from 45 to 198 cc between studies. Pooled 12-month OS rate was 0.73, and the proportion of patients experiencing grade ≥3 adverse events within 90 days after STAR was 0.11 (Figure 1). Reduction in VT burden is shown in Table 1. Although these were not pooled because of large heterogeneity in VT reduction time frame definitions, it can be appreciated that most of the patients experienced a reduction in VT burden. Conclusion The increasing evidence from prospective studies on STAR shows acceptable 12-month OS in a population of patients with advanced heart failure and refractory VT. Moreover, there is a modest rate of high-grade adverse events and most patients experience a reduction in VT burden.

Comparison of Oral Procainamide and Mexiletine Treatment of Recurrent and Refractory Ventricular Tachyarrhythmias

Background: Antiarrhythmic therapy for recurrent ventricular arrhythmias (VAs) in patients having undergone catheter ablation and in whom amiodarone and/or beta-blockers were ineffective or contraindicated is a controversial issue. Purpose: The present study sought to compare the efficacy and tolerability of oral procainamide and mexiletine in patients with recurrent ventricular arrhythmias when the standard therapy strategy failed. Methods: All patients with an implantable cardioverter defibrillator (ICD) treated with oral procainamide or mexiletine for recurrent ventricular tachycardia (VT) or ventricular fibrillation (VF) in two cardiology divisions between January 2010 and January 2020 were enrolled. Patients were divided into group A (oral procainamide) and group B (mexiletine) and the two groups were compared to each other. The primary endpoint was the efficacy of therapy; the secondary endpoint was the discontinuation of therapy. All events that occurred during procainamide or mexiletine treatment were compared with a matched duration period before the initiation of the therapy. Antiarrhythmic therapy was considered effective when a ≥80% reduction of the sustained ventricular arrhythmias burden recorded by the ICD was achieved. Results: A total of 68 consecutive patients (61 males, 89.7%; mean age 74 ± 10 years) were included in this retrospective analysis. After a median follow-up of 19 months, 38 (56%) patients had a significant reduction in the VA burden. After multivariable adjustment, therapy with procainamide was independently associated with an almost 3-fold higher efficacy on VA suppression compared to mexiletine (HR 2.54, 95% CI 1.06–6.14, p = 0.03). Only three patients (9%) treated with procainamide presented severe side effects (dyspnea or hypotension) requiring discontinuation of therapy compared with six patients (18%) treated with mexiletine who interrupted therapy because of severe side effects (p = 0.47). Conclusions: Compared to mexiletine, oral procainamide had a higher efficacy for the treatment of recurrent and refractory VAs, and showed a good profile of tolerability.

Contemporary Management and Prognostic Factors of Arrhythmia Recurrence in Patients with High-Energy Discharge of Cardiac Implantable Electronic Devices.

Background and Objectives: Understanding the underlying causes of implantable cardioverter-defibrillator (ICD) discharges is vital for effective management. This study aimed to evaluate the characteristics of patients admitted following ICD discharge, focusing on myocardial ischemia as a potential exacerbating factor and potential risk factors for VT recurrence. Materials and Methods: This retrospective, single-center study included 81 patients with high energy discharge from cardiac implantable electronic device admitted urgently to the cardiology department from 2015 to 2022. The exclusion criterion was ST-segment elevation acute coronary syndrome. Data were collected anonymously from electronic medical records. Patients were categorized based on coronary angiography, percutaneous angioplasty, presence of significant stenosis, recurrent ventricular tachycardia (VT), and catheter ablation. Clinical variables, including demographic data, echocardiographic parameters, and pharmacotherapy, were analyzed. The primary endpoint was the recurrence of VT during in-hospital stay. Results: Among 81 patients, predominantly male (86.4%), with a mean age of 63.6 years, 55 (67.9%) had coronary artery disease (CAD) as the primary etiology for ICD implantation. Coronary angiography was performed in 34 patients (42.0%) and showed significant stenosis (>50%) in 18 (41.8%) patients, while 8 (26.0%) individuals underwent percutaneous coronary intervention (PCI). Recurrent VT occurred in 21 subjects (26.3%), while ventricular catheter ablation was performed in 36 patients (44.0%). Referral for urgent coronary angiography was associated with presence of diabetes (p = 0.028) and hyperlipidemia (p = 0.022). Logistic regression analysis confirmed NYHA symptomatic class (OR 4.63, p = 0.04) and LVH (OR 10.59, p = 0.049) were independently associated with relapse of VT. CAD patients underwent catheter ablation more frequently (p = 0.001) than those with dilated cardiomyopathy. Conclusions: The study showed a low referral rate for coronary angiography among patients with ICD discharge. Presence of LVH and preexisting symptomatic class influence arrhythmia recurrence. Understanding these associations can guide personalized management strategies for ICD recipients.

Emergent Ablation for VentricularTachycardia: Predictors of Prolonged Hospitalization and Mortality.

Patients with ventricular tachycardia (VT) frequently present in unstable VT and are subject to urgent/high-risk ablation procedures. Clinical predictors of prolonged hospitalization and mortality are needed for optimal management of these patients. This study seeks to identify factors associated with prolonged hospitalization and mortality in emergent unplanned VT ablation procedures. Fifty consecutive patients hospitalized emergently for VT with structural heart disease who underwent catheter ablation were prospectively followed up for outcomes and complications. Of the 50 patients (mean ± SD age 67.6 ± 12.8 years), 86.0% were male, 62.0% had ischemic cardiomyopathy, and their median left ventricular ejection fraction was 28.5%. Hospital stay<7days (median 3days) occurred in 28 (56.0%) patients (Group 1) and >7days (median 10days) or death<7days occurred in 22 (44.0%) patients (Group 2). PAINESD score and left ventricular ejection fraction were similar between the groups. Compared with Group 1, Group 2 had significantly worse NYHA functional class III or higher (25.0% vs 63.6%; P=0.006), electrical storm (46.4% vs 77.3%; P=0.027), and prior failed VT ablation (35.7% vs 68.2%; P=0.023). Multivariable analysis showed that NYHA functional class III or higher and prior failed VT ablation were predictive of prolonged hospital stay. After ablation, compared with Group 1, Group 2 had worse heart failure (10.7% vs 54.5%; P=0.001), VT recurrences (3.6% vs 68.2%; P< 0.001), and 7 deaths within 30days. Patients undergoing emergent VT ablation are at high risk for prolonged hospital stay, which is predicted by NYHA functional class III or higher and a prior failed ablation. Early VT recurrences and worsening heart failure contribute to prolonged hospitalization and a high 30-day mortality.

Magnetic Resonance-Guided StereotacticRadioablation for SeptalVentricular Tachycardias.

Stereotactic arrhythmia radioablation (STAR) was introduced to treat ventricular tachycardia (VT) refractory to catheter ablation. No data are now available in the septal VT substrate setting, representing a challenge when using conventional techniques. This study sought to evaluate the arrhythmic burden in patients with septal VT treated with magnetic resonance-guided STAR (MRgSTAR). We enrolled consecutive patients with septal VT substrate. The therapy target was achieved by combining anatomic/functional and electrophysiologic information. Patients were treated with a single fraction of 25Gy adopting MRgSTAR. All patients were clinically followed up, and all implantable cardiac devices were remotely monitored. The efficacy outcome included recurrences of any sustained VT beyond the 6-week blanking period after MRgSTAR. The safety outcome was the incidence of adverse events and atrioventricular block. We included 11 patients with septal substrate VT (median age: 68 years; Q1-Q3: 64.5-78 years; 100% male). Clinical presentation was an electrical storm in 81.8% of patients. No complications occurred after MRgSTAR, and 6(54.5%) patients were discharged on the same day of treatment. During a mean follow-up of 12 ± 6months, the efficacy outcome occurred in 3 (27.3%) cases. A significative reduction of implantable cardioverter-defibrillator (ICD) therapy (23.6 before MRgSTAR vs 1.7 after MRgSTAR; P< 0.001) was observed. Left ventricular ejection fraction increased significantly after treatment (38% [Q1-Q3: 33.5%-42.0%] before MRgSTAR vs 43.8% [Q1-Q3: 35%-47%] after MRgSTAR; P=0.04). No adverse effects were observed in the implantable cardioverter-defibrillator and lead system; in the 7 patients with preserved atrioventricular conduction, no atrioventricular block was reported. MRgSTAR represents a safe and effective strategy for treating septal VT.

Pulsed-Field Ablation in Management of Ventricular Tachycardia: A Systematic Review of Case Reports and Clinical Outcomes.

Pulsed-field ablation (PFA) is a cutting-edge technique that employs non-thermal energy to cause cell death by inducing irreversible electroporation of cell membranes. This systematic review evaluates the PFA effectiveness as a potential alternative to radiofrequency and cryo-ablation for treating ventricular tachycardia. PubMed, Embase, Scopus, and Web of Science were systematically searched using keywords related to ventricular tachycardia and pulsed-field ablation. Eligible Studies evaluating this therapeutic approach for ventricular tachycardia were included in the final analysis. We included six studies (five case reports and one case series) in our systematic review. Eight (88.8%) of procedures were successful with 100% long-term efficacy. No procedural complications or ventricular tachycardia (VT) recurrence were observed in the cases. The absence of complications, high effectiveness, and long-term success rate make PFAs a good VT treatment option. However, PFA safety and efficacy studies for VT treatment are scarce. Thus, larger investigations on this topic are urgently needed.

3D-targeted, electrocardiographic imaging-aided stereotactic radioablation for ventricular tachycardia storm: a case report

Abstract Background Stereotactic arrhythmia radioablation (STAR) is a promising non-invasive therapy for patients with ventricular tachycardia (VT). Accurate identification of the arrhythmogenic volume, or clinical target volume (CTV), on the radiotherapy (RT) 4D planning computed tomography (CT) scan is key for STAR efficacy and safety. This case report illustrates our workflow of electro-structural image integration for CTV delineation. Case summary A 72-year-old man with ischaemic cardiomyopathy and VT storm, despite two (endocardial and epicardial) catheter-based ablations, was consented for STAR. A 3D electro-structural arrhythmia model was generated from co-registered electroanatomical voltage and activation maps, electrocardiographic (ECG) imaging, and the cardiac CT angiography scan (in ADAS 3D), pinpointing the VT isthmus and inferoapical VT exit. At this location, an area with short recovery times was found with ECG imaging. A multidisciplinary team delineated the CTV on the transmural ventricular myocardium, which was fused with the 4D planning CT scan using a digital images and communication in medicine (DICOM) radiotherapy file. The CTV was 63% smaller compared with using the conventional American Heart Association 17-segment approach (11 vs. 24 cm3). A single fraction of 25 Gy was delivered to the internal target volume. After an 8-week blanking period, no VT recurrences or radiation-related side-effects were noted. Eight months later, the patient died from end-stage heart failure. Discussion We report a novel workflow for 3D-targeted and ECG imaging-aided CTV delineation for STAR, resulting in a smaller irradiated volume compared with segmental approaches. Acute and intermediate outcome and safety were favourable. Non-invasive ECG imaging at baseline and during induced VT holds promise for STAR guidance.

Bipolar radiofrequency ablation of refractory ventricular arrhythmias: results from a multicentre network.

Advanced ablation strategies are needed to treat ventricular tachycardia (VT) and premature ventricular complexes (PVC) refractory to standard unipolar radiofrequency ablation (Uni-RFA). Bipolar radiofrequency catheter ablation (Bi-RFA) has emerged as a treatment option for refractory VT and PVC. Multicentre registry data on the use of Bi-RFA in the setting of refractory VT and PVC are lacking. The aim of this Bi-RFA registry is to determine its real-world safety, feasibility, and efficacy in patients with refractory VT/PVC. Consecutive patients undergoing Bi-RFA at 16 European centres for recurring VT/PVC after at least one standard Uni-RFA were included. Second ablation catheter was used instead of a dispersive patch and was positioned at the opposite site of the ablation target. Between March 2021 and August 2024, 91 patients underwent 94 Bi-RFA procedures (74 males, age 62 ± 13, and prior Uni-RFA range 1-8). Indications were recurrence of PVC (n = 56), VT (n = 20), electrical storm (n = 13), or PVC-triggered ventricular fibrillation (n = 2). Procedural time was 160 ± 73 min, Bi-RFA time 426 ± 286 s, and mean Uni-RFA time 819 ± 697 s. Elimination of clinical VT/PVC was achieved in 67 (74%) patients and suppression of VT/PVC in a further 10 (11%) patients. In the remaining 14 patients (15%), no effect on VT/PVC was observed. Three major complications occurred: coronary artery occlusion, atrioventricular block, and arteriovenous fistula. Follow-up lasted 7 ± 8 months. Nineteen patients (61%) remained VT free. ≥80% PVC burden reduction was achieved in 45 (78%). These real-world registry data indicate that Bi-RFA appears safe, is feasible, and is effective in the majority of patients with VT/PVC.

Catheter ablation vs advanced therapy for patients with severe heart failure and ventricular electrical storm

BackgroundCurrent data on outcomes of an initial strategy of catheter ablation vs advanced therapy in patients with severe heart failure (HF) and electric storm (ES) are limited. ObjectiveThe purpose of this study was to evaluate the outcomes of ventricular tachycardia (VT) ablation vs left ventricular assist device (LVAD) or heart transplantation (HT) in patients with severe HF and ventricular ES. MethodsPatients with severe HF and ES who underwent VT ablation, LVAD, or HT between 2012 and 2022 at our medical center were reviewed. Severe HF was defined as ejection fraction ≤ 35% or presence of severe restrictive, valvular, or genetic cardiomyopathy. We assessed in-hospital adverse events and 1-year outcomes between the 2 groups. ResultsOf the 73 patients, 43 underwent VT ablation and 30 received advanced therapy (21 HT and 9 LVAD). One-year survival was similar (76.7% vs 86.7%; log-rank, P = .308). However, 10 patients (23.3%) in the ablation group underwent HT during follow-up. After multivariable analysis, United Network for Organ Sharing status 1 or 2 by VT criteria (hazard ratio 5.52; 95% confidence interval 1.27–24.12; P = .023) and early VT recurrence (hazard ratio 5.67; 95% confidence interval 1.68–19.09; P = .005) were associated with HT or mortality in patients who underwent VT ablation. ConclusionPatients with severe HF and ES who underwent VT ablation had similar overall survival to patients who directly proceeded with advanced therapy, although rates of HT were high during follow-up. Predictors of HT or mortality after catheter ablation include United Network for Organ Sharing status 1 or 2 by VT criteria and early VT recurrence.

Clinical Course and Treatment of Patients With Apical Aneurysms Due to Hypertrophic Cardiomyopathy

BackgroundThere is controversy about risk of malignant arrhythmias and stroke in patients with apical aneurysms in hypertrophic cardiomyopathy (HCM). ObjectivesThe aim of this study was to estimate the associations of aneurysm size and major HCM risk factors with the incidence of lethal and potentially lethal arrhythmias and to estimate incidence of unexplained stroke. MethodsIn 108 patients (age 57.4 ± 13.5 years, 37% female) from 3 HCM centers, we assessed American Heart Association/American College of Cardiology guidelines risk factors and initial aneurysm size by echocardiography and cardiac magnetic resonance imaging and assessed outcomes after median 5.9 (IQR: 3.7-10.0) years. ResultsImplantable cardioverter defibrillator discharges or sudden cardiac death (SCD) occurred in 21 (19.4%) patients. Of patients with a risk factor, 55% subsequently had ventricular tachycardia (VT), ventricular fibrillation (VF), or SCD at follow-up, compared with 10% in those who did not (P < 0.001). The upper tercile of size had a 5-year cumulative risk of 35%, while the lower tercile had 5-year risk of 6% (P = 0.0046). In those with the smallest aneurysms <2 cm2 and also without risk factors VT, VF, or SCD occurred in only 2.5%. Clinical atrial fibrillation (AF) was prevalent, occurring in 49 (45%). Stroke was commonly associated with AF. Stroke without conventional cause had an incidence of 0.5%/year. Surgery in 19% was effective in reducing symptoms. VT ablation and surgery were moderately effective in preventing recurrent VT. ConclusionsRisk factors and aneurysm size were associated with subsequent VT, VF, or SCD. Patients with aneurysms in the lowest tercile of size have a low cumulative 5-year risk. Clinical AF occurred frequently. Stroke prevalence in absence of known stroke etiologies is uncommon and comparable to risk of severe bleeding.

Ventricular tachycardia ablation with pentaspline pulsed field technology in two patients with ischemic cardiomyopathy.

Due to its unique features, pulsed field ablation (PFA) could potentially overcome some limitations of current radiofrequency (RF) ventricular tachycardia (VT) ablation. However, data on the use of PFA in this setting are currently scarce. Two patients with ischemic cardiomyopathy and previously failed RF VT ablations were treated with PFA. A total of 18 bipolar applications (case1) and seven bipolar applications (case2) were delivered to the infero-lateral and infero-septal areas (case1) and to the apical lateral left ventricular (LV) wall (case2), placing the catheter adjacent to the LVwall in the flower configuration. A rapid cessation of VT and restoration of sinus rhythm were observed during PFA delivery in both cases. Further applications were delivered to achieve complete elimination of late potentials. In case 1, during the in-hospital stay, ECG monitoring did not show VT recurrences. Six-month follow-up was uneventful, with no VT recurrences at ICD interrogation. In case 2, due to postdischarge VT recurrences, a second RF procedure was scheduled 1 month later. The voltage map performed in sinus rhythm showed a low-voltage zone located at the anterolateral wall, near the previous ablation site. Numerous late potentials were recorded. At the 6-month follow-up, no further VT recurrences were documented after RF redo ablation. While the speed of application and potential transmural effect can facilitate the ablation of large diseased endocardial areas, early loss of contact due to difficult pentaspline catheter manipulation in the LV could lead to insufficient contact force and, consequently, inadequate energy penetration.