Ventricular Tachycardia Ablation In Patients Research Articles

Feasibility and Safety of Laparoscopic-Guided Epicardial Access for Ventricular Tachycardia Ablation.

BackgroundThe usual approach to epicardial access in patients with Chagas cardiomyopathy and megacolon is surgical access to avoid bowel injury. However, there are concerns regarding its safety in cases of Chagas cardiomyopathy with reports of prolonged mechanical ventilation and high mortality in this clinical setting. The aim of this study was to examine feasibility and complication rates for ventricular tachycardia ablation performed with laparoscopic‐guided epicardial access.Methods and ResultsThis single center study examined complication rates of the first 11 cases of ventricular tachycardia ablation in patients with Chagas cardiomyopathy, using laparoscopic guidance to access epicardial space. All 11 patients underwent epicardial VT ablation using laparoscopic‐guided epicardial access, and the complication rates were compared with historical medical reports. The main demographic features of our population were age, 63±13 years; men, 82%; and median ejection fraction, 31% (Q1=30% and Q3=46%). All patients were sent for ventricular tachycardia ablation because of medical therapy failure. The reason for laparoscopy was megacolon in 10 patients and massive liver enlargement in 1 patient. Epicardial access was achieved in all patients. Complications included 1 severe cardiogenic shock and 1 phrenic nerve paralysis. No intra‐abdominal organ injury occurred; only 1 death, which was caused by progressive heart failure, was reported more than 1 month after the procedure.ConclusionsLaparoscopic‐guided epicardial access in the setting of ventricular tachycardia ablation and enlarged intra‐abdominal organ is a simple alternative to more complex surgical access and can be performed with low complication rates.

Endo-epicardial ablation vs endocardial ablation for the management of ventricular tachycardia in arrhythmogenic right ventricular cardiomyopathy: A systematic review and meta-analysis.

The pathologic process of ARVC (arrhythmogenic right ventricular cardiomyopathy) typically originates in the epicardium or subepicardial layers with progression toward endocardium. However, in the most recent ARVC international task force consensus statement, epicardial ventricular tachycardia (VT) ablation is recommended as a Class I indication only in patients with at least one failed endocardial VT ablation attempt. The aim of this meta-analysis is to assess the outcomes of ARVC patients undergoing combined endo-epicardial VT ablation, as compared to endocardial ablation alone. A systematic review of PubMed, Embase, and Cochrane was performed for studies reporting clinical outcomes of endo-epicardial VT ablation vs endocardial-only VT ablation in patients with ARVC. Fixed-Effect model was used if I2 < 25 and the Random-Effects Model was used if I2 ≥ 25%. Nine studies consisting of 452 patients were included (mean age 42.3 ± 5.7 years; 70% male). After a mean follow-up of 48.1 ± 21.5 months, endo-epicardial ablation was associated with 42% relative risk reduction in VA recurrence as opposed to endocardial ablation alone (risk ratio [RR], 0.58; 95% confidence interval [CI], 0.45-0.75; P < .0001). No significant differences were noted between endo-epicardial and endocardial VT ablation groups in terms of all-cause mortality (RR, 1.19; 95% CI, 0.03-47.08; P = .93) and acute procedural complications (RR, 5.39; 95% CI, 0.60-48.74; P = .13). Our findings suggest that in patients with ARVC, endo-epicardial VT ablation is associated with a significant reduction in VA recurrence as opposed to endocardial ablation alone, without a significant difference in all-cause mortality or acute procedural complications.

Increased Rate of Pump Thrombosis and Cardioembolic Events Following Ventricular Tachycardia Ablation in Patients Supported With Left Ventricular Assist Devices.

Ventricular arrhythmias are common following left ventricular assist device implantation (LVAD), and the effects of ventricular tachycardia (VT) ablation on thrombosis and embolic events are unknown. We aimed to assess LVAD thrombosis, stroke, and embolic event rates after VT ablation. Left ventricular assist device implantation patients from two academic centers who underwent endocardial VT ablation between 2009 and 2016 were compared to a control group with VT who were not ablated and followed for one year. The primary composite outcome was confirmed or suspected LVAD thrombosis, stroke, or other embolic event. Survival analysis was conducted with Kaplan-Meier curves, log-rank tests, and Cox regression. Forty-three LVAD patients underwent VT ablation, and 73 LVAD patients had VT but were not ablated. Patients who were ablated were more likely have VT prior to LVAD (p = 0.04), monomorphic VT (p < 0.01), and to be on antiarrhythmics (p < 0.01). Fifty-eight percent of the patients in the ablation group experienced the primary composite outcome (11% had confirmed device thrombosis [DT], 41% suspected DT, 39% had a stroke or embolic event) compared to 30% in the control group (12% with confirmed DT, 11% with suspected DT, 14% with stroke or embolic event) (p = 0.002). In multivariable regression, ablation was an independent predictor of the primary composite outcome (hazard ratios, 2.24; 95% confidence interval, 1.09-4.61; p = 0.03). Patients with LVADs referred for endocardial VT ablation had elevated rates of DT and embolic events.

Ventricular scar channel entrances identified by new wideband cardiac magnetic resonance sequence to guide ventricular tachycardia ablation in patients with cardiac defibrillators.

Ventricular tachycardia (VT) substrate-based ablation has become a standard procedure. Electroanatomical mapping (EAM) detects scar tissue heterogeneity and define conduction channels (CCs) that are the ablation target. Late gadolinium enhancement cardiac magnetic resonance (LGE-CMR) is able to depict CCs and increase ablation success. Most patients undergoing VT ablation have an implantable cardioverter-defibrillator (ICD) that can cause image artefacts in LGE-CMR. Recently wideband (WB) LGE-CMR sequence has demonstrated to decrease these artefacts. The aim of this study is to analyse accuracy ofWB-LGE-CMR in identifying the CC entrances. Thirteen consecutive ICD-patients who underwent VT ablation after WB-LGE-CMR were included. Number and location of CC entrances in three-dimensional EAM and in WB-LGE-CMR reconstruction were compared. Concordance was compared with a historical cohort matched by cardiomyopathy, scar location, and age (26 patients) with LGE-CMR prior to ICD and VT ablation. In WB-CMR group, 101 and 93 CC entrances were identified in EAM and WB-LGE-CMR, respectively. In historical cohort, 179 CC entrances were identified in both EAM and LGE-CMR. The EAM/CMR concordance was 85.1% and 92.2% in the WB and historical group, respectively (P = 0.66). There were no differences in false-positive rate (CC entrances detected in CMR and absent in EAM: 7.5% vs 7.8% in WB vs. conventional CMR, P = 0.92) nor in false-negative rate (CC entrances present in EAM not detected in CMR: 14.9% vs.7.8% in WB vs. conventional CMR, P = 0.23). Epicardial CCs was predictor of poor CMR/EAM concordance (OR 2.15, P = 0.031). Use of WB-LGE-CMR sequence in ICD-patients allows adequate VT substrate characterization to guide VT ablation with similar accuracy than conventional LGE-CMR in patients without an ICD.

Corrigendum to: Preventive Ventricular Tachycardia Ablation in Patients with Ischaemic Cardiomyopathy: Meta-analysis of Randomised Trials

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Multimodality Imaging to Guide Ventricular Tachycardia Ablation in Patients with Non-ischaemic Cardiomyopathy.

Catheter ablation is an effective treatment option for ventricular tachycardia (VT) in patients with non-ischaemic cardiomyopathy (NICM). The heterogeneous nature of NICM aetiologies and VT substrate in patients with NICM play a role in long-term ablation outcomes in this population. Over the past decades, more precise identification of NICM aetiologies and better characterisation of various substrates have been made. Application of multimodal imaging has greatly contributed to the accurate diagnosis of NICM subtypes and improved VT ablation strategies. This article summarises the current knowledge of multimodal imaging used in the characterisation of non-ischaemic NICM substrates, procedural planning and image integration for the optimisation of VT ablation.

Ventricular tachycardia ablation in patients with structural heart disease: single centre experience

Objective: We intended to report our institutional experience with ventricular tachycardia (VT) ablation in patients with structural heart disease. &#x0D; Patients and Methods: A total of 36 consecutive patients (31 male, age: 62.8 ± 13.2 years) who had undergone VT ablation in our institution between 01.01.2017 and 01.05.2019 were included in the analysis. &#x0D; Results: A total of 27 patients with the diagnosis of ischemic cardiomyopathy and 9 patients with the diagnosis of nonischemic cardiomyopathy had undergone VT ablation. VT ablation was successful in 32 (88.9%) patients. There were no major procedural complications; however, one patient with ischemic cardiomyopathy died 48 hours after the procedure because of post-ablation cardiogenic shock. Another patient with unsuccessful VT ablation died during hospitalization due to electrical storm. Endocardial ablation was performed in 23 (63.9%) patients and epicardial or combined endocardial and epicardial ablation was performed in 13 (36.1%) patients. Substrate ablation was the dominant strategy in 29 (80.6%) patients whereas activation mapping and isthmus ablation was performed in 7 (19.4%) patients. &#x0D; Conclusion: Our experience confirms the effectiveness and safety of VT ablation in patients with structural heart disease who are resistant to medical therapy and/or who receive recurrent implantable cardioverter-defibrillator shocks.

Stepwise Approach for Ventricular Tachycardia Ablation in Patients With Predominantly Intramural Scar.

The goal of this study was to assess the value of a stepwise, image-guided ablation approach in patients with cardiomyopathy and predominantly intramural scar. Few reports have focused on catheter-based ventricular tachycardia (VT) ablation strategies in patients with predominantly intramural scar. The study included patients with predominantly intramural scar undergoing VT ablation. A stepwise strategy was performed consisting of a localized ablation guided by conventional mapping criteria followed by a more extensive ablation if VT remained inducible. The extensive ablation was guided by the location and extent of intramural scarring on delayed enhanced-cardiac magnetic resonance imaging. A historical cohort who did not undergo additional extensive ablation was identified for comparison. A novel measurement, the scar depth index (SDI), indicating the percent area of the scar at a given depth, was correlated with outcomes. Forty-two patients who underwent stepwise ablation (median age 61 years [interquartile range: 55 to 69 years], 35 male patients, median left ventricular ejection fraction 36.0% [25.0% to 55.0%], ischemic [n=4] or nonischemic cardiomyopathy [n=38]) were followed up for a median of 17 months (8 to 36 months). A stepwise approach resulted in a 1-year freedom from VT, death, or cardiac transplantation of 76% (32 of 42). Patients who underwent additional extensive ablation had a lower risk of events than a clinically similar historical cohort (N=19) (hazard ratio: 0.30; 95%CI: 0.13 to 0.68; p<0.004). SDI>5mm was associated with worse long-term outcomes (hazard ratio: 1.03; 95%CI: 1.01 to 1.06%; p=0.03), SDI>5mm >16.5% was associated with failed ablation (area under the curve: 0.84; 95%CI: 0.71 to 0.97). Stepwise ablation using delayed enhanced-cardiac magnetic resonance guidance is a novel approach to VT ablation in patients with predominantly intramural scarring. The SDI correlates with immediate procedural and long-term outcomes.

Ventricular Tachycardia Ablation: Past, Present, and Future Perspectives.

Although implantable cardioverter-defibrillators positively affect survival in patients at increased risk for arrhythmic sudden cardiac death, quality of life can be negatively affected by recurrent therapies. Ventricular tachycardia (VT) ablation targets clinical arrhythmias to prevent recurrence. Although treatment of VT initially required open heart surgery, it has since been replaced by percutaneous ablation, a safe and effective catheter-based therapy to ablate myocardium from either the endocardial or the epicardial surface. Four basic mapping techniques are used to guide VT ablation: activation, entrainment, and pace and substrate mapping. Current recommendations for VT ablation, especially in the setting of structural heart disease, mostly reserve this treatment for patients for whom antiarrhythmic therapy has failed or is not tolerated or desired. These recommendations derive from multiple observational reports and several randomized prospective studies in patients with VT in the setting of ischemic cardiac disease. Patients are usually referred late in their clinical course for VT ablation, limiting enrollment in clinical trials and resulting in limited prospective randomized data on long-term outcomes with ablative therapy. Future research efforts should address unmet needs, including more rigorous assessment of survival benefit from VT ablation, outcomes data of VT ablation in patients with nonischemic cardiomyopathy, and assessment of strategies to improve intramural substrate ablation. Emerging technologies with disruptive potential include the use of lower ionic strength irrigants, energy delivery guided by impedance modulation, simultaneous unipolar and bipolar ablation, and novel ablation catheters, including the retractable needle-tip electrode catheter. Promising alternatives to radiofrequency ablation include alcohol ablation from the coronary arterial or venous system, direct current or pulsed field electroporation, and stereotactic body radiotherapy guided by noninvasive substrate mapping. Future studies are needed to demonstrate the safety and efficacy of these novel technologies compared with standard radiofrequency catheter ablation.

P5692Catheter ablation of ventricular tachyarrhythmias in ischemic patients may contribute to better survival: a new clinical challenge

Abstract Background Ventricular arrhythmias contribute to significant escalation of mortality rate in patients with ischemic cardiomyopathy (ICM). Risk of sudden cardiac death (SCD) could be reduced after implantation of a cardioverter-defibrillator (ICD), yet at the same time more frequent shock episodes are associated with poor life quality and higher hospitalization rate. Radiofrequency (RF) ablation of triggering ventricular premature beats or substrate-based catheter treatment are considered to be effective in patients with ICM but prognosis remains controversial. Objective To evaluate role of catheter treatment of ventricular tachyarrhythmias (VTA) and its effect on survival in patients with ischemic cardiomyopathy. Methods We enrolled 72 consecutive patients (mean age 64±13 years, 63 male) with prior myocardial infarction (more than 40 days ago) and documented ventricular tachycardia (VT) episodes, including 12 patients which underwent emergency electrical storm ablation. Considering number of VT recurrence episodes after catheter treatment all patients were divided into two groups. First group consisted of 27 patients (37%) with recurrent sustained VT (mean age 62±10 years) while second group included 45 patients (63%) without VT recurrence (mean age 63±12 years). During follow up most of VT episodes were registered in 13±9 years after acute myocardial infarction. Catheter treatment included mapping during hemodynamically tolerated clinically relevant VT and then ablation of VT triggers with subsequent homogenization of the scar. Patients with “fast” VT underwent primary scar homogenization. Results Effectiveness of clinically relevant VT ablation in patients with ICM was 63%. During follow-up period all patients were alive and remained relatively stable. Long-term effectiveness of ES elimination was 100% while freedom from clinically significant VTA was up to 79% due to repeated ablation procedures. We also observed improvement of NYHA functional class in 80% of patients. Conclusion Catheter ablation of VTA may be effective treatment both in acute period and long term follow up. It also may be effective in improvement of heart failure NYHA functional class in some patients and contributes to better survival in patients with ICM.

Preventive Ventricular Tachycardia Ablation in Patients with Ischaemic Cardiomyopathy: Meta-analysis of Randomised Trials.

Catheter ablation of ventricular tachycardia (VT) aims to treat the underlying arrhythmia substrate to prevent ICD therapies. The aim of this meta-analysis was to assess the safety and efficacy of VT ablation prior to or at the time of secondary prevention ICD implantation in patients with coronary artery disease, as compared with deferred VT ablation. Based on a systematic literature search, three randomised trials were considered eligible for inclusion in this analysis, and data on the number of patients with appropriate ICD shocks, appropriate ICD therapy, arrhythmic storm, death and major complications were extracted from each study. On pooled analysis, there was a significant reduction of appropriate ICD shocks (OR 2.58; 95% CI [1.54–4.34]; p<0.001) and appropriate ICD therapies (OR 2.04; 95% CI [1.15–3.61]; p=0.015) in patients undergoing VT ablation at the time of ICD implantation without significant differences with respect to complications (OR 1.39; 95% CI [0.43–4.51]; p=0.581). Mortality did not differ between both groups (OR 1.30; 95% CI [0.60–2.45]; p=0.422). Preventive catheter ablation of VT in patients with coronary heart disease at the time of secondary prevention ICD implantation results in a significant reduction of appropriate ICD shocks and any appropriate ICD therapy compared with patients without or with deferred VT ablation. No significant difference with respect to complications or mortality was observed between both treatment strategies.

Long term follow-up after ventricular tachycardia ablation in patients with congenital heart disease.

Ventricular tachycardia (VT) is frequently encountered in patients with repaired and unrepaired congenital heart disease (CHD), causing significant morbidity and sudden cardiac death. Data regarding underlying VT mechanisms and optimal ablation strategies in these patients remain limited. To describe the electrophysiologic mechanisms, ablation strategies, and long-term outcomes in patients with CHD undergoing VT ablation. Forty-eight patients (mean age 41.3 ± 13.3 years, 77.1% male) with CHD underwent a total of 57 VT ablation procedures at two centers from 2000 to 2017. Electrophysiologic and follow-up data were analyzed. Of the 77 different VTs induced at initial or repeat ablation, the underlying mechanism in 62 (81.0%) was due to scar-related re-entry; the remaining included four His-Purkinje system-related macrore-entry VTs and focal VTs mainly originating from the outflow tract region (8 of 11, 72.7%). VT-free survival after a single procedure was 72.9% (35 of 48) at a median follow-up of 53 months. VT-free survival after multiple procedures was 85.4% (41 of 48) at a median follow-up of 52 months. There were no major complications. Three patients died during the follow-up period from nonarrhythmic causes, including heart failure and cardiac surgery complication. While scar-related re-entry is the most common VT mechanism in patients with CHD, importantly, nonscar-related VT may also be present. In experienced tertiary care centers, ablation of both scar-related and nonscar-related VT in patients with CHD is safe, feasible, and effective over long-term follow-up.

Rationale and design of BERLIN VT study: a multicenter randomised trial comparing preventive versus deferred ablation of ventricular tachycardia

IntroductionCatheter ablation (CA) has shown to effectively reduce the burden of ventricular tachycardia in patients with implanted cardioverter-defibrillator (ICD). However, in patients with ICD implantation for secondary prevention of ventricular...

Percutaneous left ventricular assist device support during ablation of ventricular tachycardia: A meta-analysis of current evidence.

Catheter ablation of ventricular tachycardia (VT) can be an effective therapy to reduce VT burden, but often it is limited by the potential for hemodynamic instability. Percutaneous left ventricular assist devices (pLVADs) have been used to maintain hemodynamic support during VT ablation but the evidence regarding its clinical impact has been inconclusive. We sought to assess the clinical impact of pLVAD when used in VT ablation by conducting a meta-analysis of the current evidence. We searched Pubmed and found nine observational studies that compared clinical outcomes of VT ablation in patients with pLVAD support to controls with no pLVAD support. The pooled data did not show a significant difference in mortality between both groups, nor a difference in acute procedural success or in recurrence of VT. There was also no difference in the number of patients receiving a cardiac transplant or being enrolled in the transplant list. Although there was no difference in the ablation time between the groups, patients in the pLVAD group had a longer total procedural time and more procedure-related adverse effects. This meta-analysis did not show clinical benefits from using pLVAD support during VT ablation, whereas it was associated with longer procedure times and more complications. This study was, however, limited by the observational nature of the data. In view of these data, the risk and benefit of pLVAD support during VT ablation should be considered on an individual basis.

Percutaneous epicardial approach for ventricular tachycardia ablation in patients with structural heart disease – case series presentation form University Hospital Centre Split

Epikardna VT ablacija je vrlo invazivna procedura, no kada se radi u centrima s kardiokirurskom podrskom i velikim volumenom ablacijskih procedura, nudi mogucnost sigurnog izvođenja i daje sansu ostvariti kontrolu nad aritmijama koje ugrožavaju ne samo kvalitetu, vec i život ovih pacijenata.

Electrophysiologic Substrate, Safety, Procedural Approaches, and Outcomes of Catheter Ablation for Ventricular Tachycardia in Patients After Aortic Valve Replacement

This study sought to investigate the substrate, procedural strategies, safety, and outcomes of catheter ablation (CA) for ventricular tachycardia (VT) in patients with aortic valve replacement (AVR). VT ablation in patients with AVR is challenging, particularly when mapping and ablation in the periaortic region are necessary. We identified consecutive patients with mechanical, bioprosthetic, and transcatheter AVR who underwent CA for VT refractory to antiarrhythmic drugs and analyzed VT substrate, approach to LV access, complications, and long-term outcomes. Overall, 29 patients (87% men, mean age 67.9 ± 9.8 years, left ventricular ejection fraction 39 ± 10%) with prior AVR (13 mechanical, 15 bioprosthetic, 1 transcatheter AVR) underwent 40 ablations from 2004 to 2016. Left-sided mapping/CA was performed in 27 patients (36 procedures). Access was retrograde aortic in 11 procedures (all bioprosthetic), transseptal in 24 (13 mechanical; 10 bioprosthetic; 1 transcatheter AVR), or transventricular septal in 1. Periaortic bipolar or unipolar scar was detected in all 24 patients in whom detailed periaortic mapping was performed. Clinical VT circuit(s) involved the periaortic region in 10 patients (34%), 2 (7%) had bundle branch re-entry VT, and 17 (59%) had substrate unrelated to AVR. There were 2 major complications (both related to vascular access). Only 2 patients (9.1%) had VT recurrence. Over median follow-up of 12.8 months, 11 patients died (none as a result of recurrent VT). Whereas most patients undergoing CA for VT after AVR had VT from substrate unrelated to AVR, periaortic scar is universally present and bundle branch re-entry can be the VT mechanism. CA can be safely performed with excellent long-term VT elimination.

Combined Endocardial-Epicardial Versus Endocardial Catheter Ablation Alone forVentricular Tachycardia in StructuralHeart Disease: A Systematic Review and Meta-Analysis.

This study sought to determine whether combined endocardial-epicardial (endo-epi) ablation was superior to endocardial only ablation in patients with scar-related ventricular tachycardia (VT). Limited single-center studies suggest that combined endo-epi ablation strategy may be superior to endocardial ablation (endo) alone in patients with nonischemic cardiomyopathy (NICM) and arrhythmogenic right ventricular cardiomyopathy (ARVC), and ischemic cardiomyopathy (ICM). A systematic review of Medline, Cochrane, and Embase databases was performed for studies that reported outcomes comparing endo-epi with endo VT ablation alone. Seventeen studies consisting of 975 patients were included (mean 56 ± 10 years of age; 79% male; NICM in 36.6%; ICM in 32.8%; and ARVC in 30.6%). After a mean follow-up of 27 ± 21 months, endo-epi ablation was associated with a 35% reduction in risk of VT recurrence compared with endocardial ablation alone (risk ratio [RR]: 0.65; 95% confidence interval [CI]: 0.55 to 0.78; p< 0.001). Sensitivity analysis showed lower risk of VT recurrence in ICM (RR: 0.43; 95% CI: 0.28 to 0.67; p= 0.0002) and ARVC (RR: 0.59; 95% CI: 0.43 to 0.82; p= 0.0002), with a nonsignificant trend in NICM (RR: 0.87; 95% CI: 0.70 to 1.08; p= 0.20). Endo-epi, compared with endo ablation, was associated with reduced all-cause mortality (RR: 0.56; 95% CI: 0.32 to 0.97; p= 0.04). Acute procedural complications were higher with the endo-epi approach (RR: 2.62; 95% CI: 0.91 to 7.52; p= 0.07). This meta-analysis suggests that a combined endo-epi ablation is associated with a lower risk of VTrecurrence and subsequent mortality than endo only VT ablation in patients with scar-related VT. Procedural complications, however, are higher with the endo-epi approach.

Outcomes of patients admitted with ventricular arrhythmias and sudden cardiac death in the United States

Mortality caused by ventricular arrhythmias (VAs) remains a problem of epidemic proportions. Understanding current trends on admission of VA, patient characteristics, morbidity, mortality, and health care utilization could help us improve allocation of health care resources and risk prediction. The purpose of this study was to investigate clinical outcomes of VA, including ventricular tachycardia (VT), implantable cardioverter-defibrillator (ICD) shocks, and sudden cardiac death (SCD); and to identify predictors of morbidity and mortality, patterns of utilization of ICD and VT ablation, and the impact of such metrics on overall health care utilization. From 2010-2015, we identified 290,998 VA hospitalizations, which were stratified into group 1: normal heart; group 2: ischemic heart disease (IHD); group 3: nonischemic heart disease (non-IHD); group 4: ICD shocks; and group 5: SCD (cardiac arrest without ICD shock). The number of admissions for VA decreased during the study period (except for patients with SCD and ICD shock, which increased); in-hospital mortality in patients admitted with VA and SCD increased; utilization of VT ablation in patients with ICD shocks and IHD increased; ICD implantation decreased in non-IHD patients and IHD patients; and admission for SCD was the strongest predictor of in-hospital mortality, followed by patients with non-IHD, patients with ICD shocks, and all patients with a Charlson comorbidity index ≥2. We report a decrease in admissions for VA, decreased ICD utilization, a change in pattern of VT ablation utilization, and an increase of in-hospital mortality in SCD patients. Predictors of adverse outcomes identified in our study should be considered when developing risk models for patients undergoing risk assessment for SCD.

Ventricular Tachycardia Ablation in Nonischemic Cardiomyopathy.

Catheter ablation is being increasingly performed as adjunctive treatment to prevent recurrent implantable cardioverter-defibrillator therapies in patients with nonischemic cardiomyopathy and ventricular tachycardia (VT). In the context of VT ablation, nonischemic cardiomyopathy usually refers to dilated cardiomyopathy (DCM) as one morphological phenotype. Over the past decades, progress has been made to better characterize distinct subtypes and to differentiate between causes of DCM, which has important practical and prognostic implications. The goal of this review is to summarize available data on VT ablation in patients with DCM and, more specifically, review procedural and outcome data in specific etiologies and substrate location. It will focus on our current understanding of nonischemic scars, as well as the value of multimodal imaging, image integration, and electroanatomic mapping for substrate identification, procedural planning, and ablation. In addition, recent findings from whole human heart histology of patients with DCM and VT and their potential implications for imaging and mapping will be discussed.

Catheter ablation of ventricular tachycardia in nonischemic cardiomyopathy.

The number of patients with nonischemic cardiomyopathy (NICM) undergoing catheter ablation of ventricular tachycardia (VT) has increased by the years, however, there are no randomized studies of VT ablation in this population. Many studies have reported more mixed or inferior outcome after the ablation in patients with NICM as compared to in those with ischemic cardiomyopathy (ICM)—likely because of the heterogeneous VT substrates in each etiology. While, various ablation strategies for substrate modification in the setting of ICM, including low voltage area ablation, late potential abolition, and local abnormal ventricular activity elimination, have been well established, it is still unknown which ablation strategy is effective for prevention of recurrence VTs in NICM patients. Therefore, this review will highlight the recent progress made in VT ablation in patients with NICM.