Undergoing Ventricular Tachycardia Ablation Research Articles

A screening for cerebral deoxygenation during VT ablations in patients with structural heart disease.

Patients undergoing ventricular tachycardia (VT) ablation often present with structural heart disease (SHD) and reduced ejection fraction. Inducing VT by programmed electrical stimulation (PES) puts these patients at risk for hemodynamic instability and cerebral hypoperfusion. The present study screens for cerebral oxygen desaturation phases (ODPs) in patients undergoing VT ablation. Forty-seven patients (age 61 ± 14years, 72% males) underwent ablation of sustained VT with simultaneous neuromonitoring using near-infrared spectroscopy (NIRS). Analysis of NIRS signal identified ODPs in 29 patients (62%). ODPs were associated with a higher prevalence of ischemic heart disease (IHD) (45% vs. 11%, p = 0.024), previous VT episodes (n = 16 vs. 4, p = 0.018), and VTs inducible by PES (n = 2.4 vs. 1.2, p = 0.004). Patients with ODPs were more likely to be admitted to intensive care unit (ICU) (78% vs. 33%, p = 0.005) and had more in-hospital VT recurrences (24% vs. 0%, p = 0.034). No differences were observed in VT recurrencerates after hospital discharge (41.4% vs. 44.4%, p = 0.60) and left ventricularejection fraction (34% vs. 38%, p = 0.567). IHD (OR: 32.837, p = 0.006), ICU admission (OR: 14.112, p = 0.013), and the number of VTs inducible at PES (OR: 2.705, p = 0.015) were independently associated with ODPs. This study registers episodes of cerebral hypoperfusion in 62% of patients undergoing VT ablation and identifies IHD and the number of VTs inducible at PES as possible risk factors for these episodes.

Ablation of hemodynamically unstable ventricular tachycardia guided by ultra-high density pacemapping and PASO correlation map, a multi-center clinical trial

Abstract Background Due to hemodynamic instability during ventricular tachycardia (VT), obtaining a complete electroanatomic map is often difficult if not impossible. Pace-mapping has progressed but still lacks precision and may not reveal sufficient details for complete ablation of the potential critical isthmus. Purpose We hypothesized that a novel strategy of combining ultra-high density (HD) pace-mapping using the PASO algorithm and Carto system to match the induced/clinical VT may aid in the reconstruction of the VT critical isthmus and effective VT ablation leading to reduce the risks of VT recurrence. Methods This was a prospective, multi-center trial conducted between January 2021 and July 2023. We enrolled 30 patients with ischemic heart disease and scar mediated recurrent VT clinically indicated for ablation. Following induction of clinical VT, we performed ultra-HD pace-mapping (5-10 mm distance between pacing points) of the identified ventricular substrate. Using PASO Module, a pacing correlation map (PCM) was constructed based on the percentage match to the induced VT. Using the PCM and the measured stimulation to electrogram intervals, the potential VT critical isthmus was reconstructed. Radiofrequency ablation was carried out to completely transect the delineated isthmus. Post ablation, repeat HD mapping and ablation was performed, until the PASO % correlation dropped from >93% to <70%, indicating at least uni-directional (orthodromic to the perceived VT circuit) conduction block through the ablation line. Follow-up data, including ICD interrogations were collected via chart review. Outcomes were compared to 60 propensity-score matched patients with an ICD who were enrolled in the Ranolazine in High-Risk Patients with Implanted Cardioverter-Defibrillators (RAID) trial who did not undergo VT ablation and served as the control group. The primary endpoint was the first occurrence of any VT at 1-year of follow-up. Results Patients enrolled had a mean age of 69 ± 9 years and 13% were women. Propensity matched patients from the RAID trial had similar baseline clinical characteristics to patients who underwent VT ablation (Table). At 1 year follow up, there was a significantly lower cumulative probability of VT/VF recurrent events in the patients who underwent PCM guided ablation as compared with the control group (17% vs 69%, respectively; log-rank p<0.001 Figure). There were no serious procedure related complications with all patients remaining free of adverse events or death at 30 days. Conclusion Our findings suggest that ablation for unstable or unmappable VT is enhanced by ultra-high density pace-mapping to reconstruct the potential VT circuit and is associated with a significantly lower rate of recurrent VT as compared with patients managed with aggressive and escalating medical therapy.Cumulative probability of ICD therapyBaseline clinical characteristics

Impact of functional gene groups on outcomes after ablation of ventricular tachycardia in patients with inherited left ventricular cardiomyopathy: an international multicentre study

Abstract Background Advances in genetic testing has enabled identification of pathogenic variants of different functional gene groups associated with non-dilated left ventricular cardiomyopathy (NDLCM)/dilated cardiomyopathy (DCM) and ventricular tachycardia (VT). However, there is limited data on the impact of functional groups on VT ablation outcome. Aim We aimed to assess the impact of likely pathogenic/pathogenic variants (LP/Pv) of different functional gene groups on heart failure (HF) outcomes and VT recurrence in patients with NDLCM/DCM after VT ablation. Methods Patients with NDLCM/DCM who underwent genetic testing (next-generation sequencing) and were referred for VT ablation were enrolled at 6 participating centers. Patients were followed for VT recurrence, HF-related adverse outcomes (death, left ventricular assist device [LVAD], or heart transplantation due to HF), and all-cause mortality. Results A total of 239 patients (age 55±14yrs; male n=193; LVEF 40±12%; amiodarone at admission n=103; ICD n=180) were included. LP/Pv were identified in 128 patients (54%), predominantly found in genes encoding sarcomeric (n=36/128, [28%]; titin n=20, myosin binding protein C n=12), followed by nuclear membrane (n=27/128, [22%]; lamin A/C; n=26), desmosomal (n=23/128, [18%]; desmoplakin n=11, plakophilin n=9), cytoskeleton (n=12/128, [9%]; filamin C n=8), and sarcoplasmic reticulum proteins (n=12/128, [9%]; phospholamban n=10). Variants of unknown significance (n=32) were grouped with patients who tested negative. Acute complete ablation success, defined as non-VT inducibility of any sustained monomorphic VT, was achieved in 113 patients (47%), 63 (56%) with LP/Pv. During a median follow-up of 32 months, 108 patients (45%) had VT recurrence, 41 (17%) had HF-related adverse outcomes (death with/without LVAD in 34, LVAD in 2, heart transplantation in 5) and 47 (20%) died. Patients with LP/Pv were more likely to have VT recurrence, HF-related adverse outcomes and had a higher mortality compared to those without (VT, 68 [53%] vs. 40 [36%]; HF-related adverse outcomes, 30 [23%] vs. 11 [10%]; mortality, 30 [23%] vs. 17 [15%]; log-rank, P<0.01 for all). As compared to patients without LP/Pv, those with LP/Pv in genes encoding nuclear membrane or sarcomeric proteins had significantly worse (P<0.01 for both) and those with LP/Pv in genes encoding desmosomal proteins had similar HF and VT recurrence outcomes (Figure). Of interest, patients with LP/Pv in genes encoding cytoskeleton proteins had favorable HF-related adverse outcomes, but worse VT recurrence (P=0.02) compared to those without LP/Pv (Figure). Conclusion In patients with NDLCM/DCM and VT, the impact of LP/Pv on HF and VT-recurrence outcomes after ablation differs across functional groups. Integrating genetic testing in the comprehensive evaluation of patients with NDLCM/DCM undergoing VT ablation may facilitate personalized ablation strategies and early consideration of alternative HF treatments.

Preprocedural substrate assessment with computed tomography as an adjunct to endocardial voltage mapping for ablation of ventricular tachycardia: feasibility, procedural data and outcomes

Abstract Background Catheter ablation is an established therapy for ventricular tachycardia (VT) with endocardial voltage map (EVM) being the standard tool to characterize proarrhythmic substrate. However, this method is limited in certain ways, especially as intramural or epicardial substrate is not detected. In this context, multi-detector computed tomography (MDCT) has emerged as a promising alternative to cardiac MRI for preprocedural substrate assessment. Purpose Data regarding MDCT- guided VT ablation is scarce, especially in the context of late iodine enhancement MDCT. Present study sought to assess procedural parameters, safety, and efficacy of MDCT-guided VT ablation in direct comparison with a conventional VT ablation approach and is, to the best of our knowledge, the first systematic evaluation of clinical routine use of MDCT for preprocedural substrate assessment. Methods All patients (pts) undergoing VT ablation between January 2022 and August 2023 were included in this single-center registry. For MDCT-guided VT the CT images were uploaded to an online platform and processed using a dedicated software. Procedural parameters of MDCT-guided procedures were compared with the conventional EVM approach, and the study endpoint was a composite of death from any cause, heart failure hospitalization, and recurrence of VT. Results A total of 70 consecutive pts (age 62±13 y, 83% male) was included, of those 27/70 pts (39%) undergoing MDCT-guided and 43/70 pts (61 %) conventional VT ablation. An additional EVM was acquired in all MDCT pts. Baseline characteristics were similar. At comparable procedure durations (MDCT: 217±74 min, EVM: 194±57 min, p=0.15) the MDCT group showed a trend towards shorter mapping times (MDCT: 42±18 min, EVM: 49±13 min, p=0.09), particularly in cases with non-ischemic cardiomyopathy (NICM) (MDCT: 41±20 min, EVM: 54±15 min, p=0.07). An epicardial access was obtained in 8/23 pts (30 %) in the MDCT group and in 6/47 pts (14 %) in the EVM group (p=0.13). Bipolar ablation due to intramural scar detected by MDCT was performed in 3/27 pts (11 %) and in none in the EVM group. There was no difference in manifestation of acute kidney injury (MDCT: 3/17 pts (18 %) vs. EVM: 4/24 pts (21 %), p=1.0). After a median follow-up of 116 days (IQR 80-260 days), the study endpoint occurred in 8/17 (47 %) pts after MDCT-guided and in 14/31 pts (45 %) after conventional VT ablation. In one patient in the MDCT group a relevant coronary artery stenosis with urgent revascularization occurred immediately after bipolar ablation at the LV summit. No other complications were observed. Conclusion MDCT-guided VT ablation is safe and feasible with no differences in contrast agent-induced kidney injuries. Preprocedural CT substrate assessment identified complex intramural and epicardial scar, leading to bipolar and epicardial ablation. Mapping times trended shorter in the MDCT group, particularly in non-ischemic cardiomyopathy cases.

Novel systematic processing of cardiac magnetic resonance imaging identifies target regions associated with infarct-related ventricular tachycardia

Abstract Introduction In the clinic, complete characterization of reentrant ventricular tachycardia (VT) circuits using classical electrophysiological criteria and state-of-the-art high density mapping during VT is complex, and often cannot be completed because of hemodynamic instability. This common limitation has motivated the implementation of mapping strategies during sinus rhythm or ventricular pacing aiming to identify scar regions associated with VT isthmuses or potential arrhythmogenicity. Complementary imaging-based strategies including advanced analyses of scar tissue characteristics have been also proposed for procedure planning and identification of potential arrhythmogenic regions. However, the most recent expert consensus report on catheter ablation of ventricular arrhythmia highlights the lack of agreement on the preferable signal intensity (SI) cut-off values for assessment of tissue heterogeneity and scar areas on late gadolinium enhancement cardiac magnetic resonance (LGE-CMR) images. The latter makes LGE-CMR imaging processing highly operator-dependent and potentially sensitive to selection bias. Purpose We aimed at developing and validating a systematic processing approach on LGE-CMR images to identify potential VT corridors that may include protected isthmuses associated with VT maintenance. Methods Translational study including 18 pigs with established myocardial infarction and inducible VT undergoing in vivo characterization of the anatomical and functional myocardial substrate associated with VT maintenance. Clinical validation was conducted in a multicenter series of 33 patients with ischemic cardiomyopathy undergoing VT ablation. Three-dimensional CMR-LGE images were processed using systematic scanning of 15 signal intensity cut-off ranges to obtain surface visualization of all potential VT corridors. Analysis and comparisons of imaging and electrophysiological data were performed in individuals with full electrophysiological characterization of the isthmus sites of at least one VT morphology. Results In both the experimental pig model and patients undergoing VT ablation, all the electrophysiologically-defined isthmus sites (n=11 and n=19, respectively) showed overlapping regions with CMR-based potential VT corridors. Such imaging-based VT corridors were less specific than electrophysiologically-guided ablation lesions at functionally relevant isthmus sites (Figure). However, in patients, decreasing from 15 to 7 the number of signal intensity cut-off ranges for systematic imaging processing significantly reduced the area of imaging-based potential VT corridors, without diminishing the capability to detect functionally relevant VT isthmus sites. Conclusions Systematic processing of 3D LGE-CMR images provides unbiased identification of imaging based potential VT corridors that contain functionally relevant protected isthmus sites.

Epicardial catheter ablation of ventricular tachycardia in patients of acm - from a university hospital report in switzerland

Abstract Background Arrhythmogenic left ventricular cardiomyopathy (ALVC) as a subtype of arrhythmogenic cardiomyopathy (ACM) is increasingly being recognized. Cardiac magnetic resonance (CMR) has emerged as the primary imaging modality for the diagnosis of ACM. In patients with right-dominant ACM (ARVC) and recurrent sustained ventricular tachycardia (VT), endocardial +/-epicardial ablation yields good clinical outcomes in the long-term. However, studies on VT ablation in ACM with LV involvement are scarce. Purpose We sought to investigate clinical outcomes of VT ablation in ACM patients with LV involvement. Methods The study included patients from the Zurich ACM Registry who met 2020 "Padua Criteria" for ACM and underwent VT ablation between January 2018 and July 2023. Epicardial ablation was performed in patients with recurrent sustained VT despite endocardial ablation, those lacking and endocardial substrate or if the ECG of the VT / substrate on CMR was suggestive of an epicardial origin. Catheter ablation was guided by activation/entrainment mapping for mappable VT, and pace mapping/voltage mapping during sinus rhythm for unmappable VT. Consecutive follow-up of all patients was performed according to our protocol. Results Twenty-one ACM patients underwent n=24 VT ablation procedures. Of those 20 patients, 6 patients (30%) had LV involvement on CMR. Eight (33%) patients underwent epicardial +/- endocardial ablation. Among patients receiving epicardial ablation, 3 patients (38%) had LV involvement. These three underwent a single ablation procedure, which was epicardial only. Total follow-up was 30 months (range 4-43). Three-month sustained VT/VF recurrence rates were 12% in the ACM group with LV involvement vs 25% in ACM without LV involvement. All patients with sustained VT/VF recurrence underwent repeat ablation via an epicardial approach within 3 months and were free of sustained VT/VF thereafter during a median follow-up of 12 months. One-year recurrence rate did not differ between ACM patients with LV involvement vs. without LV involvement (7.7% vs 8.3%, P＝0.117). Seven out of eight epicardial ablations achieved freedom from VT/VF after one-year follow-up. One ARVC patient with previous endocardial ablation had recurrent VT one month after epicardial ablation, which was free of VT after Flecainide combined with beta-blocker. No significant differences were found in the use of beta-blockers and antiarrhythmic drugs between both groups (ACM with LV involvement vs. without LV involvement) at baseline and during one-year follow-up. Conclusions Single or adjuvant epicardial substrate ablation of VT in arrhythmogenic cardiomyopathy is promising in terms of postprocedural VT free survival, especially in patients with left ventricular involvement demonstrated by CMR.Figure 1Figure 2

Effects of hemodynamic support on arrhythmia-free survival following catheter ablation of ventricular arrhythmias

Abstract Background Radiofrequency-guided catheter ablation is an established therapy for ventricular tachycardia (VA). Hemodynamic support (HS) is often required for patients suffering from incessant VA to guide ablation. Data on the outcome of patients receiving HS during VA ablation procedures are lacking. Purpose The aim of this observational study was to analyze the acute procedural success as well as long-term 36-month-VA-recurrence rates and mortality in patients requiring HS during VA ablation procedures. Methods Data from consecutive patients receiving HS during VA ablation procedures between 2015-2023 were analyzed. HS was defined as the use of an Impella, an extracorporeal membrane oxygenation (ECMO) or a left ventricular assist device (LVAD). HS-group patients were compared to patients that underwent VA ablation procedures without HS. All patients were continuously followed up in our outpatient clinic. Data on procedural parameters, acute success and complications as well as long-term VA-free survival and mortality were analyzed. Results A total of 95 consecutive patients (mean age 60.9 ± 11.0 years, 15% female) were included. 62 patients (65%, mean age 60.4±9.4 years, 16% female) receiving HS (ECMO or Impella: n=26, 42%; ECMO+Impella: n=7, 11%; LVAD: n=29, 47%) were compared to those without (mean age 61.7±13.5 years, 12 % female). In the HS-cohort a significantly lower left ventricular ejection fraction (LVEF) (p<0.001), a higher New York Heart Association (NYHA) functional class (p=0.013) and a more frequent antiarrhythmic drug use (p=0.045) was documented. Fluoroscopy times were significantly longer in the HS-group (HS: 10:22 ± 07:04 vs. no HS: 05:52 ± 02:50 minutes, p<0.001). Acute procedural success (HS: n=59, 95% vs. no HS: n=33, 100%, p=0.549) and major procedure complications (HS: n=4. 6% vs. no HS: n=4. 6%, p=1.000) were comparable between the two groups. Nevertheless, patients receiving HS had a significantly higher in-hospital mortality (HS: n=20, 32 % vs. no HS: n=2, 6%, p=0.004). The estimated 36-month-VA-free survival was comparable between the groups (Log-rank p=0.114). But Kaplan-Meier-plot analyses revealed a significantly higher estimated mortality in patients receiving HS (Log-rank p=0.002) (Figure 1). Between the subgroups (ECMO or Impella vs. LVAD) no statistically relevant differences were observed (Log-rank p=0.466). Multivariate analyses revealed HS as an independent predictor for mortality (Hazard ratio (HR) 3.259, Confidence Interval (CI) 1.060-10.015, p=0.039), but not for VA-recurrence. Conclusion In the specific cohort of patients receiving HS, VA ablation procedures seem to be safe and effective with comparable acute and long-term success- and complication-rates. The need for HS seems to be associated with an increased risk for mortality. Further studies are required to validate our initial observations.Kaplan-Meier-plot on 36-month survival

Exploration of peak frequency mapping for ventricular tachycardia ablation. Identification of critical isthmus zones during substrate mapping

Abstract Background/Introduction The ability to classify and differentiate between near field and far-field components of intracardiac signals is a key element in identifying critical arrhythmogenic substrate during ventricular tachycardia (VT) ablation. Near Field algorithms based on omnipolar electrograms enable detection and automation of true localised signals providing unique insights into substrate characteristics. This novel feature identifies localised signal peak frequency (PF) which can be displayed across different voltage ranges. Purpose/Aims The significance of PF mapping in the context of VT ablation is limited and its utility in the identification of the critical diastolic isthmus zone (IZ) is not known. The aim of this study is to explore the utilisation of PF mapping during VT ablation and evaluate whether significant differences in PF occur within areas of interest and critical components of the VT circuit during substrate mapping. Methods All patients underwent VT ablation using the EnSite™ X mapping system with the HDGrid omnipolar mapping catheter. Only cases with both high density sinus rhythm (SR) substrate maps and VT activation maps with clear identification of the IZ were included. VT activation and propagation maps were generated and the diastolic IZ was superimposed onto the SR substrate map. PF analysis was performed retrospectively. Surface area, omnipolar voltage and PF of the maps were measured in the SR substrate maps and co-localised with the critical IZ of the VT circuit as identified in the VT activation maps. Analysis of PF was conducted across different voltage ranges: healthy myocardium (>1.5mV), scar (1.5-0.5mV) and dense scar (0.5-0.1mV). Sensitivity and specificity measurements were made within segments of the IZ and non-isthmus zones and depicted as ROC curves. Results 55 patients underwent VT ablation over a 12-month period, with a total of 18 fulfilling the inclusion criteria. Mean age was 70 (±12.5years) with an average ejection fraction of 36%. The overall PF of the SR substrate maps was 121.85±26.85 Hz, compared to 162.22±46.22Hz within the IZ (p=0.002). Within the low voltage scar region, the overall PF was 120.86±33.24Hz compared to 188.32±81.36Hz within the IZ (p=0.003). No significant difference in PF was observed within healthy myocardium (112.70±52.06 Hz) compared to components of the IZ within the >1.5mV range (157.61±136.11Hz), p=0.207. The AUC for PF within the overall substrate map and co-localisation with the IZ was 0.67, and 0.73 within low voltage zones (<1.5mV). Conclusions PF mapping may identify critical components of the VT circuit during SR substrate mapping and its utilisation may compliment established substrate mapping approaches. PF guided ablation strategies require further evaluation in future prospective studies.

Neural network for automatic ICD-EGMs matching in pace-mapping and ablation of ventricular arrhythmias

Abstract Background Mapping of the ventricular arrhythmias (VA) is often not possible due to the non-inducibility of the electrophysiological study (EPS). Since twelve-lead electrocardiograms (ECG) of the clinical ventricular tachycardia (VT) are also often not available, therefore stored implantable cardioverter-defibrillator (ICD) electrograms (EGMs) of the clinical VT are often the only documentation. The pace mapping matching to the stored ICD-EGM template of the clinical VT can help to identify the VT exit site. Automatic objective computing of similarity scores between EGMs is impossible because ICD programmer devices do not have any interface allowing the export of digital EGMs. Therefore, images can only be accessed for similarity by subjective eyeballing. The MatcherNet Siamese neural network takes a pair of EGM images and predicts their similarity. Purpose This study aimed to assess the feasibility of the automatic ICD-EGMs matching by MatcherNet neural network for pace mapping of VT/premature ventricular contraction (PVC) exit site. Methods Consecutive patients undergoing VT ablation or ablation of ventricular fibrillation, triggered by PVC were included in the study, if the clinical VT/PVC was not inducible during EPS but ICD-EGMs of clinical VT/PVC were stored in the device. Electro-anatomical mapping was performed to reveal substrates (low-voltage areas, abnormal potentials, DEEP-potentials, conduction crowding). Subsequently, the low-output pacing from various locations tagged on the 3D map of LV was performed, and the paced ICD-EGM images were stored from the ICD programmer device for offline analysis and calculation of the similarity. RF ablation was conducted based on the substrate map findings, including the area of the most remarkable similarity between paced ICD-EGMs and clinical ICD-EGM templates assessed by eyeballing. The ICD-EGMs similarity scores (Manhattan similarity and Pearson correlation) were predicted by MatcherNet for each pacing site offline and transferred to the 3D map for the assessment of similarity distribution (Figure 1). Results We included 7 patients with VA episodes registered and stored by their ICD. The clinical characteristics are presented in Table1. In all patients, we were able to find the sites of highest ICD-EGM similarity to the clinical template with gradual decrementing of the similarity score at the increasingly distant pacing areas. The site of the highest similarity was collocated with VT substrate and ablation areas in all patients. Abrupt change of the similarity score at the adjacent pacing sites was detected in the 2 cases, indicating the possible protected VT isthmus. After ablation procedure only one patient with DCM experienced VA recurrence. Conclusion This technology opens new possibilities for the utilization of ICD-EGMs during the pace mapping of ventricular tachycardia, especially in the cases of non-inducibility during electrophysiological study.Figure 1Table 1

The importance of scar border zone size in VT presentation and recurrence in post MI patients

Abstract Introduction Available mapping data in post-myocardial infarction patients describe ventricular tachycardia (VT) re-entry circuit characteristics of slow VT, that are typically related to transmural scars. Fast VTs with cycle lengths close to the refractory period may be related to functional re-entry in the scar border zone. Functional re-entry related border zone VTs may be difficult to control by ablation. Purpose The aims of this study are (1) to describe electroanatomical voltage map (EAVM) characteristics in post myocardial infarction (MI) patients with spontaneous and inducible fast VTs and (2) to assess the relation between scar border zone size and ablation outcomes. Methods Consecutive post-MI patients undergoing VT ablation at a tertiary referral center from January 2012 to November 2018 were included. Fast VT was defined as a VT cycle length (VTCL) = ventricular refractory period + max. 30ms. Areas of scar border zone (using 0.5 – 2.1mV/3.0mV cut-offs (according to LV remodeling stage; LVEF<47% and LV end-systolic volume index of >50 ml/m2)) were measured on the EAVM and correlated with clinical outcomes. Results In total, 138 patients were included (86% male; left ventricular ejection fraction 35±10%; 86% remodeled LV). Twenty-three patients (17%) had ≥1 fast VT (mean VTCL 275±52ms) at presentation, mean VTCL of the remaining patients 397±88ms). The median scar border zone size was 27% [IQR 20-38] of the left ventricular endocardial surface. Patients who presented with a spontaneous fast VT had a larger border zone than patients with slower VT (32% [IQR 28 – 41] vs. 25% [IQR 16 – 36], p=0.01). After ablation, 79 (57%) patients remained inducible for any VT, including 59/79 (75%) for a fast VT (median VTCL fast VT 260ms [IQR 236 -280]). Patients who remained inducible for fast VTs had a larger border zone than patients who remained inducible for slower VTs (35% [IQR 27 – 44] vs. 26% [IQR 20 – 36], p<0.001). During a median follow-up of 26 months [IQR 8 – 47], 45 patients (33%) had a VT recurrence (mean VTCL 357±98ms). Patients with a below median (27%) scar border zone area had a lower VT recurrence rate compared to patients with an above median scar border zone area (recurrence rate: 16/66 (24%) vs. 29/72 (40%), p=0.03). Kaplan-Meier survival analysis showed better free VT survival in the below median border zone patients (Log-rank: p<0.05) (Figure 1). Conclusion Patients who present with spontaneous fast VTs or who remain inducible for fast VTs after ablation have larger scar border zones during EAVM compared to patients with presenting or remaining slower VTs. A larger border zone appeared to be associated with higher VT-recurrence rates. The scar border zone may play an important role as VT substrate for (fast) VTs and may not be easily targeted by current ablation techniques.VT-free survival stratified by median BZ

Scar tissue characterization to predict arrhythmia recurrence in patients undergoing ventricular tachycardia ablation: cardiac computed tomography compared with cardiac magnetic resonance

Abstract Background The role of imaging in evaluating patients undergoing ventricular tachycardia (VT) ablation is crucial for planning, procedural success, and clinical outcomes. In daily practice, cardiac computed tomography (CCT) assessing wall thinning and late iodine uptake (LI) and cardiac magnetic resonance (CMR) assessing late-gadolinium enhancement (LGE) are most commonly implemented. However, data comparing the two imaging modalities for scar tissue characterization is scarce. Aims To compare the performance of both imaging modalities for scar tissue characterization in ischemic (ICM) and non-ischemic (NICM) patients undergoing VT ablation and predict procedural outcomes. Methods In a retrospective analysis, consecutive patients undergoing both CCT and LGE-CMR before scheduled VT ablation were included. The presence and extent of scar was assessed by means of each imaging modality using dedicated softwares (MUSIC and ADAS). To compare scar distribution and agreement between the two modalities, a scar classification scheme was used for all 17 AHA segments: 0 points (no scar present), 1 point (scar <50% of total segment area), 2 points (scar representing 50-99% of total segment area) or 3 points (scar present in 100% of the segment area).<scar<100%)><scar<100%> Results 36 patients (67±10 years; 97% male; LVEF 39±10%; 72% ischemic) undergoing CCT and LGE-CMR before scheduled VT ablation were included. In the ICM group, mean detected scar burden was higher than in the NICM group on LGE-CMR (total volume: 62.3±32.9g vs. 32.8±9.5g, p<0.001), using wall thinning model (WT)(mean scar area 69.0±45.6 cm2 vs. 23.4±23.6cm2, p=0.005) as well as LI (dense scar area: 39.2±28.1 cm2 vs. 11.0±6.3 cm2 , p=0.005). The absolute score difference per segment and patient between CCT and LGE-CMR was calculated and summed for all patients divided by the number of patients. Differences were more pronounced for NICM compared to ICM and LGE-CMR showed better concordance to LI than WT in both NICMP and ICM (Figure). Total procedure time was 205±68 min (ablation time 28±16 min; fluoroscopy time 15 ± 12 min). During a follow-up period of 19±7 months, 87 sustained VT episodes in 12 patients (33%) were documented. Three patients (8%) underwent a second VT ablation and one patient (3%) died during follow-up. In ICM, total scar volume on LGE-CMR and scar area on LI showed numerically higher predictive value for VT recurrence than total scar area by means of WT (AUC: LGE 0.76, LI 0.78 and WT 0.65 respectively), while in NICM scar characterization by means of WT yielded higher performance to predict VT recurrence than LI or LGE-CMR (AUC: LGE 0.67, LI 0.58, WT 0.83 respectively). Conclusions In patients undergoing VT ablation, both LGE-CMR and CCT are valuable for scar tissue characterization. Late iodine uptake on CCT showed a high concordance with LGE-CMR in both NICM and ICM.</scar<100%></scar<100%)>

Efficacy of catheter ablation for ventricular tachycardia in ischemic cardiomyopathy patients without an ICD implantation

BackgroundThe implantable cardioverter-defibrillator (ICD) prevents sudden cardiac death in patients with ischemic cardiomyopathy (ICM). Catheter ablation has been shown to effectively reduce ventricular tachycardia (VT) recurrence, yet its efficacy in patients without an ICD implantation remains uncertain. ObjectiveWe aimed to investigate the outcomes of ablation for VT in patients with ICM without a backup ICD. MethodsPatients with ICM who received ablation for VT without an ICD implantation were included in this study. Ablation was guided by either activation mapping or substrate mapping. Endocardial ablation was the primary strategy; epicardial access was considered when endocardial ablation failed. The primary end point was VT recurrence during follow-up; secondary end points included cardiovascular rehospitalization, all-cause mortality, and a composite of these events. ResultsA total of 114 patients were included, with the mean age of 58.2 ± 11.1 years, 102 of whom (89.5%) were male. Twelve patients (10.5%) underwent endo-epicardial ablation, whereas the rest received endocardial ablation. With a median follow-up of 53.8 months (24.8–84.2 months), VT recurred in 45 patients (39.5%), and 6 patients (5.3%) died, including 2 sudden cardiac deaths. The recurrence rate of VT was significantly lower in patients undergoing endo-epicardial ablation than in those with endocardial ablation only (8.3% vs 43.1%; log-rank P = .032). After multivariate adjustment, epicardial ablation remained associated with a reduced risk of VT recurrence (hazard ratio, 0.14; 95% confidential interval, 0.02–0.98; P = .048). ConclusionPatients with ICM undergoing VT ablation without a backup ICD experienced a notably low rate of arrhythmic death. Most recurrences proved nonlethal.

Feasibility, Efficacy, and Safety of Fluoroless Ablation of VT in Patients With Structural Heart Disease

BackgroundCatheter ablation of ventricular tachycardia (VT) typically requires radiation exposure with its potential adverse health effects. A completely fluoroless ablation approach is achievable using a combination of electroanatomical mapping and intracardiac echocardiography. Nonetheless, data in patients undergoing VT ablation are limited. ObjectivesThis study aimed to determine the feasibility, efficacy, and safety of VT ablation in patients with structural heart disease using a zero-fluoroscopy approach. MethodsThis multicenter study included consecutive patients with ischemic and nonischemic cardiomyopathy undergoing fluoroless VT ablation. Patients requiring epicardial access or coronary angiography were excluded. ResultsBetween 2017 and 2023 a total of 198 patients (aged 66.4 ± 13.4 years, 76% male, 48% ischemic) were included. Most patients (95.4%) underwent left ventricular (LV) mapping and/or ablation, which was conducted via transseptal route in 54.5% (n = 103), via retrograde aortic route in 43.4% (n = 82), and using a combined approach in 2.1% (n = 4). Two-thirds of patients had a cardiac device, including a biventricular device in 15%; 2 patients had a LV assist device, and 1 patient had a mechanical aortic valve prosthesis. The mean total procedural time was 211 ± 70 minutes, and the total radiofrequency time was 30 ± 22 minutes. During a follow-up period of 22 ± 18 months, the freedom from VT recurrence was 80%, and 7.6% of patients underwent a repeated ablation. Procedural-related complications occurred in 6 patients (3.0%). ConclusionsFluoroless ablation of VT in structural heart disease is feasible, effective, and safe when epicardial mapping/ablation is not required.

Outcomes of ventricular tachycardia ablation in patients with ischemic and non-ischemic cardiomyopathy: A propensity-score matched analysis

Introduction and objectivesCatheter ablation (CA) is effective in the treatment of ventricular tachycardia (VT). Although some observational data suggest patients with non-ischemic cardiomyopathy (NICM) have less favorable outcomes when compared to those with an ischemic etiology (ICM), direct comparisons are rarely reported. We aimed to compare the outcomes of VT ablation in a propensity-score matched population of ICM or NICM patients. MethodsSingle-center retrospective study of consecutive patients undergoing VT ablation from 2012 to 2023. A propensity score (PS) was used to match ICM and NICM patients in a 1:1 fashion according to age, sex, left ventricular ejection fraction (LVEF), NYHA class, electrical storm (ES) at presentation, and previous endocardial ablation. The outcomes of interest were VT-free survival and all-cause mortality. ResultsThe PS yielded two groups of 71 patients each (mean age 63±10 years, 92% male, mean LVEF 35±10%, 36% with ES at presentation, and 23% with previous ablation), well matched for baseline characteristics. During a median follow-up of 2.3 (interquartile range IQR 1.3–3.8) years, patients with NICM had a significantly lower VT-free survival (53.5% vs. 69.0%, log-rank p=0.037), although there were no differences regarding all-cause mortality (22.5% vs. 16.9%, log-rank p=0.245). Multivariate analysis identified NICM (HR 2.34 [95% CI 1.32–4.14], p=0.004), NYHA class III/IV (HR 2.11 [95% CI 1.11–4.04], p=0.024), and chronic kidney disease (HR 2.23 [95% CI 1.25–3.96], p=0.006), as independent predictors of VT recurrence. ConclusionNon-ischemic cardiomyopathy patients were at increased risk of VT recurrence after ablation, although long-term mortality did not differ.

Impact of age on hospital outcomes after catheter ablation for ventricular tachycardia.

The real-world data on the safety profile of ventricular tachycardia (VT) ablation among elderly patients is not well-established. This study aimed to evaluate the procedural outcomes among those aged 18-64 years versus those aged ≥65 years who underwent catheter ablation of VT. Using the Nationwide Readmissions Database, our study included patients aged ≥18 years who underwent VT catheter ablation between 2017 and 2020. We divided the patients into non-elderly (18-64 years old) and elderly age groups (≥65 years old). We then analyzed the in-hospital procedural outcome and 30-day readmission between these two groups. Our study included 2075 (49.1%) non-elderly patients and 2153 (50.9%) elderly patients who underwent VT ablation. Post-procedurally, elderly patients had significantly higher rates of prolonged index hospitalization (≥7 days; 35.5% vs. 29.3%, p < .01), non-home discharge (13.4% vs. 6.0%, p < .01), 30-day readmission (17.0% vs. 11.4%, p < .01), and early mortality (5.5% vs. 2.4%, p < .01). There was no significant difference in the procedural complications between two groups, namely vascular complications, hemopericardium/cardiac tamponade, cerebrovascular accident (CVA), major bleeding requiring blood transfusion, and systemic embolization. Through multivariable analysis, the elderly group was associated with higher odds of early mortality (OR: 7.50; CI 1.86-30.31, p = .01), non-home discharge (OR: 2.41; CI: 1.93-3.00, p < .01) and 30-day readmission (OR: 1.58; CI 1.32-1.89, p < .01). Elderly patients have worse in-hospital outcome, early mortality, non-home discharge, and 30-day readmission following catheter ablation for VT. There was no significant difference between elderly and non-elderly groups in the procedural complications.

Feasibility of carbon dioxide insufflation and impact on epicardial approach utilization for ventricular tachycardia ablation in a midvolume referral center

BackgroundEpicardial access is often crucial for successful ventricular tachycardia (VT) ablation, but it is often burdened by significant procedural risk. Intentional coronary vein exit and intrapericardial CO2 insufflation (EpiCO2) can facilitate subxiphoid pericardial access. ObjectiveThis prospective study aimed to assess procedural feasibility, safety, and impact of the introduction of intrapericardial CO2 insufflation for epicardial access in a referral center for VT ablation. MethodsAll consecutive patients treated with epicardial VT ablation between November 2022 and January 2024 with the EpiCO2 technique at Pisa University Hospital were prospectively enrolled and compared in terms of feasibility, efficiency, and safety with a local retrospective cohort of patients treated with subxiphoid dry puncture between July 2018 and October 2022. ResultsTwenty-two consecutive patients (90.9% male; mean age, 54.3 years) underwent VT ablation with EpiCO2 during the study period. Epicardial access was achieved in all patients; median time from coronary sinus (CS) cannulation to epicardial access was 33 minutes. Intentional vein exit was successful in all cases, whereas CO2 insufflation was not feasible in 1 patient. There were no major complications and no significant bleeding. Since EpiCO2 introduction, epicardial approach utilization increased from 17.8% to 40% of all VT procedures. Comparison with 20 standard dry approach epicardial ablations showed no significant differences in terms of total procedural duration (322.5 [interquartile range, 296.75–363.75] minutes vs 359 [interquartile range, 323–409] minutes; P = .08). ConclusionIn our single-center experience, EpiCO2 was feasible and safe and led to significant increase in procedural volume without affecting total procedural time compared with standard dry puncture.

Catheter Ablation for Ventricular Tachycardia in Patients With Desmoplakin Cardiomyopathy

BackgroundDesmoplakin (DSP) pathogenic/likely pathogenic (P/LP) variants are associated with malignant phenotypes of arrhythmogenic cardiomyopathy (DSP-ACM). Reports of outcomes after ventricular tachycardia (VT) ablation in DSP-ACM are scarce. ObjectivesIn this study, the authors sought to report on long-term outcomes of VT ablation in DSP-ACM. MethodsPatients with P/LP DSP variants at 9 institutions undergoing VT ablation were included. Demographic, clinical, and instrumental data as well as all ventricular arrhythmia (VA) events were collected. Sustained VAs after the index procedure were the primary outcome. A per-patient before and after ablation comparison of rates of VA episodes per year was performed as well. ResultsTwenty-four DSP-ACM patients (39.3 ± 12.1 years of age, 62.5% male, median 6,116 [Q1-Q3: 3,362-7,760] premature ventricular complexes [PVCs] per 24 hours, median 4 [Q1-Q3: 2-11] previous VA episodes per patient at ablation) were included. Index procedure was most commonly endocardial/epicardial (19/24) The endocardium of the right ventricle (RV), the left ventricle (LV), or both ventricles were mapped in 8 (33.3%), 9 (37.5%), and 7 (29.2%) cases, respectively. Low voltage potentials were found in 10 of 15 patients in the RV and 11 of 16 in the LV. Endocardial ablation was performed in 18 patients (75.0%). Epicardial mapping in 19 patients (79.2%) identified low voltage potentials in 17, and 16 received epicardial ablation. Over the following 2.9 years (Q1-Q3: 1.8-5.5 years), 13 patients (54.2%) experienced VA recurrences. A significant reduction in per-patient event/year before and after ablation was observed (1.4 [Q1-Q3: 0.5-2.4] to 0.1 [Q1-Q3: 0.0-0.4]; P = 0.009). Two patients needed heart transplantation, and 4 died (3 of heart failure and 1 noncardiac death). ConclusionsVT ablation in DSP-ACM is effective in reducing the VA burden of the disease, but recurrences are common. Most VT circuits are epicardial, with both LV and RV low voltage abnormalities. Heart failure complicates clinical course and is an important cause of mortality.

VT ablation based on CT imaging substrate visualization: results from a large cohort of ischemic and non-ischemic cardiomyopathy patients.

The eradication of ventricular tachycardia (VT) isthmus sites constitutes the minimal procedural endpoint for VT ablation procedures. Contemporary high-resolution computed tomography (CT) imaging, in combination with computer-assisted analysis and segmentation of CT data, facilitates targeted elimination of VT isthmi. In this context, inHEART offers digitally rendered three-dimensional (3D) cardiac models which allow preoperative planning for VT ablations in ischemic and non-ischemic cardiomyopathies. To date, almost no data have been collected to compare the outcomes of VT ablations utilizing inHEART with those of traditional ablation approaches. The presented data are derived from a retrospective analysis of n = 108 patients, with one cohort undergoing VT ablation aided by late-enhancement CT and subsequent analysis and segmentation by inHEART, while the other cohort received ablation through conventional methods like substrate mapping and activation mapping. The ablations were executed utilizing a 3D mapping system (Carto3), with the mapping generated via the CARTO® PENTARAY™ NAV catheter and subsequently merged with the inHEART model, if available. Results showed more successful outcome of ablations for the inHEART group with lower VT recurrence (27% vs. 42%, p < 0.06). Subsequent analyses revealed that patients with ischemic cardiomyopathies appeared to derive a significant benefit from inHEART-assisted VT ablation procedures, with a higher rate of successful ablation (p = 0.05). Our findings indicate that inHEART-guided ablation is associated with reduced VT recurrence compared to conventional procedures. This suggests that employing advanced imaging and computational modeling in VT ablation may be valuable for VT recurrences.

Anesthetic Management for Ventricular Tachycardia Ablation: A National Anesthesia Clinical Outcomes Registry Analysis

Objectives: We analyzed anesthetic management trends during ventricular tachycardia (VT) ablation, hypothesizing that (1) monitored anesthesia care (MAC) is more commonly used than general anesthesia (GA), (2) MAC use significantly increased after release of the 2019 Expert Consensus Statement on Catheter Ablation of Ventricular Arrhythmias, and (3) anesthetic approach varies based on patient and hospital characteristics. Design: Retrospective study. Setting: National Anesthesia Clinical Outcomes Registry data. Participants: Patients ≥18 years who underwent elective VT ablation between 2013-2021. Interventions: None. Measurements and main results: Covariates were selected a priori within multivariate models, and interrupted time-series analysis was performed. Of the 15,505 patients who underwent VT ablation between 2013-2021, 9,790 (63.1%) received GA. After the 2019 Expert Consensus Statement on Catheter Ablation of Ventricular Arrhythmias supported avoidance of GA, no statistically significant increase in MAC was evident (immediate change in intercept post-consensus statement release AOR 1.41, p=0.1629; change in slope post-consensus statement release AOR 1.06 per quarter, p=0.1591). Multivariate analysis demonstrated that sex, ASA physical status, age, and geographic location were statistically significantly associated with anesthetic approach. Conclusions: GA has remained the primary anesthetic type for VT ablation despite the 2019 Expert Consensus Statement on Catheter Ablation of Ventricular Arrhythmias suggesting its avoidance in idiopathic VT. Achieving widespread clinical practice change is an ongoing challenge in medicine, emphasizing the importance of developing effective implementation strategies to facilitate awareness of guideline release and subsequent adherence to and adoption of recommendations.

Machine-Learning-Based Prediction of 1-Year Arrhythmia Recurrence after Ventricular Tachycardia Ablation in Patients with Structural Heart Disease.

Ventricular tachycardia (VT) recurrence after catheter ablation remains a concern, emphasizing the need for precise risk assessment. We aimed to use machine learning (ML) to predict 1-month and 1-year VT recurrence following VT ablation. For 337 patients undergoing VT ablation, we collected 31 parameters including medical history, echocardiography, and procedural data. 17 relevant features were included in the ML-based feature selection, which yielded six and five optimal features for 1-month and 1-year recurrence, respectively. We trained several supervised machine learning models using 10-fold cross-validation for each endpoint. We observed 1-month VT recurrence was observed in 60 (18%) cases and accurately predicted using our model with an area under the receiver operating curve (AUC) of 0.73. Input features used were hemodynamic instability, incessant VT, ICD shock, left ventricular ejection fraction, TAPSE, and non-inducibility of the clinical VT at the end of the procedure. A separate model was trained for 1-year VT recurrence (observed in 117 (35%) cases) with a mean AUC of 0.71. Selected features were hemodynamic instability, the number of inducible VT morphologies, left ventricular systolic diameter, mitral regurgitation, and ICD shock. For both endpoints, a random forest model displayed the highest performance. Our ML models effectively predict VT recurrence post-ablation, aiding in identifying high-risk patients and tailoring follow-up strategies.