Ventricular Tachycardia Ablation Research Articles

Sex, Race, and Rural-Urban Disparities in Ventricular Tachycardia Ablations

BackgroundVentricular ablation may be clinically indicated for patients with recurrent ventricular tachycardia (VT) and has been shown to decrease risk of recurrence and overall morbidity. However, the existence of disparities among patients receiving ventricular ablation has not been well characterized. ObjectivesIn this study, the authors examined patients hospitalized with VT to determine whether disparities exist among those receiving ablations. MethodsThe authors used the National Inpatient Sample to assess patients hospitalized with a primary diagnosis of VT in 2019 who did and did not receive catheter ablations. Multiple logistic regression was used to calculate risk factors for VT ablation based on age, sex, race/ethnicity, socioeconomic status, and hospital characteristics. ResultsAfter adjusting for baseline characteristics and comorbidities, female and Black patients hospitalized with VT had significantly lower odds of receiving ablations compared with male and White patients (OR: 0.835; 95% CI: 0.699-0.997; P = 0.047; and OR: 0.617; 95% CI: 0.457-0.832; P = 0.002, respectively). Additionally, patients at rural or nonteaching hospitals were significantly less likely to receive ablations compared with those at urban, teaching hospitals. No significant differences were noted based on income or insurance status in the adjusted models. ConclusionsThe authors identified significant disparities in the delivery of ventricular ablations among patients hospitalized with VT. Overall, patients who were female or Black as well as those who were hospitalized at rural or nonteaching hospitals were significantly less likely to receive VT ablations during hospitalization.

Editorial to “Long‐term outcomes of ventricular tachycardia ablation in repaired tetralogy of Fallot: systematic review and meta‐analysis”

Editorial to “Long‐term outcomes of ventricular tachycardia ablation in repaired tetralogy of Fallot: systematic review and meta‐analysis”

Spatial analysis and characteristics of persistent late potentials after ablation of scar-related VT substrate: Implications for late potential elimination as a procedural endpoint with high-resolution mapping

BackgroundLate potential (LP) elimination has been proposed as a surrogate endpoint for scar-related ventricular tachycardia (VT) ablation procedures. The characteristics, distribution, and predictors of persistent late potentials (pLPs) after ablation have not been studied. ObjectiveThe purpose of this study was to characterize the spatial distribution and features of pLP after catheter ablation of VT substrate with high-resolution mapping. MethodsCases of scar-related VT ablation with adequate pre- and postablation electroanatomic maps (EAMs) acquired exclusively using a high-density grid catheter were reviewed from 2021 to 2023. ResultsA total of 62 EAMs (pre- and postablation) from 31 cases using a high-density grid catheter were reviewed. pLPs were observed in 19 cases (61%) after ablation. New LP, spatially distinct from preablation LP, at the periphery of the ablation area comprised the majority of pLPs (16/19 [84%]). Isolated pLPs were more prevalent than fractionated pLPs, with a median amplitude of 0.26 mV (0.09–0.59 mV). The presence of pLP was associated with a significantly lower left ventricular ejection fraction (LVEF) and septal ablation but not low voltage, LP, or ablation area compared to absence of pLP (22.8% ± 7.8% vs 31.5% ± 8.0%, P = .008 for LVEF; 83% vs 44%, P = .033 for septal ablation). ConclusionFormation of spatially distinct new LP after targeted VT ablation is common, especially in patients with lower LVEF and septal substrate independent of ablation burden. This finding highlights the limitations of complete LP elimination as an endpoint to VT ablation procedures.

Optimized isochronal late activation methods in the visualization and isthmus identification of ventricular tachycardia

BackgroundCatheter ablation of ventricular tachycardia (VT) during sinus rhythm often relies on isochronal late activation mapping (ILAM), a validated means of isthmus identification, whereby points are binned by local activation time (LAT) into 8 isochrones, and isthmus regions are identified as regions with isochronal crowding. The resulting output, however, is inherently discretized, and loss of LAT data occurs. To improve the precision of isthmus identification, we quantify isochronal density and assess the effect of increasing the number of isochrones used and the effectiveness of continuous metrics analogous to ILAM. ObjectiveThe objective of this study was to determine whether current practices in ILAM calculation are optimized for isthmus detection. MethodsPatients undergoing VT ablation were included if high-density maps in both VT and sinus or paced rhythms were available. Isochronal density was assessed at differing numbers of isochrones, and isthmus discrimination was assessed. Continuous metrics that mimicked ILAM by assessing the local distribution of LAT values—using interquartile range or the median absolute deviation—were also defined and assessed. ResultsEight electroanatomic maps (EAMs) were included. Isthmus discrimination improved progressively from a minimum area under the curve (AUC) of 0.600 when assessing the isochronal density of 8-isochrone EAMs to a maximum of 0.776 when assessing the density of 1000-isochrone EAMs (DeLong test, P < .0001). On logistic regression, the continuous metrics using interquartile range (AUC = 0.714) and median absolute deviation (AUC = 0.721) better discriminated isthmus identity than ILAM. ConclusionUsing more isochrones or using continuous ILAM analogues improves isthmus identification. By retaining more data, these metrics could increase the precision of VT ablation.

Provisional Circulatory Support with Extracorporeal Membrane Oxygenation during Ventricular Tachycardia Ablation in Intermediate Risk Patients: A Case Series.

Background: Cardiogenic shock with acute hemodynamic decompensation may be one of the most serious risks in patients affected by ventricular tachycardia (VT). Its proper identification may have important implications in terms of pharmacological management, as might procedural planning in case of patients undergoing catheter ablation. Methods: We describe a case series of patients with provisional strategies for circulatory support in VT ablation, including the use of venoarterial extracorporeal membrane oxygenation (VA-ECMO) and vascular accesses in the electrophysiology lab but no initial ECMO activation due to an estimated intermediate pre-procedural risk from the case-series population. Results: In total, 10 patients (mean age 70 ± 11 years old, 9 males) with severe cardiomyopathy were admitted for incessant ventricular arrhythmia episodes, further diagnosis, and therapy planning; 1/10 patients (10%), documenting a PAINESD score of 14, underwent VA-ECMO cannulation due to electromechanical dissociation. All 10 patients were discharged alive. Conclusions: A pre-defined strategy before VT ablation is crucial. In our case series, the use of provisional circulatory support with VA-ECMO during incessant ablation of ventricular arrhythmia was a safe and winning alternative to upfront strategies.

Early experience with mechanical hemodynamic support for catheter ablation of malignant ventricular tachycardia

Objective: To explore the role of mechanical hemodynamic support (MHS) in mapping and catheter ablation of patients with hemodynamically unstable ventricular tachycardia (VT), report single-center experience in a cohort of consecutive patients receiving VT ablation during MHS therapy, and provide evidence-based medical evidence for clinical practice. Methods: This was a retrospective cohort study. Patients with hemodynamically unstable VT who underwent catheter ablation with MHS at Beijing Anzhen Hospital, Capital Medical University between August 2021 and December 2023 were included. Patients were divided into rescue group and preventive group according to the purpose of treatment. Their demographic data, periprocedural details, and clinical outcomes were collected and analyzed. Results: A total of 15 patients with hemodynamically unstable VT were included (8 patients in the rescue group and 7 patients in the preventive group). The acute procedure was successful in all patients. One patient in the rescue group had surgical left ventricular assist device (LVAD) implantation, remaining 14 patients received extracorporeal membrane oxygenation (ECMO) for circulation support. ECMO decannulation was performed in 12 patients due to clinical and hemodynamic stability, of which 6 patients were decannulation immediately after surgery and the remaining patients were decannulation at 2.0 (2.5) d after surgery. Two patients in the rescue group died during the index admission due to refractory heart failure and cerebral hemorrhage. During a median follow-up of 30 d (1 d to 12 months), one patient with LVAD had one episode of ventricular fibrillation at 6 months after discharge, and no further episodes of ventricular fibrillation and/or VT occurred after treatment with antiarrhythmic drugs. No malignant ventricular arrhythmia occurred in the remaining 12 patients who were followed up. Conclusions: MHS contributes to the successful completion of mapping and catheter ablation in patients with hemodynamically unstable VT, providing desirable hemodynamic status for emergency and elective conditions.

Outcomes of patients with malignancy undergoing catheter ablation for ventricular tachycardia in the United States

Outcomes of patients with malignancy undergoing catheter ablation for ventricular tachycardia in the United States

Mortality in Recipients of Durable Left Ventricular Assist Devices Undergoing Ventricular Tachycardia Ablation

BackgroundLeft ventricular assist device (LVAD) recipients have a higher incidence of ventricular tachycardia (VT). However, the role of VT ablation in this population is not well-established. ObjectivesThis single-center retrospective cohort study sought to examine the impact of post-LVAD implant VT ablation on survival. MethodsThis retrospective study examined a cohort of patients that underwent LVAD implantation at Baylor St. Luke’s Medical Center and Texas Heart Institute between January 2011 and January 2021. All-cause estimated mortality was compared across LVAD recipients based on the incidence of VT, timing of VT onset, and the occurrence and timing of VT ablation utilizing Kaplan-Meier survival analysis and Cox proportional hazards models. ResultsPost-implant VT occurred in 53% of 575 LVAD recipients. Higher mortality was seen among patients with post-implant VT within a year of implantation (HR: 1.62 [95% CI: 1.15-2.27]). Among this cohort, patients who were treated with a catheter ablation had superior survival compared with patients treated with medical therapy alone for the 45 months following VT onset (HR: 0.48 [95% CI: 0.26-0.89]). Moreover, performance of an ablation in this population aligned mortality rates with those who did not experience post-implant VT (HR: 1.18 [95% CI: 0.71-1.98]). ConclusionsVT occurrence within 1 year of LVAD implantation was associated with worse survival. However, performance of VT ablation in this population was correlated with improved survival compared with medical management alone. Among patients with refractory VT, catheter ablation aligned survival with other LVAD participants without post-implant VT. Catheter ablation of VT is associated with improved survival in LVAD recipients, but further prospective randomized studies are needed to compare VT ablation to medical management in LVAD recipients.

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.

Comparison between Remotely Supported Nurse-led Electro-Anatomic Mapping and Standard Onsite Engineer Support for Electrophysiological Procedures.

Catheter ablations of complex cardiac arrhythmias are currently guided by electro-anatomic mapping systems. The aim of this study was to compare two different approaches: remotely supported nurse-led electro-anatomic mapping with standard onsite engineer support. In this retrospective observational study, 166 patients with complex and non-complex procedures were included. 82 patients benefited from electro-anatomic mapping with remotely supported nurse-led mapping (mean age: 62±16years), while the approach for 84 patients was with standard onsite engineer support (mean age: 56±19 years). Procedural characteristics, acute results and complication rates were compared between both groups and showed similar results.Complex and non-complex procedures were conducted in both groups, including left atrial and ventricular procedures. As ventricular tachycardia and accessory pathway ablations were more frequently conducted with standard onsite engineer support, we separately analyzed the largest subgroup, 105 patients with atrial fibrillation, left atrial flutter and left atrial tachycardia. Patients in this subgroup had comparable baseline characteristics, procedure times and procedural success. Nevertheless, there were longer ablation times and more utilization of fluoroscopy in the onsite group, most likely due to more complex procedures. Our results underline the practicality of remotely supported nurse-led electro-anatomic mapping. The latter approach proved to be a safe alternative to onsite engineer support. Due to its advantages, particularly for insular settings, it will likely play a greater role in the future.

Catheter ablation compared to medical therapy for ventricular tachycardia in sarcoidosis: nationwide outcomes and hospital readmissions

BackgroundCatheter ablation (CA) for ventricular tachycardia (VT) can be a useful treatment strategy, however, few studies have compared CA to medical therapy (MT) in the sarcoidosis population. ObjectiveTo assess in-hospital outcomes and unplanned readmissions following CA for VT compared to MT in patients with sarcoidosis. MethodsData was obtained from the Nationwide Readmissions Database between 2010 and 2019 to identify patients with sarcoidosis admitted for VT either undergoing CA or MT during elective and non-elective admission. Primary endpoints were a composite endpoint of inpatient mortality, cardiogenic shock, cardiac arrest and 30-day hospital readmissions. Procedural complications at index admission and causes of readmission were also identified. ResultsAmong 1581 patients, 1217 with sarcoidosis and VT underwent MT compared to 168 with CA during non-elective admission. 63 patients admitted electively underwent CA compared with 129 managed medically. There was no difference in the composite outcome for patients undergoing catheter ablation or medical therapy during both non-elective (9.0 % vs 12.0 %, p = 0.312) and elective admission (3.2 % vs. 7.8 %, p = 0.343). The most common cause of readmission were ventricular arrhythmias (VA) in both groups, however, those undergoing elective CA were less likely to be readmitted for VA compared to non-elective CA. The most common complication in the CA group was cardiac tamponade (4.8 %). ConclusionVT ablation is associated with similar rates of 30-day readmission compared to MT and does not confer increased risk of harm with respect to inpatient mortality, cardiogenic shock or cardiac arrest. Further research is warranted to determine if a subgroup of sarcoidosis patients admitted with VT are better served with an initial conservative management strategy followed by VT ablation.

Acute post-procedural inducibility is a poor predictor of clinical outcomes in high-risk patients (PAINESD > 17) undergoing scar-related ventricular tachycardia ablation.

Ventricular tachycardia (VT) non-inducibility in response to programmed ventricular stimulation (PVS) is a widely used procedural endpoint for VT ablation despite inconclusive evidence with respect to clinical outcomes in high-risk patients. The aim is to determine the utility of acute post-ablation VT inducibility as a predictor of VT recurrence, mortality, or mortality equivalent in high-risk patients. We conducted a retrospective analysis of high-risk patients (defined as PAINESD > 17) who underwent scar-related VT ablation at our institution between July 2010 and July 2022. Patients' response to PVS (post-procedure) was categorized into three groups: Group A, no clinical VT or VT with cycle length > 240 ms inducible; Group B, only non-clinical VT with cycle length > 240 ms induced; and Group C, all other outcomes (including cases where no PVS was performed). The combined primary endpoint included death, durable left ventricular assist device placement, and cardiac transplant (Cox analysis). Ventricular tachycardia recurrence was considered a secondary endpoint (competing risk analysis). Of the 1677 VT ablation cases, 123 cases met the inclusion criteria for analysis. During a 19-month median follow-up time (interquartile range 4-43 months), 82 (66.7%) patients experienced the composite primary endpoint. There was no difference between Groups A and C with respect to the primary [hazard ratio (HR) = 1.21 (0.94-1.57), P = 0.145] or secondary [HR = 1.18 (0.91-1.54), P = 0.210] outcomes. These findings persisted after multivariate adjustments. The size of Group B (n = 13) did not permit meaningful statistical analysis. The results of post-ablation PVS do not significantly correlate with long-term outcomes in high-risk (PAINESD > 17) VT ablation patients.

Variations in threshold values for border zone and dense scar produce significant changes in scar parameters obtained by ADAS-3D

BackgroundADAS-3D software elaborates cardiac magnetic resonance (CMR) images to obtain a quantitative evaluation of dense scar and border zone (BZ), including BZ channels, which can be useful for ventricular tachycardia ablation and risk stratification. However, most prior reports with ADAS-3D used flexible thresholds (60% ± 5% and 40% ± 5% of maximum pixel signal intensity) to define dense scar and BZ. The impact of such variations of the threshold values on the measurements obtained with ADAS-3D is unknown. ObjectiveThis study aimed to quantify the degree of change in ADAS-3D measurements when different thresholds for dense scar and BZ are employed. MethodsA single-center retrospective observational cohort study including 87 consecutive patients with previous myocardial infarction who underwent CMR was conducted. ADAS-3D software semiautomatically processed CMR sequences. We compared the scar measurements obtained with the 9 possible combinations of thresholds (55%/60%/65% and 35%/40%/45% of maximum pixel signal intensity). ResultsThe overall comparison between thresholds showed highly significant differences (P < .001) in all scar parameters. Not a single patient maintained the same number of BZ channels with all the thresholds settings. A percentage difference of up to 200% in BZ channel numbers and channel mass was observed in all 36 comparisons. An absolute difference of up to 10 channels was also recorded. Of note, the highest median channel mass (obtained with the thresholds 35–65) was 59-fold higher compared with the lowest one (obtained with the 45-55 cutoffs). ConclusionVariations in threshold values result in statistically significant and high-magnitude changes in the quantification of scar parameters by ADAS-3D.

Cardiac MRI Oversampling in Heart Digital Twins Improves Preprocedure Ventricular Tachycardia Identification in Postinfarction Patients

BackgroundVentricular tachycardia (VT), which can lead to sudden cardiac death, occurs frequently in patients after myocardial infarction. Radiofrequency catheter ablation (RFA) is a modestly effective treatment of VT, but it has limitations and risks. Cardiac magnetic resonance (CMR)–based heart digital twins have emerged as a useful tool for identifying VT circuits for RFA treatment planning. However, the CMR resolution used to reconstruct these digital twins may impact VT circuit predictions, leading to incorrect RFA treatment planning. ObjectivesThis study sought to predict RFA targets in the arrhythmogenic substrate using heart digital twins reconstructed from both clinical and high-resolution 2-dimensional CMR datasets and compare the predictions. MethodsHigh-resolution (1.35 × 1.35 × 3 mm), or oversampled resolution (Ov-Res), short-axis late gadolinium–enhanced CMR was acquired by combining 2 subsequent clinical resolution (Clin-Res) (1.35 × 1.35 × 6 mm) short-axis late gadolinium–enhanced CMR scans from 6 post–myocardial infarction patients undergoing VT ablation and used to reconstruct a total of 3 digital twins (1 Ov-Res, 2 Clin-Res) for each patient. Rapid pacing was used to assess VT circuits and identify the optimal ablation targets in each digital twin. VT circuits predicted by the digital twins were compared with intraprocedural electroanatomic mapping data and used to identify emergent VT. ResultsThe Ov-Res digital twins reduced partial volume effects and better predicted unique VT circuits compared with the Clin-Res digital twins (66.6% vs 54.5%; P < 0.01). Only the Ov-Res digital twin successfully identified emergent VT after a failed initial ablation. ConclusionsDigital twin infarct geometry and VT circuit predictions depend on the magnetic resonance resolution. Ov-Res digital twins better predict VT circuits and emergent VT, which may improve RFA outcomes.

Prevalence of atrial fibrillation and/or atrial flutter in multicenter randomized controlled trials for catheter ablation of ventricular tachycardia in structural heart disease: A meta-analysis

Prevalence of atrial fibrillation and/or atrial flutter in multicenter randomized controlled trials for catheter ablation of ventricular tachycardia in structural heart disease: A meta-analysis

Long-term outcomes of ventricular tachycardia ablation in repaired tetralogy of Fallot: Systematic review and meta-analysis.

Ventricular tachycardia (VT) remains a risk in repaired Tetralogy of Fallot (rTOF); however, long-term benefits of VT ablation have not been established. This study compares the outcomes of rTOF patients with and without VT ablation. We searched multiple databases examining the outcomes of rTOF patients who had undergone VT ablation compared to those without ablation. Primary outcomes were VT recurrence, sudden cardiac death (SCD), and all-cause mortality. Subgroup analysis was conducted based on the type of ablation (catheter and surgical). Slow-conducting anatomical isthmus (SCAI)-based catheter ablation (CA) was also analyzed separately. The secondary outcome was the risk factors for the pre-ablation history of VT. Fifteen cohort studies with 1459 patients were included, 21.4% exhibited VTs. SCAI was found in 30.4% of the population, with 3.7% of non-inducible VT. Factors significantly associated with VT before ablation included a history of ventriculostomy, QRS duration ≥180 ms, fragmented QRS, moderate to severe pulmonary regurgitation, high premature ventricular contractions burden, late gadolinium enhancement, and SCAI. Ablation was only beneficial in reducing VTs recurrence in SCAI-based CA (risk ratio (RR) 0.11; 95% CI 0.03 to 0.33. p < 0.001; I2 = 0%) with no recurrence in patients with preventive ablation (mean follow-up time 91.14 ± 77.81 months). The outcomes of VT ablation indicated a favorable trend concerning SCD and all-cause mortality (RR 0.49 and 0.44, respectively); however, they were statistically insignificant. SCAI-based CA has significant advantages in reducing VT recurrence in rTOF patients. Risk stratification plays a key role in determining the decision to perform ablation.

Road-Map to Epicardial Approach for Catheter Ablation of Ventricular Tachycardia in Structural Heart Disease: Results From a 10-Year Tertiary-Center Experience.

Epicardial approach in ventricular tachycardia (VT) ablation is still regarded as a second-step strategy, due to the risk of complications. We evaluated the frequency that epicardial ablation targets were identified and ablation performed following pericardial access compared with unnecessary pericardial access for different VT causes and potential markers of epicardial VT. All VT ablation procedures including epicardial approach over a 10-year period were included. First-line epicardial approach was indicated in arrhythmogenic right ventricular cardiomyopathy (ARVC) and postmyocarditis VT; in patients with idiopathic dilated cardiomyopathy (IDCM) and postmyocardial infarction, indications resulted from available imaging techniques or 12-lead VT morphology. The epicardial approach was considered useful if epicardial ablation was performed after epicardial mapping. Feasibility, complications, and long-term outcome were reported. Four hundred and eighty-eight subjects with a median age of 60 years (interquartile range, 47-65) and of left ventricle ejection fraction 41% (interquartile range, 30-55) underwent 626 epicardial VT ablations. Percutaneous access had a success rate of 92.2% and a complication rate of 3.6%. Overall, epicardial approach was, respectively, indicated to 11.8% of postmyocardial infarction patients, 49.5% in IDCM, 94% in myocarditis, and 90.7% in ARVC. Epicardial ablation at the first ablation attempt was performed in 9.3% of postmyocardial infarction patients, 28.8% in IDCM, 86.5% in myocarditis, and 81.3% in patients with ARVC. In first-line epicardial group, ARVC and myocarditis showed the highest odds for epicardial ablation (OR, 4.057 [95% CI, 1.299-8.937]; P=0.007; OR, 3.971 [95% CI, 1.376-11.465]; P=0.005, respectively). IDCM independently predicted unnecessary epicardial approach (OR, 2.7 [95% CI, 1.7-4.3]; P<0.001). After a follow-up of 41 months (interquartile range, 19-64), patients with IDCM experienced higher rate of recurrences and mortality compared with other causes. Epicardial approach is integral part of ablation armamentarium regardless of the VT cause, with high feasibility and low complication rate in experienced centers. Our data support its use at first ablation attempt in VTs related to ARVC and myocarditis.

Periprocedural acute haemodynamic decompensation during substrate-based ablation of scar-related ventricular tachycardia: a rare and unpredictable event.

Patients with structural heart disease (SHD) undergoing catheter ablation (CA) for ventricular tachycardia (VT) are at considerable risk of periprocedural complications, including acute haemodynamic decompensation (AHD). The PAINESD score was proposed to predict the risk of AHD. The goal of this study was to validate the PAINESD score using the retrospective analysis of data from a large-volume heart centre. Patients who had their first radiofrequency CA for SHD-related VT between August 2006 and December 2020 were included in the study. Procedures were mainly performed under conscious sedation. Substrate mapping/ablation was performed primarily during spontaneous rhythm or right ventricular pacing. A purposely established institutional registry for complications of invasive procedures was used to collect all periprocedural complications that were subsequently adjudicated using the source medical records. Acute haemodynamic decompensation triggered by CA procedure was defined as intraprocedural or early post-procedural (<12 h) development of acute pulmonary oedema or refractory hypotension requiring urgent intervention. The study cohort consisted of 1124 patients (age, 63 ± 13 years; males, 87%; ischaemic cardiomyopathy, 67%; electrical storm, 25%; New York Heart Association Class, 2.0 ± 1.0; left ventricular ejection fraction, 34 ± 12%; diabetes mellitus, 31%; chronic obstructive pulmonary disease, 12%). Their PAINESD score was 11.4 ± 6.6 (median, 12; interquartile range, 6-17). Acute haemodynamic decompensation complicated the CA procedure in 13/1124 = 1.2% patients and was not predicted by PAINESD score with AHD rates of 0.3, 1.8, and 1.1% in subgroups by previously published PAINESD terciles (<9, 9-14, and >14). However, the PAINESD score strongly predicted mortality during the follow-up. Primarily substrate-based CA of SHD-related VT performed under conscious sedation is associated with a substantially lower rate of AHD than previously reported. The PAINESD score did not predict these events. The application of the PAINESD score to the selection of patients for pre-emptive mechanical circulatory support should be reconsidered.

Preprocedural imaging with cardiac computed tomography for endo-epicardial ventricular tachycardia ablation

BackgroundStudies evaluating the systematic use of cardiac computed tomography (CCT) for the preprocedural assessment of myocardial fibrosis are limited. Their implementation in the electrophysiology workflow has not been extensively described. ObjectiveThis study aimed to explore the degree of concordance between CCT and electroanatomic mapping (EAM) for the evaluation of cardiac fibrosis in patients undergoing endo-epicardial ventricular tachycardia (VT) ablation. MethodsFrom November 2017 to December 2021, patients undergoing endo-epicardial VT catheter ablation with CCT as the only source of preprocedural scar assessment were prospectively enrolled. After image integration, myocardial fibrosis detected with CCT was compared with low-voltage areas identified by endo-epicardial EAM. Postprocedural VT recurrences of this approach were evaluated after at least 1 year of follow-up. ResultsThe study enrolled 35 patients (mean age, 60.7 ± 13.2 years; 94.2% male). The most common underlying arrhythmic substrate was dilated cardiomyopathy (48.6%). CCT was employed for contraindications to cardiac magnetic resonance, such as unstable VTs (31.4%) or nonconditional implantable cardioverter-defibrillators (28.6%), but also for patients’ and operators’ preferences (14.3%–25.7%). Myocardial fibrosis was correctly identified by CCT and EAM, with strong agreement between these techniques both overall (Cohen κ for agreement, 0.933) and in per-segment analysis (κ ranging from 0.796 to 1.0). Ischemic patients showed the best correlation (κ = 1.000), whereas myocarditis showed the worst (κ = 0.750). After a median follow-up of 14 (12–24) months, 1-year freedom from recurrences was achieved in 74.3% patients; overall freedom from recurrences was 60.0%. ConclusionA CCT-based preprocedural assessment before VT ablation is feasible, showing high diagnostic concordance with EAM in detecting myocardial fibrosis.

Distribution of myocardial fibrosis in patients with nonischemic cardiomyopathy and ventricular tachycardia based on genetic variant

BackgroundMany genetic nonischemic dilated cardiomyopathies (NICMs) cause ventricular tachycardias (VTs) originating from scar substrate identified as areas of low electrogram voltage. Substrate locations vary, and the causes of scar are not well defined. ObjectiveThis study evaluated VT substrate locations in genetic NICM patients undergoing VT ablation to evaluate spatial relationships between specific variants and substrate locations. MethodsIn this retrospective case series analysis, 32 patients (aged 55 ± 16 years; 94% male; left ventricular ejection fraction, 34% ± 13%) with genetic NICM referred for VT ablation between October 2018 and November 2022 at a single medical center were evaluated. Scar locations were defined as areas of low unipolar or bipolar voltage. ResultsOf the 32 patients evaluated, mutations in TTN (n = 11), LMNA (n = 6), PKP2 (n = 5), MYBPC3 (n = 3), DSP (n = 2), TTR (n = 1), FLNC (n = 1), AGL (n = 1), DES (n = 1), and DSG2 (n = 1) were observed. Substrates associated with mutations in TTN were observed only in basal subregions, predominantly anterior (100%) and septal (50%) regions. LMNA mutations were associated with fibrosis in mid inferolateral (60%) and apical inferolateral (60%) regions. Substrate location for individuals with PKP2 mutations was solely observed in the right ventricle, predominantly basal inferolateral regions. ConclusionUnderstanding spatial relationships between genetic variants causing NICM and VT substrate locations can help lead to generalizable regions in patients with genetically related NICM presenting in VT, which can be investigated during ablation procedures.