bluuebunny/crossref_metadata_2025_split huggingface dataset:
Cardiac magnetic resonance to evaluate 3D ventricular substrate depth: Prognostic implications for VT ablation approach
Authors: Vazquez-Calvo S , Eulogio-Valenzuela F , Valerio Falzone P , Garre P , Guasch E , Porta-Sanchez A , Tolosana J M , Borras R , Arbelo E , Ortiz Perez J T , Prats S , Perea R J , Brugada J , Mont L , Roca Luque I 
Published: May 2024

Abstract

Background
The decision to perform a high-risk endo-epicardial approach for VT ablation is controversial and mostly based on previous endocardial failure or very specific etiologies. We systematically evaluated the 3D distribution of the automatically-detected conducting channels by CMR with the aim of assessing whether tissue thickness in those areas could allow for an endocardial-only approach independently of the etiology of the cardiomyopathy. This could have an important impact in terms of procedural planning.

Purpose
To study CMR channel depth as a predictor of VT recurrence after endocardial VT ablation.

Methods
Fifty-one consecutive patients with left scar-related VT undergoing ablation after CMR (October 2018 to June 2022) were included (median age 65.56±11.46 years, 94.1% male, median ejection fraction 31.82±8.76%, ischemic cardiomyopathy 72.5%). CMR channels were calculated with ADAS3D software. The depth of CMR channels was assessed based on the involved layers and the total wall thickness (WT) of the affected segment. Patients were prospectively followed for VT recurrence for one year.

Results
One-year VT recurrence was 13.7%. Overall, 159 CMR channels were analyzed (3.10±2.01 channels per patient). Univariate analysis showed that both the maximal depth of channel and the presence of an epicardial channel were the only predictors of VT recurrence during follow-up (OR 1.85 (1.11, 3.13), p=0.02 and OR 1.22 (1.05, 1.41), p=0.04 respectively). The presence of a channel with a maximal depth of more than 7.2mm from the endocardium had a sensitivity= 100%, specificity= 61.36%, negative predictive value (NPV)= 100% and positive predictive value (PPV)=29.0% with an area under the curve of 0.81 for VT recurrence. The presence of an epicardial channel showed, as well, sensitivity=100% and NPV=100% but a worse specificity (27.27%) and PPV (17.95%) compared with maximal depth of the channel. Non-ischemic cardiomyopathy was not significantly associated with a higher risk of VT recurrence after endocardial ablation in our study (OR 2.25 (0.43, 11.66), p 0.34).

Conclusions
The maximal depth of CMR channels is a predictor of VT recurrence in the follow up in patients with left scar-related VT who underwent endocardial ablation. A cutoff of maximal CMR channel depth of 7.2mm could be a better tool to select VT ablation approach than considering the type of cardiomyopathy or the presence of epicardial substrate.Examples of CMR channel depthProbability of VT recurrence
Rhythm matters: sinus and pace rhythm map significantly differ in endo/epicardial 3D electroanatomic mapping
Authors: Heil E , Gerds-Li J H , Hohendanner F 
Published: May 2024

Abstract

Introduction
Left ventricular substrate assessment utilizing ultra-high density multipolar catheters is frequently used to guide ablation procedures in patients with scar related ventricular tachycardia. However, 3D electroanatomic mapping is often performed during either sinus or paced rhythm. The effect of the modality (sinus vs. paced) used during mapping on substrate assessment remains elusive.

Methods and Results
We compared biventricular endo- and epicardial 3D high-density voltage and activation maps in sinus- and right ventricular-paced rhythm in domestic pigs. Data was acquired using a 20-polar mapping catheter with a cardiac tissue proximity filter based on catheter location and impedance measurements. Ventricular pacing (120 bmp) was performed with a permanent pacemaker electrode in right ventricular septal position, and high-density maps were acquired from the endo- and epicardium in sinus and paced rhythm (criterion for low voltage: &lt;0.5 mV). Electroanatomical voltage and activation high-density (&gt;6500 points per heart) mapping were performed with sufficient coverage in the right and left ventricles and the epicardium. The size of the low voltage area varied significantly between sinus and right ventricular-paced rhythm, particularly in epicardial mapping. In SR, the total low voltage was 7.2 ± 5.8%, while 11.1 ± 0.03% in paced rhythm. SR and paced maps revealed e.g. low voltage areas in the basal to apical anterior wall corresponding to the LAD regions, however, this was especially pronounced in sinus maps (e.g. pig 1: 64.2 cm²) compared to the paced rhythm map (e.g. pig 1: 32.8 cm²).

Conclusion
The extent of low voltage regions differed significantly in RV/LV, endo- and epicardially. Sinus maps showed the most accurate electrical representation of local voltage and corresponded correctly to local anatomical landmarks like e.g. the LAD with its surrounding epicardial fat tissue.3D biventricular epicardial voltage map
Imaging-derived tissue visualization guides catheter ablation of premature ventricular contractions
Authors: Kahle A K , Alken F A , Scherschel K , Meyer C 
Published: May 2024

Abstract

Background
The presence of myocardial scarring is associated with worse outcomes after catheter ablation of premature ventricular contractions (PVCs). Three-dimensional substrate characterization is emerging for peri-procedural ablation guidance, but its value for tissue visualization during PVC ablation is unknown.

Purpose
The aim of the present study was to assess the impact of imaging-derived tissue visualization on lesion planning, procedural and clinical outcomes of PVC ablation.

Methods
Thirteen consecutive patients (92.3% male, 62.2±12.4 years) undergoing unipolar (n=8) or bipolar (n=5) PVC catheter ablation with integrated three-dimensional imaging from multidetector computed tomography or cardiac magnetic resonance imaging were included. All patients presented with assumed myocardial scarring due to an underlying cardiomyopathy and/or after previous ablation.

Results
Among all patients (30.8% (peri-)myocarditis, 20.0% ischemic, 15.4% dilated cardiomyopathy, 15.4% idiopathic, 7.7% nonischemic, 7.7% congenital heart disease) undergoing ablation of 20 PVC morphologies (median 1 (IQR 1-2) per patient; 75.0% non-outflow tract; 70.0% left-sided), myocardial scarring was present in 11/13 (84.6%). Wall thinning &lt;5 mm covering an area of 36.1±17.8 cm² contained the PVC origin in 4/13 (30.8%) patients and was safely targeted with radiofrequency lesions with up to 45 W (maximum power: median 32 W (IQR 30-35)) (Figure 1). Imaging-guided bipolar ablation was performed in 5/8 (62.5%) patients with previously therapy-refractory PVCs including foci at the left ventricular summit and the right ventricular outflow tract each in 2 and the left coronary cusp in one patient (Figure 2). PVCs were efficiently suppressed with less radiofrequency lesions (5.4±3.8 vs. 55.8±36.9; p=0.0160) with shorter duration (4.1±3.2 min vs. 23.3±13.5 min; p=0.0152) compared to prior unipolar ablation. Bipolar lesions resulted in a higher impedance (158 Ω (IQR 101-174) vs. 106 Ω (IQR 99-124); p=0.0025), while requiring a lower temperature (36 °C (IQR 35-38) vs. 39 °C (IQR 36-43); p=0.0001) and less power (26 W (IQR 20-30) vs. 30 W (IQR 25-31); p=0.0376). Complete suppression of the clinical PVC was reached in all 13 patients. During a follow-up of 396.8±299.7 days, PVC burden decreased from 20.1±14.3% to 1.7±1.6% (p=0.0172).

Conclusions
Imaging-derived tissue visualization enables determination of myocardial wall thinning &lt;5 mm as a substrate for recurrent PVCs, which can be safely targeted. Three-dimensional imaging efficiently guides high power lesion application and bipolar ablation of PVCs at anatomically challenging foci.Anatomically challenging fociImaging-guided bipolar ablation
Long-term outcomes of ventricular tachycardia ablation in patients with ischemic and non-ischemic cardiomyopathy: a propensity-score matched analysis
Authors: Gomes D , Sousa Paiva M , Matos D , Rodrigues G , Carmo J , Moscoso Costa F , Galvao Santos P , Carmo P , Bello Morgado F , Cavaco D , Adragao P 
Published: May 2024

Abstract

Background
Catheter ablation (CA) has been shown to be effective in the treatment of ventricular tachycardia (VT). Although some observational data suggest that patients with non-ischemic cardiomyopathy (NCIM) have less favorable clinical outcomes when compared to those with an ischemic etiology (ICM), direct comparisons are scarcely reported. We aimed to compare the outcomes of VT ablation in a propensity score-matched population of ICM or NICM patients.

Methods
Single-center observational registry including 246 consecutive patients with ischemic (ICM, N=166) and non-ischemic cardiomyopathy (NICM, N=80) who underwent drug-resistant VT ablation from 2012 to 2023. A propensity score (PS) was used to match patients in a 1:1 fashion according to the following variables: age, sex, left ventricular ejection fraction (LVEF), NYHA class, electrical storm (ES) at presentation, and previous endocardial VT ablation. The outcomes of interest were VT-free survival and all-cause mortality.

Results
The PS yielded two groups of 71 patients each (mean age 63±10 years, 92.3% male, mean LVEF 35±10%, 35.9% with ES at presentation, and 23.2% with previous ablation), well matched for baseline characteristics. Those with NICM were more likely to undergo epicardial or combined VT ablation (43.7% vs. 9.9%, P&lt;0.001). The procedural complication rate was low (4.9%, N=7) and similar between groups (P&gt;0.05). During a median follow-up of 27 (IQR 15–45) months, 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) – Figure. 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. Non-inducibility of any VT immediately after ablation was associated with significantly lower rates of VT recurrence (22.8%/ year vs. 42.4%/ year, log-rank P=0.03).

Conclusion
NCIM patients are at increased risk of VT recurrence after ablation, although long-term mortality was similar to ICM in a propensity-matched cohort. Non-inducibility of any VT after CA is associated with better outcomes.Figure
Cardiac magnetic resonance - aided ventricular tachycardia substrate ablation
Authors: Letsas K , Saplaouras A , Mililis P , Kariki O , Dragasis S , Patsiotis I , Efremidis M , Nyktari E 
Published: May 2024

Abstract

Objectives
To assess feasibility and reliability of Cardiac magnetic resonance (CMR)-derived pixel signal intensity (PSI) maps obtained by Three Dimensional (3D)- Late Gadolinium Enhancement (LGE) images for detecting potential targets for VT substrate ablation procedures.

Background
Parametric imaging with color-coded PSI maps obtained from pre-ablation 3D LGE -CMR imaging can be used for identification and characterization of arrhythmic abnormal substrate. Recent publications have shown that PSI maps permit visualization of border zone areas inside the scar. Specifically, corridors of viable tissue within the scar connecting healthy myocardium define VT corridors that may be the electrical equivalent of the abnormal conducting channels on the electroanatomical mapping (EAM).

Methods
8 patients with scar-dependent monomorphic VTs who underwent 3D-LGE CMR imaging prior to substrate ablation were included in the study. The studies were performed at 1.5T scanner. We obtained two data sets of 3D whole heart LGE imaging with high resolution. Patients underwent two acquisitions: the conventional respiratory navigated, electrocardiographically-gated 3D fast gradient echo (1.3slice thickness, 256x256 matrix acquisition) and the image-navigated isotropic high resolution 3D GE with Dixon water-fat separation.
3D LGE-CMR images were processed with ADAS-VT software to produce a 3-dimensional model of the heart with 10 layers from the endocardium to epicardium and PSI maps color-coded from the LGE data projected to each of the shells (Figure 1). In the LGE-CMR PSI maps, VT corridors were obtained automatically by the ADAS VT software. Subsequently, data were given to the electrophysiologists and merged with the CARTO3 system EAM data obtained for the ablation (Figure2). CMR information was used to facilitate the identification of target ablation sites in the areas identified by CMR as abnormal substrate and radiofrequency was applied in the presence of both a pathological electrogram (EGM) and a VT corridor as identified by CMR.

Results
There was a 95% agreement between the abnormal conducting channels as detected by abnormal electrograms in the EAM and the VT corridors identified by 3D LGE CMR imaging. In two occasions, there was one VT corridor that did not correlate with abnormal electrograms and was not ablated. The two 3D LGE sequences used for ADAS-VT corridors analysis showed complete agreement in the number and location of VT corridors. Mean acquisition time for 3D LGE imaging was 11±4minutes for the conventional fast gradient echo sequence, and 5±2minutes for the novel 3D self-image navigated LGE sequence. The image quality of 3D LGE was superior with the Dixon fat-water separation. Overall CMR-aided VT ablation reduced the procedural and fluoroscopy time by 40%.

Conclusions
CMR-aided VT ablation is feasible, reliable and significantly reduces the procedural time.
Correlation between ventricular local impedance and tissue composition by MRI in chronic infarction
Authors: Aranyo Llach JÚL IA , Martinez-Falguera D , Teis A , Fadeuilhe E , Rodriguez-Leor O , Bazan V , Sarrias A , Villuendas R , Curiel C , Bayes-Genis A , Galvez-Monton C , Bisbal F 
Published: May 2024

Abstract

Background
Local impedance (LI) mapping is feasible and provides additional tissue characterization of the ventricular tachycardia substrate. Data on tissue composition underlying different LI values are lacking.

Purpose
To correlate LI with tissue composition evaluated by magnetic resonance imaging (MRI) in a chronic myocardial infarction (MI) swine model.

Methods
One-month after a non-reperfused anterior MI, eighteen Landrace X Large White pigs underwent delayed-enhancement MRI (deMRI) and endocardial LI mapping. deMRI images were post-processed off-line with commercially available dedicated software; scar subtypes (with thresholds set at 40-60% of maximal pixel signal intensity [PSI]), border-zone corridors and left ventricular wall thickness were measured. LI thresholds were set using the blood-pool LI value to define low, intermediate, and high tissue resistance subtypes. LI maps were co-registered with deMRI for analyses.

Results
Low LI zones correlated with deMRI dense and transmural scar (exhibiting endo and epicardial PSI &gt;60% in 91% and 80% of the cases, respectively). Intermediate LI tissue exhibited predominantly subendocardial scar with more heterogeneous composition (8%, 47% and 45% of the points had &lt;40%, 40-60% and &gt;60% endocardial PSI, respectively), and with less epicardial involvement (50% of points had epicardial PSI &lt;40%). Border-zone corridors co-localized with intermediate LI tissue in most of the cases (77%). Low LI zones exhibited more pronounced wall thinning compared to intermediate LI tissue (p&lt;0.001) (Figure 1).

Conclusions
LI correlated with scar density and transmurality on deMRI. Areas of low LI had higher proportion of dense, transmural scar and wall thinning compared to intermediate LI areas. MRI-detected border-zone corridors colocalized with intermediate LI in most cases.LI and deMRI data (endo and epi scar)LI and deMRI data (tissue thickness)
Predictors of improvement in LV ejection fraction post PVC ablation
Authors: Nather A , Begley D , Martin C A , Fynn S P , Heck P M , Zachariah D , Virdee M S , Mellor G , Gajendragadkar P , Agarwal S 
Published: May 2024

Abstract

Introduction
Premature ventricular contraction (PVC) is a frequently encountered finding in routine ECGs, that in certain individuals may be followed by reduction in ejection fraction (EF). This may be improved or even reversed with a medical or interventional reduction of ectopic burden.

Objective
The primary objective of this study is to assess the potential effectiveness of cardiac ablation in suppressing PVC and subsequently enhancing the EF. Further we aim to establish predictive factors of the success of the intervention.

Methods
In a retrospective data analysis at a single medical centre, we examined records of 116 patients who underwent ectopic ablation, with 10 patients having more than 1 ablation. Demographic information, heart-related conditions along with the presence of a scar on MRI, was collected. The study also recorded pre- and post-procedure PVC burden and EF measurements.

Results
Demographics and procedural details are in table 1. It was found that patients participating in this study were predominantly male (66.4%), on average 60.1 (± 13.6) years old, overweight (BMI 29.8 ± 5.4) with no additional heart disease (56%) and no scarring on MRI (55%).The PVC burden before ablation (27.9 ± 12.7) significantly reduced to 8.0 ± 11.2 post-ablation (p &lt; 0.005), marking an average relative reduction of 68.1% (± 44.1%). Successful interventions, defined by a reduction exceeding 50%, were observed in 79% of patients. The EF increased from 39.6 ± 8.9 to 47.5 ± 10.7 post-ablation (p &lt; 0.005), corresponding to an average increase by 8.4 ± 8.5. Notably amongst the patients who had a successful ablation, 36% of patients achieved normalized EF (&gt;55%) and 42% showed an improvement of at least 5%. A strong correlation emerged between the relative change in PVC and the ejection fraction measured after ablation, with an increase by 0.10 for every percent reduction (p &lt; 0.00). The relative increase in the EF% was significantly higher in patients where the PVC burden was reduced by at least 50% (figure 1).
Linear fixed effect modelling explored the influence of patient characteristics on the model. Patients with higher BMI had a lower EF after ablation with same relative reduction in PVC (p &lt; 0.03). Similarly, a scar on MRI and associated heart condition was associated with reduced improvement in ejection fraction (p &lt; 0.02). Also, for every increase in age patients had a reduction of 0.2 EF after ablation (p &lt; 0.01). Right heart PVC’s were ablated more successfully, and had higher EF post ablation (p &lt; 0.01).

Conclusion
In conclusion, reduction in PVC burden increases the EF after treatment. Increasing BMI, age and presence of associated heart disease can negatively impacted LVEF post ablation. Further research could improve the model that predicts improvement in LV function post successful PVC ablation.Figure 1Table 1
Tissue composition underlying local impedance in chronic infarction: an histological study
Authors: Aranyo J , Martinez-Falguera D , Teis A , Fadeuilhe E , Rodriguez-Leor O , Bazan V , Sarrias A , Villuendas R , Bayes-Genis A , Galvez-Monton C , Bisbal F 
Published: May 2024

Abstract

Background
Local impedance (LI) mapping is feasible and provides additional tissue characterization of the ventricular tachycardia (VT) substrate. VT isthmuses are usually located in areas of intermediate LI while low LI regions did not actively participate in the VT circuit. Histological studies evaluating the tissue composition underlying different LI values are lacking.

Purpose
To describe the tissue composition underling different LI subtypes in a chronic myocardial infarction (MI) swine model.

Methods
One-month after a non-reperfused anterior MI, five Landrace X Large White pigs underwent endocardial LI mapping (figure 1). LI thresholds were set using the blood-pool LI value to define low, intermediate, and high tissue resistance subtypes. A navigated needle-catheter was used to inject methylene-blue at sites with intermediate and low LI to guide the ex vivo tissue localization. Tissue was obtained for further histological analysis. Low and intermediate LI zones were analysed.

Results
A total of six and eight samples were analysed for low and intermediate LI, respectively. Compared to low LI zones, intermediate LI tissue displayed less Collagen I (1.03±0.26 vs. 0.34±0.35%, p=0.0082), Collagen III (9.92±2.98 vs. 6.47±1.80%, p=0.0380) and Collagen Volume Fraction (10.92±2.77 vs. 6.81±1.92, p=0.0163), without differences in the overall fibrotic and adipocytic deposition (figure 2). No significant differences in the Cx43, CTnI and SERCA2 expression were observed.

Conclusion
LI subtypes showed distinctive histological composition. Intermediate LI sites displayed less collagen content (I, III and collagen volume fraction) compared to those with low LI.Endocardial LI mappingHystological analysis: Collagen Content
Substrate characterization and outcomes of ventricular tachycardia ablation in amyloid cardiomyopathy: a worldwide study
Authors: Compagnucci P , Dello Russo A , Gasperetti A , Schiavone M , Sehrawat O , Hasegawa K , Mohanty S , Liang J , Stevenson W , Tondo C , Siontis K , Tandri H , Santangeli P , Natale A , Casella M 
Published: May 2024

Abstract

Background
the electrophysiological substrate underpinning ventricular tachycardia (VT) in cardiac amyloidosis (CA) remains elusive, and outcomes of catheter ablation in this peculiar population are currently unknown.

Purpose
we sought to describe the electrophysiological substrate and clinical outcomes of VT ablation in a cohort of patients with CA.

Methods
we included 19 consecutive patients (mean age, 69±10 years; male sex, 89%) with CA (ATTR, n=13; AL, n=6) undergoing catheter ablation for VT/ventricular fibrillation (VF) between 2013 and 2023 in a retrospective, observational, international study, involving 7 referral European and North American electrophysiology units. The primary efficacy outcome was recurrent VT/VF during follow-up, while the primary safety outcome included major procedure-related adverse events.

Results
the indication for ablation was drug-refractory VT in 16 patients (84%), and PVC-initiated polymorphic VT/VF in 3 (16%). Catheter ablation was performed using endocardial (n=14, 74%) or endo-epicardial approaches (n=5, 26%). Complete endocardial electroanatomical voltage maps of the left and right ventricles were obtained in 14 (74%) and 6 (32%) patients, respectively. Each patient had evidence of low-voltage areas, most commonly involving the interventricular septum (n=12); late potentials were recorded in 13 patients (68%). A median of 1 (1-2) VTs were inducible per patient; in 10 subjects (43% of mappable VTs), activation mapping was consistent with septal VT origin. Complete procedural success was obtained in 13 patients (68%), at the expense of 4 (21%) major procedure-related adverse events. After a median follow-up of 36 (18-54) months, sustained VT/VF recurrence was observed in 9 patients (47%); survival free from VT/VF recurrence was 74% (95%CI, 56-96%) at 12 months, and 53% (95%CI, 34-94%) at 36-month follow-up; the majority of patients remained on antiarrhythmic drugs (Figure). Low-voltage QRS (HR,21.96; p=0.022) and complete procedural success (HR,0.08; p=0.029) were associated with recurrent VT/VF at multivariable analysis (Figure).

Conclusions
catheter ablation of VT/VF is associated with favorable acute and mid-term arrhythmia control, yet with substantial risk of procedure-related complications and long-term recurrences. Septal substrate and frailty challenge successful management of patients with CA and VT/VF.Multimodality evaluation of LV substrateMain Study Outcomes