bluuebunny/crossref_metadata_2025_split huggingface dataset:
Accuracy of electroanatomical mapping guided cardiac radiotherapy for ventricular arrhytmias: pitfalls and solutions
Authors: Abdel-Kafi S , Sramko M , Omara S , De Riva M , Cvek IJ , Peichl P , Kautzner J , Zeppenfeld K 
Published: May 2021

Abstract

Funding Acknowledgements
Type of funding sources: Public grant(s) – National budget only. Main funding source(s): This work was partially supported by the grant AZV NU20-02-00244 from the Ministry of Health of the Czech Republic

OnBehalf
WECAM

Background
One of the main limitations of Radiofrequency catheter ablation (RFCA) is the difficulty in targeting specific VT substrate locations when they are deep intramural, covered by epicardial fat or in the proximity of a coronary artery. Stereotactic body radiotherapy (SBRT) has emerged as an alternative treatment for VT after RFCA failure. However, the accuracy of substrate volume delineation, the gross target volume (GTV), based on electroanatomical mapping (EAM) and interobserver agreement are still unknown.

Aim
To analyze and optimize the interobserver agreement for GTV delineation on cardiac CT (CCT) based on EAM data acquired to guide radiotherapy for ventricular arrhythmias.

Method
Available EAM data was exported and merged with the segmented CCT using manual registration by two observers. A GTV was created by the observers for predefined left ventricular (LV) areas based on preselected endocardial EAM points, indicating the 2D-surface area of interest. The interobserver (non)overlapping GTV volumes were analyzed. The influence of (interobserver) registration accuracy and availability of EAM data on the final GTV and 2D-surface location within each LV area was evaluated.

Results
The median distance between the CCT and EAM after registration was 2.7 mm, 95%th percentile 6.2 mm for observer #1 and 3.0 mm, 95%th percentile 7.6 mm for observer #2 (p = 0.9). Created GTVs were significantly different (8 vs 19 ml) with lowest GTV overlap (35%) for lateral wall target areas. Similar, the highest shift between 2D-surfaces was observed for the lateral LV (6.4mm (3.0-9.9)). The same trend is seen in the (non) overlapping volume for lateral area (P = 0.004). The optimal surface registration accuracy (2.6 mm) and interobserver agreement (Δ interobserver EAM surface registration accuracy 1.32 mm) on final GTVs could be achieved if at least three cardiac chambers were mapped, including high-density LV EAM.

Conclusion
Detailed EAM of at least three chambers allows for accurate co-registration of EAM data with CCT and high interobserver agreement on GTVs to guide radiotherapy of ventricular arrythmias. However, the substrate location should be taken in consideration when creating a treatment volume margin. Gross target volume (GTV) and InterobserGTV volume Observer #1 (cc)GTV volume Observer #2 (cc)Surface shift (mm)Basal anterior, (IQR)7.6 (6.2-11.5)9.3 (5.3-10)3.8 (2.2-4.5)Lateral, (IQR)8.0 (6.9-12.7)19.1 (15.7-21.4)6.2 (5.3-6.4)Septal, (IQR)10.1 (6.2-12.8)13.9 (7.7-14.6)6.4 (3.0-9.9)Abstract Figure. Graphical abstract
A novel ventricular map of electrograms duration as a method to identify areas of slow conduction during ablation of ventricular tachycardia
Authors: Rossi P , Cauti FM , Polselli M , Iaia L , Fanti V , Niscola M , Andreoli C , Calore F , Bianchi S 
Published: May 2021

Abstract

Funding Acknowledgements
Type of funding sources: None.
Background – Wave front inhomogeneous propagation is crucial for reentry circuit generation. Bipolar EGM duration is indicative of local conduction delay and may identify areas of low conduction as a functional substrate. This study aimed to create a map of EGM duration during the VT (VEDUM Map) to identify the area of the slowest conduction and to verify if RF delivery at this area allows to rapidly interrupt the VT.
Methods – 24 high-density VTs maps (21 patients) were analyzed. Activation maps and voltage maps during SR were performed. An offline remap confirmed with MathLab software was customized to visualize the longest duration electrogram during VT.
Results – All of the VTs were interrupted during the first RF delivery (mean time 7,3 ± 5,4 sec (range 3-25 sec)) at the area with the longest EGM duration (212 ± 47 ms (range 113-330 ms)). . In 9 pts (37,5%) the longest EGM was located at the entrance or exit area of the activation maps while in 5 pts (21%) the EGM covered the full diastolic phase. Finally, in 10 pts the longest EGM occurred in the mid-exit-diastolic phase.
Conclusions - A novel Ventricular map of Electrograms DUration (VEDUM Map) is highly accurate in defining a conductive vulnerable zone of the VT circuit. The longest EGM duration within the isthmus is highly predictive of rapid VT termination. Quantitative variablesQualitative variablesMeanMedianStandard DeviationAge71738.40BMI26.624.54.02LV EDV16315442.7LV EDD61.2629.9LV EF38.7369.74VT cycle lenght (TCL)35537556.4EGM max. duration in VT21220847EGM max dur / TCL58.260.512Maximum EGM duration localization in CLProto = 12.5%Meso = 33.3%Tele = 25%Full = 20.8%Myocardium voltage characteristics in VEDUM EGMHealthy = 25%Transition = 20.8%Scar = 41.7%Critical Isthmus area12.3107.3VT Interruption during RFYes = 79.2%No = 20.8%Time (seconds) to interruption765Access typeEndo = 58.3%Epi = 29.2%Clinical and procedural dataAbstract Figure.
Impact of age on catheter ablation of premature ventricular contractions
Authors: Badertscher P , John L , Payne J , Bainey A , Ishida Y , Field M , Winterfield J , Gold MR 
Published: May 2021

Abstract

Funding Acknowledgements
Type of funding sources: None.

Introduction
Catheter ablation (CA) of frequent premature ventricular contractions (PVC) is increasingly performed in older patients as the population ages.

Purpose
The purpose of this study was to assess the impact of age on procedural characteristics, safety and efficacy on PVC ablations.

Methods
Consecutive patients with symptomatic PVCs undergoing CA between 2015 and 2020 were evaluated. Acute ablation success was defined as the elimination of PVCs at the end of the procedure. Sustained success was defined as an elimination of symptoms, and ≥80% reduction of PVC burden determined by Holter-ECG during long-term follow. Patients were sub-grouped based on age (&lt; 65 years vs. ≥ 65 years).

Results
A total of 114 patients were enrolled (median age 64 years, 71% males) and followed up for a median duration of 228 days. Baseline and procedural data were similar in both age groups. A left-sided origin of PVCs was more frequently observed in the elderly patient group compared to younger patients (83% vs. 67%, p = 0.04, Figure 1). The median procedure time was significantly shorter in elderly patients (160 min vs. 193 min, p = 0.02). The rates of both acute (86% vs. 92%, p = 0.32) and sustained success (70% vs. 71%, p = 0.90) were similar between groups. Complications rates (3.7%) did not differ between the two groups.

Conclusion
In a large series of patients with a variety of underlying arrhythmia substrates, similar rates of acute procedural success, complications, and ventricular arrhythmia-free-survival were observed after CA of PVCs. Older age alone should not be a reason to withhold CA of PVCs. Abstract Figure 1
Ventricular tachycardia ablation in nonischemic cardiomyopathy
Authors: Nascimento Matos D , Cavaco D , Carmo P , Carvalho MS , Rodrigues G , Carmo J , Galvao Santos P , Moscoso Costa F , Mendes M , Morgado F , Adragao P 
Published: May 2021

Abstract

Funding Acknowledgements
Type of funding sources: None.

INTRODUCTION
Catheter ablation outcomes for drug-resistant ventricular tachycardia (VT) in nonischemic cardiomyopathy (NICM) are suboptimal when compared to ischemic cardiomyopathy. We aimed to analyse the long-term efficacy and safety of percutaneous catheter ablation in this subset of patients.

METHODS
Single-center observational retrospective registry including consecutive NICM patients who underwent catheter ablation for drug-resistant VT during a 10-year period. The efficacy endpoint was defined as VT-free survival after catheter ablation, while safety outcomes were defined by 30-days mortality and procedure-related complications. Independent predictors of VT recurrence were assessed by Cox regression.

RESULTS
In a population of 68 patients, most were male (85%), mean left ventricular ejection fraction (LVEF) was 34 ± 12%, and mean age was 58 ± 15 years. All patients had an implantable cardioverter-defibrillator. Twenty-six (38%) patients underwent epicardial ablation (table 1). Over a median follow-up of 3 years (IQR 1-8), 41% (n = 31) patients had VT recurrence and 28% died (n = 19). Multivariate survival analysis identified LVEF (HR= 0.98; 95%CI 0.92-0.99, p = 0.046) and VT storm at presentation (HR = 2.38; 95%CI 1.04-5.46, p = 0.041) as independent predictors of VT recurrence. The yearly rates of VT recurrence and overall mortality were 21%/year and 10%/year, respectively. No patients died at 30-days post-procedure, and mean hospital length of stay was 5 ± 6 days. The complication rate was 7% (n = 5, table 1), mostly in patients undergoing epicardial ablation (4 vs 1 in endocardial ablation, P = 0.046).

CONCLUSION
LVEF and VT storm at presentation were independent predictors of VT recurrence in NICM patients after catheter ablation. While clinical outcomes can be improved with further technical and scientific development, a tailored endocardial/epicardial approach was safe, with low overall number of complications and no 30-days mortality. Abstract Figure.
Grayzone myocardial fibrosis and ventricular arrhythmias in patients with a left ventricular ejection fraction greater than 35%
Authors: Zegard A , Okafor O , Debono J , Kalla M , Lencioni M , Marshall H , Hudsmith L , Qiu T , Steeds R , Stegemann B , Leyva F 
Published: May 2021

Abstract

Funding Acknowledgements
Type of funding sources: None.
BACKGROUND Clinical guidelines adopt LVEF cut-offs &lt;30 or &lt;35% as an indication for implantable cardioverter defibrillator (ICD) therapy. Most patients succumbing to sudden cardiac death (SCD), however, have a LVEF≥35%.
OBJECTIVES To determine whether myocardial fibrosis (MF) and grayzone fibrosis (GZF) on cardiovascular magnetic resonance (CMR) is associated with ventricular arrhythmias in patients with coronary artery disease (CAD) and a LVEF≥35%.
METHODS In this retrospective study of CAD patients, GZF mass using the 3SD method (GZF3SD) and total fibrosis mass using the 2SD method (TF2SD) on CMR were assessed in relation to the primary, combined endpoint of SCD, ventricular tachycardia, ventricular fibrillation or resuscitated cardiac arrest.
RESULTS Among 701 patients (age: 65.8 ± 12.3 yrs [mean ± SD]), 28 (3.99%) patients met the primary endpoint over 5.91 years (median; interquartile range 4.42-7.64). In competing risks analysis, a GZF3SD mass ≥ 5.0 g was strongly associated with the primary endpoint (subdistribution hazard ratio [sHR]: 17.4 [95% CI 6.64-45.5]); area under receiver operator characteristic curve [AUC]: 0.85, p &lt; 0.001). A weaker association was observed for TF2SD mass ≥ 23 g (HR: 10.4 [95% CI 4.22-25.8]; AUC: 0.80, p &lt; 0.001). The range of sHRs for GZF3SD mass (1 to 526.6) was wider than for TF2SD mass (1 to 37.6).
CONCLUSIONS In CAD patients with a LVEF≥35%, GZF3SD mass was strongly associated with the arrhythmic endpoint. These findings hold promise for its use in identifying patients with CAD and a LVEF≥35% at risk of arrhythmic events. Abstract Figure.
Short-term variability of repolarization is equally modulated by atrial and (bi)ventricular high rate pacing in patients with an indication for an implantable cardioverter defibrillator
Authors: Smoczynska A , Sprenkeler DJ , Jalink H , Ritsema Van Eck HJ , Meine M , Vos MA 
Published: May 2021

Abstract

Funding Acknowledgements
Type of funding sources: Public grant(s) – National budget only. Main funding source(s): Dutch Heart Foundation

Background
An increase in temporal dispersion of repolarization, quantified as short-term variability of the QT-interval (STV-QT), precedes ventricular arrhythmias and has therefore been proposed as a marker for monitoring of imminent arrhythmic risk. A reversal of an increased STV by high rate pacing at 100 bpm was anti-arrhythmic in the chronic atrioventricular block dog model susceptible to Torsade de Pointes arrhythmias upon challenge with an IKr-blocker. The objective of the current study was to investigate the physiological modulation of STV by pacing in patients with an indication for an implantable cardioverter defibrillator (ICD), and to compare atrial and ventricular pacing.

Methods
ECG recordings were obtained with a sampling frequency of 1200 Hz in 10 dual chamber ICD patients and 10 patients with cardiac resynchronization therapy with defibrillation function (CRT-D) during the implantation or replacement. One-minute recordings were made during sinus rhythm (SR), and during pacing at 80 and 100 beats per minute (bpm) from the atrium (AAI), atrium and right ventricle (DDD RVp), and during atrio-biventricular pacing (DDD BiVp). The QT-interval was determined offline with fiducial segment averaging at one minute of each pacing rate, and 31 consecutive beats were used to calculate STV-QT with the following formula: ∑|D(n + 1)-Dn |/(N×√2), where D represents the determinant of repolarization (in this case the QT interval), and N represents the number of beats taken into account minus 1.

Results
In the patients overall, STV-QT decreased from 1.27 ± 0.38 ms in SR (±58 bpm) to 0.86 ± 0.26 ms* during AAI80, and to 0.68 ± 0.22 ms*† during AAI100 (*p &lt; 0.05 compared to SR, †p &lt; 0.05 compared to 80 bpm). The same decrease was seen during DDD80 RVp (0.81 ± 0.28 ms*) and during DDD100 RVp (0.66 ± 0.22 ms*†) (fig. 1). Additionally, DDD BiVp decreased STV-QT to 0.78 ± 0.20 ms* at 80 bpm and to 0.62 ± 0.19 ms* at 100 bpm in CRT-D patients (fig. 2).

Conclusion
Pacing at 80 and 100 bpm decreases STV-QT compared to sinus rhythm both in dual chamber ICD patients and CRT-D patients. The modulation of STV-QT is similar during atrial, and atrio- right ventricular and atrio-biventricular pacing. Abstract Figure. Modulation of STV-QT by AAI and DDD RVp
Leadless pacemakers: where is the device?
Authors: Elrefai M , Menexi C , Roberts P 
Published: May 2021

Abstract

Funding Acknowledgements
Type of funding sources: None.
Introduction
Leadless pacemakers (LPs) were designed to avoid lead-related complications associated with transvenous pacing. To minimise the risk of complications, there is preference towards implanting LPs into the septal aspect of the right ventricle rather than the apex or free wall. The Transcatheter Pacing Study (TPS) and the international post-approval registry demonstrated the safety and reliability of the LP systems in real-world settings. The registry demonstrated that more than half of the LPs were implanted into the septum and most required &lt;2 attempts at deployment. We report a radiological method of defining LP position.
Methods
We reviewed the first 100 LPs implanted at our centre. Two independent observers who didn’t implant LPs reviewed the patients’ post-implant fluoroscopy images and/or post-implant CXRs when available. The reviewers assessed the devices’ positions in postero-anterior (PA) and/or right anterior oblique (RAO) views based on conventional fluoroscopic criteria for lead position. We used the proposed criteria interchangeably on fluoroscopic images and post implant CXRs (Figure). Differences in classification of device position were resolved by consensus.
Results
Three experienced operators implanted 100 LPs at our centre. Patients (61% male) 56.6 ± 22.2 years had normal hearts (74%), ischaemic cardiomyopathies (12%), congenital heart diseases (6%), valvular pathologies (5%) and dilated cardiomyopathies (3%). Indications for pacing were symptomatic sinus node dysfunction (36%), followed by high grade atrio-ventricular block (33%), bradyarrhythmia associated with atrial tachyarrhythmias (27%) and other indications for pacing (4%). We had a 100% successful implant rate, 88% required ≤2 attempts and 70% required one attempt. There were no major complications.
We were able to classify the site of the LPs implants in a total of 90 patients who had fluoroscopic projections or chest x-rays that would allow us to classify the implant sites. A total of 32 implants were in the apex (35.6%). 28 were in mid-septum (31.1 %), 15 in the apical septum (16.7%), 14 on the septal aspect of the right ventricular inflow (15.5%) and 1 implant (1.1%) in the septum of the RV outflow tract.

Conclusion
Our proposed method of defining LP position demonstrated that the rate of implants into the true apex at our centre was highly comparable to that of the international registry. It also showed that we had lower rates of implants into the mid-septum in favour of apical septum. There were no pericardial effusions or cardiac perforations resulting from our implant procedures regardless of the site of the implant. We utilised widely used fluoroscopic and chest x-ray criteria for categorisation of the LPs implantation sites. However, a recognised limitation to our analysis is that our findings were not validated using other imaging modalities such as echocardiogram or cardiac computerised tomography (CT). Abstract Figure. Criteria to classify device position
His pacing program: a 2-year single-centre experience
Authors: Pasara V , Brestovac M , Matasic R , Prepolec I , Radic D , Pezo-Nikolic B , Krpan M , Puljevic M , Puljevic D , Lovric Bencic M , Milicic D , Velagic V 
Published: May 2021

Abstract

Funding Acknowledgements
Type of funding sources: None.

Background
His bundle pacing (HBP) physiologically activates the ventricles by a direct stimulation of the His-Purkinje cardiac conduction system. It was first described in the 1970s, and the initial feasibility studies were reported in the early 2000s. Later on, technological advances led to its widespread adoption and growing evidence base.

Purpose
This retrospective study aimed to assess implant success rate, feasibility and safety of the His-bundle lead implantation program in our centre.

Methods
All patients who underwent His-bundle lead implantation in our centre from the start of the HBP program in November 2018 until November 2020 were analyzed. Data were collected from existing hospital electronic medical records.

Results
A total of 125 patients (64.8 % male, 65.1 ± 13.9 years) were included in the study. Nearly half of patients (47.2 %) had chronic heart failure and 39.2 % had atrial fibrillation. Indications for pacing included antibradycardia pacing (68.8 %) and cardiac resynchronization therapy (31.2 %). His-bundle lead was successfully implanted in 114 patients (91.2 % acute success), while the rest of the procedures were converted into right ventricle lead placement. 32.8 % of all patients had native narrow QRS complexes. Among patients who received HBP for cardiac resynchronization therapy, QRS duration was reduced from 177.5 ± 26.4 at baseline to 145.8 ± 23.9 after HBP (p &lt; 0.001). However, QRS duration slightly prolonged in the antibradycardia group from 118.8 ± 31.9 at baseline to 130.4 ± 25.3 after HBP (p = 0.011). Seven (8.6 %) patients in the antibradycardia group had late lead disfunction/dislodgement and therefore underwent reoperation with the conventional right ventricle lead placement. Two patients (4.7 %) from the resynchronization group had inappropriate resynchronization response and underwent the conventional coronary sinus lead implantation. Only one patient (0.8 %) had a device-associated infection.

Conclusion
Our data suggest that HBP is a feasible strategy of physiological pacing and resynchronization with an acceptable success and low complication rates. Our His-bundle implantation program results are similar to data available in the current literature.
Septal vs apical defibrillator electrode placement a systematic review
Authors: Santos H , Almeida I , Santos M , Paula S , Miranda H , Figueiredo M , Neto M , Sousa C , Sa C , Chin J , Almeida S , Almeida L 
Published: May 2021

Abstract

Funding Acknowledgements
Type of funding sources: None.

Background
The optimal right ventricular defibrillator lead placement is still a debatable matter. We attempt to performed a systemic review to evaluate whether septal and apical placement had significant differences in the follow-up with an indication for implantation of these devices.

Objective
Review the evidence regarding the efficacy and safety of right ventricular apical and septal defibrillator lead placement.

Methods
A systemic research on MEDLINE and PUBMED with the term "septal pacing", "apical pacing" "septal defibrillation" or "apical defibrillation". 309 results were identified, however, after a serious analysis, several articles were excluded. Comparisons between apical and septal placement were performed regarding R wave amplitude, pacing threshold at 0.5 ms, lead impedance, left ventricular ejection fraction (LVEF), left ventricular end-diastolic diameter (LVEDD) and lead complication that produced lead re-placement. Mean differences (MD) and confidence interval (CI) was used as a measurement of treatment.

Results
Six studies were selected, including a total of 2180 patients. The studies were performed with different techniques, analyses and goals. The studies presented heterogeneous and diverse results, with a varied follow-up period, that resulted in the exclusion of one of the studies. Mean age 64.51 years old, 76.86% male, a median ejection fraction of 27.84%, NYHA class of 2.65, ischemic etiologic in 51.10% and a follow-up period of 26.49 months. Septal defibrillator lead placement was established in 772 patients, while the apical defibrillator lead placement was performed in 1399 patients. No differences regarding the lead performance on apical and septal placement were detected regarding the R-wave (MD -0.36, CI -0.75 - +0.03, p = 0.68, I2 = 0%) (reported in 3 studies) and lead impedance (MD -23.83, CI -51.36 - +3.69, p = 0.003, I2 = 82%) (reported in 3 studies). Pacing threshold seems to be favor a septal defibrillator lead implantation (MD -0.05, CI -0.09 - -0.02, p = 0.12, I2 = 53%) (reported in 3 studies). Concerning echocardiography parameters during the follow up period, LVEF (MD -0.83, CI -3.05 - +1.38, p = 0.10, I2 = 57%) (reported in 3 studies) and LVEDD (MD -0.51, CI -2.13 - +1.10, p = 0.20, I2 = 38%) (reported in 3 studies) were not significant influenced for the defibrillator lead placement. Lead complications that provoke a lead replacement was not significant between the lead placement (MD 1.25, CI 0.53 – 2.94, p = 0.71, I2 = 0%) (reported in 3 studies).

Conclusions
Just pacing threshold proved to improve the septal defibrillator lead placement. Neither the other lead parameters or the echocardiography results during the follow-up were influenced by the lead placement. For a definitive conclusion is important to further investigation.