bluuebunny/crossref_metadata_2025_split huggingface dataset:
EGM characteristics of intramural outflow tract ventricular arrhythmias
Authors: Yalin K , Ikitimur B , Onder E , Soysal AU , Yalman H , Atici A , Aksu T 
Published: May 2022

Abstract

Funding Acknowledgements
Type of funding sources: None.

Introduction
Successful ablation of outflow ventricular premature contractions (VPC) depends on the identification of earliest activation. Annotation of bipolar (bi) EGMs can be challenging for especially multicomponent EGMs. Universally, annotation of earliest depolarization which depends on maximum dV/dt of unipolar (uni) EGMs and uni-QS morphology identify site of origin for VPC. However, identification of uni-QS morphology has limitations due to low spatial resolution. Additionally, time difference between bi- and uni-EGM can be observed and may be associated with deeper origin. Aim of this study is to compare EGM characteristics at successful ablation site in RVOT and RVOT+LVOT VPC ablation cases.

Methods
In this retrospective study, 40 patients who underwent successful RFA for RVOT and RVOT+LVOT VPCs were included. Local activation time (LAT), duration and voltage data of each bi- and uni-EGM at the successful ablation sites from RVOT and RVOT+LVOT cases were analyzed.

Results
28/40 (70%) of patients were ablated from RVOT and in 12/40 (30%) required both side ablation. All patients had acute PVC suppression. Bi-EGM-QRS onset was earlier (36.2±13.8 ms vs 28.8±7.3 ms, p=0.03), duration of bi-EGM was shorter (58.2±19.6 ms vs 83.8±22.3 ms, p=0.003) and Bi-voltage amplitude was higher (3.1±2.4 mV vs 1.2 ±0.9 mV, p=0.01) for patients with RVOT only ablation. Mean Bi-Uni EGM difference was 5.6±5.1ms in the RVOT group vs 13.5±5.4 ms in RVOT+LVOT group (p&lt;0.001). Uni-QS morphology was recorded in 3.6±4.5 vs 3.3±1.9 cm2 in RVOT and RVOT+LVOT group respectively (P=0.80). In 11/40 (28%) of patients uni-QS was not identified at successful ablation site.

Conclusion
QS in uni-EGM was not a perfect predictor for successful ablation sites. Analysis of bipolar voltage amplitude and duration with Bi-uni EGM time difference may identify deeper source.
Stereotactic body radiotherapy for refractory ventricular tachycardia: the overall czech experience
Authors: Peichl P , Haskova J , Wichterle D , Neuwirth R , Jiravsky O , Cvek J , Knybel L , Sramko M , Kautzner J 
Published: May 2022

Abstract

Funding Acknowledgements
Type of funding sources: None.

Background
Catheter ablation (CA) is a well-established treatment strategy for the management of drug-refractory ventricular tachycardia (VT) in patients with structural heart disease. Stereotactic body radiotherapy (SBRT) was proposed recently as a treatment option for cases of failed CA.

Purpose
This study reports overall experience with the SBRT from two Czech centers.

Methods
Since 2014, we enrolled consecutive patients who underwent at least one prior CA for recurrent scar-related VT and had subsequent VT recurrences due to inaccessible substrate. Single-session SBRT for VT was performed without the use of general anesthesia or sedation. A dose of 25 Gy was delivered.

Results
The study investigated 33 patients (3 women) with a mean age of 66 ± 9 years. Underlying heart disease was ischemic (58%) and nonischemic (39%) cardiomyopathy; one patient had large cardiac fibroma. The mean left ventricular ejection fraction was 31 ± 8%. Seventy-six percent of patients were on amiodarone. Before SBRT, they underwent a median of 2 (IQR: 1-3; range: 1-5) CA that included epicardial access in 42% of patients.
Following SBRT with a planned target volume of 42.6 ± 22.8 ml, the immediate effect was not observed in any patient, VT burden gradually decreased over weeks or months.
Seventeen (52%) patients died (2 of them suddenly) during the mean follow up of 29 ± 23 months mainly due to the progression of heart failure (Figure 1). One patient died due to bleeding associated with esophagopericardial fistula that developed 9 months after SBRT.
Overall, the number of DC shocks after a single procedure decreased significantly from 0.9 ± 1.9 per month in the period of 6 months before SBRT to 0.1 ± 0.3 per month in the period of 6-12 months after SBRT (P=0.008, Figure 2). However, 14 patients (42%) had to undergo additional CA due to VT recurrences at a mean interval of 13 ± 14 months after SBRT. Three patients underwent repeated SBRT (after 3, 29, and 38 months), which was successful in 2 of them.

Conclusions
SBRT in patients with refractory VT is feasible but the long-term mortality after the procedure is high and reflects mainly the severity of the underlying disease. The treatment effect of SBRT is delayed and additional CA is often necessary for VT suppression. At present, SBRT should be offered as only a bailout procedure for otherwise intractable VT.
Pacing electrodes to ablate, not to pace: what settings to use to create lesions even deep in the septum
Authors: Nedios S , Seewoester T , Darma A , Dinov B , Hildert S , Lucas J , Doering M , Dagres N , Arya A , Hindricks G , Bollmann A , Richter S 
Published: May 2022

Abstract

Funding Acknowledgements
Type of funding sources: None.

Background
Intramural septal ventricular arrhythmia remains challenging, requiring emergent technologies and experimental approaches. Although conduction system pacing (CSP) has allowed us to reach deep in the septum, ablation though pacing electrodes has not been examined yet.

Purpose
To evaluate lesion creation by radiofrequency ablation (RFA) through pacing electrodes.

Methods
A custom ex vivo swine model in a saline bath with an indifferent electrode was used to apply RFA with an 8 mm non-irrigated catheter (SJM, MN, USA) on the proximal end of pacing (CapSureFix 5086) or CSP-electrodes (SelectSecure 3830, Medtronic, MN, USA), screwed in perpendicularly to the slab. A generator (Ampere, SJM, MN, USA) applied RFA at varying settings (1-10 W, 1-20 sec). Lesion depth (D), width (W) and volume (V=3,14*W2*D/4) were assessed and analyzed (SPSS 23).

Results
A total of 80 lesions were used for analysis. Median RFA with 3 W over 6 sec resulted in an impedance drop from 200 to 140 Ω and a lesion of 2x3 mm or 9.4 mm3 (Figure 1). Higher energy settings caused impedance rise with abort (n=3, 4%) or charring (n=3, 4%). Compared to conventional electrodes, lesions with CSP-electrodes had similar volume (9.3±7 vs. 10.8±9 mm3, p=0.45) and width (2±0.8 vs. 2±0.7, p=0.58), but more depth (2.6±0.5 vs. 3±0.6, p=0.0.01). Regression analysis showed final-impedance (FI), power and duration (WS=W*Sec) as independent predictors of lesion volume (V=4.7WS-4.1WS2+4.5FI-4, p&lt;0.001).

Conclusions
Effective ablation through pacing electrodes is possible, but lesion size is limited and low-power settings are necessary. Using CSP-electrodes for effective intramural lesions is possibly a new tool for septal arrhythmias. Further in vivo studies are warranted and bailout use should be considered.
STereotactic Arrhythmia Radioablation in Europe: critical structure contouring benchmark results of the STOPSTORM Consortium
Authors: Balgobind B , Visser J , Grehn M , Knap M , De Ruysscher D , Levis M , Pruvot E , Verhoeff J , Blanck O 
Published: May 2022

Abstract

Funding Acknowledgements
Type of funding sources: Public grant(s) – EU funding. Main funding source(s): EU Horizon

Background/Introduction
In patients with refractory ventricular tachycardia (VT), STereotactic Arrhythmia Radioablation (STAR) showed promising results for otherwise untreatable patients [1]. The STOPSTORM.eu project coordinates European efforts to clinically validate STAR.

Purpose
The primary goal of the critical structures benchmark study was to harmonize contouring of organs at risk (OAR) for STAR within the STOPSTORM.eu consortium. The results enable to refine protocols and guidelines to ensure treatment harmonization.

Methods
Three well-selected STAR cases [2] were provided for this benchmark and sent to all radiation oncology centres within the consortium. Every case had a contrast-enhanced cardiac-CT which was already deformed to the primary planning-CT to contour the OAR in detail. Every centre was asked to contour 31 OAR’s according to literature-based guidelines. The resulting structure sets were evaluated within VelocityTM 4.1.

Results
Twenty centres participated in the critical structure contouring benchmark.
Contouring of the structures was performed with high accuracy according to the provided guidelines. The contours of common OAR’s in radiotherapy, such as the heart, lungs, stomach, oesophagus, bronchus, great vessels, and spinal canal were correctly contoured by all centres. In the substructures of the heart (chambers, valves, arteries, and nodes), deviations in the contours occurred more frequently, but no large systematic errors were found (see figure 1-2). The centres that already performed STAR treatments had markedly less difficulties with the contouring of the substructures. However, these structures do not have a consensus for treatment planning purposes and late toxicity but need to be contoured correctly for future analysis within the STOPSTORM project.

Conclusion
This large STOPSTORM.eu multi-centre critical structure benchmark study showed a high accuracy regarding standard critical structures. In the case of heart substructures some deviations occurred, which lead to new definitions for contouring these structures within the consortium. In addition, a close collaboration between radiation oncologist and cardiac electrophysiologist is recommended.
Cardiac resynchronization therapy in patients with a history of atrial fibrillation: insights from five major clinical trials
Authors: Dalgaard F , Fudim M , Al-Khatib S , Friedman D , Abraham WT , Cleland JF , Curtis AB , Gold MR , Kutyifa V , Linde C , Young J , Ali-Ahmad F , Olivas-Martinez A , Inoue LYT , Sanders GD 
Published: May 2022

Abstract

Funding Acknowledgements
Type of funding sources: Public Institution(s). Main funding source(s): National Heart, Lung, and Blood Institute

Background
Many patients with heart failure who are considered for cardiac resynchronization therapy (CRT) have a history of (h/o) atrial fibrillation (AF) but there are doubts about the efficacy of CRT in patients with AF.

Purpose
To investigate the association of CRT on morbidity and mortality among patients with and without a h/o AF.

Methods
Original, patient-level data from five clinical trials of CRT that permitted enrolment of patients with a h/o AF were included: COMPANION, MADIT-CRT, BLOCK HF, REVERSE, and MIRACLE trial. Patients with permanent or persistent AF were excluded from these trials, and therefore from this analysis. The outcomes of interest were the composite endpoint of time to heart failure hospitalization (HFH) or all-cause mortality or all-cause mortality alone. The association of CRT (versus no CRT) with outcomes for patients with and without a h/o AF was assessed using a Bayesian-Weibull survival regression model with random terms for the trial-specific treatment effects and the trial-specific baseline hazard functions including an interaction between history of paroxysmal AF and CRT. All results are presented as hazard ratios (HRs) with 95% posterior credible intervals (CIs) and posterior probabilities of no association, adjusting for baseline characteristics.

Results
A total of 4062 patients were included, 661 (16.3%) of whom had a h/o AF. Patients with a h/o AF were older (mean [SD] age 68 [10] years versus 64 [11] years) and had a higher proportion of ischemic cardiomyopathy (67% versus 53%, p&lt;0.001), a higher baseline serum creatinine (1.3 mg/dl versus 1.2 mg/dl, p&lt;0.001), and a lower left ventricular ejection fraction (25% versus 26%, p&lt;0.001). The HRs for all outcomes and the interaction term are shown in Table 1. For the overall population, CRT delayed the time to HFH or all-cause mortality (HR: 0.74, 95% CI: 0.62 – 0.87, p=0.005); for patients with a h/o AF, it did not (HR: 0.87, 95% CI: 0.64 to 1.19, p=0.37). In this patient-level meta-analysis, CRT was not associated with a reduction in mortality, overall or by h/o AF. Howevber, the interaction (estimate shown as a ratio of HRs) between those with or without a h/o AF and the effects of CRT was not significant for either outcome (Table 1).

Conclusion
In the largest post hoc analysis to date, we confirm the benefits of CRT in patients without a h/o AF in reducing HFH or mortality. There was no statistically significant interaction between CRT and h/o AF for any analysed outcome.
A new method for right ventricular lead implantation into the intraventricular septum
Authors: Narumi T , Naruse Y , Kaneko Y , Sano M , Urushida T , Maekawa Y 
Published: May 2022

Abstract

Funding Acknowledgements
Type of funding sources: None.

Background
Right ventricular (RV) lead placement into the interventricular septum is only accurate in 16–48% of cases under conventional fluoroscopic guidance. A previous report showed the importance of individualized left anterior oblique (LAO) projection to improve the success rate of RV lead placement into the interventricular septum. However, this procedure is complicated. We sought to investigate the preprocedural predictors of individualized LAO projection.

Methods
We assessed the relationship between preoperative electrocardiographic parameters and the angle of the interventricular septum obtained using thoracic computed tomography (CT).

Results
In the retrospective derivation cohort group (n=39), the mean angle of individualized LAO assessed by thoracic CT was 53.1±8.9°, and the preoperative electrocardiogram QRS axis was strongly correlated with the interventricular septum axis detected by thoracic CT (R2 = 0.490). In contrast, the preoperative electrocardiographic transitional zone was not associated with the interventricular septum axis (R2 = 0.041, P = 0.78). Using individual LAO projection derived from the preoperative electrocardiogram QRS axis, it was confirmed that the RV lead was placed in the interventricular septum during the pacemaker procedure in the prospective internal validation group (n=30). The success rate for placing the RV lead into the interventricular septum was significantly improved in the internal validation cohort group (93% vs. 64%, P &lt; 0.05). In addition, the N-terminal pro-brain natriuretic peptide level decreased significantly after surgery in the interventricular septal indwelling group.

Conclusions
Individualized LAO angle derived from the preoperative electrocardiogram QRS axis is a new useful and simple method for RV lead implantation into the interventricular septum.
Predictors of pacemaker dependency after transcatheter aortic valve replacement
Authors: Dias Ferreira Reis JP , Mendonca T , Castelo A , Rodrigues I , Fiarresga A , Ramos R , Cacela D , Oliveira M , Ferreira R 
Published: May 2022

Abstract

Funding Acknowledgements
Type of funding sources: None.

Background
Conduction disturbances after transcatheter aortic valve replacement (TAVR) are common with a variable risk of long-term pacemaker dependency (PD), being influenced by patient- and procedure-specific factors. As pacemaker (PM) implantation is associated with potential complications, our aim was to assess predictors of PD requirement after TAVR.

Methods
Retrospective analysis of consecutive patients (P) who underwent TAVR with a self-expanding valve from 2009 to 2020 at our institution. All P had pre-procedural clinical evaluation, cardiac computed tomographic angiography, transthoracic echocardiography and electrocardiography performed. Cumulative percentage of ventricular pacing (%Vp) was determined from stored PM data. P with a PM implanted previous to TAVR were excluded. PM implantation post-TAVR was defined as a device implant performed during hospital stay in the context of TAVR or during the first month after discharge. PD was defined as a %Vp &gt; 80% at one-year follow-up. Multivariate analysis for the prediction of PD was done using Cox regression.

Results
A total of 474 P (57% male, age 81.7±6.5 years, left ventricular ejection fraction 51.5±14.6%) were analysed. Mean follow-up was 18.7 months. Mean baseline gradient was 51.7 mmHg with a mean aortic valve area of 0.71 cm2. One hundred and four P (21.9%) required PM implantation after TAVR, with a mean %Vp of 65.3±43.4%, presenting PD in 60% of the cases at one-year follow-up. A glomerular filtration rate &gt; 60 ml/min (OR 0.87, CI 95% 0.74-0.96, p=0.021) and mean aortic annulus perimeter (OR 0.89, CI 95% 0.80-0.98, p=0.029) were independent predictors of a PD &lt; 5%. Arterial hypertension (OR 7.00, CI 95% 1.31-37.40, p=0.023), baseline right bundle branch block (OR 10.2, CI 95% 1.21-18.45, p=0.033), and the EUROSCORE II (OR 1.05, CI 95% 1.01-1.10, p=0.044) were predictors of PD &gt; 80%. Baseline left bundle branch block, implantation depth and aortic valve calcium score were not predictors of PD.

Conclusion
Predictors of PD after TAVR may influence PM implantation, as well as device selection and programming. P with a higher aortic annulus perimeter and preserved kidney function may undergo a more expectant management, as PD rates are low after 1 year follow-up.
Diagnostic reliability of AV synchrony self-diagnostics in leadless VDD pacemakers
Authors: Neugebauer F , Noti F , Van Gool S , Roten L , Baldinger SH , Seiler J , Madaffari A , Servatius H , Ryser A , Tanner H , Reichlin T , Haeberlin A 
Published: May 2022

Abstract

Funding Acknowledgements
Type of funding sources: None.

Introduction
Leadless pacemakers (PMs) capable of atrio-ventricular (AV) synchronous pacing have been introduced recently. These devices provide mechanical atrial sensing by detection of the atrial contraction via an accelerometer. Atrial tracking may be disturbed by external influences such as body motions and higher heart rates in real life. To track the amount of AV synchronous pacing, the device statistic classifies all sensed and paced QRS complexes according to presumed AV synchrony. The reliability of this self-diagnostics to estimate the true degree of AV synchrony, however, is insufficiently studied.

Purpose
To investigate the informative value of the device statistics offered by leadless VDD PMs regarding true AV snychrony.

Methods
We prospectively included all patients who received a leadless VDD PM between 07/2020 and 05/2021 at our center in this observational study. During the regular outpatient follow-ups, device interrogation was performed, which included evaluation of the PM statistics. True AV synchrony (defined as a QRS complex preceded by a p-wave within 300ms) was analyzed repeatedly during follow-up using Holter ECGs.

Results
We analysed 34 Holter ECGs from 20 outpatients (816 hours of ECG in total). Patients had a median age of 80 years (interquartile range 76-86 years), 55% were females. For Holter ECG sequences that showed high degree or complete AV-Block (&gt;80% ventricular pacing), the percentage of paced beats that were presumed to be AV synchronous by the device statistic (ratio "AM-VP"/total VP) correlated well with AV synchrony as assessed using Holter-ECGs (Kendall’s τ=0.312, p&lt;0.001). AV synchrony in the Holter ECG was different in patients with &lt;66.6% presumed AV synchrony than in patients with &gt;66.6% presumed AV synchrony (p&lt;0.001, figure). For Holter ECG sequences with mostly preserved intrinsic AV conduction (&lt;20% ventricular pacing), the ratio "AM-VP"/total VP was not predictive for true AV synchrony (Kendall’s τ=0.07, p=n.s.). In this situation, however, "VS only" (Kendall’s τ=0.110, p=0.005) correlated with true AV synchrony (due to AV conduction mode switch) and "VP only" showed an inverse correlation with AV synchrony (Kendall’s τ=-0.215, p&lt;0.001).

Conclusion
Leadless PMs provide device statistics that show a correlation with true AV synchrony. The clinical setting as well as the device programming (e.g. AV conduction mode switch) significantly influence the predictive value of the different parameters of the device’s statistics.
Electrocardiographic analysis of left bundle branch area pacing induced right ventricular activation delay
Authors: Ozpak E , Calle S , Demolder A , Kizilkilic S , Timmermans F , De Pooter J 
Published: May 2022

Abstract

Funding Acknowledgements
Type of funding sources: None.

Background
Left bundle branch area pacing (LBBAP) aims to capture the area of left bundle branch, resulting in fast activation of the left ventricle (LV) but delayed right ventricular (RV) activation. During intrinsic cardiac conduction, delayed RV activation results on the electrocardiogram (ECG) in a right bundle branch block (RBBB) pattern and is generally considered benign. As such, LBBAP-induced delayed RV activation is thought not to be harmful. However, to what extent left and right ventricular activation times during LBBAP resembles that of healthy individuals with acquired RBBB is currently not known.

Methods
Individuals with incomplete RBBB (iRBBB), complete RBBB (cRBBB) and LBBAP were included. Standard twelve lead electrocardiograms (ECG) were stored and analysed digitally using the MUSE ECG database. QRS duration was measured as global QRS duration. Left and right ventricular activation times were estimated by R-wave peak time in lead V6 (V6RWPT) and R’ peak time in lead V1 (V1RWPT), respectively. Delayed RV activation was further characterized by duration and area of R’ wave in lead V1.

Results
Paced QRS duration during LBBAP (n=86) measured 129±15ms whereas QRS duration of iRBBB (n=422) and cRBBB (n=223) individuals measured 103±8ms and 142±17ms respectively (p&lt;0.001). V6RWPT during LBBAP (47±15ms) was significantly longer than V6RWPT in iRBBB (40±5ms) and cRBBB (39±7ms) (p&lt;0.001). With LBBAP, V1RWPT (83±15ms) became delayed compared to iRBBB (74±9ms, p&lt; 0.001), but remained shorter in comparison to cRBBB (98±17ms, p&lt;0.001). Patients with LBBAP were further characterized by V1 R’ duration and R’ area which were shorter and smaller compared to cRBBB but similar to iRBBB individuals.

Conclusion
LBBAP-induced delayed RV activation resembles electrocardiographically more closely to the delayed RV activation as seen in individuals with incomplete rather than complete RBBB. Left ventricular activation times remain slightly prolonged during LBBAP as compared to RBBB individuals.