bluuebunny/crossref_metadata_2025_split huggingface dataset:
Safety and feasibility of a novel multilectrode array catheter in mapping atrial and ventricular arrhythmias with high density: results from the multi-center OPTIMUM study
Authors: Vijgen J , Rackauskas G , Dilling-Boer D , Sarkozy A , Ciconte G , Vicedomini GG , Pappone C 
Published: May 2022

Abstract

Funding Acknowledgements
Type of funding sources: Private company. Main funding source(s): This study was funded by Biosense Webster, Inc.

Background/Introduction
The novel multielectrode array mapping catheter includes 48 electrodes symmetrically distributed across and along 6 splines (Picture), with an additional unipolar reference electrode to reduce far-field signals built in at the tip of the irrigation lumen. Preclinical studies demonstrated its ability to provide high density and high resolution mapping in complex substrates, but its usability and safety in patients with atrial or ventricular arrhythmias have not been investigated.

Purpose
To assess the safety and mapping performance of the catheter with the electroanatomical navigation system for mapping in the atria and ventricle in patients with a variety of complex arrhythmias.

Methods
The OPTIMUM study was a prospective, single arm study conducted at 3 European sites. Patients with scar-related atrial tachycardia (AT), PAF and persistent AF (PsAF), ventricular tachycardia (VT), or premature ventricular complexes (PVC) underwent pre-ablation mapping with the study catheter, and subsequent ablation according to institutional standard of care practice; the follow up period was 7 days. The primary safety endpoint was the incidence of device-related serious adverse events (SAE) within 7 days following the procedure. The primary effectiveness endpoint was the completion of protocol-required fast activation and electro anatomical pre-ablation mapping without resort to non-study mapping catheter(s), including fast anatomical mapping, mapping of substrate or any area of interest, and identification of conduction channel(s), gap(s) and critical isthmuses. General procedural characteristics as well as physician feedback (7-point Likert scale: 1 = poor and 7 = excellent) on various aspects of deployment, signal quality, and learning curve were also evaluated.

Results
Thirty-one patients (mean age: 59.8±14 years, 71.0% male) were enrolled and treated (9 scar-related AT, 12 PAF, and 1 PsAF, 6 VT, and 3 PVC). There was no (0/31) SAE reported, and the primary effectiveness endpoint was achieved in all subjects (31/31). Almost all operators rated highly (≥ 5) on noise reduction in bipolar maps (30/31) and short learning curve (27/31). Bipolar signals and catheter maneuverability were rated highly favorable (≥5) in the left and right atria and met-expectation-and-above (≥4) in the left and right ventricles.

Conclusion(s)
The first-in-human clinical data demonstrate the safety and effectiveness of the novel microelectrode array mapping catheter to efficiently map various atrial and ventricular complex arrhythmias with good signal quality. Physicians indicated high satisfaction with the learning curve, catheter maneuverability, tissue characterization in all cardiac chambers.
Effectiveness and safety of bipolar ablation of heart arrhythmia. A systematic review with meta-analysis
Authors: Farkowski M , Truszkowska N , Zielinska A , Karlinski M , Futyma P , Pytkowski M , Hryniewiecki T , Maciag A 
Published: May 2022

Abstract

Funding Acknowledgements
Type of funding sources: Public grant(s) – National budget only. Main funding source(s): The National Centre for Research and Development, Poland

Introduction
Bipolar radiofrequency ablation (BFRA) emerged as a viable technique of radiofrequency ablation where the standard unipolar approach (RFA) failed. A number of studies describing BRFA were published recently suggesting high effectiveness and acceptable safety of this technology for ablation of ventricular tachycardia in structural heart disease (SHD VT), premature ventricular contractions (PVC) or atrial flutter (AFL).

Purpose
We performed a systematic review with meta-analysis of available evidence to assess contemporary evidence on the effectiveness and safety of bipolar ablation of heart arrhythmia.

Methods
We systematically searched MEDLINE, EMBASE, and CENTRAL databases from inception to 27 August 2022 for prospective and retrospective studies with or without a control group. We also contacted BRFA experts to obtain information on the most up-to-date studies or conference presentations. Case studies and papers describing technical aspects of BRFA rather than clinical outcomes were excluded. Study quality was assessed using the Newcastle–Ottawa Scale.

Results
Out of 1919 records we included 12 studies: one good quality case-control study and 11 low-quality case series without a control group. Studies described 120 patients who received BFRA: mean age 61.9±10.3 years, 81% males, mean ejection fraction 43.2±12.4, SHD 62.6%, ICD/CRT-D 52.2%. Almost all patients were qualified to BRFA due to failure of at least one unipolar RFA. Follow-up period differed between studies and ranged between 1-2 years in most cases.
The overall acute effectiveness of BRFA was 88.2% (95%CI 82.5-93.8), I2=6.7%. The overall effectiveness of a first BRFA at the end of the follow-up period was 55% (95%CI 46.2-63.7), I2=7.2%. There was a need for a re-ablation in 21.2% patients (95%CI 11.2-31.2), I2=64%. A subgroup analysis for SHD VT, PVC and AFL yielded similar results. There were 16 serious complications including one surgical intervention and no acute deaths; five patients died during the follow-up, mainly due to heart failure progression.

Conclusions
Bipolar radiofrequency ablation may be an effective and safe procedure in selected patients who failed at least one unipolar radiofrequency ablation but the quality of the supporting evidence is generally low.
Learning curve for laser balloon ablation in the treatment of atrial fibrillation: a single center experience
Authors: Martignani C , Ziacchi M , Statuto G , Spadotto A , Angeletti A , Massaro G , Bartoli L , Cascioli G , Ginex S , Grassini D , Diemberger I , Galie N , Biffi M 
Published: May 2022

Abstract

Funding Acknowledgements
Type of funding sources: None.

Background
Visually guided laser balloon ablation (LBA) is a promising method for pulmonary vein (PV) isolation in the treatment of atrial fibrillation (AF). To reduce procedural times, the rapid mode feature (RM), which offers an automated continuous 360° lesion for pulmonary vein isolation, was implemented in the latest version of the laser balloon system.

Purpose
We evaluated the learning curve for LBA in the treatment of AF

Method
We enrolled the first 74 patients with paroxysmal or persistent AF treated with LBA in our centre between September 2020 and December 2021. Exclusion criteria were any contraindication for the procedure. 3 different time intervals were considered (time 1 T1, time 2 T2 and time 3 T3), which included the first 25 patients, the next 25 patients and the last 24 patients, respectively. We compared fluoroscopy and procedural time and the number of pulmonary veins isolated by RM &gt;90% (&gt;324°) among the three group were compared.

Results
There was no difference between the three intervals in terms of age (61.2 ±9.00 vs 63.9 ±11.4 vs 58.4 ±12.9; p=n.s.), sex (68% vs 64% vs 81%; p=n.s.) and clinical characteristics. The procedural time (see picture 1) was significantly reduced from T1 to T2 (199 ±51.8 in T1 vs 159 ±38.6 in T2; p&lt; 0.01), while there was no variation between T2 and T3 (159 ±38.6 in T2 vs 153 ±51.9 in T3; p=n.s.). We detected a reduction in fluoroscopy time between T1 and T2 (38.8 ±15.2 in T1 vs 28.8 ±10.5 in T2; p&lt;0.01) but not further reduction was observed between T2 and T3 (28.8 ±10.5 in T2 vs 30.5 ±16.7 in T3; p =n.s.). Considering the use of (RM) feature, there was a progressive increase in the number of PVs isolated by RM &gt;90% over time (1.0 ±0.7 PVs in T1 vs 2.0 ±1.2 PVs in T2 vs 3.3 ±0.9 in T3: p &lt;0.01). Five pinhole balloon ruptures were observed, three in the T1 group, two in the T3 group. Temporary phrenic nerve dysfunction occurred in 1 patient in the T3 interval. No other complications were reported.

Conclusions
PV isolation by visually guided LBA is a safe procedure even during the learning curve. The system is user friendly and procedural time and fluoroscopy time reduced after a limited number of procedures.
Deep sedation with dexmedetomidine administered by electrophysiologists during COVID-19 pandemic compared with propofol administered by anesthesiologists for ablation of atrial fibrillation
Authors: Ebrille E , Lucciola MT , Amellone C , Ballocca F , Suppo M , Antonacci G , Gotta F , Birolo M , Orlando F , Favro E , Giammaria M 
Published: May 2022

Abstract

Funding Acknowledgements
Type of funding sources: None.

Background
COVID-19 pandemic, limiting the availability of anesthesiologists, has impacted heavily on the organization of invasive cardiac procedures such as transcatheter atrial fibrillation (AF) ablation.

Purpose
We compared the safety and efficacy of deep sedation with dexmedetomidine administered by electrophysiologists without anesthesiologist supervision, against the standard protocol performed with propofol.

Methods
We retrospectively included all AF ablation procedures performed in 2020: 23 patients sedated with 1% propofol (2 ml bolus followed by infusion starting at 1 mg/Kg/h), 26 patients with dexmedetomidine (infusion starting at 0.7 mcg/Kg/h). Both groups additionally received 1 mcg/Kg of midazolam as a single bolus and 0.05 mg single boluses of fentanyl prior to ablation on each pair of pulmonary veins (PV). Primary outcomes were oxygen desaturation (&lt; 90%) or need for assisted ventilation/intubation, bradycardia (heart rate &lt; 45 bpm) and persistent hypotension (systolic blood pressure &lt; 90 mmHg).

Results
Baseline characteristics and hemodynamic variables did not differ between the two groups (all p &gt; 0.05). In 8/23 (35%) patients propofol infusion velocity reduction was necessary to maintain the hemodynamic values, compared to 7/26 (27%) with dexmedetomidine.
Inter-group comparison of hemodynamic variables during the procedure showed no statistically significant difference, despite a trend in favor of dexmedetomidine (3 respiratory depressions and 3 persistent hypotension episodes with propofol vs. 0 with dexmedetomidine; p = 0.057).

Conclusion
Deep sedation with dexmedetomidine administered by electrophysiologists without anesthesiologist supervision is safe and effective for AF transcatheter ablation. A trend towards a lower incidence of hypotension and respiratory depression was noted when compared to propofol.
Systematic identification of low voltage-high frequency electrogram zones at sites of left atrial reentrant tachycardia termination
Authors: Merino JL , Kim S , Sanroman M , Castrejon S , Relan J , De La Vieja Alarcon JJ , Martinez Cossiani M , Cervantes C , Carton A , Rivero Santana B , Tauber Molina P 
Published: May 2022

Abstract

Funding Acknowledgements
Type of funding sources: Private company. Main funding source(s): Abbott

Background
Localization of the narrow isthmus of conduction of left atrial local and macro reentrant tachycardia (LAMRT) circuits within scar tissue is challenging. (Panel A). Near-field (NF) electrograms are often obscured by and difficult to distinguish from far-field (FF) activation. The peak frequency (PF) associated with bipolar electrograms is a novel parameter which may distinguish between NF and FF signals. (Panel B). However, the potential value of PF for LAMRT ablation has never been evaluated.

Purpose
1) To quantify the percentage of LA surface with low voltage (LV) and NF signals. 2) To study the proportion of LAMRT ablation sites which were located within a LV-NF region or in the vicinity of it (&lt;10 mm away).

Methods
LART bipolar voltage and activation maps were generated with a 16-pole grid catheter (HD-Grid) during tachycardia. (Panels A,B). PF maps were retrospectively computed (Panels C,D). LV zones were defined according to a cutoff &lt;0.3mV. Four different PF cut-off values (&gt;250, &gt;300, &gt;350 and &gt;400 Hz) were assessed in the delineation of overlapping LV-NF regions. (Panel E)

Results
16 consecutive patients with 24 LAMRT’s targeted for ablation were prospectively enrolled. 21/24 LAMRT’s were terminated by radiofrequency application. (Panel F). The LV area represented 47.7±14% of the LA surface. The LV-NF area represented 8.2±6.2%, 5.2±5.4%, 3.4±7.4% and 3.3±4.1% of the LA surface by using 250, 300, 350, and 400 Hz PF cutoffs respectively. There were 2.1±1 (range 0-3), 0.9±0.8(range 0-3), 0.5±0.6 (range 0-2) and 0.5±0.6 (range 0-2) LV-NF areas per patient using 250, 300, 350 and 400 Hz PF cutoffs respectively. At the optimal PF cutoff &gt; 250Hz and voltage &lt; 0.3mV, the site of tachycardia termination by radiofrequency application was found inside of a LV-NF region in 13/21 LAMRTs (sensitivity 68.4%), and within 1cm of a LV-NF region in 19/21 LAMRTs (sensitivity 89.5%) respectively.

Conclusion
1. Left atrial reentry termination sites by radiofrequency application are often within or nearby LV-NF areas as identified by the PF and voltage analysis of bipolar electrograms. 2. Beyond conventional substrate mapping, the systematic identification of high frequency activity within the low voltage zone holds promise for rapid identification of isthmus conduction critical to LAMRTs.
Correlation of local impedance, global impedance and contact force with resulting lesion size in RF ablation
Authors: Wachter A , Bahlke F , Popa M , Foerschner L , Krafft H , Maurer S , Telishevska M , Englert F , Lengauer S , Kottmaier M , Lennerz C , Reents T , Hessling G , Deisenhofer I , Bourier F 
Published: May 2022

Abstract

Funding Acknowledgements
Type of funding sources: None.

Background
During clinical application of RF-energy, several parameters are constantly observed, e.g. RF time, power, global impedance and temperature. The new parameter "local impedance" is gaining importance and might be a possible real-time marker for predicting long-lasting RF-lesions and increasing safety. The aim of this study was to investigate the correlation between local and global impedance as well as RF power and contact force.

Methods
RF-lesions were created using an ex vivo model with porcine cardiac preparations. These were put in a saline-filled container with a dispersive electrode. Global impedance was held at 120 Ohm by adjusting saline and water. Additionally, a heated thermostat and a circulation pump were installed to imitate blood flow. RF-lesions were produced with different settings of energy and contact force (20, 30, 40 and 50 watts; contact force of 0-5g, 10-15g and 20-25g). While creating the lesions, global and local impedance, temperature, energy and RF time were documented, as well as the current lesion width and depth. Local and global impedance drops were calculated as the difference between baseline impedance and current impedance.

Results
In total, 1223 measurements were made during application of RF-energy. 6 steam pops occurred. Contact force, local and global impedance changes showed highly significant correlations with lesion depth and diameter. Amongst analyzed values, local impedance drop showed highest correlation with lesion diameter and depth (r = 0,391 and 0,613; p&lt;0,001). Visualized in Figure 1 and 2, global and local impedance correlate with lesion diameter and depth.

Discussion
Local impedance was found to be a suitable real-time marker for lesion size, showing significantly higher correlations with RF lesion size than contact force and global impedance. Further investigation is necessary to find a cut off for a safe but long-lasting RF-lesion.
Arrhythmias in pregnant women without structural heart disease: characteristics and outcomes
Authors: Abdrakhmanov A , Ainabekova B , Nuralinov O , Bakytzhanuly A , Smagulova A 
Published: May 2022

Abstract

Funding Acknowledgements
Type of funding sources: None.

Background
Heart rhythm disorders are relatively common in pregnant women. There are few data of arrhythmia characteristics and perinatal outcomes in patients without any structural heart disease.

Purpose
To describe the clinical peculiarities, pregnancy course and characterize outcomes.

Methods
A total of 99 pregnant without structural heart disease with arrhythmia was included, aged: 29.05±5.37years with a mean gestation age 22.7±7.29 weeks. Clinical characteristics, obstetric and neonatal outcomes were determined.

Results
The most common reported arrhythmias were supraventricular tachycardia (n=46; 46.5%) and premature contractions (n=36; 36.3%). Advanced heart block (n=9; 9.1%) and ventricular tachycardia (n=8; 8.1%) were rare during pregnant with structurally normal heart. The 56% of arrhythmia cases among the examined patients first occurred during current pregnancy. Studying the peculiarities of arrhythmia manifestations, it was determined that in the I trimester of pregnancy the disease symptoms appeared in 11% of the examined women, in the II trimester – in 59%, in the III trimester – in 31%. In the clinic, the most common symptoms of arrhythmia were palpitations (62.6%), general weakness (59.6%), dyspnea (38,4%) and dizziness (29.9%). Pregnancy course was benign in the majority of cases. Termination of pregnancy was in three cases (3%) – in one case due to extracardial cause, in two cases due to life threatening course of ventricular tachycardia. Premature birth was in 2 cases (2.02%). In 75% of pregnancy was vaginal delivery, in 25% - cesarean section. Preeclampsia was in 2 cases (2.02%). There were 99 live births without maternal and fetal mortality.

Conclusions
In pregnant women with no structural heart disease supraventricular tachycardia and premature beats are most common. Majority of patients have good course of pregnancy and outcomes.
Comparison of left atrial and atrial appendage mechanics to stratify the risk of left atrial/atrial appendage stasis in patients with non-valvular atrial fibrillation
Authors: Mao YANKAI , Zhao HJ , Yang YUAN , Ma MM , Yu CHAN , Wang YUNHE , Jiang RUHONG , Zheng ZHELAN , Jiang CY 
Published: May 2022

Abstract

Funding Acknowledgements
Type of funding sources: None.

Background
Left atrial appendage (LAA) and left atrial (LA) dysfunction are associated with the presence of thrombus and spontaneous echo contrast (SEC) within LAA. However, the role of LAA mechanical dispersion (MD) in contributing to thrombogenesis has not been fully addressed and compared with LA MD or LA/LAA GLS. We sought to investigate the relationship of LAA MD with LAA dense SEC or thrombus, and to compare its additional value with other LA/LAA mechanical parameters in patients with nonvalvular atrial fibrillation (AF).

Methods
We conducted a cross-sectional study of 493 consecutive patients with AF (median age 65, male 66.9%) who underwent echocardiography prior to catheter ablation. Of these, 70(14.2%) patients had dense SEC or thrombus in LAA. We measured the LAA and LA longitudinal strain using speckle-tracking echocardiography (STE). LAA MD and LA MD was defined as the standard deviation (SD) of time to peak positive strain corrected by the R-R interval.

Results
Patients with LAA dense SEC/thrombus (n=70) had significantly higher LAA MD (median 14.20% (11.60%,16.80%) vs 9.35 % (6.23%,12.07%)) than controls (n = 423). Areas under the receiver-operating curve (AUC) for CHA2DS2-VASc score plus LAA MD, LAA GLS or LA GLS were comparable (0.843,0.830 and 0.809) and superior to that combined with LA MD (0.762, p&lt;0.01). Multivariable analysis showed that LAA MD was an independent determinant of LAA dense SEC/thrombus in four different models (Odds ratio, 1.23-1.24; P &lt; 0.001), and provided additional diagnostic value over clinical and standard echocardiographic parameters. Whereas LA MD was not significantly associated with LAA dense SEC/thrombus and had no incremental predictive value.

Conclusion
LAA mechanical dispersion provided incremental information over conventional risk factors in the identification of LAA dense SEC or thrombus in AF patients and is superior to LA mechanical dispersion.
Left atrium hemodynamic in atrial fibrillation and normal subjects
Authors: Falanga M , Masci A , Chiaravalloti A , Dal Monte A , Corsi C , Tomasi C 
Published: May 2022

Abstract

Funding Acknowledgements
Type of funding sources: None.

Background
A computational fluid-dynamics (CFD) model previously developed with the aim of evaluating cardioembolic risk in patient affected by atrial fibrillation (AF) was used for the characterization of the left atrium (LA) hemodynamic in normal subjects (NL), patients affected by paroxysmal atrial fibrillation (PAR-AF) and patients affected by persistent atrial fibrillation (PER-AF). Based on the fluid-dynamics simulations results, we aimed at enhancing differences in blood flow in AF patients and NL and at better understanding the relationship between AF progression and stroke risk on a patient-specific basis.

Methods
3D patient-specific anatomical and motion models were derived from ECG-gated coronary artery CT acquired with retrospective protocol. These models represented the computational domain for CFD simulations in which inflow initial conditions were derived from PW Doppler at the mitral valve and at the pulmonary veins. Velocity field and vortex structures both within the LA and left atrial appendage (LAA) were assessed in 10 NL, 5 PAR-AF and 4 PER-AF. Blood stasis was evaluated by populating the LAA with 500 particles and counting the number of particles still present after five cardiac cycles.

Results
Velocities inside the LA and in the LAA presented different amplitude and distribution in the 3 groups (peak velocity – NL: 50÷60 cm/s, PAR-AF: 40÷50 cm/s, PER-AF: 15÷25 cm/s). The mean velocity resulted lower in the PER-AF compared with PAR-AF (mean velocity – PAR-AF: 25÷35 cm/s, PER-AF: 8÷20 cm/s) at the LAA ostium and inside the LAA, in which the wash-out effect was strongly reduced (Figure 1). On the other hand, the mean velocity in the NL was higher with respect of AF patients (mean velocity – NL: 40÷45 cm/s). A higher number of vortex structures was observed in NL compared with AF patients, thus favouring the hypothesis of a more efficient wash-out of the LA and of the LAA. Blood stasis in terms of number of particles in the LAA after five cardiac cycles confirmed these results (NL: 5±2, PAR-AF: 18±3, PER-AF: 41±10).

Conclusions
The developed approach quantifies differences in LA hemodynamic between AF and NL patients, also allowing a stratification of the atrial disease progression in terms of variations in the blood velocity, organization of blood flow and quantification of blood stasis.