bluuebunny/crossref_metadata_2025_split huggingface dataset:
P1447Use of novel local impedance-based catheter in typical right atrial flutter ablation: preliminary data from a multicenter Italian study
Authors: Ducceschi V , Pandozi C , Arestia A , Rossi L , Bencardino G , Segreti L , Schillaci V , Auricchio C , Aperuta F , Malacrida M , Sangiuolo R 
Published: June 2020

Abstract

Funding Acknowledgements
NO FUNDING

Background
Many studies demonstrated the importance of an optimal tissue contact to obtain safe and effective lesions and to improve the clinical outcome in ablation of cavotricuspid isthmus (CTI) for typical right atrial flutter (AFL). Data about a novel technology able to measure local tissue impedance (LI) providing a measure of tissue characteristics and lesion formation is still lacking in right atrium or CTI working.

Purpose
This analysis explores the relationship between LI measures and ablation spot lesion locations during ablation of CTI in common AFL patients (pts).

Methods
Consecutive pts undergoing AFL ablation from the CHARISMA registry were included. A novel RF ablation catheter with dedicated algorithm (DirectSense - DS -) was used to measure LI at the distal electrode of this catheter. Each targeted spot was characterized in terms of LI parameters during RF delivery at the lateral, intermediate and posterior portions of the CTI. Successful single RF ablation was defined according with a reduction of voltage (RedV) by at least 50% or split in two separate potentials (SPL). Ablation endpoint was the creation of bidirectional conduction block across the isthmus.

Results
A total of 135 ablation spot lesions were delivered in 20 pts (median 5 [3-11] lesions per pt): 7 (5%) at lateral, 88 (65%) at intermediate and 40 (30%) at posterior portions of the CTI. Acute success was obtained in all cases and no complications were observed. The median ablation time was 26 [17 – 36] seconds per lesion. 100 (74%) and 51 (38%) ablation spots were effective according with RedV or SPL, respectively. The mean LI was 106 ± 15Ω prior to ablation and 93 ± 13Ω after ablation (p &lt; 0.0001, mean absolute LI drop 14 ± 7Ω, mean percentage LI drop 13%±6). Effective ablation spots showed a higher absolute impedance drop (15 ± 7Ω at effective RedV vs 9.6 ± 8Ω at ineffective RedV, p = 0.0001; 15.6 ± 7Ω at effective SPL vs 12.5 ± 7Ω at ineffective SPL, p = 0.0173) or % impedance drop (14%±6 at effective RedV vs 9%±7 at ineffective RedV, p &lt; 0.0001; 14.5%±6 at effective SPL vs 11.6%±6 at ineffective SPL, p = 0.0103) compared with ineffective sites. No significant differences were found in terms of starting LI, ending LI or LI drop among CTI areas. The percentage of LI drop was associated both with RedV (odd ratio 1.17 (95%CI: 1.08 to 1.26, p = 0.0001)) and with SPL (odd ratio 1.08 (1.02 to 1.14, p = 0.0132)).

Conclusion
In our preliminary experience, measured LI before and after RF delivery and LI drop appear to be consistent and homogeneous across different CTI ablation locations. The magnitude of the LI drop was associated with effective lesion formation and conduction block.
P1362Diagnostic accuracy of R-wave detection by insertable cardiac monitors
Authors: De Coster M , Demolder A , De Meyer V , Vandenbulcke F , Van Heuverswyn F , De Pooter J 
Published: June 2020

Abstract

OnBehalf
1.Department of Cardiology, Ghent University Hospital, Ghent, Belgium

Introduction
Insertable cardiac monitors (ICM) allow automatic arrhythmia detection but the diagnostic performance can be hampered by poor R-wave sensing leading to false positive recordings.

Purpose
This study assesses the prevalence and predictors of R-wave under- and oversensing among different ICM types.

Methods
Patients implanted with an ICM at the University Hospital of Ghent between January 2017 and August 2018 were included. All ICM tracings recorded at ICM interrogation or transmitted by remote monitoring were reviewed for inadequate R-wave sensing leading to false arrhythmia alerts. Inadequate R wave sensing was defined as undersensing due to sudden reduction in R wave amplitude or oversensing due to the occurrence of artefacts. Patient and implant characteristics were retrieved from the medical record and implant reports.

Results
The study screened 135 patients (age 59 ± 19 years, 44% female) implanted with different ICM types: Reveal XT and LINQ n = 92 (68%), Confirm and Confirm Rx n = 35 (26%), BioMonitor n = 8 (6%). ICM analysis was conducted in 112 patients (83%). Overall, false arrhythmia alerts due to inadequate R wave sensing occurred in 22 (20%) of the patients. Among these 22 patients, false diagnosis of bradycardia or pauses were documented in 64%, false high ventricular rates in 14% and false atrial fibrillation alerts in 22% of the patients. Of interest, in an additional 7 (6%) patients significant changes in R wave sensing occurred, although not causing false arrhythmic alerts. Occurrence of R-wave changes occurred in 19% of Reveal, 17% of Confirm and 50% of BioMonitor ICMs (p = not significant). Occurrence of R-wave changes among the different types of ICMs were not related to age, sex, BMI, time of the day, heart frequency or implant R-wave sensing.

Conclusion
Poor R wave sensing, leading to false arrhythmia detection, occurred in a significant number of ICM, and seems to occur independent of ICM type, patient or implant characteristics.
Abstract Figure.
P967Role of low voltage ablation in catheter ablation of patients with persistent AF- a single centre experience
Authors: Panagopoulos D , Nagy S , Kim S , Lampridou M , Linton N , Lefroy D , Whinnett Z , Ng F S , Koa-Wing M , Kanagaratnam P , Peters N S , Qureshi N , Lim P B 
Published: June 2020

Abstract

Funding Acknowledgements
Research grant from Abbott

Introduction
We have recently described a novel evaluation of AF voltage which correlates better with MRI-DE defined scar than sinus rhythm voltage. We evaluated the clinical efficacy of additional voltage-based substrate modification in the Persistent AF patient cohort in a single centre case series.
Methods
22 PsAF patients undergoing catheter ablation were recruited. Left atrial electroanatomical maps were created in AF before any ablation was performed in all patients. Mean peak to peak AF voltage mapping was undertaken using 8s segments of AF (&lt;0.35mV). PVI was then performed in all patients after which, further ablation lesions were delivered on the underlying scar tissue (transection, box formation or homogenisation).

Results
Of the 22 patients currently under follow up, 16 patients are more than 12 months after their initial procedure. 11/16 patients have had no recurrence and no patient is currently on anti-arrhythmic medication.

Conclusion
From our series, 69% of PsAF patients remain arrhythmia free at one year follow up post blanking period with a single procedure. Ablation of low voltage areas appears to infer incremental benefit in the Persistent AF population.
Table 1 Mean Age, yrs 64 ± 9 Male 19 (86.3) Diabetes mellitus 1 (4.5) Hypertension 7 (31.8) TIA/CVA 2 (9) Left ventricular EF ≥55% 22 (100.0) LA size (diameter, according to British Society of Echocardiography Guidelines) Normal -Mild 12 (54.5) Moderate - Severe 10 (45.5) Mean AF duration, months 24.2 ± 20.8 Current antiarrhythmic strategy Amiodarone 3 (13.6) Sotalol 1 (4.5) Current anticoagulation Warfarin 3 (13.6) Direct oral anticoagulants 19 (86.3) Values are mean ± SD or N (%) or duration in months ± SD AF = atrial fibrillation; CVA= cerebrovascular accident; EF = ejection fraction; LA = left atrium; TIA = transient ischaemic attack. Baseline characteristics of patients (n = 22)
Abstract Figure. Ablation sets and AF Voltage
P989Determinants of beat-to-beat left ventricular function during atrial fibrillation: a combined clinical-computational study
Authors: Lyon A , Van Mourik M J W , Linz D K , Cruts L , Heijman J , Bekkers S C A M , Schotten U , Crijns H J G M , Lumens J 
Published: June 2020

Abstract

Funding Acknowledgements
Netherlands Organisation for Scientific Research (NWO-ZonMw, VIDI grant 016.176.340)

Background
The rapid irregular atrial electrical activity during atrial fibrillation (AF) is associated with an irregular and variable left ventricular (LV) systolic pump function. The mechanisms determining LV function during AF remain incompletely understood.

Purpose
To assess the reliability of global longitudinal strain (GLS) as a measure of LV function during AF, and to elucidate how beat-to-beat changes in LV preload and afterload affect LV function during AF.

Methods
Beat-to-beat speckle-tracking echocardiography was performed in patients with persistent AF. A hundred consecutive beats in each patient were imaged during AF and we evaluated the relation between GLS in the image plane (4-chamber view) and (pre-)preceding cycle length (CL) in these patients. We used the CircAdapt cardiovascular system model to simulate cardiac mechanics and hemodynamics during AF for each individual patient 1) by imposing the exact irregular sequence of CL as measured in the patient and 2) by making the atrial myocardium non-contractile. These simulations enabled beat-to-beat quantification of preload (end-diastolic volume, EDV), afterload (systolic aortic pressure) and GLS during AF.

Results
Clinical data and simulations both showed a negative non-linear relation between preceding CL and GLS (Panel A). Non-linearity was more pronounced at low preceding CLs (&lt;750ms), while GLS at preceding CLs &gt;750ms showed less dependence on CL. Simulating ventricular failure by a reduction in ventricular contractility led to a lower overall GLS and a loss of non-linear response at low CL (Panel A, right, diamonds). Increased GLS at high preceding CL (purple box) was explained by a higher preceding EDV (higher preload) (p &lt; 0.002, Panel B), reflecting the Frank-Starling mechanism of contractile myocardium. At a given preceding CL, variability in GLS was explained by the afterload of the preceding beat, with a lower preceding afterload (systolic aortic pressure) leading to higher GLS (Panel C, yellow box, p &lt; 0.002), but not by changes in preceding preload (Panel C, p non-significant). Preload of the pre-preceding beat also correlated with changes in GLS (Panel C, p &lt; 0.005).

Conclusions
During AF, GLS depends non-linearly on the preceding CL, with GLS measures performed at longer preceding CLs (&gt;750ms in our cohort) showing a low beat-to-beat variability. Beat-to-beat hemodynamic changes in preceding afterload could explain differences in LV function at same preceding CL. Our combined clinical-computational study highlights the variability in GLS measurement during AF and provides new insight into the potential hemodynamic mechanisms determining LV function in AF patients.
Abstract Figure.
P1115Cardiac SABR for ventricular tachycardia - initial UK experience
Authors: Lee J , Bates M , Shepherd E , Thornley A , Kelland N , Greenhalgh D , Atherton P , Peedell C , Hatton M 
Published: June 2020

Abstract

OnBehalf
United Kingdom Cardiac SABR consortium

Background
Stereotactic Ablative Body Radiotherapy (SABR) is a novel non-invasive treatment for Ventricular Tachycardia (VT) refractory to standard catheter ablation. 3 UK hospitals have started compassionate use cardiac SABR programmes, and are working in close collaboration.

Purpose
To report initial UK experience for treatment of refractory VT with cardiac SABR.

Methods
All patients had undergone prior unsuccessful invasive ablation with VT recurrence despite anti-arrhythmic drug (AAD) use. High-resolution CT imaging with 3D reconstruction was combined with 12 lead ECGs of VT and prior invasive +/- non-invasive electrophysiology mapping data to define a cardiac target. Treatment margins were modified to account for cardiac/respiratory motion and to minimise off target treatment to other organs as per clinical SABR practice. Single fraction high dose treatment (20-25 Gy) was delivered by CT guided Linear Accelerator. Patients were assessed regularly with clinical review and remote device monitoring.

Results
3 patients have been treated so far with aetiologies of prior myocarditis, non-ischaemic dilated cardiomyopathy and ischaemic cardiomyopathy. All patients successfully received planned SABR treatment in &lt;1 hour with no peri-procedural complications. Current follow up is to 4 months. Clinical course was variable – patient 1 had a flare of VT post-SABR requiring temporary escalation of AADs before VT was suppressed, patient 2 had initial suppression of VT but died from decompensated heart failure with further VT after 4 weeks, patient 3 had further VT with a different exit site and underwent repeat invasive ablation and escalated AAD use to achieve VT suppression.

Conclusions
Cardiac SABR shows promise for VT control, but further experience and trials are needed. Integration of imaging and electrophysiology data to generate accurate targets appears critical. The effect of SABR seems to develop over several weeks after therapy. Patient selection and timing of SABR delivery is important with acknowledgement that competing causes of death exist in patients with refractory VT entering a compassionate use program.
Abstract Figure. Example SBRT plan
P336Relationship between polymorphism of NOS3 gene and primary cardiac conduction disorders
Authors: Chernova A , Nikulina S , Shulman V , Tretyakova S , Maksimov V , Voevoda M 
Published: June 2020

Abstract

Background
Inherited cardiac conduction diseases (CCD) are rare but are caused by mutations in a myriad of genes. Nitric oxide (NO) derived from endothelial NO synthase (NOS3) is crucial to ССD. Nitric oxide is a reactive free radical which acts as a biologic mediator in several processes, including neurotransmission and cardiac activities. Nitric oxide is synthesized from L-arginine by nitric oxide synthases. Multiple transcript variants encoding different isoforms have been found for this gene.
Material and methods:
A family examination was performed for 69 patients with atrioventricular block (AVB). The control group was formed by 220 patients without clinical ECG manifestations of cardiac diseases. All the examinees underwent ECG, echocardioscopy, electrophysiological examination of the heart.

Results
by results of research, it has been established that the frequency of carriers of a homozygous genotype on rare allele (4b/4b) among patients with AVB (26.1%±5.3) was higher in comparison with the controls (3.2%±1.2). The obvious tendency to decrease in carriers of a homozygous genotype on extended allele (4a/4a) among patients with AVB (47.8%±6.0) in comparison with the control group (71.4%±3.0) has also been noted.

Conclusions
In this work we revealed association between hereditary disturbances of cardiac conduction, such as AVB and polymorphism of NOS3 gene, using clinical - genetic material for the first time.
P1027Left atrial hypertension invasively measured during pulmonary vein isolation as a predictor of atrial fibrillation recurrence
Authors: Manfrin M , Mugnai G , Chierchia G B , Bilato C , Rauhe W G 
Published: June 2020

Abstract

Background
The clinical role of left atrial hypertension (LAH) in patients with atrial fibrillation (AF) and its role as predictor in those undergoing pulmonary vein (PV) isolation is still unknown.

Purpose
The aim of the present study was to analyse the prevalence of LAH in patients with nonvalvular AF and preserved left ventricular ejection fraction having undergone PV isolation and its implication for AF catheter ablation.

Methods
Consecutive patients with drug resistant AF who underwent PV isolation at San Maurizio Regional Hospital of Bolzano (Italy) as index procedure were retrospectively included in this analysis. Left atrial hypertension was defined as the LA mean pressure &gt;15 mm Hg.

Results
A total of 98 consecutive patients (71 males, 72%; mean age 60.3 ± 8.4 years) with drug resistant, non valvular AF and preserved LV ejection fraction having undergone index PV isolation procedure were included in the analysis. Eleven patients (11%) underwent radiofrequency ablation and 87 (89%) cryoballoon ablation. The mean LA pressure was 10.7 ± 4.5 mmHg; LAH occurred in 24 (24%) patients. At a mean follow up of 14.6 ± 7.1 months (median 14 months), the success rate without antiarrhythmic therapy was 71.4% (70/98; considering the blanking period). On multivariate analysis, LAH remained the only independent predictor of definitive AF recurrence (HR 3.02, 1.36-6.72, p = 0.007).

Conclusion
Left atrial hypertension was found in 24% of patients undergoing PV isolation and was found to be significantly related to both early and late AF recurrences.
Univariate and multivariate Cox regressi Univariate analysis Multivariate analysis Early Recurrence (during BP) HR 95%CI P value HR 95%CI P value Age (years) 1.06 1.02-1.10 0.005 1.05 1.00-1.09 0.03 LA volume (ml/m2) 1.02 1.00-1.05 0.04 1.02 1.00-1.05 0.05 LA hypertension 2.46 1.32-4.57 0.004 1.97 1.03-3.79 0.04 Recurrence after the BP HR 95%CI P value HR 95%CI P value Age (years) 1.05 1.00-1.11 0.04 1.04 0.98-1.09 0.15 LA hypertension 3.51 1.62-7.60 0.001 3.02 1.36-6.72 0.007 BP recurrence 1.83 0.84-3.99 0.13 AF atrial fibrillation. BMI: body mass index. LA: left atrium. CAD: coronary artery disease. BP: blanking period. HR: hazard ratio. CI: confidence intervals.
P402Analysis of right atrium remodeling by cardiac magnetic resonance in patients with atrial fibrillation and its association with left atrium
Authors: Gunturiz Beltran C , Borras-Amoraga R , Alarcon F , Garre P , Figueras R , Caixal G , Cozzari J , Trotta O , Tolosana J M , Arbelo E , Roca I , Brugada J , Guasch E , Mont L 
Published: June 2020

Abstract

Funding Acknowledgements
none

Background
Atrial fibrillation (AF) causes changes in atrial anatomy and this remodeling leads to the arrhythmogenic substrate. Most studies with cardiac magnetic resonance-late gadolinium enhancement (CMR-LGE) have focused on the left atrium (LA); The role of the right atrium (RA) in AF is unknown.

Purpose
To evaluate RA remodeling parameters and its comparison with LA in patients with AF.

Methods
Observational study. We included 109 patients: 9 healthy volunteers, 55 paroxysmal AF, 45 persistent AF. All of them had a CMR-RTG 3.0 T. Image post-processed with segmentation of both atria. Comparison of mean parameters of RA and LA (T test), correlation between them (R Pearson). Multivariate analysis (Cox regression) to study predictive factors.

Results
AF patients had a mean age of 58.5 ± 10.5 years, 70(70%) were men, without structural heart disease 80(80%), and associated atrial flutter 11(11%). The RA parameters were compared by subgroups. We found differences in (healthy/paroxAF/persistAF): area(cm2) 94.0 ± 15.9 /125.3 ± 20.8/ 152.8 ± 24.4 (p &lt;0.0001); volume (ml) 76.7 ± 19.6/ 107.0 ± 25.6/ 150.9 ± 37.6 (p &lt;0.0001); and total fibrosis (%) 3.7 ± 4.3/ 16.5 ± 14.1/ 19.4 ± 15.9 (p 0.014).
RA was higher than LA in all subgroups. There was more fibrosis in RA in paroxysmal/persistent AF. Both types of AF had at least a moderate correlation for area, volume and fibrosis (table).
Finally, RA sphericity was the only predictor factor of AF recurrence after ablation among RA remodeling parameters (HR 1.1 95%CI [1.0 -1.3], p = 0.049).

Conclusions
Area, volume and fibrosis progressively increased from healthy to paroxysmal AF, and then to persistent AF. RA was higher than LA and it also had more fibrosis in patients with AF. The size and fibrosis between both atria had at least moderate correlation. The RA sphericity was a predictor of post-ablation AF recurrences.
COMPARISON/CORRELATION RA LA p R PEARSON(RA/LA) p HEALTHY VOLUNTEERS Volume (ml) 76.7 ± 19.6 37.0 ± 9.4 &lt;0.0001 0.457 0.254 Total Fibrosis (%) 3.7 ± 4.3 5.0 ± 6.1 0.278 0.837 0.005 PAROXYSMAL AF Volume (ml) 107.0 ± 25.6 69.5 ± 26.5 &lt;0.0001 0.422 0.001 Total Fibrosis (%) 16.5 ± 14.1 8.0 ± 8.6 &lt;0.0001 0.485 &lt;0.0001 PERSISTENT AF Volume (ml) 150.9 ± 37.6 103.2 ± 28.5 &lt;0.0001 0.582 &lt;0.0001 Total Fibrosis (%) 19.4 ± 15.9 10.5 ± 11.7 &lt;0.0001 0.571 &lt;0.0001
Abstract Figure. Correlation of area and fibrosis RA/LA
P1016Correlation between cardiac magnetic resonance-late gadolinium enhancement and electro-anatomical map for right atrium
Authors: Gunturiz Beltran C , Borras-Amoraga R , Alarcon F , Garre P , Figueras R , Caixal G , Tolosana J M , Arbelo E , Roca I , Prat S , Perea M J , Brugada J , Guasch E , Mont L 
Published: June 2020

Abstract

Funding Acknowledgements
none

Background
Electroanatomical map (EAM) detects areas of low voltage as a surrogated marker of fibrosis areas, being the reference technique for its detection. Cardiac magnetic resonance with Late Gadolinium enhancement (CMR-LGE) allows non-invasive detection of atrial fibrotic areas. CMR-LGE studies have focused on the left atrium since now.

Purpose
We need to validate this test to extend its use to the right atrium (RA), since it is involved in the arrhythmogenic substrate of several arrhythmias, and probably also in atrial fibrillation (AF).

Methods
Prospective observational study. Fifteen patients undergoing a first AF ablation procedure were included. All patients had a pre-procedural LGE-CMR performed. The blood pool-normalized intensity signal (image intensity ratio-IIR) was calculated for the right atrial wall, and values projected in a shell. IIR values validated for the left atrium were used to identify dense and intermediate fibrosis, and healthy tissue (&gt;1.32, 1.2-1.32, &lt;1.2, respectively). During the procedure but before ablation, a point-by-point high density EA bipolar voltage map of RA was obtained with a multipolar catheter. Standard voltage thresholds of 0,1 mV and 0,5 mV were used to characterize fibrotic and healthy tissue in EAM. For each RA, the EAM was projected into the IIR shell, and the correlation between bipolar voltage and normalized IIR values for each shell point was quantified. Then, we also obtained its concordance (categorical variables) according to the label automatically assigned by EAM/CMR with the pre-set thresholds: healthy tissue/ intermediate fibrosis/dense fibrosis.

Results
A total of 8,830 points were obtained, mean per patient 588 (± 509) points. A global weak negative correlation was found between the EA bipolar voltage map (EAM) and IIR (CMR) (r= -0.16, p &lt; 0.0001)(figure). LGE-CMR identified more healthy tissue than EAM (81.0% vs 60.6% respectively), then CMR underestimated the fibrotic tissue in RA. Finally, we analyzed the concordance and we obtained that the degree of accuracy between both measurements was 55.7%.

Conclusion
There was an inverse correlation between the bipolar voltage EAM and IIR (CMR) of low grade but with statistical significance. CMR underestimated fibrotic tissue in RA with respect to its identification by EAM.
Abstract Figure. Correlation between bipolar voltage-IIR