bluuebunny/crossref_metadata_2025_split huggingface dataset:
Validation of coala heart monitor
Authors: Paul Nordin A , Mohammad Ali A , Carnlof C , Drca N 
Published: October 2022

Abstract

Background/Introduction
Atrial fibrillation (AF) can be asymptomatic and it is associated with stroke and heart failure which can present as first symptoms [1,2]. There is increasing evidence of benefits of screening for AF to prevent ischemic stroke by initiating anticoagulation therapy in affected individuals [3]. There are several devices used for screening of AF [4] and one of them is Coala Heart Monitor (CHM), which is a handheld device, connected by blue-tooth to a smartphone for registration of the rhythm from the chest and the thumbs. The aim with this this study was to validate the accuracy of CHM for detecting atrial tachyarrhythmia (ATA) (AF, atrial flutter or atrial tachycardia) compared to 12-lead-ECG.

Methods
Eligible participants were ≥18 years of age, planned for a 12-lead-ECG, with a history of ATA. Exclusion criteria were; pacemaker or implantable cardioverter-defibrillator (ICD)-treatment, ongoing arrhythmia that was not ATA or if the patient was unwilling or unable to provide informed consent. One hundred and eleven 12-lead-ECG were collected and immediately after a 30 + 30 second thumb-and chest-registration from CHM where collected. 12-lead-ECG independently interpreted by two electrophysiologist was used as the reference standard (100% coherence). In one patient neither chest nor thumb-registration could be interpreted due to bad quality, and this was not included in the analysis. Eight thumb-registrations and three chest-registrations could not be interpreted and in these cases the other registration could be interpreted. In one case there was disagreement between interpreter one and two, and in this case a third interpreter was involved.

Results
Mean age was 65.2±12.1 years and 28.8% were female. Prevalence of ATA was 36.4%. The sensitivity for ATA was 100% (95% CI, 96.3% - 100%) and the specificity was 100% (95% CI, 96.3% - 100%).

Conclusion
CHM provides excellent sensitivity and specificity for ATA compared to 12-lead-ECG.

Funding Acknowledgement
Type of funding sources: Public grant(s) – National budget only. Main funding source(s): Swedish Research Council
The use of novel 3D dark-blood late gadolinium enhancement MRI to determine the optimal threshold for atrial scar after pulmonary vein isolation ablation
Authors: Bijvoet G P , Hermans B J M , Holtackers R J , Luermans J G L M , Linz D , Maesen B , Mihl C , Nijveldt R , Vernooy K , Wildberger J E , Schotten U , Chaldoupi S M 
Published: October 2022

Abstract

Background
Dark-blood late gadolinium enhancement (LGE) magnetic resonance imaging (MRI) is proved to be superior to bright-blood LGE MRI in localising subtle subendocardial scar in the ventricles, because of improved contrast between myocardial scar and blood. However, dark-blood LGE MRI has not yet been applied to identify atrial scar in the left atrium (LA) and therefore its threshold to determine scar is unknown.

Purpose
To determine the optimal intensity threshold for 3D dark-blood LGE MRI for atrial ablation scar after pulmonary vein isolation (PVI)

Methods
Twelve re-do PVI patients with symptomatic atrial fibrillation (AF) who underwent pre-procedural 3D dark-blood LGE MRI were included. The image intensity ratio (IIR = myocardial intensity normalized to the blood pool) from the LGE MRI were calculated using ADAS-AF. High-density bipolar voltages (BiV) maps were recorded during sinus rhythm prior to ablation. All BiV locations ≤5 mm from the ADAS LA anatomy were compared with the corresponding IIR, using custom-made software in MATLAB. To achieve an equal ratio between scar (BiV ≤0.15 mV) and non-scar (BiV &gt;0.15 mV) for each patient, non-scar pairs were randomly resampled to the same number as scar pairs. This was repeated 10 times and for every random selection, receiver operating characteristics (ROC) analysis was performed to determine the optimal IIR threshold (provided by the Youden's index) for scar defined as BiV &lt;0.15 mV (Figure 1). All IIR thresholds and areas under the curve were averaged to determine the overall performance and optimal IIR threshold.

Results
Of the 12 included patients, 8 had prior cryo PVI, 2 radiofrequency PVI, and 2 surgical/hybrid AF ablation. ROC curve analysis estimated the average optimal threshold for predicting BiV &lt;0.15 mV to be an IIR of 1.106, with a mean area under the curve (AUC) of 0.73 (Figure 1). Figure 2 shows two examples of the IIR map (A), BiV map (B), and the correspondence map (C) providing information on spatial agreement between IIR and BiV. This individual qualitative assessment provides insight into the spatial variation between techniques and may facilitate future studies on the pathophysiological understanding of atrial ablation scarring.

Conclusion
This is the first study to use the novel 3D dark-blood whole heart LGE MRI to evaluate LA ablation scar after PVI. Based on the ROC analyses, an IIR of 1.106 is the optimal threshold for atrial ablation scar, defined as high density bipolar voltage &lt;0.15 mV.

Funding Acknowledgement
Type of funding sources: None.
Artificial intelligence to reduce artifact in cardiac electrophysiological signals
Authors: Ruiperez-Campillo S , Deb B , Feng R , Ganesan P , Tjong F V Y , Clopton P , Rogers A J , Narayan S M 
Published: October 2022

Abstract

Background/Introduction
Signals in Electrophysiology cases are often noisy despite laboratory shielding and filtering, and current noise-reduction methods are suboptimal. Template matching can identify a “nearest type” of electrogram, but libraries of signal shapes may be unavailable. Beat averaging can reduce noise but obscures beat-to-beat variations and is not optimal to analyze dynamically changing signals, such as when moving a catheter in the heart. Smoothing reduces noise yet blurs high frequency components.

Purpose
We set out to test if machine learned autoencoders could reduce noise in single beats without requiring massive training data or beat libraries. Specifically, we hypothesised that noisy electrograms in small datasets of atrial signals could be de-noised using an encoder-decoder neural network (NN) using transfer learning of machines trained to recognize key features in larger datasets of related signals.

Methods
We applied NN to monophasic action potentials (MAPs), because they have visually verifiable shapes. The NN was first trained to reconstruct 5706 left and right ventricular MAPs in 42 patients (67±13y; Fig. 1A). Transfer learning was then used to apply the NN to a much smaller dataset of 641 atrial MAPs in 21 patients (67±5y, 13 women; Fig. 1B, D, F).

Results
NN reconstructed atrial MAPs with a Pearson correlation of 0.87±0.11. After fine-tuning, NN reconstruction accuracy improved dramatically (Pearson 0.99±0.01; p&lt;0.001). In Fig. 1B–G the NN learned key MAP features (upstroke, triangular descent, terminus) and thus could eliminate ventricular artifact and electrical circuit noise without specific training or manual annotation.

Conclusion
Machine learned autoencoders are a novel and powerful approach to de-noise electrophysiological signals in a dynamic, beat-to-beat fashion. The ability to learn fundamental signal features from models trained in large datasets, and apply them via transfer learning to small datasets in different heart chambers may have wide ranging applications for automated signal annotation, mapping and ablation.

Funding Acknowledgement
Type of funding sources: Public grant(s) – National budget only. Main funding source(s): NIH
Left atrial functions in the early period after cryoballoon ablation for paroxysmal atrial fibrillation
Authors: Soysal A , Gulfidan A , Akman Z , Koroglu A E , Tokdil H , Raimoglu U , Yalman H , Aksu T , Atici A , Golcuk E , Ikitimur B , Yalin K 
Published: October 2022

Abstract

Introduction
In patients with paroxysmal atrial fibrillation (PAF), functional changes are observed in the left atrium (LA) after pulmonary vein isolation (PVI) with catheter ablation. Although previous studies have investigated the altered mechanical functions of LA with radiofrequency (RF) ablation, changes in LA functions in the early period after cryoablation have not been clearly demonstrated.

Methods
Thirty three patients (mean age: 57±11; 54.5% men) with PAF underwent cryoablation procedure with second generation cryoballoon (CB-2). All patients were in sinus rhythm before and after the procedure. LA dimensions, LA strain parameters (LAsr-LAscd-LAsct) and left ventricular diastolic function parameters were evaluated by Doppler echocardiography before and 3 months after the procedure.

Results
Acute procedural success was achieved in all cases. No major complications were occurred. A significant recovery in LA reservoir strain (p=0.009) was observed. No significant change was demonstrated in remaining echocardiographic parameters.

Conclusion
LA reservoir strain is an indicator of left atrial compliance and significant improvement in mechanical functions may occur even in the early period after cryoballoon ablation in patients with PAF in contrast to LA function deterioration observed in RF ablation.

Funding Acknowledgement
Type of funding sources: None.
Zero-fluoro AVNRT ablation
Authors: Soether C M , Boehmer A A , Dobre B C , Kaess B M , Ehrlich J R 
Published: October 2022

Abstract

Background
Atrioventricular-nodal reentry tachycardia (AVNRT) is a common supraventricular tachycardia, particularly in younger patients. First-line therapy in symptomatic patients is radiofrequency catheter ablation (RFCA). Catheter placement and ablation are typically performed by fluoroscopy guidance implying a non-negligible exposure of ionizing radiation for patient and laboratory personnel.

Purpose
We aimed to demonstrate feasibility and safety of AVNRT ablation using 3D-electroanatomic mapping (3D-EAM) as sole and additional means of catheter guidance compared to conventional fluoroscopic positioning. Endpoints were: procedure duration, fluoroscopy duration, radiation dose and occurrence of any complication.

Methods
We retrospectively included consecutive patients (n=68, mean age 55±18 years) who underwent RFCA of AVNRT between 01/2020 and 12/2021 in our hospital. One group was a priori allocated to conventional fluoroscopy mapping (convFluoro, n=30), the other procedures were performed under 3D-EAM using Ensite NavX (NavX). From the latter, slow-pathway RFCA could be performed without any fluoroscopy (zeroFluoro) in 20 patients, in 18 cases additionally fluoroscopy was used due to difficult anatomic conditions (NavX+Fluoro). Success of RFCA was defined as slow-pathway elimination.

Results
There was no significant difference in procedure duration between the convFluoro and overall NavX group (74±24 min vs. 87±29 min, P=NS). However, NavX+Fluoro group (comprising more complicated cases) had longer procedure duration compared to convFluoro group (94±30 min vs. 74±24 min, p&lt;0.05). The use of 3D-EAM significantly reduced fluoroscopy duration comparing convFluoro with NavX+Fluoro (12±9 min vs. 7±6 min, p&lt;0.05) and convFluoro with overall NavX-group (12±9 min vs. 3±5 min, p&lt;0.0001). Likewise, radiation dose was significantly decreased by means of 3D-EAM (NavX: 60±113 cG cm2 vs. convFluoro: 169±166 cG cm2, p&lt;0.01). 3D-EAM guided RFCA was successful in all patients (100%), success rate in convFluoro-group was 87% (P=NS). Minor complications occurred in two cases (7%) in the convFluoro-group and 4 cases (11%) in the NavX-group (P=NS). No severe complication, such as pericardial effusion or permanent AV-block occurred in any group.

Conclusion
Zero-fluoroscopy 3D-EAM-guided RFCA in patients with AVNRT is feasible and safe. Without prolonging procedure duration, 3D-EAM can reduce fluoroscopy duration leading to lower radiation exposure and making electrophysiological study safer for laboratory staff and patients.

Funding Acknowledgement
Type of funding sources: None.
Arrhythmia in pregnant women: what management is better?
Authors: Abdrakhmanov A , Ainabekova B , Nuralinov O , Bakytzhanuly A , Smagulova A 
Published: October 2022

Abstract

Background
Arrhythmias in pregnant women are commonly seen but have not been extensively studied. Drug therapy or catheter ablation during pregnancy may be required in cases of maternal arrhythmias. However, the studies did not examine the outcomes of pregnancy in cases with different management of arrhythmias.

Objective
We aimed to determine if there are any differences in pregnancy outcomes in women with disparate types of arrhythmia treatment.

Methods
We conducted a prospective study of all pregnant patients who were admitted to our hospital with arrhythmias from 2017–2020. For patients with benign arrhythmias drug therapy was not required (n=11; 14.5%, 1st group). Antiarrhythmic treatment was justified in cases with frequent symptoms and haemodynamic instability (n=65; 85.5%). Patients with effective antiarrhythmic therapy were included in 2nd group (n=31; 40.8%). In patients with drug refractory and dangerous rhythm disturbances (n=34; 44.7%, 3d group) were performed zero-fluoroscopy catheter ablation.

Results
A total of 76 pregnant women were admitted with arrhythmias. Mean age was 27.24±5.15 years, mean gestation age 21.27±5.34 weeks. Supraventricular tachycardia was the most common arrhythmias (n=41; 53.9%) This was followed by premature contractions (n=27; 35.6%) and ventricular tachycardia (n=8; 10.5%). There was significant difference in frequency of performed catheter ablation for disparate types of arrhythmia: 70.7% for cases of supraventricular tachycardia, 25% - ventricular tachycardia and 11.1% - premature contractions (p=0.000). Ablations were effective in all cases without adverse outcome. All ablations were performed without fluoroscopy. Vaginal delivery was in the majority in all groups (75.6% vs 62.5% vs 74.1%, p=0.736). Similarly, no differences were noted in obstetric complication (14.6% vs 12.5% vs 18.5%, p=0.656). None of them had fetal mortality.

Conclusions
Some patients with arrhythmias needed catheter ablation during pregnancy. There was no significant difference in type of delivery and neonatal outcomes in women with separate management of arrhythmias.

Funding Acknowledgement
Type of funding sources: None.
Transseptal puncture for left atrial ablation: risk factors for cardiac tamponade and a proposed causative classification system
Authors: Roelas M , Vyas R , Maclean E , Mahtani K , Butcher C , Ahluwalia N , Honarbakhsh S , Finlay M , Chow A , Earley M J , Sporton S , Lambiase P D , Schilling R J , Hunter R J , Segal O R 
Published: October 2022

Abstract

Background
Cardiac tamponade is a high morbidity complication of transseptal puncture (TSP).

Purpose
We examined the associations of TSP-related cardiac tamponade (TRCT) for all patients undergoing left atrial ablation at our centre from 2016–2020.

Methods
Patient and procedural variables were extracted retrospectively. Cases of cardiac tamponade were scrutinised to adjudicate TSP culpability. Adjusted multivariate analysis examined predictors of TRCT.

Results
3,239 consecutive TSPs were performed; cardiac tamponade occurred in 51 patients (incidence: 1.6%) and was adjudicated as TSP-related in 35 (incidence: 1.1%; 68.6% of all tamponades). Patients of above-median age (OR 2.4 (1.19–4.2), p=0.006) and those undergoing re-do procedures (OR 1.95 (1.29–3.43, p=0.042) were at higher risk of TRCT. Of the operator-dependent variables, choice of transseptal needle (Endrys vs Brockenbrough, p&gt;0.1) or puncture sheath (Swartz vs Mullins vs Agilis vs Vizigo vs Cryosheath, all p&gt;0.1) did not predict TRCT. Adjusting for operator, equipment and demographics, failure to cross the septum first pass increased TRCT risk (OR 4.42 (2.45–8.2), p=0.001), whilst top quartile operator experience (OR 0.4 (0.17–0.85, p=0.002), transoesophageal echocardiogram (TOE prevalence: 26%, OR 0.51 (0.11–0.94), p=0.023), and use of the SafeSept guidewire (OR 0.22 (0.08–0.62), p=0.001) reduced TRCT risk. An increase in SafeSept wire use over time (2016: 15.6%, 2020: 60.2%) correlated with an annual reduction in TRCT (R2=0.72, p&lt;0.001) and was associated with a relative risk reduction of 70%.

Conclusions
During left atrial ablation, the independent predictors of TRCT were patient age, re-do procedure, operator experience, unsuccessful first pass, TOE-guidance, and use of the SafeSept wire. A novel classification system for the causes of cardiac tamponade is proposed (table 1); this may be of interest to clinical trialists or auditors evaluating patient safety.

Funding Acknowledgement
Type of funding sources: None.
Cryoballoon ablation of left atrial roof with a novel cryoballoon system
Authors: Shigeta T , Yamauchi Y , Oda A , Sudo K , Arai H , Sagawa Y , Okishige K , Goya M , Sasano T 
Published: October 2022

Abstract

Introduction
A novel cryoballoon system (POLARx) has emerged and its efficacy regarding pulmonary vein isolation (PVI) has been already investigated. On the other hand, cryoballoon ablation of left atrial (LA) roof has been performed using a conventional cryoballoon system (Arctic Front Advance Pro [AFA-Pro]) in addition to PVI. However, cryoballoon ablation of LA roof with POLARx has not been investigated yet.

Methods
We performed cryoballoon ablation of LA roof with POLARx in 22 patients after we achieved PVI. After the cryoballoon ablation, complete conduction block at LA roof and isolation of all PVs were confirmed by creating an activation map during high right atrium pacing. If they could not be obtained with solely a cryoballoon, touch up ablation with radiofrequency ablation was permitted. The procedural data during ablation with POLARx was compared with those during ablation with AFA-Pro we had performed in a historical cohort of patients (n=46).

Results
Complete conduction block at LA roof without touch up ablation could be obtained in all the patients in POLARx group and 44 (95.7%) patients in AFA-Pro group. Total procedure time was almost similar in both groups (164.2±35.4 min for POLARx vs 180.3±35.4 min for AFA-Pro, p=0.10). During LA roof line ablation, nadir balloon temperature was significantly lower in POLARx group (right side: −53.6±4.4°C for POLARx vs −45.6±4.6°C for AFA-Pro, p&lt;0.01, central part: −56.4±4.3°C for POLARx vs −46.0±3.7°C for AFA-Pro, p&lt;0.01, left side: −55.1±3.5°C for POLARx vs −45.7±5.3°C for AFA-Pro, p&lt;0.01), and balloon temperature reached −40°C earlier in POLARx (right side: 30.7±8.9 sec for POLARx vs 78.0±39.8 sec for AFA-Pro, p&lt;0.01, central part: 30.6±9.3 sec for POLARx vs 65.9±33.3 sec for AFA-Pro, p&lt;0.01, left side: 30.4±4.2 sec for POLARx vs 78.8±49.6 sec for AFA-Pro, p&lt;0.01). Total freezing time required for LA roof line ablation was significantly shorter in POLARx group (589.3±163.6 sec for POLARx vs 877.5±191.7 sec for AFA-Pro, p&lt;0.01).The scar area created after LA roof line ablation was similar in both groups (9.3±4.1 cm2 for POLARx vs 11.0±4.8 cm2 for AFA-Pro, p=0.23).

Conclusion
Complete conduction block at LA roof could be obtained after cryoballoon ablation with POLARx, in the same way as AFA-Pro. Lower nadir balloon temperature could be expected in shorter freezing time during LA roof line ablation in using POLARx compared with AFA-Pro.

Funding Acknowledgement
Type of funding sources: None.
How to perform effective cryoballooon ablation of left atrial roof: considerations after experiences of more than 1000 cases
Authors: Shigeta T , Yamauchi Y , Oda A , Sudo K , Arai H , Sagawa Y , Okishige K , Goya M , Sasano T 
Published: October 2022

Abstract

Introduction
Although pulmonary vein isolation is the cornerstone of atrial fibrillation (AF) ablation, concomitant cryoballoon ablation of left atrial (LA) roof has been expected to improve clinical outcomes after ablation. We demonstrate characteristics and efficacy of cryoballoon ablation of LA roof through our experiences from a large volume of procedures.

Methods
We had performed cryoballoon ablation of LA roof in 1036 procedures including 202 redo procedures in AF patients since June 2016. Among these procedures, we analyzed 834 patients (309 paroxysmal AF) who had undergone de novo ablation for AF. We confirmed whether the complete conduction block of LA roof line was obtained after the ablation.

Results
LA roof line block was obtained in 767 patients (92.0%) without touch up ablation with a radiofrequency catheter (Group A). LA diameter (LAD) was significantly smaller (43.6±6.6mm vs 47.4±7.5mm, p&lt;0.01) and body mass index (BMI) was significantly lower (24.9±4.0kg/m2 vs 26.3±4.6kg/m2, p=0.01) in those in Group A compared with those without LA roof line block after cryoballoon ablation (Group B). Compared with those in Group B, cryoballoon application number of LA roof (4.1±1.2 vs 4.5±1.6, p&lt;0.01) and mean nadir of cryoballoon temperature during cryoballoon ablation of LA roof (−44.5±5.6°C vs −40.5±7.5°C, p&lt;0.01) were significantly lower in those in Group A. Regarding cryoballoon application number, the number of the cryoballoon application in which a cryoballoon was applied to LA roof with the guiding catheter located in a left superior pulmonary vein (LSPV) was significantly lower in patients in Group A (1.3±0.8 vs 1.6±1.0, p=0.02), and when the number was less than 2, mean nadir of cryoballoon temperature was significantly lower compared with when it was 2 or more than 2 (−44.8±5.8°C vs −42.8±5.6°C, p&lt;0.01). Among those refer to first ablation procedures, one-year Kaplan-Meier atrial arrhythmias free rate estimates, 80.6% for those in Group A and 59.0% for those in Group B (p&lt;0.01). Multivariate analysis identified LA roof line block without touch up ablation as one of the predictors of atrial arrhythmias recurrences. Atrial tachycardia depending on LA roof occurred after cryoballoon ablation of LA roof in 8 patients, although LA roof line block without touch up ablation could be obtained in the index ablation procedure in 6 patients among them.

Conclusion
LA roof line block could be obtained by solely cryoballoon with a reasonable success rate, especially in those with smaller LAD and lower BMI. To obtaine LA roof line block, cryoballoon ablation with the guiding catheter located in LSPV is preferable. LA roof line block without touch up ablation brings better clinical outcomes in those who underwent cryoballoon ablation of LA roof.

Funding Acknowledgement
Type of funding sources: None.