bluuebunny/crossref_metadata_2025_split huggingface dataset:
Technical characterization of the single-lead electrocardiogram signal from four different smartwatches and its clinical implications
Authors: Knecht S , Waldmann F , Kuhn R , Mannhart D , Kuhne M , Sticherling C , Badertscher P , Wildhaber R 
Published: May 2023

Abstract

Funding Acknowledgements
Type of funding sources: Public Institution(s). Main funding source(s): Department of Cardiology, University Hospital Basel, University of Basel, Switzerland
Institute for Medical Engineering and Medical Informatics, School of Life Sciences, University of Applied Sciences and Arts Northwestern Switzerland, Muttenz, Switzerland

Background
Smartwatches with the capability of single-lead electrocardiograms (ECGs) acquisition have been established as valuable tool for the detection of atrial fibrillation (AF). For the currently available smartwatches, however, the technical specification of the acquired ECG signal is unclear.

Purpose
The aim of the current study was to characterize quantitatively the raw signal of the single-lead ECG of four currently available smartwatches (Apple watch series 6, Withings ScanWatch, Samsung Galaxy Watch 4, Fitbit Charge 5) and assess their clinical applicability based on their technical features.

Method
A bench test was performed applying a synthetic, well-characterized signal to the electrodes of the watches (Figure: (A) Apple watch series 6, (B) Withings ScanWatch, (C) Samsung Galaxy Watch 4, (D) Fitbit Charge 5). The frequency response to this input signal was acquired and Bode plots were calculated (Figure, second column: Bode diagrams show the frequency response (upper) and the phase angles (lower)). To compare the ECG characteristics of the four watches, the synthetical response to a pre-recorded surface ECG dataset was calculated based on the frequency characteristics determined above (Figure, third column: The synthetical raw signal is shown in grey, the response of the watch in blue).

Results
The frequency responses of all four watches shows a bandpass filter, with an additional 50/60 Hz narrow-band filter (Figure). While the recommended high-pass cut-off at 0.5 Hz was fulfilled by all devices (1), a low-pass cut-off was observed for all devices below 70Hz (instead of 150Hz) resulting in a significantly damped signal. In detail, a damping of -6dB, corresponding to a signal amplitude reduction of 50%, was observed above 70 Hz and below 0.4 Hz for all watches.
A QRS complex amplitude reduction was observed for the Apple, Withings and Samsung watch. A pronounced noise filtering is visible for the Samsung and Fitbit Smartwatch. A difference for the clinically relevant characteristic fiducial points, such as the onset of the P-wave or QRS complex, cannot be observed in these examples. However, when using the tangent method to detect the end of the T-wave to calculate the QTc value, a difference between the measures can be observed for the Withings Watch.

Conclusion
The technical characteristics in terms of filtering characteristics of the single-lead ECG from four commercially available smartwatches differ and must be taken into consideration when attempting to use smartwatches beyond the detection of AF.
In silico biatrial fibrosis ablation improves atrial fibrillation outcome
Authors: Roney C , Alonso J S L , Sim I , Ulgen O , Rodero C , Strocchi M , Kotadia I , Honarbakhsh S , Narayan S , Plank G , Vigmond E , Williams S E , Niederer S 
Published: May 2023

Abstract

Funding Acknowledgements
Type of funding sources: Public grant(s) – National budget only. Main funding source(s): Medical Research Council Fellowship

Background
In DECAAF II, left atrial (LA) fibrosis ablation plus PVI did not improve AF outcome compared to PVI alone across the study cohort. We hypothesize that biatrial fibrosis ablation could improve AF ablation therapy outcome in a subset of patients with properties identified through a large virtual in silico trial.

Purpose
To investigate the effects of anatomy, fibrosis distribution, and LGE-MRI threshold on ablation outcome using a virtual cohort of 4000 patients.

Methods
We constructed 1000 biatrial models from a statistical shape model and we mapped pectinate muscles, Bachmann’s bundle and fibers from an atlas. For each of the 1000 anatomies we applied a randomly selected fibrosis map from a library of 100 clinical maps. We then created four versions of each case by assigning one of four randomly selected right atrial (RA) fibrosis distributions with Utah grades 1-4 (Fig 1A), giving 4000 virtual patients. Four ablation approaches were applied to each patient model after 5 seconds of AF: PVI, PVI & LA fibrosis, PVI & RA fibrosis, PVI & biatrial fibrosis. LGE-MRI was thresholded for fibrosis ablation at either 1.2 or 1.32 image intensity ratio (IIR). The outcome was classified 5 seconds post ablation.

Results
Biatrial fibrosis ablation is more effective than LA ablation. For patients with high (Utah 4) RA fibrosis, biatrial fibrosis ablation increases AF termination compared to LA fibrosis ablation (Figs 1B & 2A: 62% vs 14%), this compares to cases with low (Utah 1) RA fibrosis (21% vs 14%). For patients with high LA (Utah 4) fibrosis, biatrial ablation is more effective than LA ablation (Fig 2B: 52% vs 19%), this compares to patients with low (Utah 1) LA fibrosis (17% vs 7%). Increasing IIR threshold for ablation decreases termination (LA fibrosis ablation: 15.8% termination at IIR 1.2, 11.0% at IIR 1.32; biatrial: 41.5% at IIR1.2; 20.3% at IIR1.32). Anatomy has a larger effect on biatrial ablation outcome (31.2% of outcomes change between anatomies) than on PVI only ablation outcome (20.0% change).

Conclusion
Biatrial fibrosis ablation is superior to LA fibrosis ablation for cases with high RA fibrosis. Biatrial fibrosis distribution should be considered when targeting AF ablation therapy.
The Omnipolar Mapping Technology - a new mapping tool to overcome bipolar blindness resulting in true high-density maps
Authors: Dittrich S , Scheurlen C , Van Den Bruck J H , Filipovic K , Woermann J , Erlhoefer S , Schipper J H , Lueker J , Steven D , Sultan A 
Published: May 2023

Abstract

Funding Acknowledgements
Type of funding sources: None.

Background
Mapping, using the novel omnipolar technology (OT) obtains omnipolar signals displaying true voltage, real-time wavefront direction and speed, independent of catheter orientation and external reference. Employment of OT potentially overcomes so called "bipolar blindness" (conventional bipolar electroanatomic mapping). Hence, OT potentially improves substrate assessment, comprehension of tachycardia mechanisms and gap detection after previous catheter ablation (CA).

Purpose
Purposes of our study was to analyze previously performed left atrial (LA) and left ventricular (LV) maps for differences using automated OT vs. SD vs. the previously published HD Wave (HDW) algorithm.

Methods
Maps of patients undergoing CA for atrial or ventricular arrhythmia were initially acquired using HDW settings in conjunction with the Advisor HD Grid mapping catheter. These maps were then analyzed retrospectively applying the automated OT algorithm vs. SD vs. HDW. to reveal differences in voltage and point density. Additionally, detection of pulmonary vein (PV) gaps and LV scar area was evaluated.

Results
In 45 consecutive patients 135 maps were analyzed. The study population undergoing CA consisted of: 30 (22.2%) patients undergoing repeated CA for recurrence of persistent atrial fibrillation (persAF)/left atrial tachycardia (AT) and 15 (11.1%) patients with ventricular tachycardia (VT) or premature ventricular contractions (PVC). Atrial maps revealed a significantly higher point density using OT (21471) vs. SD (6682) or HDW (12189, p&lt;0.001). Mean voltage was significantly higher using OT (0.75mV) vs. SD (0.61mV) or HDW (0.64mV, p&lt;0.001). OT maps detected significantly more PV gaps vs. SD (4 vs. 2, p=0.001). In LV maps, OT revealed a significantly higher point density (25951) vs. SD (8582) and HDW (17071), p&lt;0.001. Mean voltage was significantly higher for OT (1.49mV) vs. SD (1.19mV) and HDW (1.2mV), p&lt;0.001. Detected scar area was significantly smaller using OT (25.3%) vs. SD (33.9%, p&lt;0.001).

Conclusion
Using OT results in a higher voltage and point density compared to SD and HDW. Therefore displayed scar extend is significantly smaller in atrial and ventricular maps. Also, more PV gaps were detected using OT. The OT algorithm potentially improves scar delineation, facilitates substrate characterization, and may improve procedural outcome.
Impact of increased physical activity in patients after pulmonary vein isolation - BE-ACTION trial
Authors: Seifert M S , Meretz D , Haase-Fielitz A , Georgi C , Bannehr M , Moeller V , Janssen G , Minden H H , Grosse-Meininghaus D , Butter C 
Published: May 2023

Abstract

Funding Acknowledgements
Type of funding sources: Public grant(s) – National budget only. Main funding source(s): Medical School Brandenburg and Local Government Concil Brandenburg

Background
Pulmonary vein isolation (PVI) is one of the key therapies for patients with atrial fibrillation (AF), however, there are numerous recurrences after ablation. Improving cardiorespiratory fitness (CF) may result in fewer recurrences of AF. The aim of the present study (Brandenburg Enhance ACTIvity ONset after pulmonary vein isolation - BE-ACTION) was to evaluate the impact of increased physical activity in patients after PVI on the recurrence of AF.

Methods
From January 2018 to April 2021, 200 patients with scheduled PVI were randomized at 4 different centres and fitted with an activity tracker for 24-hour activity monitoring via mobile phone. Patients aged between 50 and 77 years with a BMI between 23 and 35 kg/m2 were included. Patients with orthopaedic limitations were excluded. Patients in the ACTION group (n=99) were contacted regularly by telephone by a physical therapist and intensively motivated if the steps fell below 6,000 steps per day. Patients in the No-ACTION group (n=101) received standard of care. A loop recorder was implanted in 74 patients; those who refused loop recorder implantation underwent 7-day Holter monitoring at 6 and 12 months after PVI. Recurrence was defined as any atrial arrhythmia &gt;30 sec, cardioversion or need of redo ablation after blanking period (3 month) up to 12 month.

Results
The number of steps per day increased in all pts from 7,918 (5,725-10,989) at week 2 after PVI to 9,511 (7,230-12,800) at 6 months and to 9,788 (6,962-12,152) at 12 months (p&lt;0.001; Friedman), figure 1. In the ACTION group, the number of steps per day continued to increase between 6 and 12 months, whereas it decreased in the No-ACTION group. In total, recurrence of arrhythmia was found in 58 patients (29.9%: 31 patients with loop recorder, 14 with Holter monitoring and 13 with ECG). Recurrence occurred in 24 patients (25%) in the ACTION group and 34 patients (35%) in the No-ACTION group (p=0.140), table 1.

Conclusion
The level of daily physical activity was unexpectedly high in this study. The use of an activity tracker led to an increased daily physical activity in patients with AF after PVI. A further increase of activity did not reduce the recurrence of atrial arrhythmia in the ACTION group.
A novel saline-based occlusion tool allows for dye-less cryoballoon-based pulmonary vein isolation and fluoroscopy reduction
Authors: Rottner L , Obergassel J , Borof K , My I , Moser F , Lemoine M , Wenzel J P , Kirchhof P , Ouyang F , Reissmann B , Metzner A , Rillig A 
Published: May 2023

Abstract

Funding Acknowledgements
Type of funding sources: None.

Background
Cryoballoon (CB)- based pulmonary vein isolation (PVI) remains guided by fluoroscopy and dye. The novel saline injection-based occlusion tool allows for pulmonary vein (PV)-occlusion assessment without the need for dye injection.

Aim
To compare KODEX-EPD guided CB-PVI using the novel saline injection-based workflow with conventional cryoablation for acute efficacy, fluoroscopy exposure and dye volume.

Methods
Consecutive atrial fibrillation (AF)- patients undergoing CB-PVI in conjunction with KODEX-EPD (CryoEPD group) were analyzed. A left atrial image was created to visualize pulmonary vein (PV) anatomy prior to ablation. PV-occlusion was assessed with the KODEX-EPD occlusion tool along with saline injection. Patients undergoing conventional CB-PVI (CryoCONV group) in the same time period acted as controls.

Results
One hundred forty patients (91/140 (65%) persistent AF) were studied. Seventy patients underwent CryoEPD procedures (64 ± 13 years, 21 (30%) female) and seventy patients underwent CryoCONV procedures (68 ± 10 years, 27 (39%) female).
A total of 560 PVs were identified and successfully isolated. Mean procedure time was 66 ± 15 minutes for the CryoEPD group, and 65 ± 19 minutes for the CryoCONV group (p=0.3). Fluoroscopy time (CryoEPD 6 ± 4 minutes; CryoCONV 13 ± 6 minutes, p&lt;0.001) and dose area product (CryoEPD 193 [111; 297] cGycm2; CryoCONV 381 [268; 614] cGycm2, p&lt;0.001) were lower in patients undergoing CryoEPD compared with CryoCONV procedures. No dye was needed in the CryoEPD group while 53 ± 18 ml dye per patient were administered for the CryoCONV group (p&lt;0.001). The overall complication rate was comparable between both groups (p=0.5).

Conclusion
KODEX-EPD guided AF-ablation enables dye-free CB-based PVI with reduced fluoroscopy exposure when compared to conventional CB-ablation, without differences in acute procedural outcomes or procedure duration.
Local impedance drop guided versus lesion size index guided pulmonary vein isolation: acute success and reconnections
Authors: Lyan E , Pantlik R , Maslova V , Frank D , Demming T 
Published: May 2023

Abstract

Funding Acknowledgements
Type of funding sources: None.

Introduction
Insufficient lesion depth and discontinuity of lesion lines are reasons for reconnections after point-by-point radiofrequency pulmonary vein isolation (PVI). Different technologies have shown to be useful for prediction of effective lesions. Measurement of the magnitude of local tissue impedance drop (LID) and calculation of lesion size index (LSI) based on monitoring of contact force are examples for corresponding technologies.

Purpose
To compare the acute efficacy of LID guided with LSI guided PVI.

Methods
In this retrospective study we compared two groups of patients who underwent point-by-point radiofrequency PVI for treatment of atrial fibrillation. In the LID-guided group (n=35) energy was delivered using IntellaNav MiFi (Boston Scientific, MA, USA) ablation catheter. Ablation was terminated when LID reached a plateau (Figure A). In the LSI-guided group (n=31) lesions were created using Tacticath (Abbott, MA, USA) ablation catheter until the target LSI was reached in each point (LSI=5 for anterior and LSI=4 for posterior segments respectively, Figure B). The inter-lesion distance of &lt;6 mm with power of 40 W for anterior and 30W for posterior segments was used in both groups. A gap-map and touch-up ablation was performed along the index ablation line if the first pass PVI did not occur, or in the case of an acute reconnection after 20 min of waiting time. In the post hoc analysis initial levels and drop of local and system impedance, average contact force and LSI were included in models predicting PV gaps.

Results
All PVs were successfully isolated by encirclement of ipsilateral veins with significantly longer median ablation time 30(IQR:27-35) min in LID-guided group as compared to LSI-guided group:25 (IQR:21-31) min (p=0.035). First-pass PVI was achieved in 97 out of 132(73%) circles (LID-guided:43 out of 70 [61%] circles vs LSI-guided:54 out of 62 [87%] circles, p=0.002). Acute reconnections occurred in 14 out of 132 (11%) circles (LID-guided:9 out of 70 [13%] circles vs LSI-guided: 5 out of 62 [8%] circles, p=0.54, Figure C). Overall, significantly more patients had PV gaps when LID-guided ablation was used as compared to LSI-guided (26 out of 35[74%] vs 13 out of 31[42%] respectively, p=0.016). In the post hoc analysis a LID&lt;9.7Ω was the only predictive parameter for PV gap (sensitivity=96.4%, specificity=67%).

Conclusions
LSI-guided ablation resulted in successful PVI with significantly shorter ablation time and fewer PV gaps as compared to LID-guided. This reflects the nature of contact force guided ablation anticipating the quality of catheter-tissue interface before each application, which is not possible with an impedance-only guided approach.
Peri-procedural anesthesia and patient pain experience in pulmonary vein isolation by means of very high power short duration radiofrequency ablation
Authors: Poggi S , Strisciuglio T , Iuliano A , Spiniello G , Schillaci V , De Simone A , Stabile G , Solimene F 
Published: May 2023

Abstract

Funding Acknowledgements
Type of funding sources: None.

Background
Very high-power short-duration (vHPSD) temperature-controlled radiofrequency ablation (vHPSD) may reduce ablation times and improve patient tolerability, permitting pulmonary vein (PV) isolation under mild conscious sedation.

Purpose
Evaluate the anesthetic drugs use and patients ‘pain experience during vHPSD PV isolation.

Methods
Thirty-three consecutive patients, with paroxysmal atrial fibrillation (AF), treated with QDot Micro catheter and vHPSD (90 w for 4 s) (vHPSD Group), were compared with the last 33 consecutive patients, with paroxysmal AF, treated with a surround flow contact force-sensing catheter guided by the ablation index (450 at anterior and superior sites at 50 W, 330 at posterior and inferior sites at 40 W) (AI Group). Anesthetic drugs (midazolam and fentanyl) use were compared as well as pain experience, measured using a 0-10 scale.

Results
All PVs were isolated. PV isolation ablation time in the vHPSD Group (5.9±1.4 min) was shorter than in the AI Group (25±11 min, p&lt;0.001). Pain experience was significantly lower in vHPSD group (4.5±2 vs 6.6±1.8, p&lt; 0.001). No patients required general anesthesia; fentanyl use was required in 4 vHPSD Group patients vs 25 AI Group patients (p&lt;0.001). A lower dose of midazolam was required in vHPSD Group (2.3±1.2 mg vs 3.6±1.7 mg, p &lt; 0.001).

Conclusions
vHPSD radiofrequency ablation for PVI can be performed under conscious sedation using only benzodiazepine in most of patients without compromising patient pain experience.
Migraine care practices in primary care: results from a national US survey
Authors: Callen Elisabeth , Clay Tarin , Alai Jillian , Crawford Paul , Visconti Adam , Nederveld Andrea , Cruz Inez , Perez Bailey , Roper Karen L , Oser Tamara K , Saint Laurent May-Lorie , Jabbarpour Yalda 
Published: May 2023

Abstract

Background
Primary care clinicians play a critical role in diagnosis and treatment of migraine, yet barriers exist. This national survey assessed barriers to diagnosis and treatment of migraine, preferred approaches to receiving migraine education, and familiarity with recent therapeutic innovations.

Methods
The survey was created by the American Academy of Family Physicians (AAFP) and Eli Lilly and Company and distributed to a national sample through the AAFP National Research Network and affiliated PBRNs from mid-April through the end of May 2021. Initial analyses were descriptive statistics, ANOVAs, and Chi-Square tests. Individual and multivariate models were completed for: adult patients seen in a week; respondent years since residency; and adult patients with migraine seen in a week.

Results
Respondents who saw fewer patients were more likely to indicate unclear patient histories were a barrier to diagnosing. Respondents who saw more patients with migraine were more likely to indicate the priority of other comorbidities and insufficient time were barriers to diagnosing. Respondents who had been out of residency longer were more likely to change a treatment plan due to attack impact, quality of life, and medication cost. Respondents who had been out of residency shorter were more likely to prefer to learn from migraine/headache research scientists and use paper headache diaries.

Conclusions
Results demonstrate differences in familiarity with migraine diagnosis and treatment options based on patients seen and years since residency. To maximise appropriate diagnosis within primary care, targeted efforts to increase familiarity and decrease barriers to migraine care should be implemented.
Fast and provable tensor robust principal component analysis via scaled gradient descent
Authors: Dong Harry , Tong Tian , Ma Cong , Chi Yuejie 
Published: May 2023

Abstract
An increasing number of data science and machine learning problems rely on computation with tensors, which better capture the multi-way relationships and interactions of data than matrices. When tapping into this critical advantage, a key challenge is to develop computationally efficient and provably correct algorithms for extracting useful information from tensor data that are simultaneously robust to corruptions and ill-conditioning. This paper tackles tensor robust principal component analysis (RPCA), which aims to recover a low-rank tensor from its observations contaminated by sparse corruptions, under the Tucker decomposition. To minimize the computation and memory footprints, we propose to directly recover the low-dimensional tensor factors—starting from a tailored spectral initialization—via scaled gradient descent (ScaledGD), coupled with an iteration-varying thresholding operation to adaptively remove the impact of corruptions. Theoretically, we establish that the proposed algorithm converges linearly to the true low-rank tensor at a constant rate that is independent with its condition number, as long as the level of corruptions is not too large. Empirically, we demonstrate that the proposed algorithm achieves better and more scalable performance than state-of-the-art tensor RPCA algorithms through synthetic experiments and real-world applications.
SARS-CoV-2 Infection and Response to COVID-19 Vaccination in Patients With Primary Immunodeficiencies
Authors: Paris Robert 
Published: May 2023

Abstract
Primary immunodeficiencies (PIDs) are heterogeneous, rare disorders that increase susceptibility to infection and/or immune dysregulation. Individuals with certain PIDs are at high risk of severe or fatal outcomes from SARS-CoV-2 infections (the causative agent of COVID-19), either due to the underlying PID and/or due to the presence of comorbidities such as severe lung and liver disease. Vaccination remains the primary strategy to protect individuals with PID from COVID-19. However, populations with PID exhibit variable vaccine seroresponse rates, antibody titers, and neutralization activity depending on the type of PID and/or COVID-19 vaccine, and consequently, are at an elevated risk of severe disease. In this article, we review the COVID-19 burden in patients with PIDs and focus in-depth on findings from patients with predominantly antibody deficiencies or combined immunodeficiencies. We conclude by providing COVID-19 vaccination recommendations for this population.
Government Choices of Debt Instruments
Authors: Mosley Layna , Rosendorff B Peter 
Published: May 2023

Abstract
Governments borrow from a range of creditors—commercial banks, sovereign bondholders, official bilateral creditors, and multilateral financial institutions. Sovereigns’ creditor portfolios vary significantly across space and time. While creditor portfolios partly reflect supply-side considerations (macroeconomic profiles and associated default risk), they also reflect governments’ preferences over fiscal transparency. Governments that prefer to disclose less information about economic outcomes will choose borrowing instruments that are less public, such as private loans from banks (versus bondholders) and official sector borrowing from bilateral (versus multilateral) creditors. Empirical analyses of government debt composition across developing nations confirm these predictions. We also find support for our claims at the subnational level, using data from Mexican municipalities. We treat various types of credit (bilateral lending, multilateral finance, and sovereign bonds) as related, rather than distinct.