bluuebunny/crossref_metadata_2025_split huggingface dataset:
Clinical validation of automated QTc measurements from single lead ECG using a novel smartwatch
Authors: Mannhart D , Hennings EH , Lischer ML , Vernier CV , Du Fay De Lavallaz JDF , Knecht SK , Schaer BS , Osswald SO , Kuehne MK , Sticherling CS , Badertscher PB 
Published: May 2022

Abstract

Funding Acknowledgements
Type of funding sources: None.

Introduction
A possible side-effect of various medical drugs is prolongation of the electric repolarization of the heart, measured as the corrected QT-interval (QTc). Patients treated with these drugs should be monitored frequently via an ECG to screen for early changes indicating possible life-threating arrythmias. Especially during the Covid-19 pandemic, remote patient monitoring gained importance. The Withings Scanwatch offers automated analysis of the QTc remotely, thereby obviating the need for in-person visits. We aimed to compare automated QTc-measurements using a single lead ECG (SL-ECG) of a novel smartwatch (Withings Scanwatch, SW-ECG) with manual-measured QTc from a nearly simultaneously recorded standard 12-lead ECG.

Methods
We enrolled consecutive patients referred to a tertiary hospital for cardiac workup in a prospective, observational study. To obtain a SW-ECG, patients were instructed to keep their index finger on the stainless steel ring on the top case of the smartwatch continuously for 30 seconds The QT-interval was manually interpreted by two blinded, independent cardiologists through the tangent-method, using lead II or V5/V6. Bazett’s formula was used to calculate QTc.

Results
We prospectively enrolled 317 patients (48% female, mean age 63.3 ± 17.2 years). The smartwatch was able to automatically measure QTc-intervals in 177 patients (56%). The diagnostic accuracy of SW-ECG for detection of a QTc-interval ≥ 460ms as quantified by the area under the curve (AUC) was 0.91 (95%CI 86.4-95.9). The Bland-Altman analysis resulted in a bias of 6.6ms (95% limit of agreement (LoA) –58.6ms to 71.9ms) comparing automated QTc measurements via SW-ECG with manual QTc-measurement via 12-lead ECG (Figure 1). In 12 patients (6.9%) the difference between the two measurements was greater than the LoA. Premature ventricular complexes, noise or differences in heart rate were responsible in 8.3%, 83.0% and 8.3%, respectively, for observed outliers.

Conclusion
In this clinical validation of a direct-to-consumer smartwatch we found fair to good agreement between automated-SW-ECG QTc-measurements and manual 12-lead-QTc measurements. The SW-ECG, however, was only able to automatically calculate QTc-intervals in one half of all assessed patients. Our work shows, that the automated algorithm of the SW-ECG needs to be improved to be useful in a clinical setting.
Clinical validation of a novel smartwatch for automated detection of atrial fibrillation
Authors: Badertscher P , Lischer M , Mannhart D , Knecht S , Isenegger C , Du Fay De Lavallaz J , Spiess F , Schaer B , Osswald S , Kuehne M , Sticherling C 
Published: May 2022

Abstract

Funding Acknowledgements
Type of funding sources: None.

Introduction
The Withings Scanwatch is a novel smartwatch able to record an intelligent (i)ECG with automated detection of AF. While the iECG function from three major manufacturers have been extensively investigated, there is a paucity of data regarding the performance of the iECG function of the Withings Scanwatch.

Methods
We performed a prospective, observational study enrolling consecutive patients presenting to a cardiology service at a tertiary referral center. The aim was to assess the diagnostic performance of the iECG function of the Withings Scanwatch to detect AF compared to a simultaneously acquired cardiologist-interpreted 12-lead ECG. All iECG rhythm strips and 12-lead ECGs were anonymized and distributed to two blinded cardiologists who independently interpreted each tracing and assigned a diagnosis of sinus rhythm, AF or unclassified.

Results
iECGs and 12-lead ECGs were simultaneously recorded in 319 patients (67 yo (IQR 54-76), 48% female, Figure 1). Using the automated algorithm, rhythm was deemed inconclusive in 44 patients (14%). Overall, AF was present in 34 patients (11%). Among the tracings where the algorithm provided a diagnosis, it correctly identified AF with 76% (95%CI 55-91%) sensitivity, 99% (95%CI 97-100%) specificity, and a Kappa (K) coefficient of 0.72 when compared with cardiologist-interpreted 12-lead ECGs. Among patients in sinus rhythm, 3 were labeled AF (false-positive). From the 44 unclassified recordings, blinded cardiologists were able to correctly diagnose AF with 100% (95%CI 59-100%) sensitivity, 93% (95%CI 77-99%) specificity, and a K coefficient of 0.49. A total of 13 iECG recordings (4.1%) were determined to be noninterpretable by the cardiologists. Of the remaining 306 patients with simultaneous recordings, cardiologist interpretation of the iECG tracings demonstrated 97% (95%CI 84-100%) sensitivity, 99% (95%CI 96-100%) specificity and a K coefficient of 0.75.

Conclusion
Automatic rhythm classification was inferior to manual interpretation of iECGs. We found a lower sensitivity for the detection of AF using the Withings iECG function compared to data published on other devices. Cardiologist-iECG interpretation, however, was highly reliable with a diagnostic accuracy of 98% (95%CI 96-100%). Clinical interpretation of iECG readings by a cardiologist is therefore strongly encouraged
A webbased intervention for patients with an implantable cardioverter defibrillator, a qualitative study of nurses experiences
Authors: Helmark C , Egholm CL , Rottmann N , Skovbakke SJ , Johansen JB , Nielsen JC , Larroude CE , Riahi S , Brandt CJ , Pedersen SS 
Published: May 2022

Abstract

Funding Acknowledgements
Type of funding sources: None.

Background
Implantable cardioverter defibrillator (ICD) therapy is the gold standard for prevention of sudden cardiac death. Patients generally adapt well to living with an ICD, but 20% have difficulties adjusting, with increased risk of anxiety and depression and decreased quality of life. New web-based interventions engaging patients with an ICD might be efficient, but there is sparse knowledge on experiences with web-based care from the perspective of cardiac nurses.

Purpose
The aim of the study was to explore cardiac nurses’ experiences with a web-based intervention designed to empower patients with an ICD.

Methods
We conducted a qualitative study based on semi-structured interviews. The informants (n=9) were experienced cardiac nurses across 5 Danish university hospitals. They were delivering a comprehensive web-based intervention for patients with an ICD, including patient education, chats, monitoring of anxiety and depression and a patient forum. The intervention was tested in a randomized controlled trial. The interviews were transcribed verbatim, coded and analyzed using qualitative content analysis with NVivo software.

Results
We identified an overall theme: "Between traditional nursing and modern eHealth". The theme emerged from six categories, each covering three or four subcategories (Figure 1). The categories were: (1) comprehensive intervention, (2) patient-related differences in engagement, (3) following the protocol is a balancing act, (4) online communication challenges patient contact, (5) professional collaboration varies, and (6) an intervention with potential. Cardiac nurses were in general positive towards the concept of this web-based intervention and believe it holds a large potential. On the other hand, they were challenged by not establishing a personal relation and by losing face-to-face contact with patients, which they found valuable for getting a feeling for patients’ wellbeing and potential mental health issues. Ensuring face-to-face contact by either starting the intervention with a personal contact or including the possibility of video contacts might enhance the value of web-based interventions from the perspective of cardiac nurses. The nurses found the intervention especially suitable for patients who had suffered a cardiac arrest.

Conclusion
Specific training in eHealth communication is necessary as web-based care entails a shift in nursing role and a new format of communication for cardiac nurses. Future evaluations of web-based cardiac rehabilitation interventions in clinical practice are needed to assess the potential impact in "real-life" cardiac care.
Remote device monitoring shows long-term survival benefit in a propensity matched study of ICD patients
Authors: Kolk MZH , Tjong FVY , Knops RE 
Published: May 2022

Abstract

Funding Acknowledgements
Type of funding sources: None.

Background
Remote monitoring (RM) for implantable cardioverter defibrillators (ICDs) enables early detection of clinical events and reduces inappropriate shocks. However, although RM has been associated with improved clinical outcomes at short to medium-term follow-up, data on long-term survival benefit of RM is currently lacking.

Purpose
To investigate long-term survival of patients using RM and compare this to a propensity score matched non-RM group.

Methods
This is a retrospective, observational single-center analysis of patients ≥18 years old implanted with an ICD (single- and dual chamber, biventricular or subcutaneous ICDs) between 1995 and 2021. Data was extracted from the electronic health records. Patients were included in the RM group only if they were started on RM at some point during follow-up. To adjust for differences in baseline characteristics between RM and non-RM patients, propensity score matching was performed in a 1:1 fashion (caliper 0.20) using greedy matching. Estimation of the propensity score was done using logistic regression with RM as the outcome variable, adjusting for 17 covariates (age, gender, year of device implant, type of device, clinical variables and medication at baseline). Time-to-event analysis was performed using Kaplan Meier survival analysis, with significance indicated using a log rank P value. Hazard ratios and 95% confidence intervals (CI) were calculated using a Cox proportional-hazards model.

Results
A total of 3199 ICD patients were included in this analysis. After propensity score matching for the probability of RM use, 1160 RM patients and 1160 non-RM patients with similar baseline characteristics were selected (mean age 59.1 ±14.8 years, 72.8% male). During a mean follow-up duration of 8.1 ±5.2 years, 363 (31.3%) patients died in the non-RM group and 111 (9.6%) patients died in the RM group (log rank p&lt;0.001, Figure 1). The hazard ratio of RM for mortality was 0.261 (95 CI% 0.211 – 0.323, p=0.001).

Conclusion
Long-term retrospective analysis indicates a significant survival benefit in ICD patients using RM.
Myeloperoxidase as prognostic factor for atrial fibrillation development in patients with ST-segment elevation myocardial infarction
Authors: Rodionova I , Kutya INNA , Hilova Y , Samburg Y , Godlevskaya OLGA , Tytarenko N 
Published: May 2022

Abstract

Funding Acknowledgements
Type of funding sources: None.

Background
Arrhythmia is among the most common and severe myocardial infarction complications. Myeloperoxidase as an important immune factor can be linked to atrial fibrillation (AF) development. Previous studies indicated myeloperoxidase (MPO) as a significant mortality predictor in ST-segment elevation myocardial infarction (STEMI). The MPO role in prognosis for adverse clinical outcomes, as atrial fibrillations in STEMI patients remains not fully understood.
The purpose of the investigation was to examine the MPO in prognosis of adverse outcomes presented by atrial fibrillations in patients with STEMI.

Methods
The study included 233 STEMI patients, 112 males, 121 females, and average age 67.87±7.11 years. Follow-up period was 14 days. Adverse outcome was observed and included atrial fibrillations. Plasma MPO levels were determined by ELISA, MPO was collected on admission.

Results
Patients with indicated adverse effects showed significantly increased MPO levels compared to those without ones, 169.91 IQR [89.45; 201.98] ng/ml vs 81.4 [33.91;181.29] ng/ml; p &lt; 0.001. A ROC analysis determined a MPO cut-off value for arrhythmia (AF) development of 176.53 ng/ml with a sensitivity of 71.1% and specificity of 77.6%, AUC 0.732; 95 % CI 0.677-0.782; p &lt;0.001. Elevated MPO concentration was a significant predictor for AF (OR 1.115; 95% CI: 1.007-1.841; p&lt;0.001). Even adjusted for age and sex MPO remained significantly predictive for arrhythmia development.

Conclusions
The study suggests that increased levels of MPO are associated with the higher risk of atrial fibrillation. MPO could be a possible significant factor for therapy optimization in high-risk STEMI patients.
Increased 18F-fluorodeoxyglucose uptake in the cardiac atria: an evidence for increased atrial inflammation in patients with atrial fibrillation?
Authors: Nakamura O , Goetz C , Meyer P T , Arentz T , Jadidi A 
Published: May 2022

Abstract

Funding Acknowledgements
Type of funding sources: None.

Background
Atrial inflammation and fibrotic remodelling underlie the pathophysiology of atrial cardiomyopathy, which is associated with the development of atrial fibrillation (AF) and atrial flutter (AFL). 18F-fluorodeoxyglucose positron emission tomography/computed tomography (18F-FDG-PET/CT) has been used to detect inflammatory processes. Recent studies have revealed an increased FDG-uptake in the atria of patients with AF, but also in patients with diagnosis of cardiac sarcoidosis with ventricular inflammation.

Purpose
This study aimed to assess the capability of PET/CT to detect and quantify the degree of atrial inflammation (FDG-uptake) in a population with dedicated cardiac FDG-PET/CT.

Methods
We investigated 101 patients suspected of sarcoidosis (57±12 years, 72% male) who underwent 18F-FDG PET/CT scan with dedicated cardiac specific preparation (heparin infusion, 12 hours fasting, and high-fat low-carbohydrate diet). We excluded patients with active ventricular cardiac sarcoidosis or undergoing high-dose immunosuppressive therapy (prednisolone ≥20mg/day or prednisolone combined with other immunotherapy like methotrexate). We measured the maximum standardized uptake value (SUVmax) in atrial myocardium and mean standardized uptake value (SUVmean) in blood pool and calculated the target-to-background ratio (TBR) of SUVmax in atrial myocardium to SUVmean in blood pool. All medical records, ECG data on arrhythmia type and diagnosis of systemic sarcoidosis (with absence of ventricular involvement) were used for the analysis. Sarcoidosis was diagnosed based on the criteria established in 2006 by the Japanese Ministry of Health and Welfare. The collected data were sorted according to presence of arrhythmia and systemic sarcoidosis and TBR of each group were compared.

Results
AF or AFL was found in 30/101 patients. Systemic sarcoidosis was found in 37/101 patients. Patients with known AF/AFL had significantly increased TBR within the atrial tissue compared to those without AF/AFL: (median: 1.26, 1st-3rd quartile: 1.20-1.33) versus (median: 1.22, 1st-3rd quartile: 1.14-1.25; p = 0.004; figure A). Arrhythmia-associated atrial inflammation was consistently observed, independently of presence of concomitant systemic sarcoidosis (figure B). Patients with both atrial arrhythmias and systemic sarcoidosis had the highest atrial inflammation level, as identified by TBR (figure B).

Conclusion
Development of atrial fibrillation or flutter is associated with an increased atrial FDG-uptake as metabolic marker of atrial inflammation. The level of atrial inflammation is further enhanced by additional presence of systemic sarcoidosis.
The COVID-19 viral 3a protein forms a potassium channel that can be inhibited by antiarrhythmic drugs
Authors: Wiedmann F , Boondej E , Stanifer M , Paasche A , Kraft M , Seeger T , Uhrig U , Frey N , Boulant S , Schmidt C 
Published: May 2022

Abstract

Funding Acknowledgements
Type of funding sources: Public Institution(s). Main funding source(s): Deutsche Gesellschaft für Kardiologie /German Cardiac Society Joachim Herz Stiftung /Joachim Herz Foundation

Background/Introduction
Supraventricular and ventricular arrhythmias can often be observed in patients with COVID-19 infection. Both, the clinically observed increase in cardiac biomarkers as well as histological studies indicate virus replication within cardiomyocytes. The 3a open reading frame of the viral genome encodes for a transmembrane protein that is transported to the cell membrane where it can serve as a potassium channel.

Purpose
The aim of this study was to investigate whether COVID-19 infected induced pluripotent stem cell (iPSC)-derived cardiomyocytes also express the 3a protein and whether the potassium currents that are conducted through the 3a protein can be inhibited by clinically used antiarrhythmic drugs.

Methods and Results
iPSC-derived cardiomyocytes were infected with COVID-19 and subsequently subjected to immunoblotting, where expression of the 3a protein could be observed. Plasmid DNA, encoding the COVID-19 3a protein, was generated by gene synthesis and used for in vitro transcription of cRNA. 3–5 days after intracytoplasmic injection of the 3a protein cRNA into Xenopus laevis oocytes, potassium currents could be measured by two-electrode voltage clamp recordings. While class I and class IV antiarrhythmic drugs showed only minor effects on the potassium currents of the 3a protein, a robust inhibition by several beta-blockers and by class III antiarrhythmic drugs could be observed. The strongest effects were found with dofetilide (58.1 % inhibition at 100 µM) and amiodarone (50.1 % inhibition at 100 µM, IC50 level 4.7 µM). An in silico docking analysis, based on the recently revealed crystal structure of the 3a protein, identified the amino acid residues K61 and D142 as part of the binding site of amiodarone. After deactivation of these amino acid residues by site-directed mutagenesis, the inhibition by amiodarone was significantly attenuated.

Conclusion
The COVID-19 viral 3a protein is expressed in COVID-19-infected iPS-derived cardiomyocytes and forms a potassium channel that can be inhibited by antiarrhythmic drugs.
Using a Factorial Survey to Estimate the Relative Importance of Well-Being Dimensions According to Older People: Insights From a Repeated Survey Experiment in Flanders
Authors: Van Loon Veerle , Decancq Koen 
Published: May 2022

Abstract

Background and Objectives
Although it has become standard to include the views of older people when assessing their well-being, most existing methods are ill-suited to estimate the relative importance of well-being dimensions. This article investigates the potential of the factorial survey method to estimate the relative importance of six well-being dimensions (health, income, social relations, leisure, engaging activities, and religion) based on the views of older people themselves.

Research Design and Methods
We implemented a factorial survey in a repeated survey experiment among 800 older adults in Flanders (the Dutch-speaking northern part of Belgium). We performed several within-sample test–retests to investigate the consistency of the estimated coefficients over time (i.e., temporal reliability). In addition, we tested the feasibility of the factorial survey by studying two indicators of cognitive load: response time and response consistency.

Results
We estimated the relative importance of increases in six well-being dimensions. Increases from the lowest level to the highest level in the dimensions of health, income, and social relations had the highest effect on well-being—followed by leisure, engaging activities, and religion. The results proved to be consistent in most of the test–retest analyses. Furthermore, we found that respondents produced a high level of response consistency within an acceptable amount of response time.

Discussion and Implications
The findings suggest that the factorial survey method offers a promising way forward to elicit older people’s views on well-being and, hence, in developing tailored policies that matter to them.
Gut Microbial Ecology of Five Species of Sympatric Desert Rodents in Relation to Herbivorous and Insectivorous Feeding Strategies
Authors: Kohl Kevin D , Dieppa-Colón Etan , Goyco-Blas José , Peralta-Martínez Karen , Scafidi Luke , Shah Sarth , Zawacki Emma , Barts Nick , Ahn Young , Hedayati Stefanie , Secor Stephen M , Rowe Matthew P 
Published: May 2022

Abstract
The gut microbial communities of mammals provide numerous benefits to their hosts. However, given the recent development of the microbiome field, we still lack a thorough understanding of the variety of ecological and evolutionary factors that structure these communities across species. Metabarcoding is a powerful technique that allows for multiple microbial ecology questions to be investigated simultaneously. Here, we employed DNA metabarcoding techniques, predictive metagenomics, and culture-dependent techniques to inventory the gut microbial communities of several species of rodent collected from the same environment that employ different natural feeding strategies [granivorous pocket mice (Chaetodipus penicillatus); granivorous kangaroo rats (Dipodomys merriami); herbivorous woodrats (Neotoma albigula); omnivorous cactus mice (Peromyscus eremicus); and insectivorous grasshopper mice (Onychomys torridus)]. Of particular interest were shifts in gut microbial communities in rodent species with herbivorous and insectivorous diets, given the high amounts of indigestible fibers and chitinous exoskeleton in these diets, respectively. We found that herbivorous woodrats harbored the greatest microbial diversity. Granivorous pocket mice and kangaroo rats had the highest abundances of the genus Ruminococcus and highest predicted abundances of genes related to the digestion of fiber, representing potential adaptations in these species to the fiber content of seeds and the limitations to digestion given their small body size. Insectivorous grasshopper mice exhibited the greatest inter-individual variation in the membership of their microbiomes, and also exhibited the highest predicted abundances of chitin-degrading genes. Culture-based approaches identified 178 microbial isolates (primarily Bacillus and Enterococcus), with some capable of degrading cellulose and chitin. We observed several instances of strain-level diversity in these metabolic capabilities across isolates, somewhat highlighting the limitations and hidden diversity underlying DNA metabarcoding techniques. However, these methods offer power in allowing the investigation of several questions concurrently, thus enhancing our understanding of gut microbial ecology.