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Bachtiger P, Park S, Letchford E, et al., 2021, Triage-HF plus: 12-month study of remote monitoring pathway for triage of heart failure risk initiated during the Covid-19 pandemic, Publisher: OXFORD UNIV PRESS, Pages: 3082-3082, ISSN: 0195-668X
Katritsis G, Luther V, Jamil-Copley S, et al., 2021, Postinfarct ventricular tachycardia substrate: Characterization and ablation of conduction channels using ripple mapping, Heart Rhythm, Vol: 18, Pages: 1682-1690, ISSN: 1547-5271
BackgroundConduction channels have been demonstrated within the postinfarct scar and seem to be co-located with the isthmus of ventricular tachycardia (VT). Mapping the local scar potentials (SPs) that define the conduction channels is often hindered by large far-field electrograms generated by healthy myocardium.ObjectiveThe purpose of this study was to map conduction channel using ripple mapping to categorize SPs temporally and anatomically. We tested the hypothesis that ablation of early SPs would eliminate the latest SPs without direct ablation.MethodsRipple maps of postinfarct scar were collected using the PentaRay (Biosense Webster) during normal rhythm. Maps were reviewed in reverse, and clusters of SPs were color-coded on the geometry, by timing, into early, intermediate, late, and terminal. Ablation was delivered sequentially from clusters of early SPs, checking for loss of terminal SPs as the endpoint.ResultsThe protocol was performed in 11 patients. Mean mapping time was 65 ± 23 minutes, and a mean 3050 ± 1839 points was collected. SP timing ranged from 98.1 ± 60.5 ms to 214.8 ± 89.8 ms post QRS peak. Earliest SPs were present at the border, occupying 16.4% of scar, whereas latest SPs occupied 4.8% at the opposing border or core. Analysis took 15 ± 10 minutes to locate channels and identify ablation targets. It was possible to eliminate latest SPs in all patients without direct ablation (mean ablation time 16.3 ± 11.1 minutes). No VT recurrence was recorded (mean follow-up 10.1 ± 7.4 months).ConclusionConduction channels can be located using ripple mapping to analyze SPs. Ablation at channel entrances can eliminate the latest SPs and is associated with good medium-term results.
Oktay LA, Abuelgasim E, Abdelwahed A, et al., 2021, Factors affecting engagement in web-based health care patient information: narrative review of the literature, Journal of Medical Internet Research, Vol: 23, ISSN: 1438-8871
BACKGROUND: Web-based content is rapidly becoming the primary source of health care information. There is a pressing need for web-based health care content to not only be accurate but also be engaging. Improved engagement of people with web-based health care content has the potential to inform as well as influence behavioral change to enable people to make better health care choices. The factors associated with better engagement with web-based health care content have previously not been considered. OBJECTIVE: The aims of this study are to identify the factors that affect engagement with web-based health care content and develop a framework to be considered when creating such content. METHODS: A comprehensive search of the PubMed and MEDLINE database was performed from January 1, 1946, to January 5, 2020. The reference lists of all included studies were also searched. The Medical Subject Headings database was used to derive the following keywords: "patient information," "online," "internet," "web," and "content." All studies in English pertaining to the factors affecting engagement in web-based health care patient information were included. No restrictions were set on the study type. Analysis of the themes arising from the results was performed using inductive content analysis. RESULTS: The search yielded 814 articles, of which 56 (6.9%) met our inclusion criteria. The studies ranged from observational and noncontrolled studies to quasi-experimental studies. Overall, there was significant heterogeneity in the types of interventions and outcome assessments, which made quantitative assessment difficult. Consensus among all authors of this study resulted in six categories that formed the basis of a framework to assess the factors affecting engagement in web-based health care content: easy to understand, support, adaptability, accessibility, visuals and content, and credibility and completeness. CONCLUSIONS: There is a p
Seligman H, Zaman S, Pitcher DS, et al., 2021, Correction: Reusable snorkel masks adapted as particulate respirators, PLoS One, Vol: 16, Pages: 1-1, ISSN: 1932-6203
Jaffer U, 2021, Factors affecting engagement in online healthcare patient information: a narrative review of the literature, Journal of Medical Internet Research, Vol: 23, ISSN: 1438-8871
Background:The online world is rapidly becoming the primary source of healthcare information. There is a pressing need for online healthcare content not only to be accurate but also engaging. Improved engagement of people with online healthcare content has the potential to inform but also to influence behavioural change to make healthier choices. Factors associated with better engagement with online healthcare content have previously not been well considered.Objective:To identify factors which may improve engagement with online healthcare content and develop a framework to be considered when creating such content.Methods:The Pubmed and MEDLINE databases were searched up to January 2020 and manual cross checking of reference lists of relevant articles was performed. No restrictions on the study type were put. Abstracts and titles were reviewed by two authors independently for relevance. Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines were followed.Results:Our search returned a total of 814 articles, 56 of which met our inclusion criteria. Studies tended to be observational, non-controlled studies, and a few quasi-experimental studies. Overall, there was significant heterogeneity in the types of interventions and outcome assessments making quantitative assessment difficult. Consensus of all authors resulted in seven categories forming the basis of a framework to assess quality of engagement in online healthcare content : 1. Textual information; 2. Discussion groups; 3. Video content; 4. Visuals/ Pictograph; 5. Accessibility; 6. Stage of patient journey; 7. Credibility and completeness of information.Conclusions:Healthcare providers should recognise barriers to understanding as well as barrier to adherence with treatment. When producing online healthcare patient information, healthcare providers should consider the categories described which may improve engagement with the content being created.
Kim M-Y, Coyle C, Sohaib DT-SA, et al., 2021, GANGLIONATED PLEXUS ABLATION TO PREVENT ATRIAL FIBRILLATION (GANGLIA-AF TRIAL), HEART RHYTHM, Vol: 18, Pages: 1632-1632, ISSN: 1547-5271
Jabbour R, Owen T, Pandey P, et al., 2021, In vivo grafting of large engineered heart tissue patches for cardiac repair, JCI Insight, Vol: 6, Pages: 1-13, ISSN: 2379-3708
Engineered heart tissue (EHT) strategies, by combining cells within a hydrogel matrix, may be anovel therapy for heart failure. EHTs restore cardiac function in rodent injury models, but more dataare needed in clinically relevant settings. Accordingly, an upscaled EHT patch (2.5 cm × 1.5 cm × 1.5mm) consisting of up to 20 million human induced pluripotent stem cell–derived cardiomyocytes(hPSC-CMs) embedded in a fibrin-based hydrogel was developed. A rabbit myocardial infarctionmodel was then established to test for feasibility and efficacy. Our data showed that hPSC-CMs inEHTs became more aligned over 28 days and had improved contraction kinetics and faster calciumtransients. Blinded echocardiographic analysis revealed a significant improvement in function ininfarcted hearts that received EHTs, along with reduction in infarct scar size by 35%. Vascularizationfrom the host to the patch was observed at week 1 and stable to week 4, but electrical couplingbetween patch and host heart was not observed. In vivo telemetry recordings and ex vivoarrhythmia provocation protocols showed that the patch was not pro-arrhythmic. In summary, EHTsimproved function and reduced scar size without causing arrhythmia, which may be due to the lackof electrical coupling between patch and host heart.
Attia ZI, Kapa S, Dugan J, et al., 2021, Rapid exclusion of COVID infection with the artificial intelligence electrocardiogram, Mayo Clinic Proceedings, Vol: 96, Pages: 2081-2094, ISSN: 0025-6196
ObjectiveTo rapidly exclude severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection using artificial intelligence applied to the electrocardiogram (ECG).MethodsA global, volunteer consortium from 4 continents identified patients with ECGs obtained around the time of polymerase chain reaction–confirmed COVID-19 diagnosis and age- and sex-matched controls from the same sites. Clinical characteristics, polymerase chain reaction results, and raw electrocardiographic data were collected. A convolutional neural network was trained using 26,153 ECGs (33.2% COVID positive), validated with 3826 ECGs (33.3% positive), and tested on 7870 ECGs not included in other sets (32.7% positive). Performance under different prevalence values was tested by adding control ECGs from a single high-volume site.ResultsThe area under the curve for detection of acute COVID-19 infection in the test group was 0.767 (95% CI, 0.756 to 0.778; sensitivity, 98%; specificity, 10%; positive predictive value, 37%; negative predictive value, 91%). To more accurately reflect a real-world population, 50,905 normal controls were added to adjust the COVID prevalence to approximately 5% (2657/58,555), resulting in an area under the curve of 0.780 (95% CI, 0.771 to 0.790) with a specificity of 12.1% and a negative predictive value of 99.2%.ConclusionInfection with SARS-CoV-2 results in electrocardiographic changes that permit the artificial intelligence–enhanced ECG to be used as a rapid screening test with a high negative predictive value (99.2%). This may permit the development of electrocardiography-based tools to rapidly screen individuals for pandemic control.
Ng FS, Toman O, Petru J, et al., 2021, Novel low-voltage multiPulse therapy to terminate atrial fibrillation., JACC: Clinical Electrophysiology, Vol: 7, Pages: 988-999, ISSN: 2405-5018
OBJECTIVES: This first-in-human feasibility study was undertaken to translate the novel low-voltage MultiPulse Therapy (MPT) (Cardialen, Inc., Minneapolis, Minnesota), which was previously been shown to be effective in preclinical studies in terminating atrial fibrillation (AF), into clinical use. BACKGROUND: Current treatment options for AF, the most common arrhythmia in clinical practice, have limited success. Previous attempts at treating AF by using implantable devices have been limited by the painful nature of high-voltage shocks. METHODS: Forty-two patients undergoing AF ablation were recruited at 6 investigational centers worldwide. Before ablation, electrode catheters were placed in the coronary sinus, right and/or left atrium, for recording and stimulation. After the induction of AF, MPT, which consists of up to a 3-stage sequence of far- and near-field stimulation pulses of varied amplitude, duration, and interpulse timing, was delivered via temporary intracardiac leads. MPT parameters and delivery methods were iteratively optimized. RESULTS: In the 14 patients from the efficacy phase, MPT terminated 37 of 52 (71%) of AF episodes, with the lowest median energy of 0.36 J (interquartile range [IQR]: 0.14 to 1.21 J) and voltage of 42.5 V (IQR: 25 to 75 V). Overall, 38% of AF terminations occurred within 2 seconds of MPT delivery (p < 0.0001). Shorter time between AF induction and MPT predicted success of MPT in terminating AF (p < 0.001). CONCLUSIONS: MPT effectively terminated AF at voltages and energies known to be well tolerated or painless in some patients. Our results support further studies of the concept of implanted devices for early AF conversion to reduce AF burden, symptoms, and progression.
Wan EY, Ghanbari H, Akoum N, et al., 2021, HRS white paper on clinical utilization of digital health technology., Cardiovascular Digital Health Journal, Vol: 2, Pages: 196-211, ISSN: 2666-6936
This collaborative statement from the Digital Health Committee of the Heart Rhythm Society provides everyday clinical scenarios in which wearables may be utilized by patients for cardiovascular health and arrhythmia management. We describe herein the spectrum of wearables that are commercially available for patients, and their benefits, shortcomings and areas for technological improvement. Although wearables for rhythm diagnosis and management have not been examined in large randomized clinical trials, undoubtedly the usage of wearables has quickly escalated in clinical practice. This document is the first of a planned series in which we will update information on wearables as they are revised and released to consumers.
Bachtiger P, Adamson A, Maclean WA, et al., 2021, Determinants of shielding behaviour during the COVID-19 pandemic and associations with wellbeing in >7,000 NHS patients: 17-week longitudinal observational study., JMIR Public Health and Surveillance, Vol: 7, Pages: 1-14, ISSN: 2369-2960
BACKGROUND: The UK National Health Service (NHS) classified 2.2 million people as clinically extremely vulnerable (CEV) during the first wave of the 2020 COVID-19 pandemic, advising them to 'shield' - to not leave home for any reason. OBJECTIVE: The aim of this study was to measure the determinants of shielding behaviour and associations with wellbeing in a large NHS patient population, towards informing future health policy. METHODS: Patients contributing to an ongoing longitudinal participatory epidemiology study (LoC-19, n = 42,924) received weekly email invitations to complete questionnaires (17-week shielding period starting 9th April 2020) within their NHS personal electronic health record. Question items focused on wellbeing. Participants were stratified into four groups by self-reported CEV status (qualifying condition) and adoption of shielding behaviour (baselined at week 1 or 2). Distribution of CEV criteria is reported alongside situational variables and uni- and multivariable logistic regression. Longitudinal trends in physical and mental wellbeing were displayed graphically. Free-text responses reporting variables impacting wellbeing were semi-quantified using natural language processing. In the lead up to a second national lockdown (October 23rd, 2020), a follow-up questionnaire evaluated subjective concern if further shielding were advised. RESULTS: 7,240 participants were included. Among the CEV (2,391), 1,133 (47.3%) assumed shielding behaviour at baseline, compared with 633 (15.0%) in the non-CEV group. Those CEV who shielded were more likely to be Asian (Odds Ratio OR 2.02 [1.49-2.76]), female (OR 1.24 [1.05-1.45]), older (OR per year increase 1.01 [1.00-1.02]) and live in a home with outdoor space (OR 1.34 [1.06-1.70]) or 3-4 other inhabitants (3 = OR 1.49 [1.15-1.94], 4 = OR 1.49 [1.10-2.01]); and be solid organ transplant recipients (2.85 [2.18-3.77]) or have severe chronic lung disease (OR 1.63 [1.30-2.04]). Receipt of a government letter adv
Patel K, Li X, Quint J, et al., 2021, Increasing adiposity and the presence of cardiometabolic morbidity is associated with increased Covid-19-related mortality: results from the UK Biobank, BMC Endocrine Disorders, Vol: 21, Pages: 1-6, ISSN: 1472-6823
Background: Although obesity, defined by body mass index (BMI), has been associated with a higher risk of hospitalisation and more severe course of illness in Covid-19 positive patients amongst the British population, it is unclear if this translates into increased mortality. Furthermore, given that BMI is an insensitive indicator of adiposity, the effect of adipose volume on Covid-19 outcomes is also unknown. Methods: We used the UK Biobank repository, which contains clinical and anthropometric data, and is linked to Public Health England Covid-19 healthcare records, to address our research question. We performed age- and sex- adjusted logistic regression and Chi-squared test to compute the odds for Covid-19-related mortality as a consequence of increasing BMI, other more sensitive indices of adiposity such as waist:hip ratio (WHR) and percent body fat, as well as concomitant cardiometabolic illness.Results: 13502 participants were tested for Covid-19 (mean age 70+8 years, 48.9% male). 1,582 tested positive (mean age 68+9 years, 52.8% male), of which 305 died (mean age 75+6 years, 65.5% male). Increasing adiposity was associated with higher odds for Covid-19-related mortality. For every unit increase in BMI, WHR and percent body fat, the odds of death amongst the Covid19-positive participants increased by 1.04 (95% CI 1.01-1.07), 10.71 (95% CI 1.57-73.06) and 1.03 (95% CI 1.01-1.05), respectively (all p<0.05). Referenced to Covid-19 positive participants with a normal weight (BMI 18.5-25kg/m2), Covid-19 positive participants with BMI>35kg/m2 had significantly higher odds of Covid-19-related death (OR 1.70, 95% CI 1.06-2.74, p<0.05). Covid-19-positive participants with metabolic (diabetes, hypertension, dyslipidaemia) or cardiovascular morbidity (atrial fibrillation, angina) also had higher odds of death.Conclusions: Anthropometric indices that are more sensitive to adipose volume and its distribution than BMI, as well as concurrent cardiometabolic illnes
Mann I, Linton NWF, Coyle C, et al., 2021, RETRO-MAPPING A New Approach to Activation Mapping in Persistent Atrial Fibrillation Reveals Evidence of Spatiotemporal Stability, CIRCULATION-ARRHYTHMIA AND ELECTROPHYSIOLOGY, Vol: 14, ISSN: 1941-3149
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Bachtiger P, Adamson A, Maclean WA, et al., 2021, Determinants of Shielding Behavior During the COVID-19 Pandemic and Associations With Well-being Among National Health Service Patients: Longitudinal Observational Study (Preprint)
<sec> <title>BACKGROUND</title> <p>The UK National Health Service (NHS) classified 2.2 million people as clinically extremely vulnerable (CEV) during the first wave of the 2020 COVID-19 pandemic, advising them to “shield” (to not leave home for any reason).</p> </sec> <sec> <title>OBJECTIVE</title> <p>The aim of this study was to measure the determinants of shielding behavior and associations with well-being in a large NHS patient population for informing future health policy.</p> </sec> <sec> <title>METHODS</title> <p>Patients contributing to an ongoing longitudinal participatory epidemiology study (Longitudinal Effects on Wellbeing of the COVID-19 Pandemic [LoC-19], n=42,924) received weekly email invitations to complete questionnaires (17-week shielding period starting April 9, 2020) within their NHS personal electronic health record. Question items focused on well-being. Participants were stratified into four groups by self-reported CEV status (qualifying condition) and adoption of shielding behavior (baselined at week 1 or 2). The distribution of CEV criteria was reported alongside situational variables and univariable and multivariable logistic regression. Longitudinal trends in physical and mental well-being were displayed graphically. Free-text responses reporting variables impacting well-being were semiquantified using natural language processing. In the lead up to a second national lockdown (October 23, 2020), a follow-up questionnaire evaluated subjective concern if further shielding was advised.</p> </sec> <sec> <title>RESULTS</title>
Cannon T, Lagarto J, Dyer B, et al., 2021, Characterisation of NADH fluorescence properties under one-photon excitation with respect to temperature, pH and binding to lactate dehydrogenase, Optical Society of America Continuum, Vol: 4, Pages: 1610-1625
Reduced nicotinamide adenine dinucleotide (NADH) is the principal electron donor in glycolysis and oxidative metabolism and is thus recognized as a key biomarker for probing metabolic state. While the fluorescence characteristics of NADH have been investigated extensively, there are discrepancies in the published data due to diverse experimental conditions, instrumentation and microenvironmental parameters that can affect NADH fluorescence. Using a cuvette-based time-resolved spectrofluorimeter employing one-photon excitation at 375 nm, we characterized the fluorescence intensity, lifetime, spectral response, anisotropy and time-resolved anisotropy of NADH in aqueous solution under varying microenvironmental conditions, namely temperature, pH, and binding to lactate dehydrogenase (LDH). Our results demonstrate how temperature, pH, and binding partners each impact the fluorescence signature of NADH and highlight the complexity of the fluorescence data when different parameters produce competing effects. We hope that the data presented in this study will provide a reference for potential sources of variation in experiments measuring NADH fluorescence.
Chowdhury R, Debney M, Protti A, et al., 2021, Rotigaptide Infusion for the First 7 Days After Myocardial Infarction–Reperfusion Reduced Late Complexity of Myocardial Architecture of the Healing Border-Zone and Arrhythmia Inducibility, Journal of the American Heart Association, Vol: 10, Pages: 1-18, ISSN: 2047-9980
BackgroundSurvivors of myocardial infarction are at increased risk of late ventricular arrhythmias, with infarct size and scar heterogeneity being key determinants of arrhythmic risk. Gap junctions facilitate the passage of small ions and morphogenic cell signaling between myocytes. We hypothesized that gap junctions enhancement during infarction–reperfusion modulates structural and electrophysiological remodeling and reduces late arrhythmogenesis.Methods and ResultsInfarction–reperfusion surgery was carried out in male Sprague‐Dawley rats followed by 7 days of rotigaptide or saline administration. The in vivo and ex vivo arrhythmogenicity was characterized by programmed electrical stimulation 3 weeks later, followed by diffusion‐weighted magnetic resonance imaging and Masson's trichrome histology. Three weeks after 7‐day postinfarction administration of rotigaptide, ventricular tachycardia/ventricular fibrillation was induced on programmed electrical stimulation in 20% and 53% of rats, respectively (rotigaptide versus control), resulting in reduction of arrhythmia score (3.2 versus 1.4, P=0.018), associated with the reduced magnetic resonance imaging parameters fractional anisotropy (fractional anisotropy: −5% versus −15%; P=0.062) and mean diffusivity (mean diffusivity: 2% versus 6%, P=0.042), and remodeling of the 3‐dimensional laminar structure of the infarct border zone with reduction of the mean (16° versus 19°, P=0.013) and the dispersion (9° versus 12°, P=0.015) of the myofiber transverse angle. There was no change in ECG features, spontaneous arrhythmias, or mortality.ConclusionsEnhancement of gap junctions function by rotigaptide administered during the early healing phase in reperfused infarction reduces later complexity of infarct scar morphology and programmed electrical stimulation–induced arrhythmias, and merits further exploration as a feasible and practicable intervention in the acute myocardial infarcti
Katritsis G, Luther V, Cortez-Dias N, et al., 2021, Electroanatomic characterization and ablation of scar-related isthmus sites supporting perimitral flutter, JACC: Clinical Electrophysiology, Vol: 7, Pages: 578-590, ISSN: 2405-5018
ObjectivesThe authors reviewed 3-dimensional electroanatomic maps of perimitral flutter to identify scar-related isthmuses and determine their effectiveness as ablation sites.BackgroundPerimitral flutter is usually treated by linear ablation between the left lower pulmonary vein and mitral annulus. Conduction block can be difficult to achieve, and recurrences are common.MethodsPatients undergoing atrial tachycardia ablation using CARTO3 (Biosense Webster Inc., Irvine, California) were screened from 4 centers. Patients with confirmed perimitral flutter were reviewed for the presence of scar-related isthmuses by using CARTO3 with the ConfiDense and Ripple Mapping modules.ResultsConfirmed perimitral flutter was identified in 28 patients (age 65.2 ± 8.1 years), of whom 26 patients had prior atrial fibrillation ablation. Scar-related isthmus ablation was performed in 12 of 28 patients. Perimitral flutter was terminated in all following correct identification of a scar-related isthmus using ripple mapping. The mean scar voltage threshold was 0.11 ± 0.05 mV. The mean width of scar-related isthmuses was 8.9 ± 3.5 mm with a conduction speed of 31.8 ± 5.5 cm/s compared to that of normal left atrium of 71.2 ± 21.5 cm/s (p < 0.0001). Empirical, anatomic ablation was performed in 16 of 28, with termination in 10 of 16 (63%; p = 0.027). Significantly less ablation was required for critical isthmus ablation compared to empirical linear lesions (11.4 ± 5.3 min vs. 26.2 ± 17.1 min; p = 0.0004). All 16 cases of anatomic ablation were reviewed with ripple mapping, and 63% had scar-related isthmus.ConclusionsPerimitral flutter is usually easy to diagnose but can be difficult to ablate. Ripple mapping is highly effective at locating the critical isthmus maintaining the tachycardia and avoiding anatomic ablation lines. This approach has a higher termination rate with less radiofrequency ablation required.
Seligman H, Zaman S, Pitcher DS, et al., 2021, Reusable snorkel masks adapted as particulate respirators, PLoS One, Vol: 16, Pages: 1-11, ISSN: 1932-6203
ntroductionDuring viral pandemics, filtering facepiece (FFP) masks together with eye protection form the essential components of personal protective equipment (PPE) for healthcare workers. There remain concerns regarding insufficient global supply and imperfect protection offered by currently available PPE strategies. A range of full-face snorkel masks were adapted to accept high grade medical respiratory filters using bespoke-designed 3D-printed connectors. We compared the protection offered by the snorkel to that of standard PPE using a placebo-controlled respirator filtering test as well as a fluorescent droplet deposition experiment. Out of the 56 subjects tested, 42 (75%) passed filtering testing with the snorkel mask compared to 31 (55%) with a FFP3 respirator mask (p = 0.003). Amongst the 43 subjects who were not excluded following a placebo control, 85% passed filtering testing with the snorkel versus to 68% with a FFP3 mask (p = 0.008). Following front and lateral spray of fluorescence liquid particles, the snorkel mask also provided superior protection against droplet deposition within the subject’s face, when compared to a standard PPE combination of FFP3 masks and eye protection (3.19x108 versus 6.81x108 fluorescence units, p<0.001). The 3D printable adaptors are available for free download online at https://www.ImperialHackspace.com/COVID-19-Snorkel-Respirator-Project/.ConclusionFull-face snorkel masks adapted as particulate respirators performed better than a standard PPE combination of FFP3 mask and eye protection against aerosol inhalation and droplet deposition. This adaptation is therefore a promising PPE solution for healthcare workers during highly contagious viral outbreaks.
Handa B, Li X, Baxan N, et al., 2021, Ventricular fibrillation mechanism and global fibrillatory organisation are determined by gap junction coupling and fibrosis pattern, Cardiovascular Research, Vol: 117, Pages: 1078-1090, ISSN: 0008-6363
AimsConflicting data exist supporting differing mechanisms for sustaining ventricular fibrillation (VF), ranging from disorganised multiple-wavelet activation to organised rotational activities (RAs). Abnormal gap junction (GJ) coupling and fibrosis are important in initiation and maintenance of VF. We investigated whether differing ventricular fibrosis patterns and the degree of GJ coupling affected the underlying VF mechanism.Methods and ResultsOptical mapping of 65 Langendorff-perfused rat hearts was performed to study VF mechanisms in control hearts with acute GJ modulation, and separately in three differing chronic ventricular fibrosis models; compact (CF), diffuse (DiF) and patchy (PF). VF dynamics were quantified with phase mapping and frequency dominance index (FDI) analysis, a power ratio of the highest amplitude dominant frequency in the cardiac frequency spectrum.Enhanced GJ coupling with rotigaptide (n = 10) progressively organised fibrillation in a concentration-dependent manner; increasing FDI (0nM: 0.53±0.04, 80nM: 0.78±0.03, p < 0.001), increasing RA sustained VF time (0nM:44±6%, 80nM: 94±2%, p < 0.001) and stabilised RAs (maximum rotations for a RA; 0nM:5.4±0.5, 80nM: 48.2±12.3, p < 0.001). GJ uncoupling with carbenoxolone progressively disorganised VF; the FDI decreased (0µM: 0.60±0.05, 50µM: 0.17±0.03, p < 0.001) and RA-sustained VF time decreased (0µM: 61±9%, 50µM: 3±2%, p < 0.001).In CF, VF activity was disorganised and the RA-sustained VF time was the lowest (CF: 27±7% versus PF: 75±5%, p < 0.001). Global fibrillatory organisation measured by FDI was highest in PF (PF: 0.67±0.05 versus CF: 0.33±0.03, p < 0.001). PF harboured the longest duration and most spatially stable RAs (patchy: 1411&plusm
Bachtiger P, Adamson A, Chow J-J, et al., 2021, The Impact of the COVID-19 Pandemic on the Uptake of Influenza Vaccine: UK-Wide Observational Study, Publisher: JMIR PUBLICATIONS, INC
Bachtiger P, Adamson A, Chow J-J, et al., 2021, The impact of the Covid-19 pandemic on uptake of influenza vaccine: a UK-wide observational study., JMIR Public Health and Surveillance, Vol: 7, Pages: 1-14, ISSN: 2369-2960
BACKGROUND: In the face of the Covid-19 pandemic, the UK National Health Service (NHS) flu vaccination eligibility is extended this season to ~32.4 million (48.8%) of the population. Knowing intended uptake will inform supply and public health messaging to maximise vaccination. OBJECTIVE: The objective of this study was to measure the impact of the Covid-19 pandemic on acceptance of flu vaccination in the 2020-21 season, specifically focusing on those previously eligible who routinely decline vaccination and the newly eligible. METHODS: Intention to receive influenza vaccine in 2020-21 was asked of all registrants of the NHS's largest electronic personal health record by online questionnaire on 31st July 2020. Of those who were either newly or previously eligible but had not previously received influenza vaccination, multivariable logistic regression and network diagrams were used to examine reasons to have or decline vaccination. RESULTS: Among 6,641 respondents, 945 (14.2%) were previously eligible but not vaccinated, of whom 536 (56.7%) intended to receive flu vaccination in 2020/21, as did 466 (68.6%) of the newly eligible. Intention to receive the flu vaccine was associated with increased age, index of multiple deprivation (IMD) quintile, and considering oneself at high risk from Covid-19. Among those eligible but intending not to be vaccinated in 2020/21, 164 (30.2%) gave misinformed reasons. 47 (49.9%) of previously unvaccinated healthcare workers would decline vaccination in 2020/21. CONCLUSIONS: In this sample, Covid-19 has increased acceptance of flu vaccination in those previously eligible but unvaccinated and motivates substantial uptake in the newly eligible. This study is essential for informing resource planning and the need for effective messaging campaigns to address negative misconceptions, also necessary for Covid-19 vaccination programmes. CLINICALTRIAL: Not applicable.
Rajpal H, Sas M, Lockwood C, et al., 2021, Interpretable XGBoost based classification of 12-lead ECGs applying information theory measures from neuroscience., 2020 Computing in Cardiology, Publisher: IEEE, Pages: 1-4, ISSN: 2325-8861
Automated ECG classification is a standard feature in many commercial 12-Lead ECG machines. As part of the Physionet/CinC Challenge 2020, our team, "Mad-hardmax", developed an XGBoost based classification method for the analysis of 12-Lead ECGs acquired from four different countries. Our aim is to develop an interpretable classifier that outputs diagnoses which can be traced to specific ECG features, while also testing the potential of information theoretic features for ECG diagnosis. These measures capture high-level interdependencies across ECG leads which are effective for discriminating conditions with multiple complex morphologies. On unseen test data, our algorithm achieved a challenge score of 0.155 relative to a winning score of 0.533, putting our submission in 24th position from 41 successful entries.
Arnold AD, Shun-Shin MJ, Keene D, et al., 2021, Electrocardiographic predictors of successful resynchronization of left bundle branch block by his bundle pacing, Journal of Cardiovascular Electrophysiology, Vol: 32, Pages: 428-438, ISSN: 1045-3873
BackgroundHis bundle pacing (HBP) is an alternative to biventricular pacing (BVP) for delivering cardiac resynchronization therapy (CRT) in patients with heart failure and left bundle branch block (LBBB). It is not known whether ventricular activation times and patterns achieved by HBP are equivalent to intact conduction systems and not all patients with LBBB are resynchronized by HBP.ObjectiveTo compare activation times and patterns of His-CRT with BVP-CRT, LBBB and intact conduction systems.MethodsIn patients with LBBB, noninvasive epicardial mapping (ECG imaging) was performed during BVP and temporary HBP. Intrinsic activation was mapped in all subjects. Left ventricular activation times (LVAT) were measured and epicardial propagation mapping (EPM) was performed, to visualize epicardial wavefronts. Normal activation pattern and a normal LVAT range were determined from normal subjects.ResultsForty-five patients were included, 24 with LBBB and LV impairment, and 21 with normal 12-lead ECG and LV function. In 87.5% of patients with LBBB, His-CRT successfully shortened LVAT by ≥10 ms. In 33.3%, His-CRT resulted in complete ventricular resynchronization, with activation times and patterns indistinguishable from normal subjects. EPM identified propagation discontinuity artifacts in 83% of patients with LBBB. This was the best predictor of whether successful resynchronization was achieved by HBP (logarithmic odds ratio, 2.19; 95% confidence interval, 0.07–4.31; p = .04).ConclusionNoninvasive electrocardiographic mapping appears to identify patients whose LBBB can be resynchronized by HBP. In contrast to BVP, His-CRT may deliver the maximum potential ventricular resynchronization, returning activation times, and patterns to those seen in normal hearts.
Bachtiger P, Adamson A, Chow J-J, et al., 2020, The Impact of the COVID-19 Pandemic on the Uptake of Influenza Vaccine: UK-Wide Observational Study (Preprint)
<sec> <title>BACKGROUND</title> <p>In the face of the COVID-19 pandemic, the UK National Health Service (NHS) extended eligibility for influenza vaccination this season to approximately 32.4 million people (48.8% of the population). Knowing the intended uptake of the vaccine will inform supply and public health messaging to maximize vaccination.</p> </sec> <sec> <title>OBJECTIVE</title> <p>The objective of this study was to measure the impact of the COVID-19 pandemic on the acceptance of influenza vaccination in the 2020-2021 season, specifically focusing on people who were previously eligible but routinely declined vaccination and newly eligible people.</p> </sec> <sec> <title>METHODS</title> <p>Intention to receive the influenza vaccine in 2020-2021 was asked of all registrants of the largest electronic personal health record in the NHS by a web-based questionnaire on July 31, 2020. Of those who were either newly or previously eligible but had not previously received an influenza vaccination, multivariable logistic regression and network diagrams were used to examine their reasons to undergo or decline vaccination.</p> </sec> <sec> <title>RESULTS</title> <p>Among 6641 respondents, 945 (14.2%) were previously eligible but were not vaccinated; of these, 536 (56.7%) intended to receive an influenza vaccination in 2020-2021, as did 466 (68.6%) of the newly eligible respondents. Intention to receive the influenza vaccine was associated with increased age, index of multiple deprivation quintile, and considering oneself to be at high risk fr
Bachtiger P, Adamson A, Maclean W, et al., 2020, Inadequate intention to receive Covid-19 vaccination: indicators for public health messaging needed to improve uptake in UK, Publisher: MedRxiv
Data promising effective Covid-19 vaccines have accelerated the UK’s mass vaccination programme. The UK public’s attitudes to the government’s prioritisation list are unknown, and achieving critical population immunity will require the remaining majority to accept both vaccination and the delay in access of up to a year or more. This cross-sectional observational study sent an online questionnaire to registrants of the UK National Health Service’s largest personal health record. Question items covered willingness for Covid-19 vaccine uptake and attitudes to prioritisation. Among 9,122 responses, 71.5% indicated wanting a vaccine, below what previous modelling indicated as critical levels for progressing towards herd immunity. 22.7% disagreed with the prioritisation list, though 70.3% were against being able to expedite vaccination through payment. Age and female gender were, respectively, strongly positively and negatively associated with wanting a vaccine. Teachers and Black, Asian and Minority Ethnic (BAME) groups were most cited by respondents for prioritisation. This study identifies factors to inform the public health messaging critical to improving uptake.
Bachtiger P, Adamson A, Quint JK, et al., 2020, Belief of having had unconfirmed Covid-19 infection reduces willingness to participate in app-based contact tracing, npj Digital Medicine, Vol: 3, Pages: 1-7, ISSN: 2398-6352
<jats:title>Abstract</jats:title> <jats:p>Contact tracing and lockdown are health policies being used worldwide to combat the coronavirus (COVID-19). The UK National Health Service (NHS) Track and Trace Service has plans for a nationwide app that notifies the need for self-isolation to those in contact with a person testing positive for COVID-19. To be successful, such an app will require high uptake, the determinants and willingness for which are unclear but essential to understand for effective public health benefit. The objective of this study was to measure the determinants of willingness to participate in an NHS app-based contact-tracing programme using a questionnaire within the Care Information Exchange (CIE)—the largest patient-facing electronic health record in the NHS. Among 47,708 registered NHS users of the CIE, 27% completed a questionnaire asking about willingness to participate in app-based contact tracing, understanding of government advice, mental and physical wellbeing and their healthcare utilisation—related or not to COVID-19. Descriptive statistics are reported alongside univariate and multivariable logistic regression models, with positive or negative responses to a question on app-based contact tracing as the dependent variable. 26.1% of all CIE participants were included in the analysis (<jats:italic>N</jats:italic> = 12,434, 43.0% male, mean age 55.2). 60.3% of respondents were willing to participate in app-based contact tracing. Out of those who responded ‘no’, 67.2% stated that this was due to privacy concerns. In univariate analysis, worsening mood, fear and anxiety in relation to changes in government rules around lockdown were associated with lower willingness to participate. Multivariable analysis showed that difficulty understanding government rules was associated with a decreased inclination to download the app, with those scoring 1–2 and 3–4
Ali R, Qureshi N, Liverani S, et al., 2020, Left atrial enhancement correlates with myocardial conduction velocity in patients with persistent atrial fibrillation, Frontiers in Physiology, Vol: 11, ISSN: 1664-042X
Background: Conduction velocity (CV) heterogeneity and myocardial fibrosis both promote re-entry, but the relationship between fibrosis as determined by left atrial (LA) late-gadolinium enhanced cardiac magnetic resonance imaging (LGE-CMRI) and CV remains uncertain.Objective: Although average CV has been shown to correlate with regional LGE-CMRI in patients with persistent AF, we test the hypothesis that a localized relationship exists to underpin LGE-CMRI as a minimally invasive tool to map myocardial conduction properties for risk stratification and treatment guidance.Method: 3D LA electroanatomic maps during LA pacing were acquired from eight patients with persistent AF following electrical cardioversion. Local CVs were computed using triads of concurrently acquired electrograms and were co-registered to allow correlation with LA wall intensities obtained from LGE-CMRI, quantified using normalized intensity (NI) and image intensity ratio (IIR). Association was evaluated using multilevel linear regression.Results: An association between CV and LGE-CMRI intensity was observed at scales comparable to the size of a mapping electrode: −0.11 m/s per unit increase in NI (P < 0.001) and −0.96 m/s per unit increase in IIR (P < 0.001). The magnitude of this change decreased with larger measurement area. Reproducibility of the association was observed with NI, but not with IIR.Conclusion: At clinically relevant spatial scales, comparable to area of a mapping catheter electrode, LGE-CMRI correlates with CV. Measurement scale is important in accurately quantifying the association of CV and LGE-CMRI intensity. Importantly, NI, but not IIR, accounts for changes in the dynamic range of CMRI and enables quantitative reproducibility of the association.
Kim M-Y, Sandler B, Sikkel MB, et al., 2020, The ectopy-triggering ganglionated plexuses in atrial fibrillation, Autonomic Neuroscience, Vol: 228, ISSN: 1566-0702
BackgroundEpicardial ganglionated plexus (GP) have an important role in the pathogenesis of atrial fibrillation (AF). The relationship between anatomical, histological and functional effects of GP is not well known. We previously described atrioventricular (AV) dissociating GP (AVD-GP) locations. In this study, we hypothesised that “ET-GP” are upstream triggers of atrial ectopy/AF and have different anatomical distribution to AVD-GP.ObjectivesWe mapped and characterised ET-GP to understand their neural mechanism in AF and anatomical distribution in the left atrium (LA).Methods26 patients with paroxysmal AF were recruited. All were paced in the LA with an ablation catheter. HFS (80 ms) was synchronised to each paced stimulus (after 20 ms delay) for delivery within the local atrial refractory period. HFS responses were tagged onto CARTO™ 3D LA geometry. All geometries were transformed onto one reference LA shell. A probability distribution atlas of ET-GP was created. This identified high/low ET-GP probability regions.Results2302 sites were tested with HFS, identifying 579 (25%) ET-GP. 464 ET-GP were characterised, where 74 (16%) triggered ≥30s AF/AT. Median 97 (IQR 55) sites were tested, identifying 19 (20%) ET-GP per patient. >30% of ET-GP were in the roof, mid-anterior wall, around all PV ostia except in the right inferior PV (RIPV) in the posterior wall.ConclusionET-GP can be identified by endocardial stimulation and their anatomical distribution, in contrast to AVD-GP, would be more likely to be affected by wide antral circumferential ablation. This may contribute to AF ablation outcomes.
Keene D, Shun-Shin MJ, Arnold AD, et al., 2020, Within-patient comparison of His-bundle pacing, right ventricular pacing, and right ventricular pacing avoidance algorithms in patients with PR prolongation: Acute hemodynamic study, Journal of Cardiovascular Electrophysiology, Vol: 31, Pages: 2964-2974, ISSN: 1045-3873
AimsA prolonged PR interval may adversely affect ventricular filling and, therefore, cardiac function. AV delay can be corrected using right ventricular pacing (RVP), but this induces ventricular dyssynchrony, itself harmful. Therefore, in intermittent heart block, pacing avoidance algorithms are often implemented. We tested His‐bundle pacing (HBP) as an alternative.MethodsOutpatients with a long PR interval (>200 ms) and intermittent need for ventricular pacing were recruited. We measured within‐patient differences in high‐precision hemodynamics between AV‐optimized RVP and HBP, as well as a pacing avoidance algorithm (Managed Ventricular Pacing [MVP]).ResultsWe recruited 18 patients. Mean left ventricular ejection fraction was 44.3 ± 9%. Mean intrinsic PR interval was 266 ± 42 ms and QRS duration was 123 ± 29 ms. RVP lengthened QRS duration (+54 ms, 95% CI 42–67 ms, p < .0001) while HBP delivered a shorter QRS duration than RVP (−56 ms, 95% CI −67 to −46 ms, p < .0001). HBP did not increase QRS duration (−2 ms, 95% CI −8 to 13 ms, p = .6). HBP improved acute systolic blood pressure by mean of 5.0 mmHg (95% CI 2.8–7.1 mmHg, p < .0001) compared to RVP and by 3.5 mmHg (95% CI 1.9–5.0 mmHg, p = .0002) compared to the pacing avoidance algorithm. There was no significant difference in hemodynamics between RVP and ventricular pacing avoidance (p = .055).ConclusionsHBP provides better acute cardiac function than pacing avoidance algorithms and RVP, in patients with prolonged PR intervals. HBP allows normalization of prolonged AV delays (unlike pacing avoidance) and does not cause ventricular dyssynchrony (unlike RVP). Clinical trials may be justified to assess whether these acute
Normahani P, Sounderajah V, Harrop-Griffiths W, et al., 2020, Achieving good-quality consent: review of literature, case law and guidance, British Journal of Surgery, Vol: 4, Pages: 757-763, ISSN: 0007-1323
BackgroundInformed consent is an integral part of clinical practice. There is widespread agreement amongst health professionals that obtaining procedural consent needs to move away from a unidirectional transfer of information to a process of supporting patients in making informed, self‐determined decisions. This review aimed to identify processes and measures that warrant consideration when engaging in consent‐based discussions with competent patients undergoing elective procedures.MethodsFormal written guidance from the General Medical Council and Royal College of Surgeons of England, in addition to peer‐reviewed literature and case law, was considered in the formulation of this review.ResultsA framework for obtaining consent is presented that is informed by the key tenets of shared decision‐making (SDM), a model that advocates the contribution of both the clinician and patient to the decision‐making process through emphasis on patient participation, analysis of empirical evidence, and effective information exchange. Moreover, areas of contention are highlighted in which further guidance and research are necessary for improved enhancement of the consent process.ConclusionThis SDM‐centric framework provides structure, detail and suggestions for achieving meaningful consent.
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