G. André Ng

Aims European and American clinical guidelines for implantable cardioverter defibrillators are insufficiently accurate for ventricular arrhythmia (VA) risk stratification, leading to significant morbidity and mortality. Artificial intelligence offers a novel risk stratification lens through which VA capability can be determined from the electrocardiogram (ECG) in normal cardiac rhythm. The aim of this study was to develop and test a deep neural network for VA risk stratification using routinely collected ambulatory ECGs. Methods and results A multicentre case–control study was undertaken to assess VA-ResNet-50, our open source ResNet-50-based deep neural network. VA-ResNet-50 was designed to read pyramid samples of three-lead 24 h ambulatory ECGs to decide whether a heart is capable of VA based on the ECG alone. Consecutive adults with VA from East Midlands, UK, who …

Chronic kidney disease (CKD) and atrial fibrillation (AF) are associated with significant cardiovascular morbidity and mortality. Recent studies have highlighted an increased prevalence and incidence of AF in patients with CKD. This article aims to provide a comprehensive review of current management strategies and considerations of treating atrial fibrillation with concomitant CKD. Potential electrophysiological mechanisms between AF and CKD are explored. Current evidence and literature focusing on pharmacological rate and rhythm control along with procedural intervention is reviewed and presented. The management of AF and CKD together is complex, but particularly pertinent when considering the close cyclical relationship in the progression of both diseases.

Aims Recent trial data demonstrate beneficial effects of active rhythm management in patients with atrial fibrillation (AF) and support the concept that a low arrhythmia burden is associated with a low risk of AF-related complications. The aim of this document is to summarize the key outcomes of the 9th AFNET/EHRA Consensus Conference of the Atrial Fibrillation NETwork (AFNET) and the European Heart Rhythm Association (EHRA). Methods and results Eighty-three international experts met in Münster for 2 days in September 2023. Key findings are as follows: (i) Active rhythm management should be part of the default initial treatment for all suitable patients with AF. (ii) Patients with device-detected AF have a low burden of AF and a low risk of stroke. Anticoagulation prevents some strokes and also increases major but non-lethal bleeding. (iii) More research is needed to …

BackgroundAortic stenosis is a life-limiting condition for which transcatheter aortic valve implantation (TAVI) is an established therapy. Coronary artery disease (CAD) is frequently found in this patient group and optimal management in these patients remains uncertain.ObjectivesWe sought to examine the association of coexistent CAD on mortality and hospital readmission in patients undergoing TAVI.MethodsIn this observational cohort study, we examined patients who underwent TAVI and segregated them by the presence of obstructive epicardial CAD. The primary outcome was 3-year mortality with secondary outcomes being readmission for (1) all-causes, (2) a MACE (Major Adverse Cardiovascular Event) composite endpoint and (3) acute coronary syndrome. Subsidiary outcomes included patient angina and breathlessness scores.Results898 patients underwent TAVI, of which 488 (54.3%) had unobstructed …

Electrocardiogram (ECG) delineation to identify the fiducial points of ECG segments, plays an important role in cardiovascular diagnosis and care. Whilst deep delineation frameworks have been deployed within the literature, several factors still hinder their development: (a) data availability: the capacity of deep learning models to generalise is limited by the amount of available data; (b) morphology variations: ECG complexes vary, even within the same person, which degrades the performance of conventional deep learning models. To address these concerns, we present a large-scale 12-leads ECG dataset, ICDIRS, to train and evaluate a novel deep delineation model-ECGVEDNET. ICDIRS is a large-scale ECG dataset with 156,145 QRS onset annotations and 156,145 T peak annotations. ECGVEDNET is a novel variational encoder-decoder network designed to address morphology variations. In ECGVEDNET, we …

Background Sudden cardiac death (SCD) risk markers are needed in Chagas cardiomyopathy (CC). Action potential duration restitution (APDR) dynamics is capable of extracting information on cardiac regional heterogeneity. This study intends to develop a patient‐specific variables‐based algorithm to predict SCD in the low‐intermediate subgroups of the Rassi risk score. Methods Cross‐sectional study of patients who underwent 24‐h Holter for research purposes between January 1992 and February 2017. From 4‐h ECG segment, RR series were generated and APDR dynamics metrics were calculated. Classification tree and sensitivity analysis were applied. As outcomes, SCD, SCD‐free and non‐cardiovascular death and 34 variables were included. Results Two hundred twenty‐one (129 in the group SCD‐free, 80 in the SCD group and 12 non‐cardiovascular death group) were analyzed. In the groups …

ObjectivesLittle work has been done investigating the prevalence and impact of comorbidities on cholera outcomes within conflict settings. We describe the clinical outcomes of patients treated for cholera in Latakia, Syria, during the 2022–2023 cholera outbreak.MethodsWe performed a single-centre retrospective observational cohort study of patients admitted to the hospital with suspected cholera between 15th December 2022 and 15th February 2023 at National Hospital, Latakia, Syria. Multivariable negative binomial regression analysis was used to investigate the variables’ relationship to hospital length of stay.ResultsThe study involved 89 patients admitted to the hospital; none were vaccinated against cholera. Cholera rapid diagnostic test was positive in 91 % of patients. Half of the patients (51 %) were male; a third (35 %) had hypertension, and a fifth (19 %) had diabetes. One patient passed away during …

BackgroundDuring the COVID-19 pandemic, countries undergoing conflict have faced difficulties in mounting an effective health response. This observational cohort study describes the treatments and outcomes for inpatients with COVID-19 in the Syrian city of Latakia.Design and methodsA single-centre observational cohort study was conducted at Tishreen University Hospital, involving all patients over 18 admitted between October 1 and December 31, 2021 with a positive RT-PCR test for SARS-CoV-2. Clinical features, investigations, treatments, and outcomes were reported.ResultsIn total, 149 patients fitted the study criteria. Only one patient was double vaccinated against COVID-19. Oxygen supplementation was required in 87% (n = 130) of participants. Invasive mechanical ventilation was required in 4% (n = 5). Therapeutic anticoagulation was administered in 97.3% (n = 144). Intravenous dexamethasone …

Introduction Computed Tomography Pulmonary Angiography (CTPA) scans have become readily accessible in healthcare to diagnose Pulmonary Embolism (PE). In real-world settings, there is variability in practice patterns with a growing culture of a more pragmatic approach related to D-dimer testing and subsequent utilisation of CTPAs. However, the issue of D-dimer low specificity remains, risking increased unnecessary scanning and lower diagnostic yield. We aimed to correlate D-dimer testing to the utilisation and diagnostic outcome of CTPAs.Methods This was a single-centre retrospective observational study. We collected data on all D-Dimer tests ordered by physicians to rule out PE at a high-volume acute cardio-respiratory unit. Correlation analysis was conducted using Pearson coefficients or Spearman’s correlation, to examine D-Dimer testing correlation with CTPA utilisation and diagnostic yield …

AimsHeart failure is a clinical syndrome typified by abnormal autonomic tone, impaired ventricular function, and increased arrhythmic vulnerability. This study aims to examine electrophysiological, structural and neuronal remodeling following myocardial infarction in a rabbit heart failure model to establish its neuro-cardiac profile.Methods and resultsWeight-matched adult male New Zealand White rabbits (3.2 ± 0.1 kg, n = 25) were randomized to have coronary ligation surgeries (HF group, n = 13) or sham procedures (SHM group, n = 12). Transthoracic echocardiography was performed six weeks post-operatively. On week 8, dual-innervated Langendorff-perfused heart preparations were set up for terminal experiments. Seventeen hearts (HF group, n = 10) underwent ex-vivo cardiac MRI. Twenty-two hearts (HF group, n = 7) were examined histologically. Electrical remodeling and abnormal autonomic profile were …

The rate of successful outcomes of catheter ablation to treat persistent atrial fibrillation (persAF) using individual features including dominant frequency (DF), complex fractionated atrial fibrillation (CFAE), and rotors have been disappointing. We aim to identify the most important electrogram (EGM) features for successful ablations using a Random Forest (RF) classifier. A total of 3206 EGMs were collected using non-contact mapping catheter from 10 patients. 1490 EGMs were labelled as positive responses to ablation and 1716 EGMs as negative. Features were extracted from the three EGM signal domains (spectral, temporal and statistical) using time series feature extraction library in python. Five-fold cross validation (CV) was used for training and testing the classifier. A CV accuracy of 80.54% and F1 score of 78.23% were achieved for classifying the responses of EGMs to catheter ablation, with a sensitivity of 75.2 …

IntroductionObstructive sleep apnoea (OSA) is associated with increased cardiovascular mortality despite continuous positive airways pressure (CPAP) therapy. This excess risk may be related to increased arrhythmia risk, especially atrial fibrillation (AF). The true incidence of arrhythmia in patients with OSA is unknown. Implantable loop recorders (ILR) are powerful tools for detecting arrhythmias long-term. Cardiac autonomic function may be important in arrhythmogenesis in these patients but needs further study. We aim to identify the true incidence of arrhythmias (especially AF) using ILRs, assess cardiac autonomic function using Holter monitors in patients with OSA and explore cardiovascular outcomes.Methods and analysisA two-centre (University Hospital Coventry and St. Cross Hospital, Rugby) nested cohort study using Reveal LINQ (Medtronic, UK) ILR to identify precise arrhythmia (atrial/ventricular …

It felt like only yesterday when I took up the position as Vice President (Education & Research) of the British Cardiovascular Society (BCS) in 2020, and my 3-year term comes to an end this year. A key remit of my BCS role is to chair the Programme Committee, which is responsible for the scientific content of the Annual Conference. The Committee has had a particularly stimulating job the past 2 years. First, we had gone through the COVID-19 pandemic with lockdown mandating conversion to a virtual conference for the first time in 2021. Last year (2022) saw an enhanced centenary programme celebrating the first 100 years of the Society as the longest established professional cardiac society in the world and at the same time looking forward to the future. We were particularly honoured to have endorsement from the Princess Royal as our Royal patron for the centenary year, who delivered a fantastic keynote …

Introduction Atrial fibrillation (AF) represents a major public health challenge. Our ability to prolong our lives has inevitably led to an increase in the incidence of AF, with a subsequent increase in AF-related hospitalisations. Virtual wards could be the way forward, especially with the rise in global access to digital telecommunication post COVID-19. We implemented a virtual ward for hospital patients presenting with fast AF or atrial flutter (AFL), aiming to provide remote hospital-level care at home.Methods Patients presenting acutely with AF/AFL and rapid ventricular response to the hospital were onboarded to the virtual ward and managed remotely at home, after being given access to a single-lead ECG device (Kardia), a blood pressure monitor, and pulse oximeter with instructions to record daily ECGs, blood pressure, oxygen saturations and to complete an online AF symptom questionnaire via a smartphone app …

BackgroundAtrial fibrillation (AF) is common in individuals with heart failure (HF). Individuals with HF and AF may have a reduced functional capacity and quality of life (QoL) which leads to hospital admission and burden on clinical services. Evidence supported the effect of exercise training in individuals with HF. However, there is no existing data on the effectiveness of comprehensive cardiac rehabilitation (CR) in individuals with coexisting HF and AF.AimTo explore the effect of CR in individuals with HF and AF compared with those with HF and no-coexisting AF.MethodsUsing CR database, individuals with HF and AF were identified and propensity matched to those with no coexisting AF. The change in incremental shuttle walking test, Heart Disease Quality of Life questionnaire, Hospital Anxiety and Depression Scores were compared between groups pre-CR and post-CR.Results149 individuals were propensity …

Ablation of persistent atrial fibrillation (persAF) targets based on signal processing techniques have been disappointing. Machine learning (ML) tools may be the solution to improve the catheter ablation responses using features from three electrogram (EGM) signal domains (spectral, temporal and statistical). 3206 EGMs were collected using non-contact technique from 10 patients. 1716 EGMs have a negative catheter ablation response and 1490 EGMs a positive response. A Logistic Regression (LR) classifier was used to classify the EGMs based on responses to catheter ablation. The performance of LR for each domain features was evaluated using five different matrices (validation accuracy, sensitivity, specificity, precision and F1_score). A 5-fold cross validation (CV) accuracy of91.64%, 72.68% and 67.31% was achieved using LR based on spectral, temporal and statistical features, respectively. The four …

The autonomic nervous system consisting of two limbs, the sympathetic and parasympathetic nervous system, plays a key role in the modulation of various cardiac arrhythmias. Neurotransmitters, including catecholamines and acetylcholine, as well as other co-transmitters mediate supraventricular and ventricular arrhythmogenesis through distinctive electrophysiologic mechanisms. The intricate autonomic interplay depicts that most arrhythmias arise from sympathetic overactivity and parasympathetic attenuation, with the sympathetic nervous system mitigating the effects of antiarrhythmic drugs. While this remains true for adrenergic-driven arrhythmias such as atrial fibrillation, post-infarct ventricular tachycardia, and some long QT syndromes 1 and 2, parasympathetic nervous overactivity may act as a trigger for vagotonic arrhythmias including Brugada syndrome, long QT syndrome 3, and idiopathic ventricular …

Aims Excessive prolongation of PR interval impairs coupling of atrio‐ventricular (AV) contraction, which reduces left ventricular pre‐load and stroke volume, and worsens symptoms. His bundle pacing allows AV delay shortening while maintaining normal ventricular activation. HOPE‐HF evaluated whether AV optimized His pacing is preferable to no‐pacing, in a double‐blind cross‐over fashion, in patients with heart failure, left ventricular ejection fraction (LVEF) ≤40%, PR interval ≥200 ms and either QRS ≤140 ms or right bundle branch block. Methods and results Patients had atrial and His bundle leads implanted (and an implantable cardioverter‐defibrillator lead if clinically indicated) and were randomized to 6 months of pacing and 6 months of no‐pacing utilizing a cross‐over design. The primary outcome was peak oxygen uptake during symptom‐limited exercise. Quality of life, LVEF and patients' …

BackgroundVery high power short duration (vHPSD) radiofrequency ablation (RFA) may reduce ablation times and improve patient tolerability, permitting pulmonary vein isolation (PVI) under mild conscious sedation (mCS) and promoting same day discharge (SDD).MethodsFirst, a retrospective feasibility study was performed at 2 tertiary cardiac centres in the UK. Consecutive cases of first-time PVI using vHPSD ablation with 90 W lesions for up to 4 s were compared against cases performed using standard RF (sRF) and cryoballoon (Cryo) therapy. Subsequently, a prospective study of patients who had vHPSD or Cryo exclusively under mCS was undertaken. Questionnaires based on Likert and visual analogue scales (VAS) were used to measure anxiety, discomfort and pain.ResultsIn total, 182 patients (59 vHPSD, 62 sRF and 61 Cryo) were included in the retrospective study, with 53 (90%) of vHPSD cases …

Introduction Atrial Fibrillation (AF) is the commonest cardiac arrhythmia in clinical practice with AF-related hospital admissions driving the main cost and capacity burden. Virtual wards are novel clinical pathways that support patients remotely, whilst maintaining safe and high quality care.The conventional treatment for patients presenting acutely with AF or Atrial flutter (AFL) and rapid ventricular response is to remain in hospital for several days, until achieving their condition is stabilised with rate or rhythm control. We developed and implemented a novel AF Virtual ward run by Specialist Cardiology Advanced Care Practitioners (ACPs) with medical support; providing remote clinical out-of-hospital care whilst focusing on improving patients’ care pathway and experience.Methods A prior retrospective 8-week audit of acute AF or AFL admissions showed 51% (n=105) of patients met the proposed virtual ward criteria (i.e …

Background Device-detected atrial high-rate episodes (AHREs) are atrial arrhythmias detected by implanted cardiac devices. AHREs resemble atrial fibrillation but are rare and brief. Whether the occurrence of AHREs in patients without atrial fibrillation (as documented on a conventional electrocardiogram [ECG]) justifies the initiation of anticoagulants is not known. Methods We conducted an event-driven, double-blind, double-dummy, randomized trial involving patients 65 years of age or older who had AHREs lasting for at least 6 minutes and who had at least one additional risk factor for stroke. Patients were randomly assigned in a 1:1 ratio to receive edoxaban or placebo. The primary efficacy outcome was a composite of cardiovascular death, stroke, or systemic embolism, evaluated in a time-to-event analysis. The safety outcome was a composite of death from any cause or major bleeding. Results The …

Funding Acknowledgements Type of funding sources: None. Background Atrial Fibrillation (AF) is the most common cardiac arrhythmia. AF related hospital admissions are rising, with significant cost and capacity implications. Virtual wards are novel pathways designed to support patients remotely, whilst maintaining safe high quality patient care, changing the landscape of care provision. Purpose The standard pathway for patients presenting acutely with AF or Atrial flutter (AFL), is to remain in hospital between 2-5 days, attached to a heart monitor until achieving rate or rhythm control. We developed an AF Virtual ward run by a specialist multi-disciplinary team; to provide remote out-of-hospital care for patients with AF or AFL and rapid ventricular response whilst focusing on improving patients’ care pathway and experience. Methods …

Background Ebstein’s anomaly occurs when there is an apical displacement of the tricuspid valve with septal and posterior valve leaflets tethering. This condition often occurs in association with other congenital, structural, or conduction system diseases, including intracardiac shunts, valvular lesions, arrhythmias, accessory conduction pathways, and first-degree atrioventricular (AV) block. We present for the first time a case of a patient with Ebstein’s anomaly who presented with second-degree Mobitz II AV block and was successfully treated with conduction system pacing (CSP) due to her young age and the likelihood of a long-term high percentage of pacing. Case summary We present a case of a 42-year-old lady with a background of complex congenital heart disease, including severe pulmonary stenosis, Ebstein anomaly, and atrial septal defect (ASD). She required …

Nicotine is the primary addictive component in tobacco products. Through its actions on the heart and autonomic nervous system, nicotine exposure is associated with electrophysiological changes and increased arrhythmia susceptibility. However, the underlying mechanisms are unclear. To address this, we treated rabbits with transdermal nicotine (NIC, 21 mg/day) or control (CT) patches for 28 days prior to performing dual optical mapping of transmembrane potential (RH237) and intracellular Ca2+ (Rhod-2 AM) in isolated hearts with intact sympathetic innervation. Sympathetic nerve stimulation (SNS) was performed at the 1st - 3rd thoracic vertebrae, and β-adrenergic responsiveness was additionally evaluated as changes in heart rate (HR) following norepinephrine (NE) perfusion. Baseline ex vivo HR and SNS stimulation threshold were increased in NIC vs. CT (P = 0.004 and P = 0.003 respectively). Action potential duration alternans emerged at longer pacing cycle lengths (PCL) in NIC vs. CT at baseline (P = 0.002) and during SNS (P = 0.0003), with similar results obtained for Ca2+ transient alternans. SNS reduced the PCL at which alternans emerged in CT but not NIC hearts. NIC exposed hearts also tended to have slower and reduced HR responses to NE perfusion. While fibrosis was unaltered, NIC hearts had lower sympathetic nerve density (P = 0.03) but no difference in NE content vs. CT. These results suggest both sympathetic hypo-innervation of the myocardium and diminished β-adrenergic responsiveness with NIC. This autonomic remodeling may underlie the increased risk of arrhythmias associated with nicotine exposure, which …

Background Identifying features associated with atrial fibrillation (AF) documentation could inform screening. This study used published data to describe differences in documented and estimated AF prevalence in general practices, and explored predictors of variations in AF prevalence. Methods Cross-sectional study of 7318 general practices in England. Descriptive and inferential statistics were undertaken. Multiple linear regression was used to model the difference between estimated AF and documented AF, adjusted for population, practice and practice performance variables. Results Documented AF prevalence was lower than estimated (− 0.55% 95% confidence intervals, −1.89, 2.99). The proportion of variability accounted for in the final regression model was 0.25. Factors positively associated with AF documentation (increase in difference between …

Funding Acknowledgements Type of funding sources: Private grant(s) and/or Sponsorship. Main funding source(s): Saudi Arabia cultural Bureau. Introduction Individuals living with Atrial Fibrillation (AF) can experience a variety of symptoms such as palpitation, dyspnea, fatigue and dizziness which lead to reduced physical activity levels and quality of life.(1) Current management of AF mainly focus on pharmacological treatments and invasive procedures, while no routine prescription of exercise or rehabilitation programme is offered. Aims To understand the severity of symptoms that individuals with AF may experience and their preference of a structured rehabilitation programme. Methods A cross-sectional survey was conducted through the phone and face to face between 20th of September and 20thof December 2021 for individuals …

BackgroundPatients with ischemic stroke and atrial fibrillation (AF) are at particularly high risk for recurrent stroke and cardiovascular events. Early rhythm control has been shown to be superior to usual care for the prevention of stroke and cardiovascular events for people with early AF. There are no data on the willingness to use rhythm control for patients with AF and acute ischemic stroke in clinical practice. MethodsAn online survey was carried out among stroke physicians to assess current practice and attitudes toward rhythm control in patients with AF and acute ischemic stroke between December 22nd 2021 and March 24th 2022. ResultsThe survey was completed by 277 physicians including 237 from 15 known countries and 40 from unspecified countries. 79% (210/266) reported that they do not regularly apply treatment for rhythm control by ablation or antiarrhythmic drugs at all or only in small numbers (≤ …

Background:Open Access CorrectionCorrection: Mäkynen et al. Wearable Devices Combined with Artificial Intelligence—A Future Technology for Atrial Fibrillation Detection? Sensors 2022, 22, 8588

Background Atrial fibrillation (AF) continues to represent a global health challenge. Our ability to prolong our lives has inevitably led to an increase in the incidence of AF, with subsequent increase in AF-related hospitalisations. With at least 92% of the global population having access to a digital telecommunication medium, virtual wards could be the way forward for managing acute AF patients. Purpose We implemented a virtual ward for hospital patients presenting with fast AF or atrial flutter (AFL), aiming to provide remote hospital-level care. Methods Patients presenting acutely with AF/AFL to the hospital were onboarded to the virtual ward and managed remotely at home, after being given access to a single-lead ECG device, a blood pressure monitor and pulse oximeter with instructions to record daily ECGs, blood pressure, oxygen saturations and to …

Background Atrial fibrillation (AF) is the most common sustained arrhythmia worldwide. However, there is no data on AF inpatient management strategies and clinical outcomes in Syria. Objectives This study aims to navigate AF inpatient management and cardiovascular (CV) mortality in a tertiary cardiology centre in Latakia, Syria. Methods A single-centre retrospective observational cohort study was conducted at Tishreen University Hospital, Latakia, Syria, from June 2021 to June 2023. We included patients ≥16 years of age presenting and being treated for AF as the primary diagnosis at the emergency department. Medical records were examined for patient demographics, laboratory results, treatment plans and inpatient details. Inpatient cardiovascular mortality was the primary outcome of interest. Results The study included 596 patients. The median age was 58 and 61% were males. Only 121 patients (20.3%) were known to have AF. Rhythm control strategy was persuaded in 39% of patients, with Amiodarone being the only agent utilised while the rest adopted a rate control approach. CV Mortality occurred in 28 patients (4.7%). The presence of smoking (aOR: 1.6, 95% CI: 1.3 to 2.1, P=0.04), thyroid disease (aOR= 9.7, 95% CI= 1.2 to 91.6, P<0.001), COPD (aOR: 82, 95% CI: 12.7 to 711, P<0.001) and valvular heart disease (VHD) (aOR= 9.1, 95% CI: 1.7 to 55.1, P<0.001) were independent risk factors of cardiovascular inpatient mortality. Conclusion Current smoking, thyroid disease, COPD and VHD were independent risk factors of inpatient cardiovascular mortality with AF in Syria. Elective rhythm control was the main hurdle due to limited …

Introduction: Obesity affects nearly 650 million adults worldwide and the prevalence of obesity has been steadily increasing. Obesity has adverse effects on cardiovascular health, increasing the risk for developing hypertension, coronary artery disease, heart failure and atrial fibrillation (AF). It is well known that anticoagulation is warranted in patients with AF, however the safety and efficacy of direct oral anti-coagulant (DOAC) over vitamin K antagonist (VKA) are not well explored in the obese population. This meta-analysis aimed to compare DOAC to VKA in obese populations with AF. Methods: The PRISMA guidelines were followed for this meta-analysis, and it was registered in PROSPERO (CRD42023392711). PubMed, Medline, Embase, Cochrane Library and Scopus databases were searched for relevant articles from inception through January 2023. Two independent authors screened title and abstract …

Funding Acknowledgements Type of funding sources: Public Institution(s). Main funding source(s): The pilot phase of the Virtual Ward was funded by Leicester, Leicestershire and Rutland Clinical Commissioning Group and supported by a Digital Healthcare Partnership Award from NHS Innovation (now Transformation Directorate). Background The current model of care for patients with atrial fibrillation (AF) is born out of legacy physician-centred care models. The development and acceptance of digital technology have enabled the advent of novel telemedicine-based models for patients with fast AF. Purpose A virtual AF ward was implemented as a proof-of-concept care model for patients with AF and rapid ventricular response. Methods Patients presenting acutely with AF or Atrial flutter (AFL) to the hospital were onboarded to the …

BackgroundAtrial fibrillation (AF) represents a growing healthcare challenge, mainly driven by acute hospitalisations. Virtual wards could be the way forward to manage acute AF patients through remote monitoring, especially with the rise in global access to digital telecommunication and the growing acceptance of telemedicine post-COVID-19.MethodsAn AF virtual ward was implemented as a proof-of-concept care model. Patients presenting acutely with AF or atrial flutter and rapid ventricular response to the hospital were onboarded to the virtual ward and managed at home through remote ECG-monitoring and ‘virtual’ ward rounds, after being given access to a single-lead ECG device, a blood pressure monitor and pulse oximeter with instructions to record daily ECGs, blood pressure, oxygen saturations and to complete an online AF symptom questionnaire. Data were uploaded to a digital platform for daily review …

MethodsA retrospective deep case control design was undertaken at University Hospitals Leicester and Kettering, UK. The SCD cohort was entire cohort available combined with the availability of Holter data between 2018-2022. A convenience sample of normal Holters was used as the comparator cohort over 5 days. Single lead 128Hz Spacelabs Lifecard CF Holter monitors were sampled to couple fastest and slowest 10 second intervals as inputs to the AI to capture morphology and heart rate variability signals. Data was split 80/20 train/test sets by subjects, ensuring no data leakage. Each Holter recording was sampled 40 times to increase the number of inputs for the model. Time-frequency representations of 10s ECGs were generated using Short-time Fourier transform. InceptionResNetV2, a pre-trained convolutional neural network was further trained to classify Holter recordings as SCD or normal until there …

Most resuscitated cardiac arrest patients are comatose and often die due to severe brain injury. With the uncertainty of which patient will survive or not, it is important for the right prognosis to be given. This would help decide which patient intensive care should be focused on. Machine learning, which is a revolutionary computer program that can work without explicit instructions, could be used to study neurological patterns, and make better prognosis. As part of the Predicting Neurological Recovery from Coma After Cardiac Arrest: The George B. Moody Physionet Challenge 2023, our team, Leicester Fox, focused on the comparison of the effectiveness of shallow and deep learning machine learning models in giving the right prognosis on chances of survival of cardiac arrest comatose patients. Features extracted from the electroencephalography (EEG) of 607 patients are used for this analysis. Three groups of …

Introduction Obstructive sleep apnoea (OSA) is associated with increased cardiovascular mortality despite continuous positive airways pressure (CPAP) therapy. This excess risk may be related to increased arrhythmia risk, especially atrial fibrillation (AF). The true incidence of arrhythmia in patients with OSA is unknown. Implantable loop recorders (ILR) are powerful tools for detecting arrhythmias long-term. Cardiac autonomic function may be important in arrhythmogenesis in these patients but needs further study. We aim to identify the true incidence of arrhythmias (especially AF) using ILRs, assess cardiac autonomic function using Holter monitors in patients with OSA and explore cardiovascular outcomes. Methods and analysis A two-centre (University Hospital Coventry and St. Cross Hospital, Rugby) nested cohort study using Reveal LINQ (Medtronic, UK) ILR to identify precise arrhythmia (atrial/ventricular …

Cardiac rhythm disturbances, including arrhythmias and sudden cardiac death (SCD), represent a major worldwide public health problem, accounting for 15%–20% of all deaths (Mehra, 2007; Srinivasan and Schilling, 2018). The electrophysiological mechanisms underlying certain cardiac arrhythmias and SCD are not completely understood. There is still strong debate whether rhythm disturbances such as atrial and ventricular fibrillation are caused entirely by disorganized rhythms, sustained by multiple wavefronts, or if they are caused by organized drivers with subsequent wave breaks and fibrillatory conduction (Nattel, 2003; Nash et al., 2006).Computational methods for prediction, classification and therapy of cardiac arrhythmias and SCD are of great interest to improve the clinical outcomes of these disorders. However, considerable challenges persist that limit the efficacy and cost-effectiveness of available methodologies. It is therefore vital to develop computational tools to help better understand the underlying mechanisms and improve effectiveness and efficacy of current therapies.

Purpose: Several studies have emphasised the significance of high dominant frequency (HDF) and rotors in the perpetuation of AF. However, the co-localisation relationship between both attributes is not completely understood yet. In this study, we aim to evaluate the spatial distributions of HDF regions and rotor sites within the left atrium (LA) pre and post HDF-guided ablation in PersAF.Methods: This study involved 10 PersAF patients undergoing catheter ablation targeting HDF regions in the LA. 2048-channels of atrial electrograms (AEG) were collected pre- and post-ablation using a non-contact array (EnSite, Abbott). The dominant frequency (DF, 4–10 Hz) areas with DF within 0.25 Hz of the maximum out of the 2048 points were defined as “high” DF (HDF). Rotors were defined as PSs that last more than 100 ms and at a similar location through subsequent phase frames over time.Results: The results indicated an extremely poor spatial correlation between the HDF regions and sites of the rotors in pre-versus post-ablation cases for the non-terminated (pre: CORR; 0.05 ± 0.17. vs. post: CORR; −0.030 ± 0.19, and with terminated patients (pre: CORR; −0.016 ± 0.03. post: CORR; −0.022 ± 0.04). Rotors associated with AF terminations had a long-lasting life-span post-ablation (non-terminated vs. terminated 120.7 ± 6.5 ms vs. 139.9 ± 39.8 ms), high core velocity (1.35 ± 1.3 mm/ms vs. 1.32 ± 0.9 mm/ms), and were less meandering (3.4 ± 3.04 mm vs. 1.5 ± 1.2 mm). Although the results suggest a poor spatial overlapping between rotors’ sites and sites of AFCL changes in terminated and non-terminated patients, a higher correlation was determined in …

Background People living with Atrial Fibrillation (AF) can experience symptoms such as palpitation, dyspnea, fatigue and dizziness which lead to reduced physical activity levels and quality of life [1,2]. Current management of AF mainly focus on pharmacological treatments and invasive procedures, while no routine prescription of exercise or rehabilitation programme is offered. Purpose To assess the views and opinions of healthcare professionals about delivering a tailored exercise/cardiac rehabilitation programme to people living with AF, and to explore the barriers in referral to this programme. Methods A cross-sectional survey was conducted online between April and September 2021 for healthcare professionals who are involved in the care for adults with AF in UK. A range of professions were targeted, including general practitioners, cardiac physicians …

Background Atrial fibrillation (AF) hospital admissions represent significant AF related treatment costs nationally. In the year 2019–2020 our hospital reported 1,333 admissions with a primary diagnosis of AF, with a 10% annual increase. A virtual ambulatory AF ward providing multidisciplinary care with remote hospital-level monitoring could reshape the future model of AF management. Methods An AF virtual ward was implemented at our UK tertiary centre, as a proof-of-concept model of care. Patients admitted with a primary diagnosis of AF satisfying the AF virtual ward (AFVW) entry criteria (i.e., haemodynamically stable, HR <140 bpm with other acute conditions excluded) were given access to a single lead ECG recording device, a Bluetooth integrated blood pressure machine and pulse oximeter with instruction to record daily ECGs, blood pressure readings, oxygen …

Minocycline, a tetracycline group of antibiotics, is commonly used to treat various infections, dermatological conditions and rarely used to treat rheumatoid arthritis. Prolonged use of minocycline in higher doses can rarely cause skin hyperpigmentation. Minocycline-induced hyperpigmentation can also involve the sclera and retina in the eyes. It can rarely involve nail beds as well.

Background Minimizing right ventricular (RV) pacing to reduce the progression of heart failure is an established practice. Proprietary algorithms to reduce unnecessary RV pacing have been incorporated into both simple and complex cardiac pacemaker devices, for reducing the possibility of heart failure and arrhythmias. Case summary We present a case of a 43-year-old male implanted with a dual-chamber primary prevention implantable cardioverter-defibrillator (AUTOGEN EL, Boston Scientific) for sudden cardiac death. At the time of implant, the patient had hypertrophic cardiomyopathy with mild left ventricular (LV) systolic impairment, and sinus rhythm with intact atrioventricular (AV) conduction. The patient developed progression of his disease with symptoms (dyspnoea) and LV impairment. This led to a decision to activate the minimal RV pacing algorithm (RYTHMIQ™). A …

BackgroundPulmonary vein isolation (PVI) is the cornerstone treatment for patients with atrial fibrillation (AF) refractory to medical therapy. Recent advancements has led to the development of contact-force (CF) sensing very-high-power short-duration (vHPSD) radiofrequency (RF) ablation (90W/4 seconds). Previous RF ablation utilised Ablation Index (AI) as a marker of lesion quality to guide the operator which is not utilised in QMODE+(vHPSD) and thus, there is limited information on effective lesion formation. In this study, we evaluated the correlation between various lesion parameters to identify relationships and potential surrogate markers for effective lesion formation. Moreover, we studied the relationship between different anatomical locations on these parameters to gain further insight. Method50 consecutive AF patients (33 males, age 62.0±1.31 years, 66% paroxysmal AF) underwent first time PVI using …

Sodium-glucose co-transporter 2 (SGLT2) inhibitors have been shown to improve cardiovascular outcomes not only in patients with diabetes but also in those with heart failure, irrespective of diabetic status. However, the mechanisms underlying the cardioprotective effects of these newer anti-diabetic drugs remain to be fully elucidated. One exciting avenue that has been recently explored in both preclinical and clinical studies is the modulation of the cardiovascular autonomic nervous system. A reduction in sympathetic nervous system activity by SGLT2 inhibitors may potentially translate into a reduction in arrhythmic risk and sudden arrhythmic death, which may explain, at least partly, the cardioprotection shown in the cardiovascular outcome trials with different SGLT2 inhibitors. Although some of the data from the preclinical and clinical studies are promising, overall the findings can be contradictory. This …

Background Pulmonary vein isolation (PVI) is the cornerstone treatment for patients with atrial fibrillation (AF) refractory to medical therapy. Recent advancements have led to the development of contact-force (CF) sensing very-high-power short-duration (vHPSD) radiofrequency (RF) ablation (90W/4 seconds). Previous RF ablation utilized Ablation Index (AI) as a marker of lesion quality to guide the operator which is not utilized in QMODE+ (vHPSD) and thus, there is limited information on effective lesion formation. In this study, we evaluated the correlation between various lesion parameters to identify relationships and potential surrogate markers for effective lesion formation. Moreover, we studied the relationship between different anatomical locations on these parameters to gain further insight. Methods 50 consecutive AF patients (33 males, age 62.0±1.31 years, 66 …

Introduction: Exposure to air pollution is a recognised risk factor for cardiovascular disease and has been associated with supraventricular arrhythmias. The effect of air pollution on ventricular arrhythmias is less clear. This scoping review assessed the effects of particulate and gaseous air pollutants on the incidence of ventricular arrhythmias.Methods: MEDLINE and EMBASE databases were searched for studies assessing the effects of air pollutants on ventricular tachycardia and ventricular fibrillation. These pollutants were particulate matter (PM) 2.5, PM10, Nitrogen Dioxide (NO 2), Carbon Monoxide (CO), Sulphur Dioxide (SO 2), and Ozone (O 3).Results: This review identified 27 studies: nine in individuals with implantable cardioverter defibrillators, five in those with ischaemic heart disease, and 13 in the general population. Those with ischaemic heart disease appear to have the strongest association with …

Introduction The purpose of this study is to assess the ability of two new ECG markers (Regional Repolarisation Instability Index (R2I2) and Peak Electrical Restitution Slope) to predict sudden cardiac death (SCD) or ventricular arrhythmia (VA) events in patients with ischaemic cardiomyopathy undergoing implantation of an implantable cardioverter defibrillator for primary prevention indication.Methods and analysis Multicentre Investigation of Novel Electrocardiogram Risk markers in Ventricular Arrhythmia prediction is a prospective, open label, single blinded, multicentre observational study to establish the efficacy of two ECG biomarkers in predicting VA risk. 440 participants with ischaemic cardiomyopathy undergoing routine first time implantable cardioverter-defibrillator (ICD) implantation for primary prevention indication are currently being recruited. An electrophysiological (EP) study is performed using a non …

Aims Treatment patterns were compared between randomized groups in EAST-AFNET 4 to assess whether differences in anticoagulation, therapy of concomitant diseases, or intensity of care can explain the clinical benefit achieved with early rhythm control in EAST-AFNET 4. Methods and results Cardiovascular treatment patterns and number of visits were compared between randomized groups in EAST-AFNET 4. Oral anticoagulation was used in >90% of patients during follow-up without differences between randomized groups. There were no differences in treatment of concomitant conditions between groups. The type of rhythm control varied by country and centre. Over time, antiarrhythmic drugs were given to 1171/1395 (84%) patients in early therapy, and to 202/1394 (14%) in usual care. Atrial fibrillation (AF) ablation was performed in 340/1395 (24%) patients randomized …

Introduction Pulmonary vein isolation (PVI) ablation is the established gold standard therapy for patients with symptomatic drug refractory atrial fibrillation (AF). PVI ablation is commonly carried out with either radiofrequency (RF) thermal energy or cryoenergy. Recent advancements in RF ablation, have led to the development of the novel contact force-sensing temperature-controlled very high-power short-duration (vHPSD) RF ablation. This setting delivers 90W for up to 4 seconds with a constant irrigation flow rate of 8 ml/min. The aim of this study was to compare procedural outcomes and safety with conventional radiofrequency ablation. MethodsA single centre observational study was conducted with patients who underwent first time PVI ablation from 2019 to 2021. The cohort was divided in to: 1) vHPSD ablation – QMODE+ via QDOT MICRO TM catheter, 2) QMODE via QDOT MICRO TM catheter and 3 …

Aims Atrial flutter (AFlut) is a common re-entrant atrial tachycardia driven by self-sustainable mechanisms that cause excitations to propagate along pathways different from sinus rhythm. Intra-cardiac electrophysiological mapping and catheter ablation are often performed without detailed prior knowledge of the mechanism perpetuating AFlut, likely prolonging the procedure time of these invasive interventions. We sought to discriminate the AFlut location [cavotricuspid isthmus-dependent (CTI), peri-mitral, and other left atrium (LA) AFlut classes] with a machine learning-based algorithm using only the non-invasive signals from the 12-lead electrocardiogram (ECG). Methods and results Hybrid 12-lead ECG dataset of 1769 signals was used (1424 in silico ECGs, and 345 clinical ECGs from 115 patients—three different ECG segments over time were extracted from each patient …

Introduction Pulmonary vein isolation (PVI) ablation is the established gold standard therapy for patients with symptomatic drug refractory atrial fibrillation (AF). Advancements in radiofrequency (RF) ablation, have led to the development of the novel contact force-sensing temperature-controlled very high-power short-duration (vHPSD) RF ablation. This setting delivers 90W for up to 4 seconds with a constant irrigation flow rate of 8ml/min. The aim of this study was to compare procedural outcomes and safety with conventional radiofrequency ablation. Methods An observational study was conducted with patients who underwent first time PVI ablation from 2019 to 2021. The cohort was divided in to: 1) vHPSD ablation – QMODE+ via QDOT MICRO catheter, 2) QMODE via QDOT MICRO catheter and 3) Conventional power-controlled RF (PCRF) ablation via THERMOCOOOL …

Atrial fibrillation (AF) is the most common cardiac arrhythmia in the world. The arrhythmia and methods developed to cure it have been studied for several decades. However, professionals worldwide are still working to improve treatment quality. One novel technology that can be useful is a wearable device. The two most used recordings from these devices are photoplethysmogram (PPG) and electrocardiogram (ECG) signals. As the price lowers, these devices will become significant technology to increase sensitivity, for monitoring and for treatment quality support. This is important as AF can be challenging to detect in advance, especially during home monitoring. Modern artificial intelligence (AI) has the potential to respond to this challenge. AI has already achieved state of the art results in many applications, including bioengineering. In this perspective, we discuss wearable devices combined with AI for AF detection, an approach that enables a new era of possibilities for the future.

IntroductionThe purpose of this study is to assess the ability of two new ECG markers (Regional Repolarisation Instability Index (R2I2) and Peak Electrical Restitution Slope) to predict sudden cardiac death (SCD) or ventricular arrhythmia (VA) events in patients with ischaemic cardiomyopathy undergoing implantation of an implantable cardioverter defibrillator for primary prevention indication.Methods and analysisMulticentre Investigation of Novel Electrocardiogram Risk markers in Ventricular Arrhythmia prediction is a prospective, open label, single blinded, multicentre observational study to establish the efficacy of two ECG biomarkers in predicting VA risk. 440 participants with ischaemic cardiomyopathy undergoing routine first time implantable cardioverter-defibrillator (ICD) implantation for primary prevention indication are currently being recruited. An electrophysiological (EP) study is performed using a non …

Aims Clinical practice guidelines restrict rhythm control therapy to patients with symptomatic atrial fibrillation (AF). The EAST-AFNET 4 trial demonstrated that early, systematic rhythm control improves clinical outcomes compared to symptom-directed rhythm control. Methods and results This prespecified EAST-AFNET 4 analysis compared the effect of early rhythm control therapy in asymptomatic patients (EHRA score I) to symptomatic patients. Primary outcome was a composite of death from cardiovascular causes, stroke, or hospitalization with worsening of heart failure or acute coronary syndrome, analyzed in a time-to-event analysis. At baseline, 801/2633 (30.4%) patients were asymptomatic [mean age 71.3 years, 37.5% women, mean CHA2DS2-VASc score 3.4, 169/801 (21.1%) heart failure]. Asymptomatic patients randomized to early rhythm control (395/801) received …

It felt rather daunting when I took up as Vice President (Education & Research) of the British Cardiovascular Society (BCS) in 2019 to find that 2022 would be the centenary year of the BCS which my tenure would cover and be responsible for coordinating the annual conference for this important milestone. The COVID-19 pandemic hit and events took over which included the challenges in having to deliver the conference for the first time as a virtual event last year but thankfully it went smoothly and was well received. Nerves are building up now as the date draws near for the centenary conference to be held 6–8 June 2022. On behalf of the President, Board, Executive and Programme Committee at the BCS, we look forward to welcoming you at the BCS Centenary Conference 2022 at Manchester Central. We have prepared an exciting programme to celebrate the BCS being the oldest professional cardiac society of …

Dilated cardiomyopathy (DCM) is a common yet challenging cardiac disease. Great strides have been made in improving DCM prognosis due to heart failure but sudden cardiac death (SCD) due to ventricular arrhythmias remains significant and challenging to predict. High-risk patients can be effectively managed with implantable cardioverter defibrillators (ICDs) but because identification of what is high risk is very limited, many patients unnecessarily experience the morbidity associated with an ICD implant and many others are not identified and have preventable mortality. Current guidelines recommend use of left ventricular ejection fraction and New York Heart Association class as the main markers of risk stratification to identify patients who would be at higher risk of SCD. However, when analysing the data from the trials that these recommendations are based on, the number of patients in whom an ICD delivers …

Congenital heart illnesses impact roughly 1% of newborns, and they are a significant cause of morbidity and mortality in a variety of serious situations, including progressive heart failure. Phonocardiogram (PCG) studies can reveal crucial clinical information about heart malfunction caused by congenital and acquired heart disease. One of the 23th PhysioNet/Computing in Cardiology Challenge 2022 tasks is to develop computer tools for detecting the presence or absence of murmurs from multiple heart sound recordings from multiple auscultation locations. Mel spectrograms were generated from up to 30 seconds per recording and reshaped at input of pre-trained AlexNet. The last three layers of AlexNet were modified to suit the task as multilabel classification. The database was split into 80% for training and 20% for validation. The database appeared imbalanced, so the class with small number of data entries was …

Background Atrial fibrillation (AF) is common in individuals with heart failure (HF). Individuals with either or both HF and AF may have a reduced functional capacity and quality of life which leads to hospital admission and burden on clinical services. Evidence supports the effect of exercise training in individuals with HF. However, there is little existing data on the effectiveness of comprehensive cardiac rehabilitation (CR) programme in individuals with HF and AF.Aim To explore the effect of a comprehensive CR programme for individuals with HF and AF compared to those with no-coexisting AF.Methods Using Glenfield Hospital CR database, individuals with HF and co-existing AF were identified, and propensity matched 1:1 to those with HF and no co-existing AF. Matching was conducted using age, gender, Body Mass Index (BMI), Left Ventricular Ejection Fraction (LVEF) and New York Heart Association (NYHA …

Purpose Sites of highest dominant frequency (HDF) are implicated by many proposed mechanisms underlying persistent atrial fibrillation (persAF). We hypothesized that prospectively identifying and ablating dynamic left atrial HDF sites would favorably impact the electrophysiological substrate of persAF. We aim to assess the feasibility of prospectively identifying HDF sites by global simultaneous left atrial mapping. Methods PersAF patients with no prior ablation history underwent global simultaneous left atrial non-contact mapping. 30 s of electrograms recorded during AF were exported into a bespoke MATLAB interface to identify HDF regions, which were then targeted for ablation, prior to pulmonary vein isolation. Following ablation of each region, change in AF cycle length (AFCL) was documented (≥ 10 ms considered significant). Baseline isopotential maps of ablated regions were retrospectively analyzed …

Funding Acknowledgements Type of funding sources: None. Introduction Chronic right ventricular apical pacing can lead to pacing induced cardiomyopathy in a significant proportion of patients. Conduction system pacing may restore more physiological activation of the heart, and has recently been shown to have favourable outcomes in clinical trials. However there remains concern regarding the long-term outcomes due to lead displacement and high pacing thresholds. The most widely used technique in current practice is to pace the His bundle proximal to the tricuspid valve. Distal His bundle pacing has a number of advantages over proximal His pacing, including, lower capture thresholds, a more stable lead position, less far field atrial sensing and better spacing from the AV node in case ablation of this is required for AF rate control. Despite these, outcomes of distal His …

Background Abnormal autonomic activity including impaired parasympathetic control is a known hallmark of heart failure (HF). Vagus nerve stimulation (VNS) has been shown to reduce the susceptibility of the heart to ventricular fibrillation, however the precise underlying mechanisms are not well understood and the detailed stimulation parameters needed to improve patient outcomes clinically are currently inconclusive. Objective To investigate NO release and cardiac electrophysiological effects of electrical stimulation of the vagus nerve at varying parameters using the isolated innervated rabbit heart preparation. Methods The right cervical vagus nerve was electrically stimulated in the innervated isolated rabbit heart preparation (n = 30). Heart rate (HR), effective refractory period (ERP), ventricular fibrillation threshold (VFT) and electrical restitution were measured as well as NO release from the left ventricle …

Sequential electrogram collection using multipolar catheters (Pantaray, HD Grid, etc.) is increasingly used in persistent atrial fibrillation (persAF) mapping. However, it is unknown whether sequential mapping is suitable for dominant frequency (DF) mapping, as DF tends to be spatiotemporally unstable. We aim to model and compare simultaneously and sequentially collected EGMs for DF mapping.

Aims Most patients who receive implantable cardioverter defibrillators (ICDs) for primary prevention do not receive therapy during the lifespan of the ICD, whilst up to 50% of sudden cardiac death (SCD) occur in individuals who are considered low risk by conventional criteria. Machine learning offers a novel approach to risk stratification for ICD assignment. Methods and results Systematic search was performed in MEDLINE, Embase, Emcare, CINAHL, Cochrane Library, OpenGrey, MedrXiv, arXiv, Scopus, and Web of Science. Studies modelling SCD risk prediction within days to years using machine learning were eligible for inclusion. Transparency and quality of reporting (TRIPOD) and risk of bias (PROBAST) were assessed. A total of 4356 studies were screened with 11 meeting the inclusion criteria with heterogeneous populations, methods, and outcome measures …

IntroductionAtrial fibrillation (AF) is the commonest arrhythmia in clinical practice with significant detrimental health impacts. Much effort has been spent in mapping AF, determine its triggers and drivers, and how to develop tools to eliminate these triggers.Areas CoveredIn this state of-the-art review article, we aim to highlight the recent techniques in catheter-based management of Atrial Fibrillation; including new advancements either in the catheter design or the software used. This includes a comprehensive summary of the most recent tools used in AF mapping and subsequent ablation.Expert opinionElectrical isolation of the pulmonary veins has been developed and established as the cornerstone in AF ablation with good results in patients with paroxysmal AF (PAF) whilst new ablation tools are aimed at streamlining the procedure. However, the quest for persistent AF (PeAF) remains. The future of AF ablation, we …

Funding Acknowledgements Type of funding sources: None. Introduction Many patients with atrial fibrillation (AF) do not benefit from rhythm control due to failed catheter ablation, advanced left atrial disease and comorbidities. "Pace and AV node (AVN) ablation" strategy is often adopted for rate control but with a substantial risk of pacing-induced cardiomyopathy. His bundle pacing (HBP) enables physiological biventricular activation through the His Purkinje conduction system. However, the proximity of the HBP lead to the site of AV node ablation may potentially compromise lead integrity in patients who undergo conventional HBP and AVN ablation. Therefore, we have modified HBP by placing the HBP lead distally at the ventricular side of the His bundle (D-HBP) before AVN ablation in patients with symptomatic AF. All patients had a backup RV lead. Method …

Background Atrial fibrillation (AF) hospital admissions represent significant AF related treatment costs nationally. In the year 2019–2020 our hospital reported 1,333 admissions with a primary diagnosis of AF, with a 10% annual increase. A virtual ambulatory AF ward providing multidisciplinary care with remote hospital-level monitoring could reshape the future model of AF management.Methods An AF virtual ward was implemented at our UK tertiary centre, as a proof-of-concept model of care. Patients admitted with a primary diagnosis of AF satisfying the AF virtual ward (AFVW) entry criteria (i.e., haemodynamically stable, HR<140bpm with other acute conditions excluded) were given access to a single lead ECG recording device (AliveCor), a Bluetooth integrated blood pressure machine and pulse oximeter with instruction to record daily ECGs, blood pressure readings, oxygen saturations and fill an online AF …

A method for assessing the electrical function of a heart that includes:(1) for each of a plurality of leads of an ECG, determining a value derived from the output of that lead and which corresponds to an action potential duration;(2) for each of the plurality of leads of the ECG, determining a value derived from the output of that lead and which corresponds to a diastolic interval;(3) for each of the plurality of leads of the ECG, determining a relationship between the determined values for action potential duration and for diastolic interval; and (4) assessing the differences between the determined relationships for each of the plurality of leads. The invention further relates to apparatus and a computer program that may be used in the method.

Point-by-point radiofrequency ablation (RF) and one-shot cryoballoon ablation (CRYO) electrically isolate pulmonary veins (PVs) in atrial fibrillation (AF) using different techniques and energies. This study aimed to examine differences in PVs reconnection pattern and ablation lesions required to re-isolate PVs after failed RF and failed CRYO. Methods Twenty-four patients who had their repeat ablation between January 2017-December 2020 were studied with six months of learning curve for CRYO. Fourteen patients had paroxysmal atrial fibrillation (PAF). Failed first ablations were defined by electrocardiogram (ECG) documented AF within twelve months following three months blanking period. Repeat ablations were performed using CARTO3® mapping system, which was utilized to locate ablation lesions and impedance drop details. Results 2,260 …

Background: Electrographic flow (EGF) mapping estimates electrical wavefront propagation through atrial myocardium as a result of transmembrane voltage changes represented by unipolar electrograms (EGMs). Putative AF sources have been shown to manifest unipolar QS EGMs. Objective: Examine correlation between EGF-identified source locations and QS unipolar EGM morphology. Methods: Recordings from 64-pole basket catheters in persistent AF patients were analyzed. For patients with a putative AF source identified by EGF and who had the source ablated, we analyzed unipolar EGM morphologies pre-and post-ablation. We averaged signal morphology over a full minute. Based on EGF-identified source location, we defined a priori where QS should be and examined neighboring electrodes. For comparison, a random electrode and its neighbors were also selected for QS analysis.Results: Twelve patients with 23 sources underwent EGF-guided ablation providing 883,200 signals for analysis. Preablation, at a putative source, mean% of signals with QS morphology during 1 minute was 53.2 6 7.8% and ablation resulted in a 40.7% decrease such that post-ablation% QS was only 12.5 6 5.4%. Among randomly selected electrodes (nonablation locations), pre-ablation% QS 5 25.3 6 6.9%(p50. 006 vs source locations) and post-ablation% QS 5 32.1 6 7.3%(p5NS vs pre-ablation).Conclusion: Putative AF sources identified by EGF mapping algorithms are characterized by a dominant QS unipolar morphology present over the course of a 1 minute recording that is significantly higher than at randomly selected locations. Postablation,% QS …

Purpose: Identifying targets for catheter ablation remains challenging in persistent atrial fibrillation (persAF). The dominant frequency (DF) of atrial electrograms during atrial fibrillation (AF) is believed to primarily reflect local activation. Highest DF (HDF) might be responsible for the initiation and perpetuation of persAF. However, the spatiotemporal behavior of DF remains not fully understood. Some DFs during persAF were shown to lack spatiotemporal stability, while others exhibit recurrent behavior. We sought to develop a tool to automatically detect recurrent DF patterns in persAF patients. Methods: Non-contact mapping of the left atrium (LA) was performed in 10 patients undergoing persAF HDF ablation. 2,048 virtual electrograms (vEGMs, EnSite Array, Abbott Laboratories, USA) were collected for up to 5 min before and after ablation. Frequency spectrum was estimated using fast Fourier transform and DF was identified as the peak between 4 and 10 Hz and organization index (OI) was calculated. The HDF maps were identified per 4-s window and an automated pattern recognition algorithm was used to find recurring HDF spatial patterns. Dominant patterns (DPs) were defined as the HDF pattern with the highest recurrence. Results: DPs were found in all patients. Patients in atrial flutter after ablation had a single DP over the recorded time period. The time interval (median [IQR]) of DP recurrence for the patients in AF after ablation (7 patients) decreased from 21.1 s [11.8 49.7 s] to 15.7 s [6.5 18.2 s]. The DF inside the DPs presented lower temporal standard deviation (0.18 ± 0.06 Hz vs. 0.29 ± 0.12 Hz, p < 0.05) and higher OI (0.35 ± 0.03 vs. 0 …

Results: The best classifier using a complete set of clinical and simulation data showed an average accuracy 5 0.78, ROC AUC 5 0.78, sensitivity 5 0.75, specificity 5 0.8, that were much higher than in the model built on the clinical data only. Seven out of ten clinical non-responders were classified as responders based on model simulations with predicted optimal lead location. Conclusion: Our pilot results show that combination of clinical and simulation data significantly increases the accuracy of classification models for CRT outcome. Our results suggest that model predictions on the optimal ventricular lead location may essentially increase the probability of CRT success.

Background Even on optimal therapy, many patients with heart failure and atrial fibrillation experience cardiovascular complications. Additional treatments are needed to reduce these events, especially in patients with heart failure and preserved left ventricular ejection fraction. Methods This prespecified subanalysis of the randomized EAST-AFNET4 trial (Early Treatment of Atrial Fibrillation for Stroke Prevention Trial) assessed the effect of systematic, early rhythm control therapy (ERC; using antiarrhythmic drugs or catheter ablation) compared with usual care (allowing rhythm control therapy to improve symptoms) on the 2 primary outcomes of the trial and on selected secondary outcomes in patients with heart failure, defined as heart failure symptoms New York Heart Association II to III or left ventricular ejection fraction [LVEF] <50%. Results This analysis included 798 patients (300 [37.6%] female, median age 71 …

Introduction Sudden cardiac death (SCD) risk assessment is limited, particularly in patients with nonischemic cardiomyopathies. This is the first application, in patients with cardiomyopathies, of two novel risk markers, regional restitution instability index (R2I2) and peak electrocardiogram restitution slope (PERS), which have been shown to be predictive of ventricular arrhythmias (VA) or death in ischemic heart disease patients. Methods Blinded retrospective study of 50 patients: 33 dilated cardiomyopathy and 17 other; undergoing electrophysiological study (EPS) for SCD risk stratification, and 29 controls with structurally normal hearts undergoing EPS. R2I2 was calculated from an EPS using electrocardiogram surrogates for action potential duration and diastolic interval. Cut‐offs for high and low R2I2/PERS were predefined. Results R2I2 was significantly higher in study than control patients (0.99 ± 0.05 vs. 0.63 …

Introduction Pulmonary vein isolation (PVI) is an established treatment strategy for atrial fibrillation (AF). Radiofrequency (RF) ablation technology has evolved over the last decade with the very high-power short-duration (vHPSD) temperature-controlled ablation approach emerging as the latest development. The aim of this study was to determine the procedural efficacy, metrics and safety of vHPSD ablation with conventional power-controlled RF (PCRF) ablation and cryo-energy ablation (CRYO).Methods A prospective single tertiary centre analysis was performed on patients undergoing first time PVI ablation from 2019 to 2020. The population was divided in to 4 treatment arms; QMode Plus (vHPSD), Qmode (Qmode), PCRF using THERMOCOOL SMARTTOUCH ® SF Catheter (STSF) and CRYO. Demographics, clinical and procedural metrics such as PVI duration, ablation time and sedation requirement were …

Identifying ablation targets in persistent atrial fibrillation (PersAF) remains challenging. This study aims to investigate the spatiotemporal stability of PersAF drivers within 5 min recordings of virtual atrial electrograms (VEGMs). 2048-channel VEGMs (EnSite Array, Abbott) were analysed for 5 patients undergoing substrate-guided ablation. Following QRST subtraction, dominant frequency (DF, 4–10 Hz) and organization index (OI) were identified using fast Fourier transform (4 s windows; 50% overlap). Areas with DF within 0.25 Hz below or equal the maximum out of the 2048 points were defined as the highest DF (HDF). Stable DFs (SDFs) were defined as DF patterns with the highest recurrence over consecutive time windows. Rotors were defined as phase singularities (PSs) with ≥100 ms. The 5 min VEGMs were divided into segments of 30, 60, 90, and 120 s. 2D correlation coefficients (CORR) was used to …

Background The subcutaneous (S) implantable cardioverter-defibrillator (ICD) is safe and effective for sudden cardiac death prevention. However, patients in previous S-ICD studies had fewer comorbidities, had less left ventricular dysfunction, and received more inappropriate shocks (IAS) than in typical transvenous ICD trials. The UNTOUCHED trial (Understanding Outcomes With the S-ICD in Primary Prevention Patients With Low Ejection Fraction) was designed to evaluate the IAS rate in a more typical, contemporary ICD patient population implanted with the S-ICD using standardized programming and enhanced discrimination algorithms. Methods Primary prevention patients with left ventricular ejection fraction ≤35% and no pacing indications were included. Generation 2 or 3 S-ICD devices were implanted and programmed with rate-based therapy delivery for rates ≥250 beats per minute and morphology …

Introduction Radiofrequency (RF) ablation for atrial fibrillation (AF) has traditionally been performed under general anaesthesia (GA) to improve procedure tolerance and efficacy, but this has been compromised during the COVID-19 pandemic due to a reduction in GA availability. A very high-power short duration (vHPSD) energy delivery protocol may reduce RF delivery times and hence overall procedure duration, potentially obviating the need for GA when using such an approach. However, the use of vHPSD under conscious sedation has not previously been reported.We sought to evaluate first-time AF ablation using a vHPSD approach during the COVID-19 pandemic by comparing the procedural metrics and same day discharge (SDD) rates of vHPSD against cryoballoon ablation.Methods Procedural data was collected from consecutive patients undergoing first-time AF ablation at two UK centres from …

The combined use of dominant frequency (DF) and organization index (OI) might help to identify atrial regions with organized, fast activation rates in persistent atrial fibrillation (persAF). We determined adaptive thresholds for DF and OI based on electrophysiological responses following AF substrate modification. 2048-channel electrograms (3206 EGMs, 30 s, EnSite Array) were analyzed from 10 persAF patients undergoing DF-guided ablation. After QRST subtraction, fast Fourier transform was used to calculate DF and OI. AF cycle length (AFCL) was measured before and after each ablation point (left atrium appendage). EGMs were grouped in two classes: collected at regions whose ablation resulted in AFCL increase and AFCL non-increase . Patient-specific z-score DF (DFz) and IO(OIz) were tested to separate the two classes (individually and AND-logic). Informedness (J), accuracy (Acc) and F1 score were …

We have recently shown the feasibility of unsupervised classification to identify clusters of persistent atrial fibrillation (persAF) atrial electrograms (AEGs) using attributes calculated by electroanatomic mapping systems. In the present work, we sought to extend this analysis to a set of reduced dimension principal component scores (PCSs) estimated from AEG-derived markers. 956 bipolar AEGs were collected from 11 persAF patients. Principal component analysis (PCA) was implemented on 28 markers obtained from different perspectives of the AEGs – such as information theory, spectral analysis, and nonlinear dynamics. The three PCSs with the highest variances were selected and used to perform an unsupervised classification with k-means. The electrophysiological characteristics of the identified groups were further investigated using six AEG markers: sample entropy (SampEn), wave similarity (WS), cycle …

A trial fibrillation (AF) increases cardio-embolic stroke risk, yet AF diagnosis and subsequent prophylactic anticoagulant prescription rates are suboptimal globally. This project aimed to increase AF diagnosis and subsequent anticoagulation prescription rates in East Midlands Clinical Commissioning Groups (CCGs).

Funding Acknowledgements Type of funding sources: None. Pulmonary vein isolation (PVI) is an effective and established therapy for paroxysmal atrial fibrillation (PAF) . PVI can be performed using point by point ablation with radiofrequency (RF) or with single shot techniques such as cryoballoon (CRYO). As P waves represent atrial depolarization, we aimed to study whether P wave metrics may change after PVI and if there are differences between RF and CRYO approaches. Methods We studied 88 matched patients who had PVI for PAF between January 2017 and December 2018 (RF = 44, CRYO = 44). Each patient was in sinus rhythm (SR) prior to ablation. Patients on amiodarone and those who had additional linear ablation were excluded. Patients had continuous ECG monitoring using Labsystem Pro (Boston Scientific Inc). Sampled at 1kHz during the procedure. One-minute recordings before and …

The diagnosis and management of patients with broad complex tachycardia (BCT) can be challenging and requires careful assessment. While the acute treatment is guided by the patient’s immediate clinical status, invasive electrophysiological (EP) testing is of particular value in differentiating ventricular tachycardia from supraventricular tachycardia with aberrancy and for guiding the definitive treatment. We describe an unusual and challenging case of a patient presenting with BCT who underwent an EP study, revealing 3 distinct tachycardias utilizing a Mahaim and left lateral accessory pathway, both of which were successfully treated with catheter ablation. Mahaim fibers, originally described by Mahaim and Winston in 1941, 1 are rare accessory pathways with unique properties, usually found on the right side of the heart, that can present with an antidromic atrioventricular reentrant tachycardia (AVRT) with the …

Automatic detection and classification of cardiac disorders play a critical role in the analysis of clinical electrocardiogram (ECG). Deep learning methods are effective for automated feature extraction and have shown promising results in ECG classification. In this work, we proposed a deep spatio-temporal ECG network (ST-ECGNet) to extract robust spatio-temporal features for detecting multiple cardiac disorders from the multi-lead ECG data. The proposed ST-ECGNet combines a Convolutional Neural Network (CNN) module for extracting local spatial features, an attention module for capturing global spatial features, and a Bi-directional Gated Recurrent Unit (Bi-GRU) module for extracting temporal features from ECG data. Specifically, the attention mechanism enables our deep learning architecture to focus on the most important and useful parts of the input to make more accurate predictions. In PhysioNet …

In the absence of effective targeted therapies for COVID-19, optimisation of supportive care is essential. Lung injury with features of acute respiratory distress syndrome (ARDS) appears to be the principal characteristic of severe acute respiratory syndrome coronavirus 2 infection. 1 Recent guidance by the UK Intensive Care Society (ICS) advocates awake prone positioning to become standard of care for suspected or confirmed COVID-19, in patients requiring an FiO2≥ 28% 0. 2 These recommendations are extrapolated from physiological principles and clinical evidence obtained in a distinct study population—patients with severe ARDS undergoing invasive mechanical ventilation (IMV).The physiological rationale behind prone positioning in typical ARDS is to reduce ventilation/perfusion mismatching, hypoxaemia and shunting. 2 Prone positioning decreases the pleural pressure gradient between dependent and …

Changes in atrial fibrillation cycle length (AF-CL) are broadly used as a ‘ground truth’ to assess the effect of substrate modification during AF ablation. This work sought to optimize thresholds for changes in coronary sinus CL (CS-CL) after local ablation using different atrial electrogram (AEG)-derived markers. 834 AEGs were collected from 11 patients undergoing persAF ablation. CS-CL was measured before and after each ablation point. Five AEG-derived markers were tested as classifiers for CS-CL changes: ICL (Biosense Webster), CFE-Mean (St. Jude Medical), Wave Similarity, Shannon Entropy and AEG-CL. The area under the receiver operating characteristic (AUROC) curve was used to assess the quality of classification for each marker. Maximum AUROC was found at threshold values between 9 and 14 ms in all markers, except for Shannon Entropy. The average AUROC of the five markers reached a …

Automated detection and classification of clinical electrocardiogram (ECG) play a critical role in the analysis of cardiac disorders. Deep learning is effective for automated feature extraction and has shown promising results in ECG classification. Most of these methods, however, assume that multiple cardiac disorders are mutually exclusive. In this work, we have created and trained a novel deep learning architecture for addressing the multi-label classification of 12-lead ECGs. It contains an ECG representation work for extracting features from raw ECG recordings and a Graph Convolutional Network (GCN)for modelling and capturing label dependencies. In the Phy-sioNet/Computing in Cardiology Challenge 2020 [1], our team, Leicester-Fox, reached a challenge validation score of 0.395, and full test score of −0.012, placing us 34 out of 41 in the official ranking.