The Use of App-based Follow-up of Cardiac Implantable Electronic Devices

There has been a steady rise in the number of patients treated with cardiac implantable electrical devices. Remote monitoring and remote follow-up have proven superior to conventional care in the follow-up of these patients and represent the new standard of care. With the widespread availability of smartphones and with more people using them for health queries, app-based remote care offers a promising new digital health solution promoting the shift of follow-up to exception-based assessments. It focuses on patients’ enablement and has shown promising results, but also highlights the need to increase the system’s automaticity to achieve acceptable follow-up adherence rates. MyCareLink Heart is a fully automated app-based system that represents the next generation of app-based monitoring and is currently being evaluated in an international study with promising initial results

Deep learning methods for screening patients' S-ICD implantation eligibility.

Acknowledgments The work of Anthony J. Dunn is jointly funded by Decision Analysis Services Ltd. and EPSRC through the Studentship with Reference EP/R513325/1. The work of Alain B. Zemkoho is supported by the EPSRC grant EP/V049038/1 and the Alan Turing Institute under the EPSRC grant EP/N510129/1. The feedback provided by Sion Cave (DAS Ltd) on the initial draft of the paper is gratefully acknowledged.Peer reviewedPublisher PD

Electrocardiographic changes during haemodialysis and the potential impact on subcutaneous implantable cardioverter defibrillator eligibility

Acknowledgments The authors would like to acknowledge the kindness and support that they received from all of the patients and staff at the Chandler's Ford Dialysis Unit. Funding This research did not receive any specific grant from funding agencies in the public, commercial, or not-for-profit sectors.Peer reviewedPublisher PD

Correlation analysis of deep learning methods in S-ICD screening

© 2023 The Authors. Annals of Noninvasive Electrocardiology published by Wiley Periodicals LLC.Peer reviewedPublisher PD

Deep learning methods for screening patients' S-ICD implantation eligibility

Subcutaneous Implantable Cardioverter-Defibrillators (S-ICDs) are used for prevention of sudden cardiac death triggered by ventricular arrhythmias. T Wave Over Sensing (TWOS) is an inherent risk with S-ICDs which can lead to inappropriate shocks. A major predictor of TWOS is a high T:R ratio (the ratio between the amplitudes of the T and R waves). Currently patients' Electrocardiograms (ECGs) are screened over 10 seconds to measure the T:R ratio, determining the patients' eligibility for S-ICD implantation. Due to temporal variations in the T:R ratio, 10 seconds is not long enough to reliably determine the normal values of a patient's T:R ratio. In this paper, we develop a convolutional neural network (CNN) based model utilising phase space reconstruction matrices to predict T:R ratios from 10-second ECG segments without explicitly locating the R or T waves, thus avoiding the issue of TWOS. This tool can be used to automatically screen patients over a much longer period and provide an in-depth description of the behaviour of the T:R ratio over that period. The tool can also enable much more reliable and descriptive screenings to better assess patients' eligibility for S-ICD implantation

A study on mechanical properties and structure of anhydrite binder modified by ultra-dispersed siltstone

This research is devoted to modification of physical and mechanical properties and structure of a binder based on natural anhydrite. A sedimentary rock siltstone was added into the composition as a mineral ultrafine additive. The presence of aluminosilicate minerals proves that finely ground siltstone can be used as a mineral additive in the composition of the anhydrite binder, accelerating crystallization of gypsum new formations and densifying the structure of gypsum stone. For the first time, the effectiveness of using sodium and ammonium phosphates as hardening activators of an anhydrite binder was shown. Siltstone, added to the composition in the amount from 0 to 5%, lead to up to 40% increase in strength, which is due to the action of siltstone particles as “crystallization centers” and formation of crystalline hydrates of calcium sulfate dihydrate on their surface. Combined action of calcined siltstone and lime leads to a 45% increase in strength due to the additional compaction by new hydration products formed in the course of metakaolin and lime interaction. Microstructural analysis showed that samples with calcined siltstone and lime have a more dense and uniform structure with a lower porosity, compared to those with only natural siltstone. First published online 03 February 202

Incidence of premature battery depletion in subcutaneous cardioverter-defibrillator patients: insights from a multicenter registry.

BACKGROUND The subcutaneous ICD established its role in the prevention of sudden cardiac death in recent years. The occurrence of premature battery depletion in a large subset of potentially affected devices has been a cause of concern. The incidence of premature battery depletion has not been studied systematically beyond manufacturer-reported data. METHODS Retrospective data and the most recent follow-up data on S-ICD devices from fourteen centers in Europe, the US, and Canada was studied. The incidence of generator removal or failure was reported to investigate the incidence of premature S-ICD battery depletion, defined as battery failure within 60 months or less. RESULTS Data from 1054 devices was analyzed. Premature battery depletion occurred in 3.5% of potentially affected devices over an observation period of 49 months. CONCLUSIONS The incidence of premature battery depletion of S-ICD potentially affected by a battery advisory was around 3.5% after 4 years in this study. Premature depletion occurred exclusively in devices under advisory. This is in line with the most recently published reports from the manufacturer. TRIAL REGISTRATION ClinicalTrials.gov Identifier: NCT04767516

Subcutaneous implantable cardiac defibrillator - A personalised approach

Sudden cardiac death (SCD) remains one of the leading causes of death in the modern world with most of these deaths being attributed to ventricular arrhythmias. Implantable cardiac defibrillators (ICDs) are well established treatment and are recommended by the international guidelines for prevention of sudden cardiac death triggered by ventricular arrhythmias in high-risk populations. But they are not risk-free, and traditional transvenous ICDs are associated with long-term complications with potentially fatal consequences. The subcutaneous ICD (S-ICD) was designed utilising a totally extra-thoracic approach avoiding the complications which have been associated with transvenous ICDs (TV-ICD). The results of clinical trials demonstrated the efficacy of the S-ICD systems in recognising and treating ventricular arrythmias with fewer lead-related complications when compared to the TV-ICDs. However, the downside of the S-ICDs is that unlike TV-ICDs, they are unable to provide bradycardia pacing or Anti-tachycardia pacing (ATP) therapy to terminate ventricular arrythmias painlessly without the need to deliver a shock. Also, they exhibit a relatively higher rate of inappropriate shocks when compared with TV-ICDs. Most of these shocks can be attributed to Twave oversensing (TWO), an inherent risk to the sensing mechanism of the S-ICD. Not all patients are eligible for S-ICDs and mandatory screening of all potential candidates following device manufacturer guidelines helps identify eligible patients based on their underlying ECG morphology. Variable rates of screening success and S-ICD eligibility are reported in the literature. In this thesis I will start by reporting a retrospective analysis of S-ICD eligibility using current recommended screening practices at a tertiary centre for cardiac devices (University Hospital of Southampton). I will then proceed to suggest adopting a different approach towards screening of S-ICD candidates which considers the dynamicity of the ECG signal. I will explore the role of applying prolonged screening using Holter monitors in a wide range of patients’ cohorts and prove there is variation in the S-ICD eligibility overtime which can explain oversensing and inappropriate shocks in S-ICDs despite current screening practices. I will also introduce and explain a novel technique utilising artificial intelligence and deep learning methods which has the potential to be applied to clinical practice to help identify S-ICD eligible patients as well as guide vector selection in S-ICD recipients. I will justify choosing R:T ratio as the main determinant of S-ICD eligibility and validate the novel deep learning methodology used in my studies by comparing the outcomes to those produced by the “gold standard” S-ICD simulator. I will then proceed to propose targeting less strict R:T ratios in S-ICD screening in vectors that prove to be stable with prolonged screening. I will then compare the eligibility rates for S-ICD using different R:T ratios, proposing that it is reasonable to revisit the S-ICD Screening thresholds if we adopt prolonged screening approaches. Afterwards, I will address the inability of S-ICDs to provide pacing therapy and the need to coimplant pacemaker devices to cover pacing therapy when clinically indicated. I will highlight that the effect of pacing on the S-ICD sensing has not been well studied before. I will proceed by first introducing a simple radiological method to define the LP position, then demonstrate that there is no effect of LP position on short- and long-term LPs performances. Afterwards I will show that pacing regardless of the pacing site has a significant effect on the R:T ratio, one of the main determinants of S-ICD eligibility and increases the risk of S-ICD oversensing. However, I will conclude that with adoption of personalised approach towards device therapy, it is theoretically feasible to utilise concomitant device therapies in most patients, without increasing the risk of adverse clinical events. In summary, I believe that extravascular cardiac devices are soon to establish themselves as the new standard of care to provide defibrillation protection and pacing therapy. Current issues with S-ICDs can be overcome by incorporating efficient artificial intelligence methods to help with more accurate and yet efficient screening for better patient selection. Together with adopting a personalised approach, higher S-ICD eligibility can be achieved, and the risk of inappropriate shocks can be mitigated