419 research outputs found
Global Substrate Mapping and Targeted Ablation with Novel Gold-tip Catheter in De Novo Persistent AF
No full textResults from catheter ablation for persistent AF are suboptimal, with no strategy other than pulmonary vein isolation showing clear benefit. Recently employed empirical strategies beyond pulmonary vein isolation involve widespread atrial ablation in all patients and do not take into account patient-specific differences in AF mechanisms or phenotype. Charge density mapping using the non-contact AcQMap system (Acutus Medical) allows visualisation of whole-chamber activation during AF and reveals localised patterns of complex activation thought to represent important mechanisms for AF maintenance that can be targeted with focal ablation. In this review, the authors outline the fundamentals of this technology, the initial data exploring the mechanistic role of activation patterns seen and the application to ablation of persistent AF
Dataset supporting thesis titled: Investigation of monitoring technologies to deliver ‘Pill-in-the-Pocket’ oral anticoagulation in atrial fibrillation
No full textThis zip file contains the spreadsheets for the following publications:
Chapter 3: 'Pill-in-the-pocket' Oral Anticoagulation Guided by Daily Rhythm Monitoring for Stroke Prevention in Patients with AF: A Systematic Review and Meta-analysis.
Briosa E Gala A, Pope MTB, Leo M, Sharp AJ, Tsoi V, Paisey J, Curzen N, Betts TR.
Arrhythm Electrophysiol Rev. 2023 Mar 2;12:e05. doi: 10.15420/aer.2022.22. eCollection 2023.
Chapter 4: "Real-world" performance of the Confirm Rx™ SharpSense AF detection algorithm: UK Confirm Rx study.
Gala ABE, Pope MTB, Leo M, Sharp AJ, Banerjee A, Field D, Thomas H, Balasubramaniam R, Hunter R, Gardner RS, Wilson D, Gallagher MM, Ormerod J, Paisey J, Curzen N, Betts TR.
J Arrhythm. 2024 Sep 3;40(5):1093-1101. doi: 10.1002/joa3.13124. eCollection 2024 Oct.
Chapter 5: Diagnostic performance of single-lead electrocardiograms from a smartwatch and a smartring for cardiac arrhythmia detection.
Briosa E Gala A, Sharp AJ, Schramm D, Pope MTB, Leo M, Varini R, Banerjee A, Win KZ, Kalla M, Paisey J, Curzen N, Betts TR.Hea rt Rhythm O2. 2025 Mar 26;6(6):808-817. doi: 10.1016/j.hroo.2025.03.019. eCollection 2025 Jun.
Chapter 6: Real-time smartphone alerts during atrial fibrillation episodes with implantable cardiac monitors and wearable devices: SMART-ALERT study.
Briosa E Gala A, Sharp AJ, Pope MTB, Leo M, Varini R, Paisey J, Curzen N, Banerjee A, Betts TR.
Heart Rhythm. 2025 Apr 15:S1547-5271(25)02331-8. doi: 10.1016/j.hrthm.2025.04.015. Online ahead of print.</span
High-density mapping of left atrial endocardial activation during sinus rhythm and coronary sinus pacing in patients with paroxysmal atrial fibrillation
No full textIntroduction: This study was designed to record global high-density maps of left atrial endocardial activation during sinus rhythm and coronary sinus pacing.Method and Results: Noncontact mapping of the left atrium was performed in nine patients with paroxysmal atrial fibrillation undergoing pulmonary vein ablation procedures. High-density isopotential and isochronal activation maps were superimposed on three-dimensional reconstructions of left atrial geometry. Mapping was repeated during pacing from sites within the coronary sinus. Earliest left atrial endocardial activation occurred anterior to the right pulmonary veins in seven patients and on the anterosuperior septum in two patients. A line of conduction block was seen in the posterior wall and inferior septum in all patients. The direction of activation in the left atrial myocardium overlying the coronary sinus was different from the electrogram sequence in the coronary sinus catheter in 6 of 9 patients. During coronary sinus pacing, activation entered the left atrium a mean (SD) of 41 (13) ms after the pacing stimulus at a site 12 (10) mm from the endocardium overlying the pacing electrode. Lines of conduction block were present in the posterior wall and inferior septum.Conclusion: In patients with paroxysmal atrial fibrillation, lines of conduction block are present in the left atrium during sinus rhythm and coronary sinus pacing. Electrograms recorded in the coronary sinus infrequently correspond to the direction of activation in the overlying left atrial myocardium
Effect of post-ablation monitoring strategy on long-term outcome for catheter ablation of persistent atrial fibrillation: a sub-study of the STAR AF II trial
No full textAbstract not availableSergio Conti, Chen-yang Jiang, Timothy R. Betts, Jian Chen, Isabel Deisenhofer, Roberto Mantovan ... et al
Radiofrequency ablation of idiopathic ventricular fibrillation guided by noncontact mapping
No full textA 32-year-old man with idiopathic ventricular fibrillation and an implantable cardioverter defibrillator presented during a ventricular fibrillation storm. Frequent monomorphic ventricular ectopics with left bundle branch block morphology were documented, some of which initiated fibrillation. He underwent noncontact mapping of the right ventricle, during which the ventricular ectopics were mapped to a site in the free wall displaying a diastolic potential 80 ms before ectopic QRS onset. Following three radiofrequency energy applications, the ectopics were abolished. After 11-month follow-up, he has experienced no further arrhythmias. Noncontact mapping may identify ablatable triggers of ventricular fibrillation and lead to successful outcomes even when only single ectopics are present
NICE atrial fibrillation guideline snubs wearable technology: a missed opportunity?
No full textAtrial fibrillation (AF) is the most common sustained cardiac arrhythmia and a growing public health epidemic. In the UK, over 1.3 million people have a diagnosis of AF and an estimated 400,000 remain undiagnosed. AF-related strokes account for a quarter of all strokes and, as AF episodes are often asymptomatic, are still often the first manifestation of AF. Early diagnosis and initiation of oral anticoagulation, where appropriate, may prevent some of these thromboembolic strokes. Public Health England is committed to decrease the incidence of AF-related strokes and has sponsored initiatives aimed at improving AF detection by promoting the uptake of wearable technologies. However, the National Institute for Health and Care Excellence (NICE) has not recommended wearable technology in their recent AF diagnosis and management guidelines (NG196). Diagnostic accuracy of single-lead electrocardiography (ECG) generated by the latest iteration of wearable devices is excellent and, in many cases, superior to general practitioner interpretation of the 12-lead ECG. High-quality ECG from wearable devices that unequivocally shows AF can expedite AF detection. Otherwise, there is a real risk of delaying AF diagnosis with the potential of devastating consequences for patients and their families.</p
PO-05-156 software automation for delivery of pill-in-pocket anticoagulation (PIPOAC): experience from Oxford, UK
No full textBackground: PIPOAC is an emerging approach for suitable AF patients (infrequent AF episodes, short episode duration, lower CHA2DS2-VASC).PIPOAC is taken during AF and temporarily after. Time from AF onset to starting PIPOAC must be minimised to allow prompt anticoagulation.Continuous monitoring for AF onset is achieved using implantable cardiac monitors (ICM). ICM transmission surveillance and patient communication must currently be performed by healthcare staff.A continuous automated process would reduce clinical workload and ensure PIPOAC is commenced promptly.Objective: design software to continuously screen Medtronic Carelink platform to view transmissions from patient LINQ II devices. Program must trigger SMS alert to patients for AF episodes over 60 minutes (as per our PIPOAC criteria).Methods: program code written using .NET open-source application between 2021-24 in four phases. Code improvements made over time to deal with minor bugs, unexpected scenarios, upgrades to .NET, and changes to Carelink website.Program decision tree for new transmissions shown (Image 1).Results: software test over 35 days between Oct and Dec 2024 including 32 patients monitored by LINQ II.Phase one: AF episodes in seven patients. 91.7% of alerts delivered (Table 1). Three AF episodes missed in one patient who triggered transmissions using symptom activator. The program didn't recognize “AF (Symptom)” episodes. Code updated to recognize this category for phase two.Phase two: AF episodes in five patients. 100% of alerts delivered, none missed.Median time from AF episode onset to SMS 04:11 hours.Conclusion: an automated system can effectively and quickly deliver patient alerts for AF. This approach could facilitate wider use of PIPOAC
Transvenous or subcutaneous implantable cardioverter defibrillator: a review to aid decision-making.
No full textThe implantable cardioverter-defibrillator (ICD) is a proven treatment for preventing sudden cardiac death. Transvenous leads are associated with significant mortality and morbidity, and the subcutaneous ICD (S-ICD) addresses this. However, it is not without limitations, in particular the absence of anti-tachycardia pacing. The decision of which device is most suitable for an individual patient is often complex. Here, we review the relative merits and weaknesses of both the transvenous and S-ICD. We summarise the available evidence for each device in particular patient cohorts, namely: ischaemic and non-ischaemic cardiomyopathy, idiopathic ventricular fibrillation, Brugada syndrome, long QT syndrome, arrhythmogenic right ventricular cardiomyopathy, and hypertrophic cardiomyopathy
Multi-modal integration of MRI and global chamber charge density mapping for the evaluation of atrial fibrillation.
No full textAtrial fibrillation (AF) is the most prevalent clinical arrhythmia, posing significant mortality and morbidity challenges. Outcomes of current catheter ablation treatment strategies are suboptimal, highlighting the need for innovative approaches. A major obstacle lies in the inability to comprehensively assess both structural and functional remodelling in AF. Combining magnetic resonance imaging (MRI)'s detailed structural insights with global chamber charge density mapping (CDM)'s functional mapping capabilities holds promise for advancing AF management. Our research introduces a novel tool for three-dimensional reconstruction of left atrial geometries from MRI, facilitating integration into CDM systems. We comprehensively assess our tool by generating three-dimensional left atrial meshes from MRIs of eight patients with AF and compare them with the established CDM intra-chamber ultrasound approach utilizing both geometric and clinical parameters. We apply the CDM inverse algorithm to both sets of reconstructions in order to compare derived conductions across various heart rhythms and AF conduction patterns. Finally, we explore the potential utility of our integrated pipeline through an exploration of the relationship between AF conduction patterns and their proximity to adjacent thoracic structures. Ultimately, this multifaceted approach aims to unveil insights into AF mechanisms, potentially improving treatment outcomes through personalized ablation strategies targeting arrhythmogenic atrial substrate
Water uptake in barley grain: physiology; genetics and industrial applications
No full textAbstract not availableSuong Cu, Helen M. Collins, Natalie S. Betts, Timothy J. March, Agnieszka Janusz, Doug C. Stewart, Birgitte Skadhauge, Jason Eglinton, Bianca Kyriacou, Alan Little, Rachel A. Burton, Geoffrey B. Finche
- …
