Search

Competing Interests: Disclosures Mr Monkhouse has received speaker fees from Abbott, Boston Scientific, Biotronik, Medtronic, and Phillips. He has received consulting fees from Medtronic. Prof Hunter has received speaker fees from Medtronic and Biosense Webster, educational grant from Biosense Webster, and an institutional research grant from Medtronic. Prof Lambiase has received research grants and speaker fees from Boston Scientific, Abbott, and Medtronic. He is supported by University College London Biomedicine National Institute of Health Research and Barts Biomedical Research Centre. The rest of the authors report no conflicts of interest.

We describe two cases of secondary prevention subcutaneous implantable cardioverter defibrillator (S-ICD) implantation and subsequent S-ICD electrode displacement which initially went undetected. One presentation was a result of a coincidental chest x-ray for respiratory exacerbation and another with an untreated episode highlighted via remote monitoring, both patients were booked to clinic for further investigation. Our findings highlighted had there been a comparison of the existing subcutaneous electrogram (S-ECG) to captured S-ECGs at time of implant the electrode displacement would have been detected beforehand. This underpins the importance of introducing the simple management strategy into routine follow-up., (© 2024 Wiley Periodicals LLC.)

Background: Remote monitoring (RM) is recommended for the ongoing management of patients with cardiac implantable electronic devices (CIEDs). Despite its benefits, RM adoption has increased the workload for cardiac rhythm management teams. This study used a modified Delphi method to develop a consensus on optimal RM management for adult patients with a CIED in the UK., Methods: A national steering committee comprising cardiac physiologists, cardiologists, specialist nurses, support professionals and a patient representative developed 114 statements on best RM practices, covering capacity, support, service delivery, coordination and clinical escalation. An online questionnaire was used to gather input from UK specialists, with consensus defined as ≥75% agreement., Results: Between 16 October 2023 and 4 December 2023, 115 responses were received. Of the statements, 79 (69%) achieved high agreement (≥90%), 20 (18%) showed moderate agreement (75%-89%) and 15 (13%) did not achieve consensus. The highest agreement focused on patient education and support, while the lowest concerned workload distribution., Conclusions: There is strong agreement on best practices for RM of CIEDs among UK healthcare professionals. Key recommendations include ensuring patient access, providing adequate resources, adopting new working methods, enhancing patient education, establishing clear clinical escalation pathways and standardising national policies. Implementing these best practices, tailored to local capabilities, is essential for effective and equitable RM services across the UK., Competing Interests: Competing interests: MFP holds an NIHR clinical postdoctoral fellowship and has received honoraria from Medtronic, Abbott, GE Healthcare and AstraZeneca. JG holds an NIHR postdoctoral fellowship outside of this work and has received honoraria and consulting fees from Medtronic, Abbott and MicroPort. SS holds an NIHR Academic Clinical Lectureship outside of this work and has received speaker’s fees and non-financial support from Astra Zeneca. JC has received honoraria and consulting fees from MicroPort. FA has received honoraria and speaker fees from Medtronic and Abbott. All other authors report no competing interests., (© Author(s) (or their employer(s)) 2024. Re-use permitted under CC BY. Published by BMJ.)

Competing Interests: Disclosures The authors have no conflicts to disclose.

Implantable cardiac devices are a vital treatment option in the management of tachy/brady-arrhythmias and heart failure with conduction disease. In the recent years, these devices have become increasingly sophisticated, with high implantation success rates and longevity. However, these devices are not without risks and complications, which need to be carefully considered before implantation. In an era of rapidly evolving cardiac device therapies, this review article will provide an update on the literature and outline some of the emerging technologies that aim to maximise the efficiency of implantable devices and reduce complications. We discuss novel pacing techniques, including alternative pacing sites in anti-bradycardia and biventricular pacing, as well as the latest evidence surrounding leadless device technologies and patient selection for implantable device therapies., Competing Interests: CM has received speaker fees from Abbott, Boston Scientific, Biotronik, Medtronic, and Phillips and has received consulting fees from Medtronic. As of April 2023 CM is supported by a research grant provided by Boston Scientific. None of the other authors had any conflicts of interest., (Copyright: © 2024 The Author(s). Published by IMR Press.)

Background: Remote monitoring (RM) of implantable cardiac devices provides substantial and complex information, presenting new challenges such as detection of a patient's death., Objective: This study aims to describe RM transmissions indicating death and propose a management strategy for services., Methods: The study included consecutive ambulatory outpatients whose deaths were detected via RM. Clinical and device data were collected from electronic records, and ethical approval was obtained from the service's institutional review board., Results: Over a 9-year period (2014-2023), 28 patients were detected. The deceased patients had implantable cardioverter-defibrillators, pacemakers, and implantable loop recorders. In 54% of the cases, the patient's death had already been recognized. Alert transmissions indicating death were commonly related to ventricular arrhythmia events, but also due to lead measurements, and implantable loop recorder battery status. Several diagnostic features may indicate a patient's death. The most reliable was the presenting electrogram, demonstrating base rate pacing with no capture. Device diagnostics, lead parameters, and arrhythmia recordings may indicate death; however, not all cases present with recordings and diagnosis may not be conclusive. A majority (82%) had ventricular arrhythmia at the time of death. In cases where defibrillator shocks were delivered, the arrhythmia reinitiated shortly after successful cardioversion. Delayed therapy was observed, and some patients did not receive defibrillator shocks because of discriminators or because the arrhythmia rate fell below the shock zone., Conclusion: Detecting a patient death via RM presents unique challenges and considerations for services. Standard operational policies and legal consultation should be established to address the implications., Competing Interests: Disclosures Mr Monkhouse has received speaker fees from Abbott, Boston Scientific (St Paul, MN), Biotronik, Medtronic, and Phillips and has received consulting fees from Medtronic. As of April 2023, Mr Monkhouse is supported by a research grant provided by Boston Scientific that was awarded to Dr Ahsan. Prof Hunter has received speaker fees from Medtronic and Biosense Webster (Irvine, CA), educational grant from Biosense Webster, and an institutional research grant from Medtronic. Prof Lambiase has received research grants and speaker fees from Boston Scientific, Abbott, and Medtronic and is supported by University College London Biomedicine National Institute of Health Research and Barts Biomedical Research Centre. Dr Sporton has received speaker fees from Medtronic. The rest of the authors report no conflicts of interest., (Copyright © 2023 Heart Rhythm Society. Published by Elsevier Inc. All rights reserved.)

Background: Antimicrobial envelopes reduce the incidence of cardiac implantable electronic device infections, but their cost restricts routine use in the United Kingdom. Risk scoring could help to identify which patients would most benefit from this technology., Methods: A novel risk score (BLISTER [Blood results, Long procedure time, Immunosuppressed, Sixty years old (or younger), Type of procedure, Early re-intervention, Repeat procedure]) was derived from multivariate analysis of factors associated with cardiac implantable electronic device infection. Diagnostic utility was assessed against the existing PADIT score (Prior procedure, Age, Depressed renal function, Immunocompromised, Type of procedure) in both standard and high-risk external validation cohorts, and cost-utility models examined different BLISTER and PADIT score thresholds for TYRX (Medtronic; Minneapolis, MN) antimicrobial envelope allocation., Results: In a derivation cohort (n=7383), cardiac implantable electronic device infection occurred in 59 individuals within 12 months of a procedure (event rate, 0.8%). In addition to the PADIT score constituents, lead extraction (hazard ratio, 3.3 [95% CI, 1.9-6.1]; P <0.0001), C-reactive protein >50 mg/L (hazard ratio, 3.0 [95% CI, 1.4-6.4]; P =0.005), reintervention within 2 years (hazard ratio, 10.1 [95% CI, 5.6-17.9]; P <0.0001), and top-quartile procedure duration (hazard ratio, 2.6 [95% CI, 1.6-4.1]; P =0.001) were independent predictors of infection. The BLISTER score demonstrated superior discriminative performance versus PADIT in the standard risk (n=2854, event rate: 0.8%, area under the curve, 0.82 versus 0.71; P =0.001) and high-risk validation cohorts (n=1961, event rate: 2.0%, area under the curve, 0.77 versus 0.69; P =0.001), and in all patients (n=12 198, event rate: 1%, area under the curve, 0.8 versus 0.75, P =0.002). In decision-analytic modeling, the optimum scenario assigned antimicrobial envelopes to patients with BLISTER scores ≥6 (10.8%), delivering a significant reduction in infections (relative risk reduction, 30%; P =0.036) within the National Institute for Health and Care Excellence cost-utility thresholds (incremental cost-effectiveness ratio, £18 446)., Conclusions: The BLISTER score (https://qxmd.com/calculate/calculator&#95;876/the-blister-score-for-cied-infection) was a valid predictor of cardiac implantable electronic device infection, and could facilitate cost-effective antimicrobial envelope allocation to high-risk patients., Competing Interests: Disclosures None.

Background: There is a paucity of data comparing vitamin K antagonists (VKAs) to direct oral anticoagulants (DOACs) at the time of cardiac implantable electronic device (CIED) surgery. Furthermore, the best management of DOACs (interruption vs continuation) is yet to be determined., Objectives: This study aimed to compare the incidence of device-related bleeds and thrombotic events based on anticoagulant type (DOAC vs VKA) and regimen (interrupted vs uninterrupted)., Methods: This was an observational multicenter study. We included patients on chronic oral anticoagulation undergoing CIED surgery. Patients were matched using propensity scoring., Results: We included 1,975 patients (age 73.8 ± 12.4 years). Among 1,326 patients on DOAC, this was interrupted presurgery in 78.2% (n = 1,039) and continued in 21.8% (n = 287). There were 649 patients on continued VKA. The matched population included 861 patients. The rate of any major bleeding was higher with continued DOAC (5.2%) compared to interrupted DOAC (1.7%) and continued VKA (2.1%) (P = 0.03). The rate of perioperative thromboembolism was 1.4% with interrupted DOAC, whereas no thromboembolic events occurred with DOAC or VKA continuation (P = 0.04). The use of dual antiplatelet therapy, DOAC continuation, and male sex were independent predictors of major bleeding on a multivariable analysis., Conclusions: In this large real-world cohort, a continued DOAC strategy was associated with a higher bleeding risk compared to DOAC interruption or VKA continuation in patients undergoing CIED surgery. However, DOAC interruption was associated with increased thromboembolic risk. Concomitant dual antiplatelet therapy should be avoided whenever clinically possible. A bespoke approach is necessary, with a strategy of minimal DOAC interruption likely to represent the best compromise., Competing Interests: Funding Support and Author Disclosures Dr Creta has received speaker fees from Boston Scientific. Dr Finlay has received research support and speaker fees from Abbott Ltd, Medtronic Ltd, and Biosense Webster; is Chief Medical Officer, Founder, and Shareholder of Echopoint Medical Ltd; is Director, Founder, and Shareholder of Rhythm AI; is Founder and Shareholder of Epicardio Ltd; and has received research funding from National Institutes of HealthR Barts BRC funding. Dr Lambiase has received educational grants from Medtronic and Boston Scientific; and is supported by UCLH Biomedicine National Institute for Health and Care Research and Barts BRC funding. Dr Schilling has had research agreements and has received speaker fees from Abbott, Medtronic, Boston Scientific, and Biosense Webster; and is a shareholder of AI Rhythm. All other authors have reported that they have no relationships relevant to the contents of this paper to disclose., (Copyright © 2024 American College of Cardiology Foundation. Published by Elsevier Inc. All rights reserved.)

Aims: Arrhythmogenic right ventricular cardiomyopathy (ARVC) patients develop ventricular arrhythmias (VAs) responsive to anti-tachycardia pacing (ATP). However, VA episodes have not been characterized in accordance with the device therapy, and with the emergence of the subcutaneous implantable cardioverter defibrillator (S-ICD), the appropriate device prescription in ARVC remains unclear. Study aim was to characterize VA events in ARVC patients during follow-up in accordance with device therapy and elicit if certain parameters are predictive of specific VA events., Methods and Results: This was a retrospective single-centre study utilizing prospectively collated registry data of ARVC patients with ICDs. Forty-six patients were included [54.0 ± 12.1 years old and 20 (43.5%) secondary prevention devices]. During a follow-up of 12.1 ± 6.9 years, 31 (67.4%) patients had VA events [n = 2, 6.5% ventricular fibrillation (VF), n = 14], 45.2% VT falling in VF zone resulting in ICD shock(s), n = 10, 32.3% VT resulting in ATP, and n = 5, 16.1% patients had both VT resulting in ATP and ICD shock(s). Lead failure rates were high (11/46, 23.9%). ATP was successful in 34.5% of patients. Severely impaired right ventricular (RV) function was an independent predictor of VT resulting in ATP (hazard ratio 16.80, 95% confidence interval 3.74-75.2; P < 0.001) with a high predictive accuracy (area under the curve 0.88, 95%CI 0.76-1.00; P < 0.001)., Conclusion: VA event rates are high in ARVC patients with a majority having VT falling in the VF zone resulting in ICD shock(s). S-ICDs could be of benefit in most patients with ARVC with the absence of severely impaired RV function which has the potential to avoid consequences of the high burden of lead failure., Competing Interests: Conflict of interest: S.H. has received speaker’s fees from Abbott. R.J.H. has received speaker’s fees, research, and educational grants from Abbott, Medtronic, and Boston Scientific. S.H. and R.J.H. are inventors of the STAR Mapping system and co-Founder of Rhythm AI. S.H. is a British Heart Foundation Clinical Intermediate Fellow and receives funding from the British Heart Foundation. P.D.L. receives speaker frees and research grants from Medtronic, Abbott, and Boston Scientific. P.D.L. is supported by UCL/UCLH Biomedicine NIHR and Barts BRC. All remaining authors have declared no conflicts of interest., (© The Author(s) 2023. Published by Oxford University Press on behalf of the European Society of Cardiology.)

Aims: The SMART Pass™ (SP) algorithm is a high-pass filter that aims to reduce inappropriate therapy (IT) in subcutaneous internal cardiac defibrillator (S-ICD), but SP can deactivate due to low amplitude sensed R waves or asystole. The association between IT and SP deactivation and management strategies were evaluated, hypothesizing SP deactivation increases the risk of IT and device re-programming, or lead/generator re-positioning could reduce this risk., Methods and Results: Retrospective single-centre audit of Emblem™ S-ICD devices implanted 2016 to 2020 utilizing health records and remote monitoring data. Cox regression models evaluated associations between SP deactivation and IT. A total of 348 patients (27 ± 16.6 months follow-up) were studied: 73% primary prevention. Thirty-eight patients (11.8%) received 83 shocks with 27 patients (7.8%) receiving a total of 44 IT. Causes of IT were oversensing (98%) and aberrantly conducted atrial fibrillation (2%). SP deactivation occurred in 32 of 348 patients (9%) and was significantly associated with increased risk of IT (hazard ratio 5.36, 95% CI 2.37-12.13). SP deactivation was due to low amplitude R waves (94%), associated with a higher defibrillation threshold at implant and presence of arrhythmogenic right ventricular cardiomyopathy. No further IT occurred 16 ± 15.5 months after corrective interventions, with changing the sensing vector being successful in 59% of cases., Conclusion: To reduce the risk of IT, the cause of the SP deactivation should be investigated, and appropriate reprogramming, device, or lead modifications made. Utilizing the alert for SP deactivation and electrograms could pro-actively prevent IT., Competing Interests: Conflict of interest: C.M. has received speaker fees from Abbott, Boston Scientific, Biotronik, Medtronic, and Phillips and has received consulting fees from Medtronic. As of April 2023 CM is supported by a research grant provided by Boston Scientific. Z.C. has received speaker fees from Abbott. R.H. has received speaker fees from Medtronic and Biosense Webster; educational grant from Biosense Webster; and an institutional research grant from Medtronic. A.C. has received an institutional research grant from Abbott and has received an educational grant from Abbott and Boston Scientific. P.D.L. has received research grants and speaker fees from Boston Scientific, Abbott, and Medtronic and is supported by UCL/UCLH Biomedicine NIHR and Barts BRC., (© The Author(s) 2023. Published by Oxford University Press on behalf of the European Society of Cardiology.)

Aim: Implantable loop recorders (ILRs) are now routinely implanted for long-term cardiac monitoring in the clinical setting. The aim of this study was to examine the real-world performance of these devices focusing on the management changes made in response to ILR-recorded data., Methods and Results: This was a single-centre, prospective observational study of consecutive patients undergoing ILR implantation. All patients who underwent implantation of a Medtronic Reveal LINQ device from September 2017 to June 2019 at Barts Heart Centre were included. Five hundred and one patients were included. Three hundred and two (60%) patients underwent ILR implantation for an indication of pre-syncope/syncope, 96 (19%) for palpitations, 72 (14%) for atrial fibrillation (AF) detection with a history of cryptogenic stroke, and 31 (6%) for high risk of serious cardiac arrhythmia. The primary outcome of this study was that an ILR-derived diagnosis altered management in 110 patients (22%). Secondary outcomes concerned subgroup analyses by indication: in patients who presented with syncope/pre-syncope, a change in management resulting from ILR data was positively associated with age [hazard ratio (HR) 1.04, 95% confidence interval 1.02-1.06; P &lt; 0.001] and negatively associated with a normal electrocardiogram at baseline (HR 0.54 [0.31-0.93]; P = 0.03). Few patients (1/57, 2%) aged &lt;40 years in this group underwent device implantation, compared to 19/62 patients (31%) aged 75 years and over (P = 0.0024). Out of 183 (12%) patients, 22 in the 40-74 age range had a device implanted. Among patients who underwent ILR insertion following cryptogenic stroke, 13/72 (18%) had AF detected, leading to a decision to commence anticoagulation., Conclusion: These results inform the utility of ILR in the clinical setting. Diagnoses provided by ILR that lead to changes in management are rare in patients under age 40, particularly following syncope, pre-syncope, or palpitations. In older patients, new diagnoses are frequently made and trigger important changes in treatment., (© The Author(s) 2021. Published by Oxford University Press on behalf of the European Society of Cardiology.)

Objectives: Diagnosing atrial fibrillation (AF) in patients following Cryptogenic stroke (CS) has therapeutic implications that can reduce the risk of further strokes. However, it's indolent and paroxysmal nature makes this challenging. Prolonged rhythm monitoring using implantable loop recorders (ILRs) can significantly increase the AF detection rate in the clinical trial paradigm. Whether this can be translated to real-world practice is unknown. An evaluation of referral pathways, workload and real-world efficacy may help select patients and inform service development., Materials and Methods: Retrospective review of all patients with CS referred to a tertiary electrophysiology referral hospital for ILR implantation between February 2017 and October 2020 for AF detection was conducted. The electronic health record was used to determine demographic and mortality data. Remote monitoring was used to identify AF occurrence., Results: 107 patients were included. The average time from stroke to ILR implantation was 10.5 (5.9-18.6) months. The average monitoring duration was 18.1 ± 11.2 months with 15 (14.0%) patients diagnosed with AF and commenced on anticoagulation. One diagnosis were made in the first 30 days whereas 11 (73%) were made within 12 months. Paroxysmal AF episodes ranged from 6 min to 13 h. Patients with CHA 2 DS 2 -VASc >3 were more likely to have AF (20.3% vs 4.7%, p = 0.02). Age was independently associated with AF detection after multi-variate regression. 352 ± 1171 unique events were recorded per patient, 75% of which were for suspected AF. External manufacturer-led triage of transmissions reduced transmission volume by 33%., Conclusions: ILR-based AF detection rate was high among referred CS patients, despite implantation occurring relatively late. Older patients may be less likely to be referred despite positive correlation between age and AF detection. Although recording algorithms and external triage reduced transmission volume, specialist analysis was required to manage the ILR event burden., Competing Interests: Declaration of Competing Interest Dr Malcolm Finlay receives research support, speakers fees and advisory board fees from Medtronic Ltd, Johnson & Johnson Inc, Abbott Inc and Boston Scientific Ltd., (Copyright © 2022 Elsevier Inc. All rights reserved.)

Background: Conventional superior access for cardiac implantable electronic devices (CIEDs) is not always possible and femoral CIEDs (F-CIED) are an alternative option when leadless systems are not suitable. The long-term outcomes and extraction experiences with F-CIEDs, in particular complex F-CIED (ICD/CRT devices), remain poorly understood., Methods: Patients referred for F-CIEDs implantation between 2002 and 2019 at two tertiary centers were included. Early complications were defined as ≤30 days following implant and late complications >30 days., Results: Thirty-one patients (66% male; age 56 ± 20 years; 35% [11] patients with congenital heart disease) were implanted with F-CIEDs (10 ICD/CRT and 21 pacemakers). Early complications were observed in 6.5% of patients: two lead displacements. Late complications at 6.8 ± 4.4 years occurred in 29.0% of patients. This was higher with complex F-CIED compared to simple F-CIED (60.0% vs. 14.3%, p = .02). Late complications were predominantly generator site related (n = 8, 25.8%) including seven infections/erosions and one generator migration. Eight femoral generators and 14 leads (median duration in situ seven [range 6-11] years) were extracted without complication., Conclusions: Procedural success with F-CIEDs is high with clinically acceptable early complication rates. There is a notable risk of late complications, particularly involving the generator site of complex devices following repeat femoral procedures. Extraction of chronic F-CIED in experienced centers is feasible and safe., (© 2022 The Authors. Pacing and Clinical Electrophysiology published by Wiley Periodicals LLC.)

Background: The risk factors for developing pacing induced left ventricular dysfunction (LVD) in patients with high burden of right ventricular pacing (RVP) is poorly understood. Therefore, in the present study, we aimed to assess the determinants of pacing induced LVD., Methods: Our data were retrospectively collected from 146 patients with RVP > 40% who underwent generator change (GC) or cardiac resynchronization therapy (CRT) upgrade between 2016 and 2019 who had left ventricular ejection fraction (EF) ≥50% at initial implant., Results: A total of 75 patients had CRT upgrade due to pacing induced LVD (EF < 50%) and 71 patients with preserved LV function (EF ≥ 50%) had a GC. Primary indication for pacing in both groups was complete heart block. Male predominance (p = .008), prior myocardial infarction (MI) (p = .001), atrial fibrillation (AF) (p = .009), chronic kidney disease (CKD) (p = .005), and borderline low systolic function (BLSF) (EF 50%-55%) (p = .04) were more prevalent in the CRT upgrade group. Presence of AF (odds ratio [OR] = 3.05, 95% confidence interval [CI] 1.42-6.58; p = .004), BLSF (OR = 3.8, 95% CI 1.22-11.8; p = .02), and male gender (OR = 2.41, 95% CI 1.14-5.08; p = .02) were independent predictors for RVP induced LVD. Age (OR = 1.08, 95% CI 1.02-1.14; p = .005) and BLSF (OR = 5.33, 95% CI 1.26-22.5; p = .023) were independent predictors of earlier development of LVD after implant., Conclusions: Our results suggested that AF, BLSF, and male gender are predictors for development of pacing induced LVD in patients with high RVP burden. LVD can occur at any time after pacemaker implant with BLSF and increasing age associated with earlier development of LVD., (© 2022 Wiley Periodicals LLC.)

The coronavirus disease 2019 (COVID-19) pandemic has had a dramatic impact on the way that medical care is delivered. To minimise hospital attendance by both patients and staff, remote clinics, meetings and investigations have been used. Technologies including hand-held ECG monitoring using smartphones, patch ECG monitoring and sending out conventional Holter monitors have aided remote investigations. Platforms such as Google Meet and Zoom have allowed remote multidisciplinary meetings to be delivered effectively. The use of phone consultations has allowed outpatient care to continue despite the pandemic. The COVID-19 pandemic has resulted in a radical, and probably permanent, change in the way that outpatient care is delivered. Previous experience in remote review and the available technologies for monitoring have allowed the majority of outpatient care to be conducted without obviously compromising quality or safety., Competing Interests: Disclosure: RJH has received research grants, educational grants and speaker fees from Biosense Webster and Medtronic. SH and RJH are shareholders in Rhythm AI. CM has received speaker fees from Abbott, BIOTRONIK, Boston Scientific and Medtronic. All other authors have no conflicts of interest to declare., (Copyright © 2021, Radcliffe Cardiology.)

Background Recognizing the etiology of sudden cardiac arrest (SCA) has an enormous impact on the management of victims and their immediate families. A significant proportion of SCA survivors with a structurally normal heart are not offered a diagnosis and there is no clear consensus on the type and duration of follow-up. We aimed to assess the utility of a multidisciplinary approach in optimizing diagnosis of cardiac arrest etiology during follow-up. Methods and Results We retrospectively assessed 327 consecutive SCA survivors (mean age 61.9±16.2 years, 80% men) who underwent secondary prevention implantable cardioverter defibrillators between May 2015 and November 2018. The initial diagnosis was recorded at the time of admission and follow-up diagnosis was deduced from subsequent clinic records, investigations, and outcomes of multidisciplinary team meetings. Structural heart disease accounted for 282 (86%) of SCAs. Forty-five (14%) patients had a structurally normal heart and underwent comprehensive testing and follow-up (mean duration 93±52 weeks). On initial evaluation, 14/45 (31%) of these received a diagnosis, rising to 29/45 (64%) with serial reviews during follow-up. Discussion in multidisciplinary team meetings and imaging reassessment accounted for 47% of new diagnoses. No additional diagnoses were made beyond 96 weeks. Nineteen (5.8%) fatalities occurred in the entire cohort, exclusively in patients with structural heart disease. Conclusions Systematic comprehensive testing combined with multidisciplinary expert team review of SCA survivors without structural heart disease improves the yield and time to diagnosis compared with previously published studies. This approach has positive implications in the management of SCA survivors and their families.

A 52-year-old gentleman with a subcutaneous implantable cardioverter defibrillator (S-ICD) implanted in 2015 for primary prevention and a background of hypertrophic cardiomyopathy presented via remote monitoring alert (Boston Scientific Latitude NXT) with an aborted charge episode. The episode showed myopotential noise with baseline wander, and an urgent outpatient follow-up was arranged. Upon investigation the S-ICD lead had retracted to the pocket of the generator via a reel mechanism, wrapping the lead around the can. This was likely to be caused by insufficient suturing of the lead collar at the base of xiphisternum. The device had automatically disabled the SmartPass filter, which does not currently have an alert mechanism. This case highlights the rare occurrence of S-ICD lead displacement and components of the SmartPass system which can provide an early warning to lead problems., (© 2020 Wiley Periodicals LLC.)

A 73-year-old gentleman with dilated cardiomyopathy, left bundle branch block and a left ventricular (LV) ejection fraction of 20% was implanted with two LV leads in a tri-ventricular cardiac resynchronisation therapy defibrillator (CRT-D) trial. As a part of the trial he was programmed with fusion-based CRT therapy with dual LV lead only pacing. The patient presented to local heart failure service 12 years after implant, after a positive response to CRT therapy, with increase in fatigue, shortness of breath and bilateral pitting oedema. The patient sent a remote monitoring transmission that suggested loss of capture on one of the LV leads. This coupled with atrial ectopics was producing a high burden of pacemaker-mediated tachycardia (PMT) that was not seen when both LV leads had been capturing. What is the mechanism for this? Dual LV-lead tri-ventricular leads have been shown to have variable improvements in CRT response but with an increased complexity of implant procedure. This is the first case report of PMT-induced heart failure exacerbation in a tri-ventricular device following loss of LV capture of one lead., (© 2020 Wiley Periodicals LLC.)

Introduction: Implantable loop recorders (ILR) are predominantly implanted by cardiologists in the catheter laboratory. We developed a nurse-delivered service for the implantation of LINQ (Medtronic; Minnesota) ILRs in the outpatient setting. This study compared the safety and cost-effectiveness of the introduction of this nurse-delivered ILR service with contemporaneous physician-led procedures., Methods: Consecutive patients undergoing an ILR at our institution between 1st July 2016 and 4th June 2018 were included. Data were prospectively entered into a computerized database, which was retrospectively analyzed., Results: A total of 475 patients underwent ILR implantation, 271 (57%) of these were implanted by physicians in the catheter laboratory and 204 (43%) by nurses in the outpatient setting. Six complications occurred in physician-implants and two in nurse-implants (P = .3). Procedural time for physician-implants (13.4 ± 8.0 minutes) and nurse-implants (14.2 ± 10.1 minutes) were comparable (P = .98). The procedural cost was estimated as £576.02 for physician-implants against £279.95 with nurse-implants, equating to a 57.3% cost reduction. In our center, the total cost of ILR implantation in the catheter laboratory by physicians was £10 513.13 p.a. vs £6661.55 p.a. with a nurse-delivered model. When overheads for running, cleaning, and maintaining were accounted for, we estimated a saving of £68 685.75 was performed by moving to a nurse-delivered model for ILR implants. Over 133 catheter laboratory and implanting physician hours were saved and utilized for other more complex procedures., Conclusion: ILR implantation in the outpatient setting by suitably trained nurses is safe and leads to significant financial savings., (© 2019 Wiley Periodicals, Inc.)

Objectives: This study sought to assess immediate and short-term performance of the Medtronic Attain Stability Quadripolar 4798 lead (Medtronic, Dublin, Ireland)., Background: Cardiac resynchronization therapy (CRT) is an established treatment for appropriately selected patients with left ventricular (LV) systolic dysfunction. The most common reason for failure to implant a lead is the lack of a suitable epicardial vein, due either to an absent vessel in the target site, an unacceptably high threshold, lead instability, phrenic nerve stimulation, or a combination of reasons. In August 2017, a novel quadripolar active fixation LV lead (Medtronic) was released. This paper reports the initial clinical experience with lead implantation and specifically immediate and short-term pacing parameters across 3 United Kingdom centers., Methods: Consecutive patients eligible for CRT were deemed suitable for this lead. Immediate and short-term lead performance data regarding LV threshold, impedance, and displacement rates were collected at standard pacing checks (1 day, 5 weeks, 3 months, and 9 months post-implantation)., Results: CRT using this lead was attempted in 82 cases and was successful in 81 cases (98.8%). LV thresholds and impedance levels were 1.22 ± 0.75 V and 737 ± 319 Ω at implantation; 1.16 ± 0.71 V and 597 ± 218 Ω at day 1; 1.02 ± 0.48 V and 579 ± 148 Ω at week 6; 0.98 ± 0.49 V and 569 ± 133 Ω at 3 months; and 1.06 ± 0.48 V and 570 ± 140 Ω at 9 months. As of the publication of this paper, no LV lead has been displaced., Conclusions: CRT using the Medtronic lead was successful in more than 98% of the patients. Short-to-medium-term data regarding lead performance and stability were excellent, with zero displacements as of the publication of this paper., (Copyright © 2019 American College of Cardiology Foundation. All rights reserved.)

An 85-year-old male was admitted to our center with a non-ST elevation myocardial infarction. The patient had a dual-chamber pacemaker in situ with an atrial and His lead. A transient increase in His threshold and loss of nonselective capture occurred at the presentation of right coronary artery infarction, peaking during rotational atherectomy therapy causing loss of capture and complete atrioventricular block. A follow-up interrogation, 2 weeks postrevascularization, showed a return to a normal nonselective capture morphology and threshold measurements. Physicians should be aware of this complication in patients with His leads, particularly those with a history of coronary artery disease., (© 2019 Wiley Periodicals, Inc.)

A 73-year-old male with dual-chamber implantable cardioverter defibrillator (Teligen, Boston Scientific, Marlborough, MA, USA) had multiple episodes of automatic mode switch (AMS) during clinical follow-up. Over 50% of these demonstrated a similar pattern of initiation. AV Search+ in combination with sensor rate pacing can cause short-coupled atrial paced intervals that can be proarrhythmic. After programming changes were made AMS burden has significantly decreased., (© 2018 Wiley Periodicals, Inc.)