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Background: Previous studies have demonstrated that microvolt T-wave alternans (MTWA) testing is a robust predictor of ventricular tachyarrhythmias and sudden cardiac death (SCD) in at-risk patients. However, recent studies have suggested that MTWA testing is not as good a predictor of "appropriate" implantable cardioverter-defibrillator (ICD) therapy as it is a predictor of SCD in patients without ICDs.Objective: To evaluate the utility of MTWA testing for SCD risk stratification in patients without ICDs.Methods: Patient-level data were obtained from 5 prospective studies of MTWA testing in patients with no history of ventricular arrhythmia or SCD. In these studies, ICDs were implanted in only a minority of patients and patients with ICDs were excluded from the analysis. We conducted a pooled analysis and examined the 2-year risk for SCD based on the MTWA test result.Results: The pooled cohort included 2883 patients. MTWA testing was positive in 856 (30%), negative in 1627 (56%), and indeterminate in 400 (14%) patients. Among patients with a left ventricular ejection fraction (LVEF) of ≤35%, annual SCD event rates were 4.0%, 0.9%, and 4.6% among groups with MTWA positive, negative, and indeterminate test results. The SCD rate was significantly lower among patients with a negative MTWA test result than in patients with either positive or indeterminate MTWA test results (P <.001 for both comparisons). In patients with an LVEF of >35%, annual SCD event rates were 3.0%, 0.3%, and 0.3% among the groups with MTWA positive, negative, and indeterminate test results. The SCD rate associated with a positive MTWA test result was significantly higher than that associated with either negative (P <.001) or indeterminate MTWA test results (P = .003).Conclusions: In patients without ICDs, MTWA testing is a powerful predictor of SCD. Among patients with an LVEF of ≤35%, a negative MTWA test result is associated with a low risk for SCD. Conversely, among patients with an LVEF of >35%, a positive MTWA test result identifies patients at significantly heightened SCD risk. These findings may have important implications for refining primary prevention ICD treatment algorithms. [ABSTRACT FROM AUTHOR]

Background: Transvenous Lead extraction (TLE) success and safety are heavily influenced by lead dwell time., Objective: In this study, we aim to compare the clinical effectiveness and safety of transvenous lead extraction between young and old leads., Methods: We retrospectively identified all TLE procedures at Emory Healthcare from 2007-2023. Baseline patients' characteristics and procedural details were collected. The cohort was categorized based on the oldest lead dwell time in each procedure. The very long-dwell time (VLDT) group included all procedures with the oldest lead dwell time ≥15 years, whereas the control group included all procedures with the oldest lead dwell time <15 years. TLE outcomes were compared between the 2 groups., Results: Of the 1717 TLE procedures, 114 procedures (6.6%) included leads with dwell times ≥15 years. Patients in the VLDT group were older and had a higher number of targeted leads. 57% of TLE in the VLDT group were for infectious indications. Lead extraction procedural and clinical success were significantly lower in the VLDT group compared to the control group (75% vs 95%, 83% vs 97%, p<0.001, respectively). There was a trend towards a higher major complications rate in the VLDT group compared to the control group (3.5% vs 1.3%, p=0.058)., Conclusion: TLE of VLDT leads has a lower procedural and clinical success and a higher complication rate than TLE of leads with a shorter dwell time. These results will allow electrophysiologists to quantify risks and benefits of abandoning leads at the time of lead revisions or upgrades., (Copyright © 2024 Heart Rhythm Society. Published by Elsevier Inc. All rights reserved.)

Background: Most studies of device-detected atrial fibrillation (AF) have recommended indefinite anticoagulation once a patient crosses a particular threshold for AF duration or burden. However, durations and burdens are known to fluctuate over time, but little is known about the magnitude of spontaneous fluctuations and the potential impact on anticoagulation decisions., Objective: To quantify spontaneous fluctuations in AF duration and burden in patients with implantable loop recorders (ILRs) METHODS: We reviewed all ILR interrogations for patients with non-permanent AF at our institution from 2018 to 2023. We excluded patients treated with rhythm control. The duration of longest AF episode at each interrogation was classified as < 6, 6-24, and > 24 h, and the AF burden reported at each interrogation was classified as < 2%, 2%-11.4%, and > 11.4%., Results: Out of 156 patients, the mean age at ILR implant was 70.9 ± 12.5 years, CHA 2 DS 2 -VASc score was 4.2 ± 1.8, duration of ILR follow-up was 23.4 ± 11.2 months, and number of ILR interrogations per patient was 18.0 ± 8.9. The duration of longest AF episode at any point during follow-up was < 6 , 6-24 , and > 24 h in 110, 30, and 16 patients, respectively. Among the 30 patients with a longest AF episode of 6-24 h at some point during follow-up, out of 594 total ILR interrogations, only 75 (12%) showed a longest episode of 6-24 h. In the remaining 519 interrogations, the longest episode was < 6 h. In patients with a longest episode of > 24 h at any point during follow-up (n = 16), only 47 out of 320 total ILR interrogations (15%) showed an episode of > 24 h. When evaluating AF burden, 96, 38, and 22 patients had maximum reported AF burdens of < 2%, 2%-11.4%, and > 11.4% at any point during ILR follow-up. Among those with a maximum burden of 2%-11.4% at some point during follow-up (n = 38), out of 707 ILR interrogations, only 76 (11%) showed a burden of 2%-11.4%. In the remaining 631 interrogations, the burden was < 2%. In the 22 patients with a burden > 11.4% at some point during follow-up, only 80 out of 480 interrogations (17%) showed a burden of > 11.4%. In 65% of interrogations, the burden was < 2%., Conclusion: Significant, spontaneous fluctuations in AF burden and duration are common in patients with ILRs. Even in patients with AF episodes of 6-24 h or > 24 h at some point during follow-up, the vast majority of interrogations show episodes of < 6 h. Similarly, in patients with burdens of 2%-11.4% or > 11.4% at some point during follow-up, the vast majority of interrogations show burdens of < 2%. More data are needed to determine whether crossing an AF burden or duration threshold once is sufficient to merit lifelong anticoagulation or whether spontaneous fluctuations in AF burden and duration should impact anticoagulation decisions., (© 2024 Wiley Periodicals LLC.)

Background: The subcutaneous implantable cardioverter-defibrillator (ICD) is associated with fewer lead-related complications than a transvenous ICD; however, the subcutaneous ICD cannot provide bradycardia and antitachycardia pacing. Whether a modular pacing-defibrillator system comprising a leadless pacemaker in wireless communication with a subcutaneous ICD to provide antitachycardia and bradycardia pacing is safe remains unknown., Methods: We conducted a multinational, single-group study that enrolled patients at risk for sudden death from ventricular arrhythmias and followed them for 6 months after implantation of a modular pacemaker-defibrillator system. The safety end point was freedom from leadless pacemaker-related major complications, evaluated against a performance goal of 86%. The two primary performance end points were successful communication between the pacemaker and the ICD (performance goal, 88%) and a pacing threshold of up to 2.0 V at a 0.4-msec pulse width (performance goal, 80%)., Results: We enrolled 293 patients, 162 of whom were in the 6-month end-point cohort and 151 of whom completed the 6-month follow-up period. The mean age of the patients was 60 years, 16.7% were women, and the mean (±SD) left ventricular ejection fraction was 33.1±12.6%. The percentage of patients who were free from leadless pacemaker-related major complications was 97.5%, which exceeded the prespecified performance goal. Wireless-device communication was successful in 98.8% of communication tests, which exceeded the prespecified goal. Of 151 patients, 147 (97.4%) had pacing thresholds of 2.0 V or less, which exceeded the prespecified goal. The percentage of episodes of arrhythmia that were successfully terminated by antitachycardia pacing was 61.3%, and there were no episodes for which antitachycardia pacing was not delivered owing to communication failure. Of 162 patients, 8 died (4.9%); none of the deaths were deemed to be related to arrhythmias or the implantation procedure., Conclusions: The leadless pacemaker in wireless communication with a subcutaneous ICD exceeded performance goals for freedom from major complications related to the leadless pacemaker, for communication between the leadless pacemaker and subcutaneous ICD, and for the percentage of patients with a pacing threshold up to 2.0 V at a 0.4-msec pulse width at 6 months. (Funded by Boston Scientific; MODULAR ATP ClinicalTrials.gov NCT04798768.)., (Copyright © 2024 Massachusetts Medical Society.)

Introduction: To evaluate the cost and efficiency of suture-mediated percutaneous closure (SMC) compared to manual compression (MC) after atrial fibrillation (AF) ablation. SMC has been demonstrated to be efficacious in reducing hemostasis and bedrest times after AF ablation. To date, randomized data comparing the direct and indirect cost between the two techniques have not been described., Methods: We conducted a 1:1 randomized trial comparing SMC to MC following AF ablation. The primary endpoints have been previously published. However, secondary endpoints pertinent to indirect cost including complication rates, hospital utilization (i.e., delays in discharge, additional patient encounters, nursing utilization), pain, patient reported outcomes, as well as the direct costs of care associated with AF ablation were collected. We also performed secondary analysis of the primary endpoint to evaluate for a learning curve, and subgroups analysis comparing efficacy across different numbers of access sites and compared to those in the MC group with a figure-of-eight suture (Fo8), that could potentially have impacted the relative efficiency of the procedure., Results: A total of 107 patients were randomized and included: 53 in the SMC group and 54 in MC. A learning curve was observed in the SMC group between the first and second half of the study group (p = 0.037), with no such difference in the MC group. After accounting for the number of access sites, time to hemostasis remained shorter in the SMC Group (p = 0.002). Compared to those in the Fo8 arm (n = 37), the time to hemostasis remained shorter in the SMC group (p = 0.001). Among those planned for same-day discharge, there were more delays in the MC group (31.5% vs. 11.3%, p = 0.0144). Rates of major and minor complications were similar between SMC and MC groups at discharge (p = 0.243) and 30 days (p = 1.00), as were nursing utilization, self-reported pain, and overall patient reported outcomes. The overall cost of care related to the procedure was similar between the MC and SMC groups ($56 533.65 [$45 699.47, $66 987.64] vs. $57 050.44 [$47 251.40, $66 426.34], p = 0.601)., Conclusion: SMC has been shown to decrease time to hemostasis and ambulation and facilitate earlier same-day discharge after AF ablation without an increase in direct or indirect costs., (© 2024 The Author(s). Journal of Cardiovascular Electrophysiology published by Wiley Periodicals LLC.)

Competing Interests: Funding Support and Author Disclosures The authors have reported that they have no relationships relevant to the contents of this paper to disclose.

Introduction: The Centers for Medicare & Medicaid Services (CMS) required a shared decision-making (SDM) interaction, with an "independent" physician, before left atrial appendage closure (LAAC). The purpose of this study is to better understand how this requirement is implemented in clinical practice., Methods: We surveyed LAAC-performing centers. The characteristics of respondent and nonrespondent hospitals were compared using the CMS Provider of Services File for 2017., Results: We received 86 responses out of 269 surveys mailed (32%). Respondent and nonrespondent hospital affiliations were similar: mean hospital size 525 beds, 15% for-profit, and 34% teaching hospitals. Thirty-four respondents (39.5%) stated that the implanting physician conducts some or all of the SDM interactions. The percentage of patients who decide not to undergo LAAC after the SDM interaction was estimated at 8.1%. Out of 72 responses to an open-ended question about the benefit of the SDM interaction, 44 (61%) described the requirement in negative terms, of which most felt the requirement was burdensome for patients and providers. Only 28 respondents (39%) described the requirement in positive or mixed terms., Conclusion: In violation of the letter of the CMS policy for LAAC, implanting physicians perform the SDM interaction at nearly 40% of responding hospitals. Most respondents felt the SDM requirement was burdensome for patients. More detailed guidance from CMS on how to comply with the policy may result in better alignment between the intent of the policy and how it is implemented., (© 2024 Wiley Periodicals LLC.)

Background: Because of differences in chest wall anatomy, female patients may have higher rates of subcutaneous implantable cardioverter-defibrillator (S-ICD) pocket-related complications., Objective: We sought to evaluate sex-based outcomes after S-ICD implantation., Methods: Patients implanted with an S-ICD at Emory Healthcare between 2010 and 2023 were included in the analysis. Patients' clinical characteristics and post-S-ICD implantation complications were collected., Results: There were 429 male patients (68%) and 199 female patients (32%) observed for a median duration of 2.3 years (0.6-4.4 years). Male and female patients had comparable rates of diabetes (28%), end-stage renal disease (29.5%), ejection fraction (30.2% ± 13.4%), and body mass index (29.1 ± 6.6 kg/m 2 ). There was no statistical difference in the incidence of shocks between men and women (26.3% vs 20.1%; P = .09), including appropriate shocks (14.7% vs 12%; P = .98) and inappropriate shocks (11.7% vs 9.5%; P = .98). Pocket-related complications occurred in 21 patients; these included pocket infection (n = 12), wound dehiscence (n = 7), and hematoma requiring drainage (n = 2). Female patients had a significantly higher pocket-related complication rate compared with male patients (7.2% vs 2.5%; P = .016). In controlling for age, body mass index, diabetes, and end-stage renal disease, female patients had higher odds of pocket-related complications compared with male patients (odds ratio, 3.15; 95% confidence interval, 1.27-7.75). Pocket-related complications decreased after 2018 compared with before 2018 (6% vs 2.6%, P = .052), mainly driven by reduction in complications in women (12.3% vs 3.2%; P = .034) but not in men (2.8% vs 2.4%; P = 1)., Conclusion: In this cohort of S-ICD patients, women had a higher rate of post-S-ICD pocket-related complications that could be explained by sex-based differences in anatomy., Competing Interests: Disclosures V.J. received funding from the Katz foundation. B.R.R. received funding from NIH and AHRQ. D.B.D. is a consultant for Boston Scientific, Abbott, and AtriCure. M.S.L. is a consultant for Medtronic and Boston Scientific. M.F.E. is a consultant for Medtronic and Boston Scientific., (Copyright © 2024 Heart Rhythm Society. Published by Elsevier Inc. All rights reserved.)

Background: Lead-related venous stenosis and occlusion can complicate the insertion or replacement of transvenous leads in patients with cardiac implantable electronic devices (CIEDs). A possible solution is to tunnel the lead from the contralateral vasculature to the ipsilateral generator. Procedural complications and long-term outcomes remain unclear with this technique., Objective: We sought to assess outcomes of tunneled transvenous leads., Methods: We retrospectively identified all patients who underwent transvenous CIED lead tunneling to a contralateral pocket at our institution between 2014 and 2024. Clinical characteristics, indications for lead implantation, postoperative complications, and long-term outcomes were collected., Results: We identified that 27 patients underwent transvenous lead tunneling at our institution. Most patients were men (20, 74%) with a mean age of 68.8 ± 18.3 years. Most patients had nonischemic cardiomyopathy (16, 59%) with a mean ejection fraction of 29.3% ± 11.3%. The tunneled leads were coronary sinus leads (20, 74%), followed by defibrillator leads (5, 18.5%) and right ventricular pacing leads (2, 7.4%). Implantation procedures were primarily for device upgrade (18), lead revisions (8), or de novo lead placement (1). No postoperative complications were seen. Patients were followed for a mean of 2.2 ± 1.4 years. One tunneled defibrillator lead (3.7%) had low shock impedance 3 years after implantation, which was monitored and did not require an intervention., Conclusion: In patients with ipsilateral venous occlusion, contralateral lead tunneling appears to be an effective and safe approach to manage patients with CIEDs and occluded ipsilateral subclavian veins., Competing Interests: Disclosures Dr El-Chami is a consultant for Medtronic and Boston Scientific. The rest of the authors report no conflicts of interest., (Copyright © 2024 Heart Rhythm Society. Published by Elsevier Inc. All rights reserved.)

Background: Human in vivo data on the chemical stability of different transvenous lead materials, particularly Optim TM leads, are lacking., Objectives: The purpose of this study was to determine the chemical reactivity of insulation materials by analyzing the molar mass of extracted pacing and defibrillator leads METHODS: We collected extracted leads at Emory University Hospitals and sent the leads with thermoplastic outer insulation material for molar mass analysis, a material characteristic that informs biostability. Leads were separated based on the chemical identity of the outer insulation material, and the molar mass was measured by an independent party. The extent of chemical reaction was compared across leads having different materials: poly(ether)urethane 55D, poly(ether)urethane 80A, and Optim., Results: A total of 70 leads were extracted. The subset of extracted leads having outer insulation materials composed of PEU or Optim were analyzed for molar mass, where implant times ranged from 0.12 to 16.26 years. The rate of chemical degradation was compared by plotting the extent of reaction [M n (t = 0)/M n (t)] as a function of implant time. The Optim molar mass decreased to 40% of its initial value at 10 years of implant. No change in the molar mass of the PEU insulations could be resolved over the same 10-year implant time., Conclusion: Because the molar mass of a polymer is directly related to its mechanical integrity, the observed decrease in molar mass of Optim likely translates into premature insulation defects and is consistent with the observed increased rate of electrical malfunction/noise in this subset of cardiac leads., Competing Interests: Disclosures Dr El-Chami reports honoraria/speaking/consulting fees from Boston Scientific and Medtronic. Dr Lloyd reports honoraria/speaking/consulting fees from Medtronic and Boston Scientific. Dr Chaffin is an employee of Medtronic. All other authors have no conflicts to disclose., (Copyright © 2024 Heart Rhythm Society. Published by Elsevier Inc. All rights reserved.)

Background: Data on transvenous (TV) lead-associated superior vena cava (SVC) syndrome are limited. The management of this problem might require a multidisciplinary approach, often involving transvenous lead extraction (TLE) followed by angioplasty and stenting., Objective: The purpose of this study was to describe the management and outcome of TV lead-associated SVC syndrome., Methods: We retrospectively identified patients with a diagnosis of SVC syndrome and TV leads at Emory Healthcare between 2015 and 2023., Results: Fifteen patients with lead-related SVC syndrome were identified. The cohort average age was 50 years. Symptoms included swelling of the face, neck, and upper extremities (67%); shortness of breath (53%); and lightheadedness (40%). Patients had an average of 2 ± 0.7 leads crossing the SVC, with a lead dwell time of 9.8 ± 7.5 years. Thirteen patients were managed with TLE, followed by SVC stenting and angioplasty in 10 and angioplasty alone in 2; 1 patient had no intervention after TLE. One patient was managed with anticoagulation, and another had angioplasty and stenting with lead jailing. One patient experienced SVC perforation and cardiac tamponade during SVC stenting, which was managed successfully with a covered stent and pericardiocentesis. Among the 12 patients with TLE and angioplasty ± stenting, 7 underwent reimplantation of a transvenous lead. Two of those patients had symptoms recurrence, and none of the 5 patients without lead reimplantation had recurrence of symptoms., Conclusion: Lead-related SVC syndrome management requires a multidisciplinary approach often including TLE followed by angioplasty and stenting. Avoiding TV lead reimplantation might help reduce symptoms recurrence., Competing Interests: Disclosures Dr El-Chami is a consultant for Medtronic and Boston Scientific. All other authors have no conflicts of interest to disclose., (Copyright © 2024 Heart Rhythm Society. Published by Elsevier Inc. All rights reserved.)

Background: Early guidance recommended a bolus of intravenous heparin at the beginning of leadless pacemaker (LP) implantation procedures. However, due to concern about bleeding complications, more recent practice has tended toward omitting the bolus and only running a continuous heparin infusion through the introducer sheath. The impact of omitting the heparin bolus on procedural outcomes is not clear., Methods: We reviewed all Medtronic Micra LP implants at our institution from 9/2014 to 9/2022. The decision to bolus with heparin was at operator discretion., Results: Among 621 LP implants, 326 received an intravenous heparin bolus, 243 did not, and 52 patients were excluded because heparin bolus status could not be confirmed. There was a trend toward more frequent omission of the heparin bolus with more recent implants. Median follow-up after LP implant was 14.3 (interquartile range [IQR]: 8.4-27.9) months. There was no difference between heparin bolus and no bolus groups in the number of device deployments/recaptures (1.42 ± 0.81 vs. 1.31 ± 0.66, p = .15). Implant-related adverse events were also similar between heparin bolus and no bolus groups: access-site hematoma requiring intervention (7 vs. 5, p = .99), pseudoaneurysm (1 vs. 1, p = .99), cardiac perforation (1 vs. 1, p = .99), intraprocedural device thrombus formation (2 vs. 4, p = .41), 30-day rehospitalization (21 vs. 15, p = .98), and 30-day all-cause mortality (16 vs. 14, p = .70). There was one additional nonfatal cardiac perforation in a patient who was excluded due to unknown heparin bolus status. Regarding device electrical parameters between heparin bolus and no bolus groups, there were no significant differences at the time of implant: pacing capture threshold 0.5 ± 0.4 vs. 0.5 ± 0.3, p = .10; pacing impedance 739.9 ± 226.4 vs. 719.1 ± 215.4, p = .52; R wave sensing 11.7 ± 5.7 vs. 12.0 ± 5.4, p = .34). Long-term device performance was also similar between groups., Conclusion: Omission of the systemic heparin bolus at the time of LP implantation appears safe in appropriately selected patients. Heparin bolus may still be considered in long cases requiring multiple device deployments or in patients at high risk for thrombotic complications., (© 2024 Wiley Periodicals LLC.)

Introduction: Transvenous leads have been implicated in tricuspid valve (TV) dysfunction, but limited data are available regarding the effect of extracting leads across the TV on valve regurgitation. The aim of this study is to quantify tricuspid regurgitation (TR) before and after lead extraction and identify predictors of worsening TR., Methods: We studied 321 patients who had echocardiographic data before and after lead extraction. TR was graded on a scale (0 = none/trivial, 1 = mild, 2 = moderate, 3 = severe). A change of >1 grade following extraction was considered significant., Results: A total of 321 patients underwent extraction of a total of 338 leads across the TV (1.05 ± 0.31 leads across the TV per patient). There was no significant difference on average TR grade pre- and postextraction (1.18 ± 0.91 vs. 1.15 ± 0.87; p = 0.79). TR severity increased after extraction in 84 patients, but was classified as significantly worse (i.e., >1 grade change in severity) in only 8 patients (2.5%). Use of laser lead extraction was associated with a higher rate of worsening TR postextraction (44.0% vs. 31.6%, p = 0.04)., Conclusion: In our single-center analysis, extraction of leads across the TV did not significantly affect the extent of TR in most patients. Laser lead extraction was associated with a higher rate of worsening TR after extraction., (© 2024 Wiley Periodicals LLC.)

Competing Interests: Declaration of Competing Interest The authors have no competing interests to declare.

Aims: The mechanisms of transition from regular rhythms to ventricular fibrillation (VF) are poorly understood. The concordant to discordant repolarization alternans pathway is extensively studied; however, despite its theoretical centrality, cannot guide ablation. We hypothesize that complex repolarization dynamics, i.e. oscillations in the repolarization phase of action potentials with periods over two of classic alternans, is a marker of electrically unstable substrate, and ablation of these areas has a stabilizing effect and may reduce the risk of VF. To prove the existence of higher-order periodicities in human hearts., Methods and Results: We performed optical mapping of explanted human hearts obtained from recipients of heart transplantation at the time of surgery. Signals recorded from the right ventricle endocardial surface were processed to detect global and local repolarization dynamics during rapid pacing. A statistically significant global 1:4 peak was seen in three of six hearts. Local (pixel-wise) analysis revealed the spatially heterogeneous distribution of Periods 4, 6, and 8, with the regional presence of periods greater than two in all the hearts. There was no significant correlation between the underlying restitution properties and the period of each pixel., Conclusion: We present evidence of complex higher-order periodicities and the co-existence of such regions with stable non-chaotic areas in ex vivo human hearts. We infer that the oscillation of the calcium cycling machinery is the primary mechanism of higher-order dynamics. These higher-order regions may act as niduses of instability and may provide targets for substrate-based ablation of VF., Competing Interests: Conflict of interest: None declared., (© The Author(s) 2023. Published by Oxford University Press on behalf of the European Society of Cardiology.)

Aims: Single-connector (DF4) defibrillator leads have become the predominantly implanted transvenous implantable cardioverter-defibrillator lead. However, data on their long-term performance are derived predominantly from manufacturer product performance reports., Methods and Results: We reviewed medical records in 5289 patients with DF4 leads between 2011 and 2023 to determine the frequency of lead-related abnormalities. We defined malfunction as any single or combination of electrical abnormalities requiring revision including a sudden increase (≥2×) in stimulation threshold, a discrete jump in high-voltage impedance, or sensing of non-physiologic intervals or noise. We documented time to failure, predictors of failure, and management strategies. Mean follow-up after implant was 4.15 ± 3.6 years (median = 3.63), with 37% of leads followed for >5 years. A total of 80 (1.5%) leads demonstrated electrical abnormalities requiring revision with an average time to failure of 4 ± 2.8 years (median = 3.5). Of the leads that malfunctioned, 62/80 (78%) were extracted and replaced with a new lead and in the other 18 cases, malfunctioned DF4 leads were abandoned, and a new lead implanted. In multivariable models, younger age at implant (OR 1.03 per year; P < 0.001) and the presence of Abbott/St. Jude leads increased the risk of malfunction., Conclusion: DF4 defibrillator leads demonstrate excellent longevity with >98.3% of leads followed for at least 5 years still functioning normally. Younger age at implant and lead manufacturer are associated with an increased risk of DF4 lead malfunction. The differences in lead survival between manufacturers require further investigation., Competing Interests: Conflict of interest:  A.d.S.: honoraria/speaking/consulting fee—Baylis Medical Company. M.S.L.: honoraria/speaking/consulting fee—Medtronic; Boston Scientific. D.B.D.L.: honoraria/speaking/consulting fee—Boston Scientific; Medtronic; AtriCure, Inc. A.M.P.: honoraria/speaking/consulting fee—Biosense Webster, Inc. M.F.E.-C.: honoraria/speaking/consulting fee—Boston Scientific; Medtronic. The rest of the authors have no disclosures, (© The Author(s) 2023. Published by Oxford University Press on behalf of the European Society of Cardiology.)

Background: Same-day discharge (SDD) after cardiovascular procedures is rapidly gaining ground., Objective: We sought to evaluate the safety of SDD after transvenous lead extraction (TLE)., Methods: We performed a retrospective chart review of patients who underwent elective TLE between January 2020 and October 2021 at our institution. The primary outcome was SDD, and major procedural complications and readmissions within 30 days of the procedure were secondary outcomes., Results: In this analysis of 111 patients who underwent elective TLE, 80 patients (72%) were discharged on the same day (SDD group) while 31 patients (28%) stayed overnight (overnight group). Lead malfunction was the most common indication for TLE in both groups. Patients in the overnight group were more likely to have a lead dwell time of ≤10 years than those in the SDD group (38.7% vs 20% of all leads in each group; P = .042), have laser sheaths used for extraction and a higher number of leads extracted. No major complications were reported in both groups. In a multivariate analysis, lower body mass index and the use of laser sheath during TLE were predictors of overnight stay. Patients who underwent a procedure using advanced extraction techniques were 3.5 times more likely to stay overnight (95% confidence interval 1.27-9.78; P = .016)., Conclusion: In appropriately selected patients undergoing elective lead extraction, SDD is feasible and safe. Higher body mass index, fewer extracted leads, shorter lead dwell times (<10 years), and less frequent use of laser-powered extraction sheaths were associated with an increased likelihood of SDD., (Copyright © 2023 Heart Rhythm Society. Published by Elsevier Inc. All rights reserved.)

Introduction: The need for pacemaker is a common complication after transcatheter aortic valve replacement (TAVR). We previously described the Emory Risk Score (ERS) to predict the need for new pacemaker implant (PPM) after TAVR. Metrics included in the score are a history of syncope, pre-existing RBBB, QRS duration ≥140 ms, and prosthesis oversizing ≥16%. To prospectively validate the previously described risk score., Methods: We prospectively evaluated all patients without pre-existing pacemakers, ICD, or pre-existing indications for pacing undergoing TAVR with the Edwards SAPIEN 3 prosthesis at our institution from March 2019 to December 2020 (n = 661). Patients were scored prospectively; however, results were blinded from clinical decision-making. The primary endpoint was PPM at 30 days after TAVR. Performance of the ERS was evaluated using logistic regression, a calibration curve to prior performance, and receiver operating characteristic (ROC) analysis., Results: A total of 48 patients (7.3%) had PPM after TAVR. A higher ERS predicted an increased likelihood of PPM (OR 2.61, 95% CI: 2.05-3.25 per point, p < 0.001). There was good correlation between observed and expected values on the calibration curve (slope = 1.04, calibration at large = 0.001). The area under the ROC curve was 0.81 (95% CI [0.74-0.88], p < 0.001)., Conclusions: The ERS prospectively predicted the need for PPM in a serial, real-world cohort of patients undergoing TAVR with a balloon-expandable prosthesis, confirming findings previously described in retrospective cohorts. Notably, the prospective performance of the score was comparable with that of the initial cohorts. The risk score could serve as a framework for preprocedural risk stratification for PPM after TAVR., (© 2023 Wiley Periodicals LLC.)

Introduction: Permanent pacing indications are common after cardiac surgery and transcatheter structural valve interventions. Leadless pacemakers (LPs) have emerged as a useful alternative to transvenous pacemakers. However, current commercially available LPs are unable to provide atrial pacing or cardiac resynchronization and relatively little is known about LP outcomes after cardiac surgery and transcatheter valve interventions., Methods: This retrospective study included patients who received a Micra VR (Micra TM MC1VR01) or Micra AV (Micra TM MC1AVR1) (Medtronic) leadless pacemaker following cardiac surgery or transcatheter structural valve intervention between September 2014 and September 2022. Device performance and clinical outcomes, including ventricular pacing burden, ejection fraction, and need for conversion to transvenous pacing systems, were evaluated during follow-up., Results: A total of 78 patients were included, of whom 40 received a Micra VR LP implant, and 38 received a Micra AV LP implant. The mean age of the cohort was 65.9 ± 17.9 years, and 48.1% were females. The follow-up duration for the entire cohort was 1.3 ± 1.1 years: 1.6 ± 1.3 years for the Micra VR group and 0.8 ± 0.5 years for the Micra AV group. Among the cohort, 50 patients had undergone cardiac surgery and 28 underwent transcatheter structural valve interventions. Device electrical performance was excellent during follow-up, with a small but clinically insignificant increase in ventricular pacing threshold and a slight decrease in pacing impedance. The mean right ventricle pacing (RVP) burden significantly decreased over time in the entire cohort (74.3% ± 37.2% postprocedure vs. 47.7% ± 40.6% at last follow-up, p < .001), and left ventricle ejection fraction (LVEF) showed a modest but significant downward trend during follow-up (55.0% ± 10.6% vs. 51.5% ± 11.2% p < .001). Patients with Micra VR implants had significantly reduced LVEF during follow-up (54.1% ± 11.9% vs. 48.8% ± 11.9%, p = .003), whereas LVEF appeared stable in the Micra AV group during follow-up (56.1% ± 9.0% vs. 54.6% ± 9.7%, p = .06). Six patients (7.7%) required conversion to transvenous pacing systems, four who required cardiac resynchronization for drop in LVEF with high RVP burden and two who required dual-chamber pacemakers for symptomatic sinus node dysfunction., Conclusion: Leadless pacemakers provide a useful alternative to transvenous pacemakers in appropriately selected patients after cardiac surgery and transcatheter structural valve interventions. Device performance is excellent over medium-term follow-up. However, a significant minority of patients require conversion to transvenous pacing systems for cardiac resynchronization or atrial pacing support, demonstrating the need for close electrophysiologic follow-up in this cohort., (© 2023 Wiley Periodicals LLC.)

Competing Interests: Disclosures Dr Hoskins is a consultant for Boston Scientific and Abbott Medical; Drs Greenbaum and Babaliaros have received institutional research support from Abbott Vascular, Ancora Heart, Edwards Lifesciences, Gore Medical, JenaValve, Medtronic, Polares Medical, Transmural Systems, and 4C Medical; have received consulting fees from Abbott Vascular, Edwards Lifesciences, and Medtronic; and have an equity interest in Transmural Systems. Dr Lloyd is a consultant for Medtronic and Boston Scientific. Drs Gleason, Byku, Greenbaum, and Babaliaros have institutional research contracts for clinical investigation of transcatheter aortic, mitral, and tricuspid devices from Edwards Lifesciences, Abbott Vascular, Medtronic, and Boston Scientific. Dr El-Chami is a consultant for Boston Scientific, Medtronic and Biotronik. Dr Lederman is coinventor on patents assigned to the National Institutes of Health, for electrosurgical devices including for septal reduction therapy. The other authors report no conflicts.

Nonischemic cardiomyopathy (NICM) is common and patients are at significant risk for early mortality secondary to ventricular arrhythmias. Current guidelines recommend implantable cardioverter-defibrillator (ICD) therapy to decrease sudden cardiac death (SCD) in patients with heart failure and reduced left ventricular ejection fraction. However, in randomized clinical trials comprised solely of patients with NICM, primary prevention ICDs did not confer significant mortality benefit. Moreover, left ventricular ejection fraction has limited sensitivity and specificity for predicting SCD. Therefore, precise risk stratification algorithms are needed to define those at the highest risk of SCD. This review examines mechanisms of sudden arrhythmic death in patients with NICM, discusses the role of ICD therapy and treatment of heart failure for prevention of SCD in patients with NICM, examines the role of cardiac magnetic resonance imaging and computational modeling for SCD risk stratification, and proposes new strategies to guide future clinical trials on SCD risk assessment in patients with NICM., Competing Interests: Funding Support and Author Disclosures Dr Chrispin has received consulting fees from Biosense Webster; and has received honorarium from Abbott. Dr Navara has equity ownership in SafeBeat Rx. Dr Torbe has ownership of Boston Scientific stocks. Dr Cheung has received consulting fees from Abbott, Biotronik, and Boston Scientific; has received research grant support from Boston Scientific; and has received fellowship grant support from Abbott, Biosense, Biotronik, Boston Scientific, and Medtronic. Dr Lakdawala has received research support from Pfizer Inc; and has received consulting fees from Pfizer Inc, Bristol Myers Squibb, Cytokinetics, and Tenaya Inc. All other authors have reported that they have no relationships relevant to the contents of this paper to disclose., (Copyright © 2023 American College of Cardiology Foundation. Published by Elsevier Inc. All rights reserved.)

Background: Subcutaneous implantable cardioverter defibrillators (S-ICDs) are an attractive alternative to transvenous ICDs among those not requiring pacing. However, the risks of damage to the S-ICD electrode during sternotomy and adverse interactions with sternal wires remain unclear. We sought to determine the rates of damage to the S-ICD lead during sternotomy, inappropriate shocks from electrical noise due to interaction with sternal wires, and failure to terminate spontaneous or induced ventricular arrhythmias., Methods: Retrospective, multicenter study of patients undergoing sternotomy before or after S-ICD implantation. Clinical, procedural, and device-related data were collected by each center and analyzed by the coordinating center. These data were compared with a historical control cohort of nonsternotomy patients., Results: Of 196 identified patients (52±16 years, 47 women), 166 underwent S-ICD implantation after sternotomy and 30 sternotomy after S-ICD. There was no damage to any lead among those who underwent sternotomy after S-ICD. Defibrillation threshold testing was performed in 63% at implant, with 91% first shock success. During a median follow-up of 29 months (range, 1-188), S-ICD first shocks successfully terminated spontaneous ventricular arrhythmias in 31 of 32 patients (97%). Inappropriate shocks occurred in 22 patients, most commonly related to T wave oversensing (n=14). Compared with the nonsternotomy controls, there were no differences in rates of first shock success for induced or spontaneous arrhythmias or rate of inappropriate shocks., Conclusions: Sternotomy before or after S-ICD does not confer additional risk relative to a historical control group without sternotomy., Competing Interests: Disclosures Dr Frankel reports receiving consulting fees from Boston Scientific and lecture honoraria from Medtronic. The other authors report no conflicts.

Background: Shared decision-making is mandated for patients receiving primary prevention implantable cardioverter defibrillators (ICDs). Less attention has been paid to generator exchange decisions, although at the time of generator exchange, patients' risk of sudden cardiac death, risk of procedural complications, quality of life, or prognosis may have changed. This study was designed to explore how patients make ICD generator exchange decisions., Methods: Emory Healthcare patients with primary prevention ICDs implanted from 2013 to 2021 were recruited to complete in-depth interviews exploring perspectives regarding generator exchanges. Interviews were conducted in 2021. Transcribed interviews were qualitatively coded using multilevel template analytic methods. To investigate benefit thresholds for pursuing generator exchanges, patients were presented standard-gamble type hypothetical scenarios where their ICD battery was depleted but their 5-year risk of sudden cardiac death at that time varied (10%, 5%, and 1%)., Results: Fifty patients were interviewed; 18 had a prior generator exchange, 16 had received ICD therapy, and 17 had improved left ventricular ejection fraction. As sudden cardiac death risk decreased from 10% to 5% to 1%, the number of participants willing to undergo a generator exchange decreased from 48 to 42 to 33, respectively. Responses suggest that doctor's recommendations are likely to substantially impact patients' decision-making. Other drivers of decision-making included past experiences with ICD therapy and device implantation, as well as risk aversion. Therapeutic inertia and misconceptions about ICD therapy were common and represent substantive barriers to effective shared decision-making in this context., Conclusions: Strong defaults may exist to continue therapy and exchange ICD generators. Updated risk stratification may facilitate shared decision-making and reduce generator exchanges in very low-risk patients, especially if these interventions are directed toward clinicians. Interventions targeting phenomena such as therapeutic inertia may be more impactful and warrant exploration in randomized trials., Competing Interests: Disclosures Dr Rao reports receiving research funding from National Institutes of Health grant UL1TR002378, TL1TR002382, and from the Agency for Healthcare Research and Quality grant 1F32HS028558. Dr Dickert reports receiving research funding from the Agency for Healthcare Research and Quality, National Institutes of Health and Patient-Centered Outcomes Research Institute, and the Greenwall Foundation and consulting fees from Abiomed. Dr Kramer reports support from National Institutes of Health grants R01AG068141 and R01HL161697. Dr Horný reports receiving research funding from the National Institutes of Health, Centers for Disease Control and Prevention and Harvey L. Neiman Health Policy Institute. The other authors report no conflicts.

Background: Class IC antiarrhythmic agents are effective for treating atrial tachyarrhythmias, but their use is restricted in patients with coronary artery disease (CAD). Data on the safety of the use of IC agents in patients with CAD in the absence of recent acute coronary syndromes are lacking., Objectives: This study sought to evaluate the safety and feasibility of treatment with IC agents in patients with varying degrees of CAD in a large serial, real-world cohort., Methods: We retrospectively identified all patients at our institution from January 2005 to February 2021 on a IC agent (n = 3,445) and those on sotalol or dofetilide (n = 2,216) as controls, excluding those with a prior history of ventricular tachycardia, implantable cardioverter-defibrillator placement, or nonrevascularized myocardial infarction. Baseline clinical characteristics included degree of CAD (categorized as none, nonobstructive, or obstructive), other comorbid illness, and medication use. Clinical outcomes, including survival, were ascertained. We performed Cox regression analysis to evaluate the effect of IC use on event-free survival across varying degrees of CAD., Results: After adjustment for baseline characteristics, there was an independent association between IC use and improved mortality. However, there was an interaction between IC use and degree of CAD (compared to sotalol) demonstrating poorer event-free survival among those with obstructive coronary disease (HR: 3.80; 95% CI: 1.67-8.67; P = 0.002)., Conclusions: Among select patients with nonobstructive CAD and without a history of ventricular tachycardia, IC agents are not associated with increased mortality. Therefore, these agents may be an option for some patients in whom they are frequently restricted. Further prospective studies are warranted., Competing Interests: Funding Support and Author Disclosures The authors have reported that they have no relationships relevant to the contents of this paper to disclose., (Copyright © 2023 American College of Cardiology Foundation. Published by Elsevier Inc. All rights reserved.)

Introduction: Hemodynamic decompensation during catheter ablation occurs due to prolonged procedure time and irrigant delivery directly into the cardiac chambers. Real-time hemodynamic monitoring of patients undergoing catheter ablation procedures may identify patients at risk of decompensation; we set out to assess the feasibility of a novel, real-time, intracardiac pressure monitoring system using a standard irrigated ablation catheter., Methods: We studied 13 consecutive who underwent pressure measurement of the left atrium (LA) and left ventricle (LV) via transeptal access with a Swan Ganz (SG) catheter followed by two commercially available irrigated ablation catheters. Pressure waveform data was extracted to compare LA peak pressure, LV peak systolic pressure, LV end-diastolic pressure, and waveform analysis., Results: Comparison between the SG and ablation catheters (AblA; AblB) demonstrated that LV systolic pressure (0.61-16.8 mmHg; 1.32-18.2 mmHg), and LV end-diastolic pressure (-3.4 to 2.8 mmHg; -3.0 to 3.35 mmHg) were well correlated and had accepted repeatability. Ablation waveforms demonstrated an 89.9 ± 6.4% correlation compared to SG waveforms., Conclusion: Pressure measurements derived from an irrigated ablation catheter are accurate and reliable when compared to an SG catheter. Further studies are needed to determine how real-time pressure monitoring can improve outcomes during ablation procedures., (© 2023 Wiley Periodicals LLC.)

Background: Shared decision-making using a decision aid is required for patients undergoing implantation of primary prevention implantable cardioverter-defibrillators (ICD). It is unknown how much this process has impacted patients' experiences or choices. Effective shared decision-making requires an understanding of how patients make ICD decisions. A qualitative key informant study was chosen to capture the breadth of patients' experiences making ICD decisions in the context of required shared decision-making., Methods and Results: We conducted in-depth interviews with 20 patients referred to electrophysiology clinics for the consideration of primary prevention ICD implantation. Purposeful sampling from a prior survey study evaluating mandated shared decision-making was based on patient characteristics and responses to the initial survey questions. Qualitative descriptive analysis of the interviews was performed using a multilevel coding strategy. Patients' paths to an ICD decision often involved multiple visits with multiple clinicians. However, the decision aid was almost exclusively provided to the patient during electrophysiology clinic visits. Some patients used the numeric data in the decision aid to make an ICD decision based on the risk-benefit profile; others made decisions based on other data or based on trust in clinicians' recommendations. Patients highlighted information related to living with the device as particularly important in helping them to make their ICD decisions. Some patients struggled with the emotional aspects of making an ICD decision., Conclusions: Patients' ICD decision-making paths poses a challenge to episodic shared decision-making and may make tools such as decision aids perfunctory if used solely during the electrophysiology visit. Understanding patients' ICD decision-making paths, especially in the context of encounters with primary cardiologists, can inform the implementation strategies of shared decision-making help to enhance its impact. Components of decision aids focusing on the experience of living with an ICD rather than probabilistic data may also be more impactful, although the nature of their impact will differ., Competing Interests: Declaration of Competing Interest Dr Rao reports receiving research funding from NIH grant # UL1TR002378, #TL1TR002382, and from AHRQ grant #1F32HS028558. Dr Dickert reports receiving research funding from AHRQ, NIH, PCORI, and the Greenwall Foundation., (Copyright © 2022 Elsevier Inc. All rights reserved.)

Objectives: This study sought to analyze the impact of the American College of Cardiology, American Heart Association, and Heart Rhythm Society (ACC/AHA/HRS) guidelines for cardiac resynchronization therapy with defibrillator (CRT-D) update on utilization and efficacy of CRT-D., Background: In September 2012, the ACC/AHA/HRS guidelines for CRT-D were modified to include left bundle branch block (LBBB) as a Class I indication., Methods: The IBM Watson MarketScan Database was queried between January 1, 2003, and December 31, 2018, for CRT-D implants or upgrades. The primary outcome was heart failure (HF) hospitalization following left ventricular lead implant. Secondary outcomes included all-cause mortality and device-related lead revision., Results: A total of 27,238 patients were analyzed: 18,384 pre-update and 8,854 post-update. Mean age was 69 ± 11 years, 73% men, and 98% with history of HF hospitalization. The proportion of patients with LBBB increased from 29% to 55% (P < 0.001) after the update. Patients receiving CRT-D post-update demonstrated a greater prevalence of comorbidities, including atrial fibrillation (47% vs 40%; P < 0.001), diabetes mellitus (45% vs 39%; P < 0.001), chronic kidney disease (24% vs 15%; P < 0.001), and HF hospitalization in the year before CRT-D (40% vs 37%; P < 0.001). Despite greater baseline comorbidities, HF hospitalization significantly declined post-update (HR: 0.89; P < 0.001). Multivariate predictors of reduced HF hospitalization included angiotensin receptor neprilysin inhibitor prescription (HR: 0.48; P < 0.001) and presence of LBBB (HR: 0.71; P < 0.001). All-cause mortality was not significantly different between the 2 groups, and fewer lead revisions were noted post-update (0.6% vs 1.7%; P < 0.001)., Conclusions: The revised 2012 guidelines led to an increased proportion of LBBB patients receiving CRT-D at the population-level. This change was associated with reduced HF hospitalization, despite broadening therapy to patients with more comorbid conditions., Competing Interests: Funding Support and Author Disclosures Dr Allaw was supported by the Pritzker School of Medicine. Dr Mittal has performed speaking or consulting for Abbott, Boston Scientific, and Medtronic. Dr Aziz has served as a speaker for Biotronik. Dr Nayak has served as a speaker for Boston Scientific, Medtronic, and Biotronik. Dr Tung has served as a speaker for Abbott, Biotronik, and Boston Scientific. Dr Upadhyay has served as a speaker for Abbott, BioTel, Biotronik, Medtronic, and Zoll Medical. All other authors have reported that they have no relationships relevant to the contents of this paper to disclose., (Copyright © 2022 American College of Cardiology Foundation. Published by Elsevier Inc. All rights reserved.)

Background: As targeted treatments for amyloid transthyretin cardiomyopathy (ATTR-CM) are becoming available, we aim to characterize the rates of ventricular arrhythmias (VAs), implantable cardioverter-defibrillator (ICD) utilization, and their impact on survival., Methods: This is a retrospective cohort study of 130 patients with ATTR-CM diagnosed at Emory University's Cardiac Amyloidosis Center between April 2012 and September 2020. VAs were defined as nonsustained or sustained ventricular tachycardia and ventricular fibrillation., Results: Of 130 patients, 42 had wild-type disease (wtATTR) and 88 had hereditary variants (hATTR), most commonly Val122Ile (89%). At ATTR-CM diagnosis, 80 (62%) patients had EF ≤ 40% consistent with systolic heart failure. Of the 69 (53%) patients with documented VAs significantly higher rates occurred among those with EF ≤ 40% compared with EF > 40% (67% vs. 28%, p = .001). Thirty-two patients (25 hATTR, 7 wtATTR) had primary prevention ICDs implanted. Eight (25%) of these patients received appropriate ICD therapy while two (6%) experienced inappropriate therapy. Comparing patients with EF ≤ 35% with and without ICDs did not reveal any survival difference (3.3 ± 0.5 vs. 2.8 ± 0.4 years, p = .699)., Conclusions: High rates of VAs and appropriate ICD therapy were found among a unique cohort of largely hereditary ATTR-CM patients with a high rate of systolic heart failure., (© 2022 Wiley Periodicals LLC.)

Background: In 2018, the Centers for Medicare and Medicaid Services (CMS) mandated that patients considering implantation of an implantable cardioverter-defibrillator (ICD) for primary prevention of sudden cardiac death undergo shared decision-making (SDM) using a decision-aid., Objective: To observe the impact of the CMS's mandate on core measures of SDM using a natural experiment., Research Design, Subjects, and Measures: Patients who underwent implantation of a primary prevention ICD within the Emory Healthcare system between 2017-2019 (pre and post SDM mandate) were surveyed. Survey domains included knowledge about the ICD, decisional conflict, values-choice concordance, and engagement in decision-making. Patients who had an ICD implant after the mandate were also asked about their views of the decision aid (DA). Responses of patients who had ICD implanted prior to the mandate were compared to those after the mandate using either Student t test or Chi-Squared tests., Results: Of 101 patients who completed the survey, 45 had an ICD placed before the mandate and 56 had an ICD placed after. There were no major differences between knowledge, decisional conflict, values choice concordance, or patient engagement. Compared to patients with ICDs placed before the mandate, patients with ICDs after the mandate were more likely to subjectively feel more informed about the benefits of the procedure but were less likely to be able to correctly identify the frequency of complications., Conclusions: Policy effects to promote SDM that solely focus on a decision-aid may not substantively impact patient centered care., (© 2021 Wiley Periodicals LLC.)

Increasing maternal mortality and incidence of arrhythmias in pregnancy have been noted over the past 2 decades in the United States. Pregnancy is associated with a greater risk of arrhythmias, and patients with a history of arrhythmias are at significant risk of arrhythmia recurrence during pregnancy. The incidence of atrial fibrillation in pregnancy is rising. This review discusses the management of tachyarrhythmias and bradyarrhythmias in pregnancy, including management of cardiac arrest. Management of fetal arrhythmias are also reviewed. For patients without structural heart disease, β-blocker therapy, especially propranolol and metoprolol, and antiarrhythmic drugs, such as flecainide and sotalol, can be safely used to treat tachyarrhythmias. As a last resort, catheter ablation with minimal fluoroscopy can be performed. Device implantation can be safely performed with minimal fluoroscopy and under echocardiographic or ultrasound guidance in patients with clear indications for devices during pregnancy. Because of rising maternal mortality in the United States, which is partly driven by increasing maternal age and comorbidities, a multidisciplinary and/or integrative approach to arrhythmia management from the prepartum to the postpartum period is needed., Competing Interests: Funding Support and Author Disclosures Dr Vaseghi was supported by NIH R01 HL148190. Dr Mason has been a consultant for Medtronic and Boston Scientific. Dr Russo has received research funding from or has been a member of steering committees for Boston Scientific, Kestra, Medilynx, and Medtronic; and has been a consultant for Atricure, Biosense Webster, and Medtronic. Dr Volgman has been a MSD/Bayer Virtual Global Advisory Board Member; has been a member Bristol Myers Squibb Foundation of the Diverse Clinical Investigator Career Development Program; has been a member of the National Advisory Committee; and holds stock in Apple. Dr Vaseghi holds stock in Secures Inc., (Copyright © 2022 American College of Cardiology Foundation. Published by Elsevier Inc. All rights reserved.)

Background Accurate detection of arrhythmic events in the intensive care units (ICU) is of paramount significance in providing timely care. However, traditional ICU monitors generate a high rate of false alarms causing alarm fatigue. In this work, we develop an algorithm to improve life threatening arrhythmia detection in the ICUs using a deep learning approach. Methods and Results This study involves a total of 953 independent life-threatening arrhythmia alarms generated from the ICU bedside monitors of 410 patients. Specifically, we used the ECG (4 channels), arterial blood pressure, and photoplethysmograph signals to accurately detect the onset and offset of various arrhythmias, without prior knowledge of the alarm type. We used a hybrid convolutional neural network based classifier that fuses traditional handcrafted features with features automatically learned using convolutional neural networks. Further, the proposed architecture remains flexible to be adapted to various arrhythmic conditions as well as multiple physiological signals. Our hybrid- convolutional neural network approach achieved superior performance compared with methods which only used convolutional neural network. We evaluated our algorithm using 5-fold cross-validation for 5 times and obtained an accuracy of 87.5%±0.5%, and a score of 81%±0.9%. Independent evaluation of our algorithm on the publicly available PhysioNet 2015 Challenge database resulted in overall classification accuracy and score of 93.9% and 84.3%, respectively, indicating its efficacy and generalizability. Conclusions Our method accurately detects multiple arrhythmic conditions. Suitable translation of our algorithm may significantly improve the quality of care in ICUs by reducing the burden of false alarms.

Background: Little is known about health status and quality of life (QoL) after implantable cardioverter-defibrillator (ICD) generator exchange (GE)., Methods: We prospectively followed patients undergoing first-time ICD GE. Serial assessments of health status were performed by administering the 36-Item Short Form Survey (SF-36)., Results: Mean age was 67.5 ± 14.3 years, left ventricle ejection fraction (LVEF) was 36.5% ± 15.0% and over 40% of the cohort had improved LVEF to > 35% at the time of GE. SF-36 scores were significantly worse in physical/general health domains compared to domains of emotional/social well-being ( P < 0.001 for each comparison). Physical health scores were significantly worse among those with medical comorbidities including diabetes, chronic obstructive pulmonary disease and atrial fibrillation. Mean follow-up was 1.6 ± 0.5 years after GE. Overall SF-36 scores remained stable across all domains during follow-up. Survival at 3 years post-GE was estimated at 80%. Five patients died during follow-up and most deaths were adjudicated as non-arrhythmic in origin. Four patients experienced appropriate ICD shocks after GE, three of whom had LVEF which remains impaired LVEF (i.e., < 35%) at the time of GE., Conclusion: Patients undergoing ICD GE have significantly worse physical health compared to emotional/social well-being, which is associated with the presence of medical comorbidities. In terms of clinical outcomes, the incidence of appropriate shocks after GE among those with improvement in LVEF is very low, and most deaths post-procedure appear to be non-arrhythmic in origin. These data represent an attempt to more fully characterize the spectrum of QoL and clinical outcomes after GE., Competing Interests: None., (Copyright and License information: Journal of Geriatric Cardiology 2021.)