Transseptal left atrial catheterization is routinely used for many common catheter-based interventions. Tools for transseptal catheterization have advanced over the recent years. Such tools include imaging advances with intracardiac echocardiology as well as an array of needles, wires, and dilators to achieve transseptal access with greater ease and safety. This review will discuss the contemporary tools for transseptal catheterization and guidance for difficult cases.

Background: Infection remains a major complication of cardiac implantable electronic devices (CIEDs) and can lead to significant morbidity and mortality. Extrathoracic devices that avoid epicardial or transvenous leads, such as the subcutaneous implantable cardioverter-defibrillator (S-ICD), can reduce the risk of serious infection-related complications, such as bloodstream infection and infective endocarditis. While the 2017 AHA/ACC/HRS guidelines include recommendations for S-ICD use for patients at high risk of infection, currently, there are no clinical trial data that address best practices for the prevention of S-ICD infections. Therefore, an expert panel was convened to develop consensus on these topics. Methods: An expert process mapping methodology was used to achieve consensus on the appropriate steps to minimize or prevent S-ICD infections. Two face-to-face meetings of high-volume S-ICD implanters and an infectious diseases specialist, with expertise on cardiovascular implantable electronic device infections, were conducted to develop consensus on useful strategies pre-, peri-, and post-implant to reduce S-ICD infection risk. Results: Expert panel consensus of recommended steps for patient preparation, S-ICD implantation, and post-operative management were developed to provide guidance in individual patient management. Conclusion: Achieving expert panel consensus by process mapping methodology for S-ICD infection prevention was attainable, and the results should be helpful to clinicians in adopting interventions to minimize risks of S-ICD infection.

In the context of atrial fibrillation (AF), traditional clinical practices have thus far fallen short in several domains such as identifying patients at risk of incident AF or patients with concomitant undetected paroxysmal AF. Novel approaches leveraging artificial intelligence have the potential to provide new tools to deal with some of these old problems. In this review we focus on the roles of artificial intelligence-enabled ECG pertaining to AF, potential roles of deep learning (DL) models in the context of current knowledge gaps, as well as limitations of these models. One key area where DL models can translate to better patient outcomes is through automated ECG interpretation. Further, we overview some of the challenges facing AF screening and the harms and benefits of screening. In this context, a unique model was developed to detect underlying hidden AF from sinus rhythm and is discussed in detail with its potential uses. Knowledge gaps also remain regarding the best ways to monitor patients with ESUS and who would benefit most from oral anticoagulation. The AI-enabled AF model is one potential way to tackle this complex problem as it could be used to identify a subset of high-risk ESUS patients likely to benefit from empirical oral anticoagulation. Role of DL models assessing AF burden from long duration ECG data is also discussed as a way of guiding management. There is a trend towards the use of consumer-grade wristbands and watches to detect AF from photoplethysmography data. However, ECG currently remains the gold standard to detect arrythmias including AF. Lastly, role of adequate external validation of the models and clinical trials to study true performance is discussed.

Background: Implantable cardioverter defibrillators (ICD) are indicated for primary and secondary prevention of sudden cardiac arrest. Despite enhancements in design and technologies, the ICD lead is the most vulnerable component of the ICD system and failure of ICD leads remains a significant clinical problem. A novel, small diameter, lumenless, catheter delivered, defibrillator lead was developed with the aim to improve long term reliability. Methods and Results: The Lead Evaluation for Defibrillation and Reliability (LEADR) study is a multi-center, single-arm, Bayesian, adaptive design, pre-market interventional pivotal clinical study. Up to 60 study sites from around the world will participate in the study. Patients indicated for a de novo ICD will undergo defibrillation testing at implantation and clinical assessments at baseline, implant, pre-hospital discharge, 3 months, 6 months, and every 6 months thereafter until official study closure. Patients will participate for a minimum of 18 months to approximately 3 years. Fracture-free survival will be evaluated using a Bayesian statistical method that incorporates both virtual patient data (combination of bench testing to failure with in-vivo use condition data) with clinical patients. The clinical subject sample size will be determined using decision rules for number of subject enrollments and follow-up time based upon the observed number of fractures at certain time points in the study. The adaptive study design will therefore result in a minimum of 500 and a maximum of 900 patients enrolled. Conclusion: The LEADR Clinical Study was designed to efficiently provide evidence for short- and long-term safety and efficacy of a novel lead design using Bayesian methods including a novel virtual patient approach.

Subcutaneous implantable cardioverter defibrillators (S-ICDs) are currently indicated for patients who meet ICD implantation criteria for the prevention of sudden cardiac death (SCD). In December 2020, a unique cardiac implantable electronic device (CIED) situation arose as both the S-ICD generator and electrode were under a device advisory. We would recommend all future CIED implantation guidelines receive a caveat regarding checking current CIED advisories, in order to avoid future similar scenarios.

A document by Emily Zeitler. Click on the document to view its contents.

Leadless Pacemaker Implantation after Lead Extraction for Cardiac Implanted Electronic Device InfectionJamia Kowal, D.O.andGeorge H. Crossley, M.D., F.H.R.S, F.A.C.C.

Background: Insertable cardiac monitors (ICMs) are essential for ambulatory arrhythmia diagnosis. However, definitive diagnoses still require time-consuming, manual adjudication of electrograms (EGMs). Objective: To evaluate the clinical impact of selecting only key EGMs for review. Methods: Retrospective analyses of randomly selected Abbott Confirm Rx TM devices with ≥90 days of remote transmission history was performed, with each EGM adjudicated as true or false positive (TP, FP). For each device, up to 3 “key EGMs” per arrhythmia type per day were prioritized for review based on ventricular rate and episode duration. The reduction in EGMs and TP days (patient-days with at least 1 TP EGM), and any diagnostic delay (from the first TP), were calculated vs. reviewing all EGMs. Results: In 1,000 ICMs over a median duration of 8.1 months, at least one atrial fibrillation (AF), tachycardia, bradycardia, or pause EGM was transmitted by 424, 343, 190, and 325 devices, respectively, with a total of 95716 EGMs. Approximately 90% of episodes were contributed by 25% of patients. Key EGM selection reduced EGM review burden by 43%, 66%, 77%, and 50% (55% overall), while reducing TP days by 0.8%, 2.1%, 0.2%, and 0.0%, respectively. Despite reviewing fewer EGMs, 99% of devices with a TP EGM were ultimately diagnosed on the same day vs. reviewing all EGMs. Conclusions: Key EGM selection reduced the EGM review substantially with no delay-to-diagnosis in 99% of patients exhibiting true arrhythmias. Implementing these rules in the Abbott patient care network may accelerate clinical workflow without compromising diagnostic timelines.

Introduction: The extravascular ICD (EV ICD) system with substernal lead placement is a novel non-transvenous alternative to current commercially available ICD systems. The EV ICD provides defibrillation and pacing therapies without the potential long-term complications of endovascular lead placement. Methods: This paper summarizes the development of the EV ICD, including the pre-clinical and clinical evaluations that have contributed to system and procedural refinements to date. Results: Extensive pre-clinical research evaluations and 4 human clinical studies with >140 combined acute and chronic implants have enabled the development and refinement of the EV ICD system, currently in worldwide pivotal study. Conclusion: The EV ICD may represent a clinically valuable solution in protecting patients from sudden cardiac death while avoiding the long-term consequences of transvenous hardware. The EV ICD offers advantages over transvenous and subcutaneous systems by avoiding placement in the heart and vasculature; relative to subcutaneous systems, EV ICD requires less energy for defibrillation, enabling a smaller device, and provides pacing features such as anti-tachycardia and asystole pacing in a single system.

Title: Gradual prolongation of PR interval followed by a pause. What’s the mechanism?

Objective: The implantation depth and membranous septum (MS) length are established as the predictors of new-onset conduction disturbance (CD) after transcatheter aortic valve replacement (TAVR) for tricuspid aortic valve (TAV) stenosis. However, little is known about the predictors with bicuspid aortic valve (BAV). This study investigated the role of MS length and implantation depth in predicting CD following TAVR with a balloon-expandable valve in patients with BAV. Methods and results: This retrospective study analyzed 169 patients who underwent TAVR for BAV with balloon-expandable valve, and TAV cohort was established as a control group using propensity score (PS) matching. The primary endpoint was in-hospital new-onset CD (new-onset left bundle branch block or new permanent pacemaker implantation). New-onset CD developed in 37 patients (21.9%). Multivariate analysis revealed severe LVOT calcification (Odds ratio [OR]: 5.83, 95% confidence interval [CI]: 1.08 – 31.5, p = 0.0407) and implantation depth – MS length (OR: 1.30, 95% CI: 1.12 – 1.51, p = 0.0005) as the predictors of new-onset CD within BAV cohort. The matched comparison between BAV and TAV groups showed similar MS length (3.0 vs 3.2mm, p = 0.5307), but valves were implanted deeper in BAV than TAV group (3.9 vs 3.0mm, p < .0001). New-onset CD was more frequent in patients having BAV (22.3% vs 13.9%, p = 0.0458). Conclusion: The implantation depth - MS length, and severe LVOT calcification predicted new-onset CD following TAVR in BAV with balloon-expandable valve. High implantation technique could be considered to avoid new-onset CD in BAV anatomy.

Title:Taking the “Pulse” of Pulsed Field Ablation: Real-World Experience

A document by Lynda Rosenfeld. Click on the document to view its contents.

Catheter ablation for atrial fibrillation has emerged as a main stay for management of atrial fibrillation. It has been shown to be clinically effective and cost effective in multiple trials .

Catheter Ablation of Ventricular Arrhythmias in patients with Prior Mitral Valve Surgery: Challenging, but Feasible and Effective!Amrish Deshmukh, MD; Frank Bogun, MD; Jackson J. Liang, DOElectrophysiology Section, Division of Cardiology; University of Michigan, Ann Arbor, MIFunding: NoneDisclosures: None

Another recent evidence of the clinical utility of the high-power, short-duration radiofrequency ablation strategyKoichiro Ejima, MD, PhD,1, 2 Kyoichiro Yazaki, MD,1 Morio Shoda, MD, PhD, 1, 2Nobuhisa Hagiwara, MD, PhD 11. Department of Cardiology, Tokyo Women’s Medical University2. Clinical Research Division for Heart Rhythm Management, Department of Cardiology, Tokyo Women’s Medical UniversityDepartment of Cardiology, Tokyo Women’s Medical University, Tokyo, Japan8-1, Kawada-cho, Shinjuku-ku, Tokyo, 162-8666 JapanFunding : (None)Disclosures : (None)Corresponding author : Koichiro EjimaE-mail address : [email protected] of Cardiology, Tokyo Women’s Medical University, Tokyo, Japan8-1, Kawada-cho, Shinjuku-ku, Tokyo, 162-8666 JapanTel : +81-3-3353-8111 FAX : +81-3-3356-0441Winkle et al. reviewed the literature of the high-power, short-duration (HPSD) radiofrequency ablation strategy.1We appreciate that they included our study that compared an HPSD ablation with a low-power, long-duration (LPLD) ablation using unipolar signal modification (USM) as a local endpoint during atrial fibrillation (AF) ablation.2 This study included 32 patients (paroxysmal 22, persistent 10) who underwent AF ablation using the HPSD strategy and 32 using the LPLD, and the median follow-up period was 10 months. After that, we reported another study that compared the HPSD ablation with the LPLD ablation using the USM as a local endpoint during AF ablation, which included only patients with paroxysmal AF.3 The number of patients included in the study was larger (HPSD 60, LPLD 60), and the follow-up duration was longer (mean follow-up period of the HPSD group, 12.5 months) than that in our former study. In this study, the freedom from recurrence after a single ablation procedure without any antiarrhythmic drugs was higher in the HPSD group than LPLD group (88.3% vs. 73.3% at 12-months after the procedure, log-rank; P=0.0423). This article was electrically published on May 15, 2020, more than 6 months before Winkle’s review article was received by the editorial office of the Journal of Cardiovascular Electrophysiology (December 4, 2020).We believe that this study is also worth being included the Winkle’s review article and might contribute to future investigators.

Please let me know if it is necessary…we are working on a reply to a previous work

A 27-year-old female presenting palpitation without ECG documentation underwent electrophysiology study. EP study revealed atrioventricular accessory pathway with poor and unidirectional pathway conduction, and a fasciculoventricular pathway. During isoproterenol infusion, delta wave promptly became prominent, after which an antidromic AV reentrant tachycardia was induced. When the pathway was mapped, widely split double pathway potentials were observed at 12 o'clock site of tricuspid annulus during mild preexcitation, demonstrating an example of intra-pathway conduction delay, which can be reversed by isoproterenol. Ablation at the site caused accelerated pathway rhythm and eliminated the pathway, rendering the tachycardia non-inducible.