Leadless cardiac pacemaker : Overview, tips, and tricks

The importance of leadless pacemaker positioning in relation to subcutaneous implantable cardioverter-defibrillator sensing in completely leadless cardiac resynchronization and defibrillation systems

Advances in management of electrophysiology and atrial fibrillation in the cardiac catheter laboratory: implications for anaesthesia

Be-All End-All Real-World Evidence on the Subcutaneous ICD.

Perplexing Results From the PRAETORIAN Trial: Revisiting the Debate About the Value of Antitachycardia Pacing.

Implantable cardioverter-defibrillators (ICDs) have revolutionized the treatment of patients at risk for sudden cardiac death. In the nearly 3 decades since the first human ICD implant,1 millions of devices have been implanted worldwide and innumerable lives have been saved. Successful resuscitation of a potentially lethal ventricular arrhythmia by an ICD system depends on successful arrhythmia detection and timely delivery of therapy. Both the ICD generator and the ICD lead are critical components of this system. The lead, in particular, is literally a lifeline whose purpose is to convey critical information about the heart’s rhythm to the ICD generator and, in turn, to deliver life-sustaining therapy when needed. Failure of an ICD lead may result in significant clinical events, including failure to pace, failure to defibrillate, inappropriate shocks, and even death. Article p 2727 ICD leads, like many medical technologies, have undergone a remarkable transformation. Epicardial leads, which necessitated a thoracotomy for lead placement, have given way to transvenous leads, which are easier to implant, less costly, and associated with decreased morbidity and mortality.2 Important advances in transvenous lead technology, such as the development of steroid elution, smaller diameter leads, novel insulations, and multipolar leads, have translated into meaningful clinical benefits for patients. Although modern ICD leads consist primarily of electrodes, conductors, insulation, and a fixation mechanism to attach the lead to the myocardium, lead design and performance vary from model to model. Indeed, monitoring of performance is critical not only to identify products with increased failure rates but also to provide physicians and patients with realistic expectations of device performance. In the current issue of Circulation , Eckstein et al add to our understanding of ICD lead performance.3 The investigators conducted a retrospective analysis of 1317 consecutive patients who received ICD systems (including 38 different ICD lead …

Acute and 3-Month Performance ofaCommunicating Leadless Antitachycardia Pacemaker and Subcutaneous Implantable Defibrillator.

Lower brain stem dysfunction in huntington's disease

Subcutaneous ICD: Current standards and future perspective

The subcutaneous implantable cardioverter-defibrillator (S-ICD) and leadless pacemaker (LP) are evolving technologies that do not require intracardiac leads. However, interactions between these two devices are unexplored. We investigated the feasibility, safety, and performance of combined LP and S-ICD therapy, considering (i) simultaneous device-programmer communication, (ii) S-ICD rhythm discrimination during LP communication and pacing, and (iii) post-shock LP performance. The study consists of two parts. Animal experiments: Two sheep were implanted with both an S-ICD and LP (Nanostim, SJM), and the objectives above were tested. Human experience: Follow-up of one S-ICD patient with bilateral subclavian occlusion who received an LP and two LP (all Nanostim, SJM) patients (without S-ICD) who received electrical cardioversion (ECV) are presented. Animal experiments : Simultaneous device-programmer communication was successful, but LP-programmer communication telemetry was temporarily lost (2 ± 2 s) during ventricular fibrillation (VF) induction and 4/54 shocks. Leadless pacemaker communication and pacing did not interfere with S-ICD rhythm discrimination. Additionally, all VF episodes (n = 12/12), including during simultaneous LP pacing, were detected and treated by the S-ICD. Post-shock LP performance was unaltered, and no post-shock device resets or dislodgements were observed (24 S-ICD and 30 external shocks). Human experience : The S-ICD/LP patient showed adequate S-ICD sensing during intrinsic rhythm, nominal, and high-output LP pacing. Two LP patients (without S-ICD) received ECV during follow-up. No impact on performance or LP dislodgements were observed. Combined LP and S-ICD therapy appears feasible in all animal experiments (n = 2) and in one human subject. No interference in sensing and pacing during intrinsic and paced rhythm was noted in both animal and human subjects. However, induced arrhythmia testing was not performed in the patient. Defibrillation therapy did not seem to affect LP function. More data on safety and performance are needed.

Defibrillator therapy in patients with tricuspid valve clips: Which device to choose?

Introduction Conventional implantable cardioverter-defibrillators (ICDs) and pacemakers carry a risk of mainly pocket- and lead-related complications. To avoid these complications, extravascular devices (EVDs) have been developed, such as the subcutaneous ICD (S-ICD) and leadless pacemaker (LP). However, data on the actual adoption of EVDs for patient or center characteristics is lacking. Purpose To assess real-world nationwide trends in adoption of EVDs in the Netherlands. Methods Using the Netherlands Heart Registration, all consecutive patients with a de novo S-ICD or conventional single-chamber ICD implantation between 2012-2020, or with a de novo LP or conventional single-chamber pacemaker implantation between 2014-2020 were included. Trends in adoption of EVDs are described for different patient and hospital characteristics (tertiles of device-implanting volume and whether cardiothoracic surgery back-up was available). Differences between patients with EVDs and non-EVDs and differences between implanting centers of EVDs and non-EVDs were tested for by Student’s T-test, Chi-square and Fisher’s exact test. Trends in adoption over time were calculated with linear and logistic regression analysis. Results From 2012-2020, 2190 S-ICDs and 10683 conventional ICDs were implanted; from 2014-2020, 712 LPs and 11103 conventional pacemakers were implanted. The general adoption of both increased (S-ICDs, 8% to 21%; LPs, 1% to 8%), but the increase seems to reach a plateau (Fig. 1). S-ICD recipients were younger than conventional ICD recipients (p<0.001) and more likely to be female (p<0.001); LP recipients were younger than conventional pacemaker recipients (p<0.001) and more likely to be male (p=0.03). Both S-ICDs and LPs were mainly implanted in high-volume centers with thoracic surgery on-site (Fig. 2). Conclusions In this nationwide study we observed a relative quick adoption of innovative EVDs with a plateau after approximately 4 years. The relative adoption of S-ICDs is especially high in younger patients. EVDs are overall mainly implanted in high-volume centers with cardiothoracic surgery available. As LPs can only be implanted in centers with cardiothoracic surgery in the Netherlands, this may have limited its adoption.

Rate-dependent change in capture threshold following implantation of a leadless pacemaker

BACKGROUND:MODULAR antitachycardia pacing (ATP), a multicenter, international trial, assesses a modular cardiac rhythm management system: a subcutaneous implantable cardioverter defibrillator in wireless communication with a leadless pacemaker (LP) capable of pace-terminating ventricular tachycardia.METHODS:Enrolees had one or more clinical risk factors for ventricular tachycardia and did not require chronic pacing. Complications included prespecified major LP system- and procedure-related complications, and any complication related to the LP, subcutaneous implantable cardioverter defibrillator, implantation, or study protocol. Survival analysis was performed to identify complication-free rates, therapy delivery, and all-cause mortality.RESULTS:The 297 patients enrolled had an ejection fraction of 35±13%, 43% secondary prevention indications, and 59% with prior ventricular arrhythmias. Of 286 patients undergoing LP implantation (100% success), 251 patients completed 12-month follow-up. Mortality rate was 6%, with none related to the implant procedure. Median follow-up duration was 23.4 months (interquartile range, 17.9–28.1). The LP major complication-free rate was 97.2%, exceeding the performance goal. The overall LP+ subcutaneous implantable cardioverter defibrillator system-related complication-free rate was 88.5%. Appropriate tachyarrhythmia-therapy (ATP+shock) rates were 14.4%, and appropriate shock rates were 8.5%. Inappropriate total tachyarrhythmia therapy was 9.5% of which 8.5% were shocks. ATP was 67.3% successful in terminating ventricular arrhythmia episodes and accelerated ventricular arrhythmias in 10.1% of episodes. Overall therapy burden (ATP+shock) was 96/100 patient-years, of which 44/100 patient-years was for shock delivery.CONCLUSIONS:One-year outcomes of the first modular pacing-defibrillator system reveal low system and LP complication rates and good ATP efficacy rates, suggesting that the modular cardiac rhythm management is a viable alternative to single-chamber implantable cardioverter defibrillators using low-energy pacing capability without the need for transvenous leads.CLINICAL TRIAL REGISTRATION:URL: https://clinicaltrials.gov/; Unique identifier: NCT04798768.

Inappropriate Shocks From Subcutaneous vs Transvenous Implantable Cardioverter-Defibrillators: Individual Participant Data Meta-Analysis of Randomized Trials.

The development of communicating modular cardiac rhythm management systems relies on effective intrabody communication between a subcutaneous implantable cardioverter-defibrillator (S-ICD) and a leadless pacemaker (LP), using conducted communication. Communication success is affected by the LP and S-ICD orientation. This study is designed to evaluate the orientation of the LP and S-ICD in canine subjects and measure success and threshold of intrabody communication. To gain more human insights, we will explore device orientation in LP and S-ICD patients. Canine subjects implanted with a prototype S-ICD and LP (both Boston Scientific, MA, USA) with anterior-posterior fluoroscopy images were included in this analysis. For comparison, a retrospective analysis of human S-ICD and LP patients was performed. The angle of the long axis of the LP towards the vertical axis of 0°, and distance between the coil and LP were measured. Twenty-three canine subjects were analysed. Median angle of the LP was 29° and median distance of the S-ICD coil to LP was 0.8 cm. All canine subjects had successful communication. The median communicating threshold was 2.5 V. In the human retrospective analysis, 72 LP patients and 100 S-ICD patients were included. The mean angle of the LP was 56° and the median distance between the S-ICD coil and LP was 4.6 cm. Despite the less favourable LP orientation in canine subjects, all communication attempts were successful. In the human subjects, we observed a greater and in theory more favourable LP angle towards the communication vector. These data suggests suitability of human anatomy for conductive intrabody communication.