Leadless Cardiac Pacemakers

Emerging Therapeutic Strategies in Cardiovascular Diseases

Cardiovascular diseases (CVDs), including ischemic heart disease and stroke, are the leading cause of mortality worldwide, causing nearly 20 million deaths annually. Traditional therapies, while effective, have not curbed the rising prevalence of CVDs driven by aging populations and lifestyle factors. This review highlights innovative therapeutic strategies that show promise in improving patient outcomes and transforming cardiovascular care. Emerging pharmacological treatments, such as proprotein convertase subtilisin/kexin type 9 (PCSK9) inhibitors and sodium-glucose co-transporter 2 (SGLT2) inhibitors, introduce novel mechanisms to complement existing therapies, significantly reducing cardiovascular events and mortality. These advancements emphasize the necessity of ongoing clinical trials and research to discover new therapeutic targets. Advanced biological therapies, including gene therapy, stem cell therapy, and RNA-based treatments, offer groundbreaking potential for repairing and regenerating damaged cardiovascular tissues. Despite being in various stages of clinical validation, early results are promising, suggesting these therapies could fundamentally change the CVD treatment landscape. Innovative medical devices and technologies, such as implantable devices, minimally invasive procedures, and wearable technology, are revolutionizing CVD management. These advancements facilitate early diagnosis, continuous monitoring, and effective treatment, driving care out of hospitals and into homes, improving patient outcomes and reducing healthcare costs. Personalized medicine, driven by genetic profiling and biomarker identification, allows for tailored therapies that enhance treatment efficacy and minimize adverse effects. However, the adoption of these emerging therapies faces significant challenges, including regulatory hurdles, cost and accessibility issues, and ethical considerations. Addressing these barriers and fostering interdisciplinary collaboration are crucial for accelerating the development and implementation of innovative treatments. Integrating emerging therapeutic strategies in cardiovascular care holds immense potential to transform CVD management. By prioritizing future research and overcoming existing challenges, a new era of personalized, effective, and accessible cardiovascular care can be achieved.

Next-Generation Cardiac Interfacing Technologies Using Nanomaterial-Based Soft Bioelectronics

Cardiac interfacing devices are essential components for the management of cardiovascular diseases, particularly in terms of electrophysiological monitoring and implementation of therapies. However, conventional cardiac devices are typically composed of rigid and bulky materials and thus pose significant challenges for effective long-term interfacing with the curvilinear surface of a dynamically beating heart. In this regard, the recent development of intrinsically soft bioelectronic devices using nanocomposites, which are fabricated by blending conductive nanofillers in polymeric and elastomeric matrices, has shown great promise. The intrinsically soft bioelectronics not only endure the dynamic beating motion of the heart and maintain stable performance but also enable conformal, reliable, and large-area interfacing with the target cardiac tissue, allowing for high-quality electrophysiological mapping, feedback electrical stimulations, and even mechanical assistance. Here, we explore next-generation cardiac interfacing strategies based on soft bioelectronic devices that utilize elastic conductive nanocomposites. We first discuss the conventional cardiac devices used to manage cardiovascular diseases and explain their undesired limitations. Then, we introduce intrinsically soft polymeric materials and mechanical restraint devices utilizing soft polymeric materials. After the discussion of the fabrication and functionalization of conductive nanomaterials, the introduction of intrinsically soft bioelectronics using nanocomposites and their application to cardiac monitoring and feedback therapy follow. Finally, comments on the future prospects of soft bioelectronics for cardiac interfacing technologies are discussed.

Perioperative Considerations for Modern Leadless Pacemakers

Since their initial approval by the Food and Drug Administration in 2016, leadless pacemakers have become increasingly prevalent. This growth has been driven by an improved adverse effect profile when compared to traditional pacemakers, including lower rates of infection, as well as eliminated risk of pocket hematoma and lead complications. More recently, technology enabling leadless synchronized atrioventricular pacing in patients with atrioventricular block has vastly expanded the indications for these devices. Anesthesiologists will increasingly be relied upon to safely care for patients with leadless pacemakers undergoing non-electrophysiology procedures and surgery. This article provides an overview of the technology, evidence base, current indications, and unique perioperative considerations for leadless pacemakers.

Epicardial Implantation of a Micra™ Pacemaker in a Premature Neonate with Congenital Complete Heart Block

Pacemaker implantation in neonates can be challenging due to their small size. Even pulse generators adapted for pediatric patients, such as the Microny device (Abbott, Chicago, IL, USA), are proportionately large in comparison to the size of the smallest newborns. Due to anatomic considerations, such as small vascular and ventricular sizes, leadless pacemakers and transvenous implantation in the youngest neonatal population remain unsuitable. Even so, the desire for leadless devices has prompted the industry to create the smallest pacemakers available. Adapting the smaller Micra™ transcatheter leadless pacing system (Medtronic, Minneapolis, MN, USA) for an epicardial pacing application may be advantageous to the smallest patients. This case illustrates the use of a Micra™ device modified with a header block to serve as the pulse generator in a ventricular epicardial pacing system for a 1-day-old, 2.68-kg patient with complete heart block.

Evolution of Pacemakers and Implantable Cardioverter Defibrillators (ICDs) in Cardiology

Pacemakers and implantable cardioverter defibrillators (ICDs) have revolutionized cardiology by providing life-saving interventions for patients with cardiac rhythm disturbances. Pacing the heart is an effective treatment for people suffering from bradycardia caused by sinus node dysfunction or atrioventricular (AV) block, and electronic pacing has saved countless lives since its introduction into clinical practice. AV synchronization is the typical cycle of atrial depolarization and contraction followed by ventricular depolarization and contraction. The continuation of this cycle leads to appropriate ventricular filling and cardiac output. By contrast, the failure of the cycle results in AV asynchrony, which may result in heart failure. Cardiac resynchronization treatment (CRT) involves using customized pacemakers with or without implantable cardioverter defibrillators and tries to resynchronize the failing heart by enhancing myocardial contraction without increasing energy consumption. This review delves into the extensive journey of pacemakers and ICDs in the field of cardiology. It highlights the transformative impact of these devices on patient care and quality of life, emphasizing technological advancements, clinical applications, and prospects. This comprehensive review aims to provide insights into the dynamic landscape of cardiac rhythm management.

Prospects of self-powering leadless pacemakers using piezoelectric energy harvesting technology by heart kinetic motion

This paper studies the possibility of heart kinetic motion for designing a self-powered intracardiac leadless pacemaker by piezoelectric energy harvesting. A Doppler laser displacement sensor measures in vivo heart kinetic motion. Cantilevered and four-point bending piezoelectric harvesters are studied under the measured in vivo heart kinetic motion. The heart movement is above 15 mm. The cantilevered and four-point bending harvesters generate a maximum voltage of ~ 0.28 V and 0.8 V, respectively with the measured heart motion with a heart rate of 168 beats per minute. Two DC/DC converters, LTC3588 and MAX17220, combined with full-bridge rectifiers and their start-up performance are tested.Clinical Relevance-This paper analyzed the heart kinetic motion and establishes the piezoelectric energy harvesting for a new era of self-powered leadless pacemakers.

Antimicrobial Peptides: Challenging Journey to the Pharmaceutical, Biomedical, and Cosmeceutical Use

Antimicrobial peptides (AMPs), or host defence peptides, are short proteins in various life forms. Here we discuss AMPs, which may become a promising substitute or adjuvant in pharmaceutical, biomedical, and cosmeceutical uses. Their pharmacological potential has been investigated intensively, especially as antibacterial and antifungal drugs and as promising antiviral and anticancer agents. AMPs exhibit many properties, and some of these have attracted the attention of the cosmetic industry. AMPs are being developed as novel antibiotics to combat multidrug-resistant pathogens and as potential treatments for various diseases, including cancer, inflammatory disorders, and viral infections. In biomedicine, AMPs are being developed as wound-healing agents because they promote cell growth and tissue repair. The immunomodulatory effects of AMPs could be helpful in the treatment of autoimmune diseases. In the cosmeceutical industry, AMPs are being investigated as potential ingredients in skincare products due to their antioxidant properties (anti-ageing effects) and antibacterial activity, which allows the killing of bacteria that contribute to acne and other skin conditions. The promising benefits of AMPs make them a thrilling area of research, and studies are underway to overcome obstacles and fully harness their therapeutic potential. This review presents the structure, mechanisms of action, possible applications, production methods, and market for AMPs.

Analysis of prescription medication rules of traditional Chinese medicine for bradyarrhythmia treatment based on data mining

BACKGROUND

Multiple studies have revealed that Traditional Chinese Medicine (TCM) prescriptions can provide protective effect on the cardiovascular system, increase the heart rate and relieve the symptoms of patients with bradyarrhythmia. In China, the TCM treatment of bradyarrhythmia is very common, which is also an effective complementary therapy. In order to further understand the application of Chinese medicines in bradyarrhythmia, we analyzed the medication rules of TCM prescriptions for bradyarrhythmia by data mining methods based on previous clinical studies.

METHODS

We searched studies reporting the clinical effect of TCM on bradyarrhythmia in the PubMed and Chinese databases China National Knowledge Infrastructure database, and estimated publication bias by risk of bias tools ROB 2. Descriptive analysis, hierarchical clustering analysis and association rule analysis based on Apriori algorithm were carried out by Microsoft Excel, SPSS Modeler, SPSS Statistics and Rstidio, respectively. Association rules, co-occurrence and clustering among Chinese medicines were found.

RESULTS

A total of 48 studies were included in our study. Among the total 99 kinds of Chinese medicines, 22 high-frequency herbs were included. Four new prescriptions were obtained by hierarchical cluster analysis. 81 association rules were found based on association rule analysis, and a core prescription was intuitively based on the grouping matrix of the top 15 association rules (based on confidence level), of which Guizhi, Zhigancao, Wuweizi, Chuanxiong, Danshen, Danggui, Huangqi, Maidong, Dangshen, Rougui were the most strongly correlated herbs and in the core position.

CONCLUSION

In this study, data mining strategy was applied to explore the TCM prescription for the treatment of bradyarrhythmia, and high-frequency herbs and core prescription were found. The core prescription was in line with the treatment ideas of TCM for bradyarrhythmia, which could intervene the disease from different aspects and adjust the patient's Qi, blood, Yin and Yang, so as to achieve the purpose of treatment.

Polymeric Coatings and Antimicrobial Peptides as Efficient Systems for Treating Implantable Medical Devices Associated-Infections

Many infections are associated with the use of implantable medical devices. The excessive utilization of antibiotic treatment has resulted in the development of antimicrobial resistance. Consequently, scientists have recently focused on conceiving new ways for treating infections with a longer duration of action and minimum environmental toxicity. One approach in infection control is based on the development of antimicrobial coatings based on polymers and antimicrobial peptides, also termed as “natural antibiotics”.

Design and implementation of compact dual-band conformal antenna for leadless cardiac pacemaker system

The leadless cardiac pacemaker is a pioneering device for heart patients. Its rising success requires the design of compact implantable antennas. In this paper, we describe a circularly polarized Hilbert curve inspired loop antenna. The proposed antenna works in the WMTS (Wireless Medical Telemetry Services) 1.4 GHz and ISM (Industrial, Scientific, and Medical) 2.45 GHz bands. High dielectric constant material Rogers RT/Duroid 6010 LM ([Formula: see text]=10) and fractal geometry helps to design the antenna with a small footprint of 9.1 mm³ (6 mm × 6 mm × 0.254 mm). The designed antenna has a conformal shape that fits inside a leadless pacemaker's capsule is surrounded by IC models and battery, which are tightly packed in the device enclosure. Subsequently, the integrated prototype is simulated deep inside at the center of the multi-layer canonical heart model. To verify experimentally, we have put dummy electronics (IC and battery) inside the 3D printed pacemaker's capsule and surfaced the fabricated conformal antenna around the inner curved body of the TCP (Transcatheter Pacing) capsule. Furthermore, we have tested the TCP capsule by inserting it in a ballistic gel phantom and minced pork. The measured impedance bandwidths at 1.4 GHz and 2.45 GHz are 250 MHz and 430 MHz, whereas measured gains are - 33.2 dBi, and - 28.5 dBi, respectively.

Technological Improvement Rates and Evolution of Energy-Based Therapeutics

This paper examines the field of energy-based medical therapies based on the analysis of patents. We define the field as the use of external stimuli to achieve biomedical modifications to treat disease and to increase health. Based upon distinct sets of patents, the field is subdivided into sub-domains for each energy category used to achieve the stimulation: electrical, magnetic, microwave, ultrasound, and optical. Previously developed techniques are used to retrieve the relevant patents for each of the stimulation modes and to determine main paths along the trajectory followed by each sub-domain. The patent sets are analyzed to determine key assignees, number of patents, and dates of emergence of the sub-domains. The sub-domains are found to be largely independent as to patent assignees. Electrical and magnetic stimulation patents emerged earliest in the 1970s and microwave most recently around 1990. The annual rate of improvement of all sub-domains (12-85%) is found to be significantly higher than one we find for an aggregate pharmaceutical domain (5%). Overall, the results suggest an increasingly important role for energy-based therapies in the future of medicine.

Major adverse clinical events associated with implantation of a leadless intracardiac pacemaker

BACKGROUND

Leadless intracardiac pacemakers were developed to avoid the complications of transvenous pacing systems. The Medtronic Micra™ transcatheter pacemaker is one such system. We found an unexpected number of major adverse clinical events (MACE) in the Food and Drug Administration's Manufacturers and User Facility Device Experience (MAUDE) database associated with Micra implantation.

OBJECTIVE

The purpose of this study was to describe these MACE and compare them to implant procedure MACE in MAUDE for Medtronic CapSureFix™ active-fixation transvenous pacing leads.

METHODS

During January 2021, we queried the MAUDE database for reports of MACE for Micra pacemakers and CapSureFix leads using the simple search terms "death," "tamponade," and "perforation." Reports from 2016-2020 were included.

RESULTS

The search identified 363 MACE for Micra and 960 MACE for CapSureFix leads, including 96 Micra deaths (26.4%) vs 23 CapSureFix deaths (2.4%) (P <.001); 287 Micra tamponades (79.1%) vs 225 tamponades for CapSureFix (23.4%) (P <.001); and 99 rescue thoracotomies for Micra (27.3%) vs 50 rescue thoracotomies for CapSureFix (5.2%) (P <.001). More Micra patients required cardiopulmonary resuscitation (21.8% vs 1.1%) and suffered hypotension or shock (22.0% vs 5.8%) than CapSureFix recipients (P <.001). Micra patients were more likely to survive a myocardial perforation or tear if they had surgical repair (P = .014).

CONCLUSION

Micra leadless pacemaker implantation may be complicated by myocardial and vascular perforations and tears that result in cardiac tamponade and death. We estimate the incidence is low (<1%). Rescue surgery to repair perforations may be lifesaving. MACE are significantly less for implantation of CapSureFix transvenous ventricular pacing leads.

Cardiac Stimulation in the Third Millennium: Where Do We Head from Here?

Over the years, pacemakers have evolved from a life-saving tool to prevent asystole to a device to treat heart rhythm disorders and heart failure, aiming at improving both cardiac function and clinical outcomes. Cardiac stimulation nowadays aims to correct the electrophysiologic roots of mechanical inefficiency in different structural heart diseases. This has led to awareness of the concealed risks of customary cardiac pacing that can inadvertently cause atrioventricular and inter-/intra-ventricular dyssynchrony, and has promoted the development of new pacing modalities and the use of stimulation sites different from the right atrial appendage and the right ventricular apex. The perspective of truly physiologic pacing is the leading concept of the continued research in the past 30 years, which has made cardiac stimulation procedure more sophisticated and challenging. In this article, we analyze the emerging evidence in favor of the available strategies to achieve an individualized physiologic setting in bradycardia pacing.

Pacing devices to treat bradycardia: current status and future perspectives

Introduction: Cardiac stimulation evolved from life-saving devices to prevent asystole to the treatment of heart rhythm disorders and heart failure, capable of remote patient and disease-progression monitoring. Cardiac stimulation nowadays aims to correct the electrophysiologic roots of mechanical inefficiency in different structural heart diseases.Areas covered: Clinical experience, as per available literature, has led to awareness of the concealed risks of customary cardiac pacing, that can inadvertently cause atrio-ventricular and inter/intra-ventricular dyssynchrony. New pacing modalities have emerged, leading to a new concept of what truly represents 'physiologic pacing' beyond maintenance of atrio-ventricular coupling. In this article we will analyze the emerging evidence in favor of the available strategies to achieve an individualized physiologic setting in bradycardia pacing, and the hints of future developments.Expert opinion: 'physiologic stimulation' technologies should evolve to enable an effective and widespread adoption. In one way new guiding catheters and the adoption of electrophysiologic guidance and non-fluoroscopic lead implantation are needed to make His-Purkinje pacing successful and effective at long term in a shorter procedure time; in the other way leadless stimulation needs to upgrade to a superior physiologic setting to mimic customary DDD pacing and possibly His-Purkinje pacing.

Implantation of the Micra transcatheter pacing system: A single center North India experience

Background

The leadless pacemaking transcatheter system, Micra, is a miniaturized, single-chamber pacemaker system. We report herein our experience with implantation of the Micra TPS system.

Objective

The current study was conducted to evaluate the safety and efficacy of the leadless Micra Transcatheter Pacemaker System (Medtronic).

Research design and methods

This was a prospective single centre nonrandomized study without controls. A transcatheter pacemaker was implanted in patients who had guideline based indications for ventricular pacing. 28 subjects were screened based on the selection criteria. Mica TPS was implanted. Parameters assessed were: duration of procedure (from femoral vein puncture to venous access closure), fluoroscopy time, number of device repositions, periprocedural electrical measurements (sensing, threshold and impedance) and in-hospital, intermediate to long term adverse events related to procedure.

Result and conclusion

s: The device was successfully implanted in 28 subjects. The mean intraoperative sensing value was 9.04 ± 1.5 mV and the impedance was 766.89 ± 213.9 Ω. At discharge from hospital, those values were 13.2 ± 15.83 mV and 855 ± 111.7, respectively. The recommended pacing threshold value as achieved in all subjects was 0.78 V, i.e. ≤ 1 V at 0.24 ms. There was no adverse event or complications reported for any of the subjects. Mean time from hospitalization to discharge was 1.5 days. Implantation of leadless pacemakers is feasible, safe and provides advantages over the conventional system.

New frontiers in cardiac devices

This article provides an overview of current cardiac device management, complications, and future areas for development. The last 70 years have seen huge advances in the field of implantable cardiac devices, from diagnostic tools to electrical therapies for bradycardia, ventricular arrhythmia and cardiac resynchronisation. While out-of-hours specialist cardiology cover and regional arrhythmia pathways are increasingly established, they are not universal, and the management of arrhythmia remains an important facet of clinical medicine for the general physician. This article discusses core recommendations from international guidelines with respect to heart rhythm diagnostics, pacing for bradycardia, cardiac resynchronisation and implantable cardioverter defibrillators, along with common complications. Finally, future innovations such as the diagnostic potential of portable technologies, antibiotic envelopes for cardiac devices and the increasing use of leadless pacemakers are described.

Wide Frequency Characterization of Intra-Body Communication for Leadless Pacemakers

Leadless Cardiac Pacemakers (LCP) have the potential to revolutionize Cardiac Rhythm Management (CRM). Current LCPs can only pace a single location of the heart limiting their use to patients requiring single-chamber stimulation. A Multi-node system of synchronized LCPs could be used in a significantly larger patient population. Synchronization using standard communication techniques involves high power consumption decreasing the longevity of the device. In this work, we investigate Galvanic Intra Body Communication (IBC) as a method to synchronize multi-node LCP systems. First, an accurate computational torso model was used for quasi-static simulations to estimate channel pathloss in the frequency range [40 kHz-20 MHz]. The model was then verified with in-vivo measurements using a novel experimental setup, where two LCP devices were placed in the right atrium, right ventricle and left ventricle. All channels involved in a potential multi-node LCP system were characterized. The orientation of the transducers relative to each other had a great impact on the results, with the attenuation level ranging between 55 dB and 70 dB between the best and worst orientations. The best results were achieved in the MHz range. Coupled with the fact that it does not require additional electrodes, this study suggests Galvanic IBC be superior to conventional communication methods for LCP devices. This analysis defines a methodology for galvanic IBC channel characterization for LCP systems, which is an important step for the design of efficient transceivers for IBC applications. More experiments with larger datasets are needed to bring this method to practice.

Energy-efficiency of Cardiomyocyte Stimulation with Rectangular Pulses

In cardiac pacemaker design, energy expenditure is an important issue. This work aims to explore whether varying stimulation pulse configuration is a viable optimization strategy for reducing energy consumption by the pacemaker. A single cardiomyocyte was used as an experimental model. Each cardiomyocyte was stimulated with different stimulation protocols using rectangular waveforms applied in varying number, in short succession. The amplitude, the width of each pulse, and the interval between consecutive pulses were modified. The application of multiple pulses in a short sequence led to a reduction of the threshold voltage required for stimulation when compared to a single pulse. However, none of the employed multi-pulse sequences reduced the overall energy expenditure of cell stimulation when compared to a single pulse stimulation. Among multiple pulse protocols, a combination of two short pulses (1 ms) separated with a short interval (0.5 ms) had the same energy requirements as a single short pulse (1 ms), but required the application of significantly less voltage. While increasing the number of consecutive pulses does not reduce the energy requirements of the pacemaker, the reduction in threshold voltage can be considered in practice if lower stimulation voltages are desired.

Splinting and mechanical disruption of the mitral valve apparatus by an endocardial left ventricular lead while delivering cardiac resynchronization therapy

Splinting and mechanical disruption of the mitral valve apparatus is an important limitation of an endocardial left ventricular (LV) pacing lead. Further, long-term data are required before this approach is more widely adopted.

Nanostim-leadless pacemaker

Nanostim™ (St. Jude Medical Inc., Saint Paul, MN, USA; now Abbott Medical Inc. Abbott Park, IL, USA) was the first self-contained intracardiac pacemaker to be implanted in a human patient. A total of 1423 Nanostim devices were implanted worldwide between 2013 and 2016 and three clinical trials were initiated. Although the device was recalled in 2016 owing to rare but serious battery failures, the concept of leadless pacing has gained widespread acceptance and is expanding beyond the initial single-chamber devices to dual-chamber systems, biventricular pacing, and combinations with defibrillators. This review describes the design, results from initial clinical trials, and long-term experiences with Nanostim. It discusses the lessons learned from the pioneering device's successes and shortcomings, many of which are valid for leadless pacemakers in general. This article also considers the Nanostim experience in comparison with the early years of clinical use for other pioneering device therapies. Important questions include how to minimize the risk for short-term complications by appropriate operator training and evaluation of suitable patients, what the long-term performance tells us about safety, as well as the necessity and feasibility of device explantation.

Vein Management for Cardiac Device Implantation

Transvenous approaches for pacemaker and defibrillator lead insertion offer numerous advantages over epicardial techniques. Although the cephalic, axillary, and subclavian veins are most commonly used in clinical practice, they each offer their own set of advantages and disadvantages that leave their usage dependent on patient anatomy and physician preference. Alternative methods using the upper and lower venous circulation have been described when these veins are not available or practical for lead insertion. Until current technology is superseded by leadless pacing systems, the search for the optimal lead insertion technique continues.

Imaging features of leadless cardiovascular devices

Cardiovascular devices and hemodynamic monitoring systems continue to evolve with the goal of allowing for rapid clinical intervention and management. Cardiovascular devices including the CardioMicroelectromechanical (CardioMEMS) device, implantable loop recorder, and right ventricular (RV) leadless pacemaker are now widely used for treatment and monitoring of advanced cardiac conditions, as many of these devices have been shown to significantly improve patient outcomes. Additionally, hemodynamic monitoring devices have shown utility in monitoring patients with aortic aneurysms after endovascular aortic repair (EVAR) for early detection of Type I and Type II endoleaks. There is limited published data regarding the imaging features of these devices. As these devices become more widely used, it is important for radiologists to become familiar with the normal imaging features and potential complications. The goal of this review is to summarize the data regarding the use of leadless cardiovascular devices including the CardioMEMS device, implantable loop recorder, and RV leadless pacemaker, and to present cases demonstrating their utility and normal imaging features.

Future of Smart Cardiovascular Implants

Cardiovascular disease remains the leading cause of death in Western society. Recent technological advances have opened the opportunity of developing new and innovative smart stent devices that have advanced electrical properties that can improve diagnosis and even treatment of previously intractable conditions, such as central line access failure, atherosclerosis and reporting on vascular grafts for renal dialysis. Here we review the latest advances in the field of cardiovascular medical implants, providing a broad overview of the application of their use in the context of cardiovascular disease rather than an in-depth analysis of the current state of the art. We cover their powering, communication and the challenges faced in their fabrication. We focus specifically on those devices required to maintain vascular access such as ones used to treat arterial disease, a major source of heart attacks and strokes. We look forward to advances in these technologies in the future and their implementation to improve the human condition.

A Decade of Information on the Use of Cardiac Implantable Electronic Devices and Interventional Electrophysiological Procedures in the European Society of Cardiology Countries: 2017 Report from the European Heart Rhythm Association

Aims

The aim of this analysis was to provide comprehensive information on invasive cardiac arrhythmia therapies in the European Society of Cardiology (ESC) area over the past 10 years.

Methods and results

The European Heart Rhythm Association (EHRA) has collected data on invasive arrhythmia therapies since 2008. This year 53 of the 56 ESC member countries provided data for the EHRA White Book. Here we present updated data on procedure rates together with information on demographics, economy, vital statistics, local healthcare systems and training activities. Considerable heterogeneity in the access to invasive arrhythmia therapies still exists across the five geographical ESC regions. In 2016, the device implantation rates per million population were 3-6 times higher in the Western region than in the non-European and Eastern ESC member countries. Catheter ablation activity was highest in the Western countries followed by the Northern and Southern areas. In the non-European countries, atrial fibrillation ablation rate was more than tenfold lower than in the European countries. On the other hand, the growth rate over the past ten years was highest in the non-European and Eastern countries. In some Eastern European countries with relative low gross domestic product the procedure rates exceeded the average values.

Conclusion

It was encouraging to note that during the past decade the growth in invasive arrhythmia therapies was greatest in the areas historically with relatively low activity. Nevertheless, there is substantial disparity and continued efforts are needed to improve harmonization of cardiac arrhythmia therapies in the ESC area.

Next-generation pacemakers: from small devices to biological pacemakers

Electrogenesis in the heart begins in the sinoatrial node and proceeds down the conduction system to originate the heartbeat. Conduction system disorders lead to slow heart rates that are insufficient to support the circulation, necessitating implantation of electronic pacemakers. The typical electronic pacemaker consists of a subcutaneous generator and battery module attached to one or more endocardial leads. New leadless pacemakers can be implanted directly into the right ventricular apex, providing single-chamber pacing without a subcutaneous generator. Modern pacemakers are generally reliable, and their programmability provides options for different pacing modes tailored to specific clinical needs. Advances in device technology will probably include alternative energy sources and dual-chamber leadless pacing in the not-too-distant future. Although effective, current electronic devices have limitations related to lead or generator malfunction, lack of autonomic responsiveness, undesirable interactions with strong magnetic fields, and device-related infections. Biological pacemakers, generated by somatic gene transfer, cell fusion, or cell transplantation, provide an alternative to electronic devices. Somatic reprogramming strategies, which involve transfer of genes encoding transcription factors to transform working myocardium into a surrogate sinoatrial node, are furthest along in the translational pipeline. Even as electronic pacemakers become smaller and less invasive, biological pacemakers might expand the therapeutic armamentarium for conduction system disorders.

Leadless Pacemakers - Implant, Explant and Long-Term Safety and Efficacy Data

Implantable cardiac pacemakers have seen remarkable progress in the last sixty years and remained as cornerstone therapy for symptomatic bradycardia. Despite this progress the current day traditional transvenous implanted pacemaker systems are limited by the need for a surgically created pocket for the generator, indwelling leads in the vascular system and lastly passage through the tricuspid valve. A majority of the implant and explant related complications are due to the surgical pocket and indwelling leads. Leadless pacemakers represent a major leap in technology and emerged as an alternative to traditional systems promises to eliminate lead and pocket associated complications. As with any disruptive technology, some questions remain unanswered with the leadless pacing systems, specifically longevity and end of life management for the device. Despite the unknowns, as the technology progresses, it is possible that pacing leads will become extinct and pacemakers will miniaturize even further. This review summarizes the available technology, implant and explant details, and long-term safety and efficacy data for leadless pacemakers.

Successful percutaneous retrieval of a leadless pacemaker due to an acute rise in pacing threshold

Leadless cardiac pacemakers (LCP) have become available recently. Both its acute and long-term performance in a large population of patients remain to be tested. Subacute rise in pacing threshold has been reported as an uncommon complication. On the other hand, the retrieval technique for LCP with passive fixation mechanism has not been previously described in details. Herein we report a newly recognized complication of an acute rise in pacing threshold very soon after implantation of an LCP without radiographic dislodgement. Percutaneous retrieval of this LCP with passive fixation mechanism was successful using a novel technique with the cryoballoon steerable sheath and a snare.

Advances and Future Directions in Cardiac Pacemakers: Part 2 of a 2-Part Series

In the second part of this 2-part series on pacemakers, we present recent advances in pacemakers and preview future developments. Cardiac resynchronization therapy (CRT) is a potent treatment for heart failure in the setting of ventricular dyssynchrony. Successful CRT using coronary venous pacing depends on appropriate patient selection, lead implantation, and device programming. Despite optimization of these factors, nonresponse to CRT may occur in one-third of patients, which has led to a search for alternative techniques such as multisite pacing, His bundle pacing, and endocardial left ventricular pacing. A paradigm shift in pacemaker technology has been the development of leadless pacemaker devices, and on the horizon is the development of batteryless devices. Remote monitoring has ushered in an era of greater safety and the ability to respond to device malfunction in a timely fashion, improving outcomes.

Leadless Cardiac Pacemakers: Current status of a modern approach in pacing

Since the first transvenous pacemaker implantation, which took place 50 years ago, important progress has been achieved in pacing technology. Consequently, at present, more than 700,000 pacemakers are implanted annually worldwide. However, conventional pacemakers' implantation has a non-negligible risk of periprocedural and long-term complications associated with the transvenous leads and pacemaker pocket. Recently, leadless pacing systems have emerged as a therapeutic alternative to conventional pacing systems that provide therapy for patients with bradyarrhythmias, while eliminating potential transvenous lead- and pacemaker pocket-related complications. Initial studies have demonstrated favorable efficacy and safety of currently developed leadless pacing systems, compared to transvenous pacemakers. In the present paper, we review the current evidence and highlight the advantages and disadvantages of this novel technology. New technological advances may allow the next generation of leadless pacemakers to further expand, thereby offering a wireless cardiac pacing in future.

Permanent Leadless Cardiac Pacemaker Therapy

A new technology, leadless pacemaker therapy, was recently introduced clinically to address lead- and pocket-related complications in conventional transvenous pacemaker therapy. These leadless devices are self-contained right ventricular single-chamber pacemakers implanted by using a femoral percutaneous approach. In this review of available clinical data on leadless pacemakers, early results with leadless devices are compared with historical results with conventional single-chamber pacing. Both presently manufactured leadless pacemakers show similar complications, which are mostly related to the implant procedure: cardiac perforation, device dislocation, and femoral vascular access site complications. In comparison with conventional transvenous single-chamber pacemakers, slightly higher short-term complication rates have been observed: 4.8% for leadless pacemakers versus 4.1% for conventional pacemakers. The complication rate of the leadless pacemakers is influenced by the implanter learning curve for this new procedure. No long-term outcome data are yet available for the leadless pacemakers. Larger leadless pacing trials, with long-term follow-up and direct randomized comparison with conventional pacing systems, will be required to define the proper clinical role of these leadless systems. Although current leadless pacemakers are limited to right ventricular pacing, future advanced, communicating, multicomponent systems are expected to expand the potential benefits of leadless therapy to a larger patient population.

Research Update: Materials design of implantable nanogenerators for biomechanical energy harvesting

Implantable nanogenerators are rapidly advanced recently as a promising concept for harvesting biomechanical energy in vivo. This review article presents an overview of the most current progress of implantable piezoelectric nanogenerator (PENG) and triboelectric nanogenerator (TENG) with a focus on materials selection, engineering, and assembly. The evolution of the PENG materials is discussed from ZnO nanostructures, to high-performance ferroelectric perovskites, to flexible piezoelectric polymer mesostructures. Discussion of TENGs is focused on the materials and surface features of friction layers, encapsulation materials, and device integrations. Challenges faced by this promising technology and possible future research directions are also discussed.

Leadless Pacemakers

Leadless pacing is an emerging technology with the potential to significantly improve outcomes associated with the need for long-term pacing. Specifically, the major advantage of leadless systems is abolishing the need for transvenous leads and subcutaneous pockets, both of which account for most adverse events associated with traditional pacemakers. Two leadless pacemakers are currently available: the Nanostim (leadless cardiac pacemaker [LCP]) device (St. Jude Medical, Sylmar, California) and the Micra Transcatheter pacing system (Medtronic, Minneapolis, Minnesota). These 2 pacemakers have shown promising results in clinical trials. In conclusion, in this review we summarize the results of the 2 investigational device exemption trials and compare the pros and cons of these devices to traditional transvenous pacemakers.

Anaesthetic consideration in patients with cardiac implantable electronic devices scheduled for surgery

With advances in cardiology and cardiothoracic surgery, several newer implantable cardiac devices have become common in the surgical population. Multichamber pacemakers, implanted cardiac defibrillators and ventricular assist devices are frequent in current day practice. Many of the newer implantable cardiac electronic devices are targeted at managing heart failure. While managing such patients for non-cardiac surgeries, specific issues related to equipment characteristics and troubleshooting should be a priority for the anaesthesiologists. There is a possibility of malfunction of the devices resulting in catastrophic outcomes. Therefore, it is imperative to understand the pathophysiology, device characteristics and troubleshooting before embarking on anaesthetising patients with implantable cardiac electronic devices.