Search Results (31)

This paper proposed an ultra-miniaturized four-port dual-band multi-input multi-output (MIMO) antenna designed for wireless biomedical implantable devices, including wireless capsule endoscopy (WCE) and cardiac leadless pacemakers. The antenna supports operation in the wireless medical telemetry service (WMTS) band of 1.395–1.4 GHz and the industrial, scientific, and medical (ISM) band of 2.4–2.4835 GHz for wireless power transfer and data telemetry applications. Miniaturization is achieved through a partial meandered structural configuration, yielding an overall size of 8 × 6.4 × 0.5 mm³. The antenna is encapsulated within implantable biomedical devices containing batteries, sensors, and electronic components, and evaluated in both homogeneous and realistic heterogeneous body phantoms, including the large intestine and heart. The full-wave electromagnetic simulation results demonstrate good performance, including reflection coefficients of −31.19 dB and −30.07 dB, gains of −27.5 dBi and −17.5 dBi, −10 dB impedance bandwidths of 170 MHz and 370 MHz, mutual coupling below 20 dB, and fractional bandwidths of 12.2% and 15.1% at 1.4 GHz and 2.45 GHz, respectively. Specific absorption rate (SAR) analysis satisfies implantation safety limits. Link budget analysis confirms reliable communication over distances more than 20 m in both frequency bands with high-data rates up to 100 Mbps. MIMO channel parameters such as envelope correlation coefficient (ECC), diversity gain (DG), channel capacity loss (CCL), and total active reflection coefficient (TARC) confirm the usefulness of the proposed MIMO antenna. Consequently, the proposed MIMO antenna emerges as a highly promising candidate with, ultra-miniaturization, isolation, multiband operation ability with omnidirectional-like radiation pattern characteristics for several biomedical implants in wireless health monitoring systems. Full article

This work presents a highly compact triple-band multi-input-multi-output (MIMO) implantable antenna for wireless capsule endoscopy (WCE) and leadless cardiac pacemakers. The proposed antenna operates at industrial, scientific, and medical (ISM) bands of 2.400 to 2.480 GHz and 5.725 to 5.875 GHz for data telemetry and the wireless medical telemetry service (WMTS) band of 1.395 to 1.432 GHz for efficient wireless power transfer. The four-element design measures 8.5 × 8.5 × 0.26 mm³ and achieves low mutual coupling through a planar four-port configuration with optimized inter-element spacing. The antenna is integrated within realistic capsule devices containing batteries, sensors, and electronic components, and evaluated in both homogeneous and realistic heterogeneous body phantoms, including the large intestine and heart. The design yields maximum reflection coefficients of −26.15 dB, −15 dB, and −36.32 dB, −10 dB bandwidths of 260 MHz, 160 MHz, and 160 MHz, mutual coupling of −37.74 dB, −44.55 dB, −26.48 dB, and peak realized gains of −35 dBi, −25 dBi, and −15 dBi at 1.4 GHz, 2.45 GHz, and 5.8 GHz, respectively. Specific absorption rate (SAR) analysis satisfies implantation safety limits. Link budget analysis confirms reliable communication over distances > 20 m in all bands with data rates up to 100 Mbps. MIMO channel parameters such as envelope correlation coefficient (ECC) and diversity gain (DG) remain within acceptable limits. Owing to its multi-band operation, miniaturization, and isolation, the proposed four-port antenna is a good candidate for next-generation WCE and leadless pacemaker systems. Full article

Tricuspid regurgitation (TR) in patients with transvalvular cardiac implantable electronic device (CIED) leads is increasingly encountered as transcatheter tricuspid valve interventions (TTVI) expand, yet integrated guidance for managing this “two-device problem” remains limited. We performed a focused synthesis of contemporary evidence, organizing findings around mechanisms and diagnosis of TR in the setting of CIED leads, lead–device interactions across TTVI platforms, and clinical trade-offs of transvenous lead extraction (TLE) versus lead preservation or jailing. CIED-associated TR can arise from lead–leaflet impingement, leaflet injury, fibrotic adhesion, pacing-induced remodeling, or infection; true CIED-induced TR accounts for a minority of clinically significant TR, yet progression of TR after lead implantation occurs in 7–45% of patients, and moderate-to-severe TR in CIED populations is associated with 1.6- to 2.5-fold increased mortality risk. Lead conflict and lifetime consequences differ by TTVI modality: repair approaches are generally more lead-tolerant, whereas valve replacement creates obligate lead jailing with implications for lead performance, future extraction feasibility, and infection management. Management of TR with transvalvular CIED leads requires integrated Heart Team planning that anticipates downstream device needs. Standardized TR phenotyping, lead-aware TTVI selection, valve-sparing rhythm-device strategies, and structured post-procedural surveillance may improve outcomes; prospective studies are needed to define optimal extract-versus-jail pathways. Full article

Cardiac pacing has undergone a significant transformation in the last decade. Leadless pacing (LP), once only a conceptual idea stemming from the early interest in eliminating lead-related complications of transvenous pacemakers, has now become a reality in clinical practice. Since the introduction of the first human single-chamber asynchronous leadless ventricular pacing in 2012, atrioventricular-synchronized single- or dual-chamber leadless pacing systems have been approved for clinical use since 2020. Leadless cardiac resynchronization therapy (CRT) has shown optimistic results in case series and awaits its full utility in real-world clinical practice. With the successful feasibility study of leadless conduction system pacing, we are eagerly awaiting long-term safety and efficacy data on a large scale. Another important frontier is the development of self-rechargeable LP, which may be an ideal pacemaker for the future and may reduce the burden of multiple device replacements as batteries near the end-of-service. Totally extravascular percutaneous leadless pericardial micro-pacemaker system implantation is under development. In this state-of-the-art review, we examine the evolution of cardiac pacing, emphasizing the development and utility of LP to meet maximum physiological pacing needs, optimize atrioventricular synchrony and cardiac resynchronization, and broaden its indications. Full article

Pacing in complex congenital heart disease can be difficult and with significant drawbacks due to issues with infection and long-term leads within the vasculature. Leadless pacemakers have emerged as a new technology with a strong safety and efficacy record in normal cardiac anatomy. Here, we review the current available technology, current evidence in complex congenital pacing and how leadless pacemakers may be used in complex congenital heart disease. Full article

Background: Cardiac implantable electronic devices (CIEDs) have become indispensable tools in the management of bradyarrhythmia and heart failure, prompting a surge in research activity. To characterize the evolving research landscape, we conducted a bibliometric analysis focused on institutional contributions, author networks, journal trends, funding patterns, and emerging thematic hotspots in the field of cardiac devices to highlight keywords and identify knowledge development timelines and emerging trends, providing a comprehensive overview of the current state of research in this area. Methods: We conducted a bibliometric analysis of cardiac devices using the Web of Science Core Collection (WOSCC) on 27 November 2024, with search terms “ST (cardiac defibrillator) OR (pacemaker)”. Data from 1 January 2019 to 1 January 2024 resulted in 3753 articles, refined to 1000 after excluding non-English and methodologically inappropriate papers. VosViewer, Excel, and Drawio facilitated data visualization, creating networks where node size indicates frequency, line thickness shows association strength, and colors denote clusters. This approach helped identify key research trends and collaborations in the field. Results: The United States led in publication volume (362 papers) and citations (7198), with Emory University emerging as the most prolific institution. Heart Rhythm was the most productive journal, while Europace was the most co-cited. Kurt Stromberg was the leading author by publications and citations. Funding was predominantly from U.S. agencies, with the NIH and HHS each supporting 127 studies. Co-citation and keyword analyses revealed three dominant research clusters: (1) leadless pacemakers; (2) permanent pacemaker implantation following transcatheter aortic valve replacement (TAVR); and (3) development of self-powered pacing technologies, including piezoelectric and bioresorbable systems. Conclusions: This study offers a comprehensive overview of recent trends and intellectual structures in cardiac device research. By identifying key contributors, collaborative networks, and thematic evolutions, it provides a valuable reference for researchers, clinicians, and innovators seeking to navigate or shape the rapidly advancing field of cardiac electrophysiology and device therapy. Full article

Deeply implanted biomedical devices like leadless pacemakers require an antenna with minimal volume and high radiation efficiency to ensure reliable in-body communication and long operational time within the human body. This paper introduces a novel implantable antenna designed to significantly reduce the spatial requirements within an implantable capsule while maintaining high radiation efficiency in lossy media like heart tissue. The design principles of the proposed antenna are outlined, followed by antenna parameters and an equivalent circuit study that demonstrates how to fine-tune the antenna’s resonant frequency. The radiation characteristics of the antenna are thoroughly investigated, revealing a radiation efficiency of up to 28% at the Medical Implant Communication System (MICS) band and 56% at the 2.4 GHz ISM band. The transmission efficiency between two deeply implanted antennas within heart tissue has been improved by more than 15 dB compared to the current state of the art. The radiation and transmission performance of the proposed antennas has been validated through comprehensive simulations using anatomical human body models, phantom measurements, and in vivo animal experiments, confirming their superior radiation performance. Full article

Background: Cardiac implantable electronic device (CIED) infections necessitate extraction and subsequent pacing interventions. Conventional methods after removing the infected CIED system involve temporary or semi-permanent pacing followed by delayed permanent pacemaker (PPM) implantation. Leadless pacemakers (LPs) may offer an alternative, allowing immediate PPM implantation without increasing infection risks. Our objective is to evaluate the safety and cost-effectiveness of LP implantation during the same procedure of CIED extraction, compared to conventional two-stage approaches. Methods: Pacemaker-dependent patients with systemic or pocket infection undergoing device extraction and LP implantation during the same procedure at Sheba Medical Center, Israel, were compared to a historical group of patients undergoing a semi-permanent (SP) pacemaker implantation during the procedure, followed by a permanent pacemaker implantation. Results: The cohort included 87 patients, 45 undergoing LP implantation and 42 SP implantation during the extraction procedure. The LP group demonstrated shorter intensive care unit stay (1 ± 3 days vs. 7 ± 12 days, p < 0.001) and overall hospital days (11 ± 24 days vs. 17 ± 17 days, p < 0.001). Rates of infection relapse and one-year mortality were comparable between groups. Economic analysis revealed comparable total costs, despite the higher initial expense of LPs. Conclusions: LP implantation during CIED extraction offers significant clinical and logistical advantages, including reduced hospital stays and streamlined treatment, with comparable safety and cost-effectiveness to conventional approaches. Full article

Background and Objectives: Leadless pacemakers provide an innovative alternative to traditional transvenous pacemakers for managing cardiac arrhythmias. The objective of this systematic review is to conduct a meta-analysis comparing acute complication and mortality rates associated with leadless pacemakers versus transvenous pacemaker placements using national-level data. Specifically, we aim to summarize the current evidence and calculate pooled odds ratios for acute overall complications, acute device-related complications, and acute mortality to assess the early safety outcomes of leadless pacemaker placement relative to traditional transvenous pacemakers. Materials and Methods: A systematic search of PubMed, Scopus, ScienceDirect, and Google Scholar was conducted by two independent researchers using a predefined search protocol. The search included articles published up to 10 October 2024, without limits on review depth. Studies were included if they provided national-level data comparing leadless pacemaker and traditional pacemaker recipients in terms of acute mortality, acute overall complications, and acute device-related complications. Outcomes were pooled to calculate odds ratios using a random-effects model in RStudio (version 2024.12.1+563). Results: A total of five studies met the eligibility criteria. The pooled odds ratio for acute mortality was 2.03 (95% CI: 0.65–6.34, I² = 99%; p < 0.01), for acute overall complications was 1.08 (95% CI: 0.45–2.61, I² = 99%; p < 0.01), and for acute device-related complications was 1.02 (95% CI: 0.23–4.44, I² = 99%; p < 0.01). Conclusions: The reviewed studies suggest that leadless pacemakers offer a promising alternative to transvenous pacemakers, offering a comparable short-term safety profile. Ongoing technological advancements may further enhance their applicability in clinical practice. Full article

Adult congenital heart disease (ACHD) represents a significant portion of congenital anomalies, and with improved treatments leading to an increased life expectancy, its prevalence has been increasing over the past few decades. Nonetheless, a considerable number of patients with ACHD require cardiac rhythm management devices during their lifetime. Traditionally, transvenous pacemaker placement has been the standard mode of treatment for these patients. However, some patients with ACHD have anatomical barriers that obscure this mode of treatment. Leadless pacing systems (LPSs) have changed the field of pacing. Currently, two different LPSs are available. In a real-world setting, implanting an LPS in patients after tricuspid valve (TV) surgery seems to be a straightforward procedure with a low risk of complications, with patients showing no valvular dysfunction after the intervention. LPS implantation is an option to avoid device-related complications in patients with previous TV surgery. Moreover, it has been demonstrated that even the jugular approach seems as safe as the femoral approach and could be considered an alternative implantation method for LPSs. The Aveir VR leadless pacemaker is a helix LPS with unique features, such as its capacity as a dual-chamber leadless pacemaker, the ability to map electrical parameters before releasing the device, and its possibility of being retrievable. Hereby, we present the case of Ebstein’s anomaly, atrial septal defect closure, and previous TV surgery with symptomatic intermittent advanced atrioventricular block. This case illustrates that a transjugular approach for LPSs is also feasible in patients with ACHD. Full article

Background: In total, 6.6% to 11% of patients with an initially implanted implantable cardioverter-defibrillator (ICD) will develop significant bradycardia and the need for pacing in subsequent years. As the leadless pacemaker (LP) and subcutaneous implantable cardioverter-defibrillator (S-ICD) population comorbidities are often similar, both groups would benefit from a hybrid solution. Unfortunately, currently, there is no commercially available and sufficiently validated interconnected set of S-ICD and LP. Methods: In this single-center, prospective observational study, 32 pacing-dependent patients after implantation of a Micra LP were screened for S-ICD on the left and right sides of the sternum using the EMBLEM Automated Screening Tool. At least one positive, both in the supine and standing positions, was considered a positive screening. The impact of various clinical variables and morphology of paced QRS on screening results was assessed. Moreover, the function of the tricuspid valve was evaluated before and after LP implantation to consider whether there is a relationship between paced QRS and worsening tricuspid regurgitation. Results: Patients with paced heart rhythm were divided into two groups based on screening results for S-ICD. The positive screening outcome was achieved in 10 patients (31.25%). No correlation between any clinical variable and screening results was found. However, right axis deviation [RAD] of paced QRS seems to be a strong predictor of positive S-ICD screening (RAD in 9/32 patients, sensitivity 90%, specificity 100%, PPV 100%, NPV 96% for passing screening), and negative polarity of paced QRS in inferior leads predicts negative screening results (positive polarity in II, III, and aVF in 12/32 patients, sensitivity 100%, specificity 90%, PPV 83%, NPV 100% for passing screening). Conclusions: Right axis deviation of the paced rhythm, positive QRS polarity of leads II, III, and aVF, and negative QRS polarity in leads I and aVL seem to predict a positive screening result for S-ICD. Such a position of LP does not seem to worsen tricuspid regurgitation. Full article

The widespread use of Cardiac Implantable Electronic Devices (CIEDs) has transformed the management of cardiac arrhythmias, improving survival and quality of life for millions. However, this progress has introduced a range of device-related complications, which can significantly impact patient outcomes. This review examines “new diseases” linked to CIEDs, categorizing them into physical (e.g., infections, venous obstruction, lead failure, and device recalls) and functional complications (e.g., arrhythmias, pacemaker syndrome, and left ventricular dysfunction). Prevention and management strategies are emphasized. Emerging technologies, such as leadless devices, quadripolar leads, and remote monitoring systems, hold promise in reducing risks and enhancing patient care. Future directions include integrating artificial intelligence for real-time monitoring, improving device durability, and exploring novel materials to minimize infections and mechanical failures. Understanding CIED-related complications is essential for healthcare providers to balance the benefits and risks of these life-saving technologies. Full article

Cardiac Resynchronization Therapy (CRT) has been established as a major component of heart failure management, resulting in a significant reduction in patient morbidity and death for patients with increased QRS duration, low left ventricular ejection fraction (LVEF), and high risk of arrhythmias. The ability to synchronize both ventricles, lower heart failure hospitalizations, and optimize clinical outcomes are some of the attractive characteristics of biventricular pacing, or CRT. However, the high rate of CRT non-responders has led to the development of new modalities including leadless CRT pacemakers (CRT-P) and devices focused on conduction system pacing (CSP). This comprehensive review aims to present recent findings from CRT clinical trials and systematic reviews that have been published that will likely guide future directions in patient care. Full article

Although significant strides have been made in cardiac pacing, the field is still evolving. While transvenous permanent pacing is highly effective in the management of bradyarrhythmias, it is not risk free and may result in significant morbidity and, rarely, mortality. Transvenous leads are often the weakest link in a pacing system. They may dislodge, fracture, or suffer breaches in their insulation. This review was undertaken to clarify leadless risks, benefits, and alternatives to transvenous cardiac pacing for bradyarrhythmias and heart failure management. In order to clarify the role(s) of leadless pacing, this narrative review was undertaken by searching MEDLINE to identify peer-reviewed clinical trials, randomized controlled trials, meta-analyses, and review articles, as well as other clinically relevant reports and studies. The search was limited to English-language reports published between 1932 and 2024. Leadless pacing was searched using the terms Micra™, Nanostim™, AVEIR™, single-chamber leadless pacemaker, dual-chamber leadless pacemaker, cardiac resynchronization therapy (CRT), cardiac physiological pacing (CPP) and biventricular pacing (BiV). Google and Google Scholar, as well as bibliographies of identified articles were also reviewed for additional references. The advantages and limitations of leadless pacing as well as options that are under investigation are discussed in detail. Full article

Background: Leadless pacemakers offer a safe and effective alternative pacing strategy. However, limited data are available for patients with end stage renal disease (ESRD), a population of significant relevance. Methods: Using the Nationwide Readmission Database, we extracted data from all adult patients with ESRD who underwent traditional transvenous or leadless pacemaker implantation between 2016 and 2021. We compared in-hospital mortality, 30-day readmission rates, complication rates, and healthcare resource utilization between the two cohorts. Results: A total of 6384 (81.2%) patients were included in the transvenous pacemaker cohort, and 1481(18.8%) patients were included in the leadless pacemaker cohort. In patients with ESRD, leadless pacemaker implantation was linked to higher in-hospital complications when compared to transvenous pacemakers. These included the need for blood transfusion (aOR 1.85, 95% CI 1.32–2.60, p < 0.01), vascular complications (aOR 3.6, CI 1.40–9.26, p = 0.01), and cardiac complications (aOR 4.12, CI 1.70–9.98, p < 0.01). However, there were no differences between the two groups in terms of in-hospital mortality and 30-day readmission rates. The median length of stay was longer for leadless pacemaker implantation than transvenous pacemaker implantation (5 days vs. 4 days, p < 0.01). The total hospitalization charges were also higher ($139,826 vs. $93,919, p < 0.01). Conclusions: Although previous studies have demonstrated lower long-term complication rates with leadless pacemakers than transvenous pacemakers, our analysis shows a higher risk of short-term in-hospital complications in ESRD patients, though no differences in in-hospital mortality and 30-day readmissions. Full article