Advancements in Finite Element Modeling for Cardiac Device Leads and 3D Heart Models.

The human heart's remarkable vitality necessitates a deep understanding of its mechanics, particularly concerning cardiac device leads. This paper presents advancements in finite element modeling for cardiac leads and 3D heart models, leveraging computational simulations to assess lead behavior over time. Through detailed modeling and meshing techniques, we accurately captured the complex interactions between leads and heart tissue. Material properties were assigned based on ASTM (American Society for Testing and Materials) standards and in vivo exposure data, ensuring realistic simulations. Our results demonstrate close agreement between experimental and simulated data for silicone insulation in pacemaker leads, with a mean force tolerance of 19.6 N ± 3.6 N, an ultimate tensile strength (UTS) of 6.3 MPa ± 1.15 MPa, and a percentage elongation of 125% ± 18.8%, highlighting the effectiveness of simulation in predicting lead performance. Similarly, for polyurethane insulation in ICD leads, we found a mean force of 65.87 N ± 7.1 N, a UTS of 10.7 MPa ± 1.15 MPa, and a percentage elongation of 259.3% ± 21.4%. Additionally, for polyurethane insulation in CRT leads, we observed a mean force of 53.3 N ± 2.06 N, a UTS of 22.11 MPa ± 0.85 MPa, and a percentage elongation of 251.6% ± 13.2%. Correlation analysis revealed strong relationships between mechanical properties, further validating the simulation models. Classification models constructed using both experimental and simulated data exhibited high discriminative ability, underscoring the reliability of simulation in analyzing lead behavior. These findings contribute to the ongoing efforts to improve cardiac device lead design and optimize patient outcomes.

Safety of magnetic resonance imaging in patients with cardiac implantable electronic devices and abandoned or epicardial leads: a systematic review and meta-analysis.

AIMS: Persistent reluctance to perform magnetic resonance imaging (MRI) in patients with abandoned and/or epicardial leads of cardiac implantable electronic devices is related to in vitro studies reporting tip heating. While there is a plethora of data on the safety of MRI in conditional and non-conditional implantable devices, there is a clear lack of safety data in patients with abandoned and/or epicardial leads. METHODS AND RESULTS: Relevant literature was identified in Medline and CINAHL using the key terms 'magnetic resonance imaging' AND 'abandoned leads' OR 'epicardial leads'. Secondary literature and cross-references were supplemented. For reporting guidance, the Preferred Reporting Items for Systematic reviews and Meta-Analyses 2020 was used. International Prospective Register of Systematic Reviews (PROSPERO) registration number 465530. Twenty-one publications with a total of 656 patients with 854 abandoned and/or epicardial leads and 929 MRI scans of different anatomical regions were included. No scan-related major adverse cardiac event was documented, although the possibility of under-reporting of critical events in the literature should be considered. Furthermore, no severe device dysfunction or severe arrhythmia was reported. Mainly transient lead parameter changes were observed in 2.8% in the subgroup of patients with functional epicardial leads. As a possible correlate of myocardial affection, subjective sensations occurred mainly in the subgroup with abandoned epicardial leads (4.0%), but no change in myocardial biomarkers was observed. CONCLUSION: Existing publications did not report any relevant adverse events for MRI in patients with abandoned and/or epicardial leads if performed according to strict safety guidelines. However, a more rigorous risk-benefit calculation should be made for patients with epicardial leads.

Endocardial lead insulation wear in a scanning and optical microscope.

BACKGROUND: The path and interaction of leads within the cardiovascular system are influenced by various factors, including the implantation technique. Furthermore, the multifaceted composition of these leads, often comprising multiple materials, can contribute to their potential degradation and wear over time. OBJECTIVES: Our aim was to investigate the wear of lead insulation following the removal of transvenous leads and pinpoint the regions of the lead most vulnerable to damage. MATERIAL AND METHODS: We undertook a prospective analysis of patients from a single tertiary center who underwent transvenous lead explantation (TLE) between October 1, 2013, and July 31, 2015. Specifically, our examination focused on endocardial leads removed using simple screw-out and gentle traction techniques. Subsequent lead evaluations were conducted utilizing scanning electron and optical microscopes. RESULTS: Among the 86 patients who underwent the TLE procedure, 26 patients (30%) required the removal of 39 leads through simple traction. Inspection using scanning electron microscopy consistently indicated insulation damage across all leads. A total of 347 damaged sites were identified: 261 without lead unsealing and 86 exhibiting unsealing. Notably, the sections of the leads located within the intra-pocket area demonstrated the highest vulnerability to damage (odds ratio (OR): = 9.112, 95% confidence interval (95% CI): 3.326-24.960), whereas the intravenous regions displayed the lowest susceptibility (OR: 0.323, 95% CI: 0.151-0.694). CONCLUSIONS: Our study reveals that all evaluated leads exhibited insulation damage, with the intra-pocket segments manifesting a notably higher prevalence of damage than the intravenous segments.

Multidimensional Optimization of R-LE001 for New Leads with Enhanced Antifungal Profiles.

Scaffold hopping and structural fine-tuning are important strategies for agrochemical innovation. Multidimensional optimization of the prevalidated antifungal lead R-LE001 was conducted via the design, synthesis, and bioevaluation of 53 new compounds differing in either scaffold or substituent. The antifungal structure-activity relationship (SAR) revealed that a number of amides containing 2-(2-oxazolinyl) aniline (NHPhOx) or 2-(2-thiazolinyl) aniline (NHPhthiOx) demonstrated a more promising antifungal effect than both R-LE001 and the positive control boscalid. Specifically, compound 10 (encoded LEX-K01) shows an excellent antifungal effect against Botrytis cinerea with an EC50 value lower than 0.11 µM. This small change leads to a significant improvement (over 1 order of magnitude) in bioactivity compared to that of either R-LE001 (EC50 = 1.41 µM) or boscalid (EC50 = 2.01 µM) and fluxapyroxad (EC50 = 4.35 µM). With much lower resistance factors, LEX-K01 (10) was more efficacious against the two boscalid-resistant strains of B. cinerea TZ01 and NJBH2017. A combination of LEX-K01 (10) and boscalid in a ratio of 1:3 showed synergistic effects against resistant B. cinerea TZ01 and NJBH2017, with SR values of 3.01 and 2.55, respectively. LEX-K01 (10) has a curative efficacy (70.3%) more prominent than that of boscalid (51.2%) in controlling disease caused by B. cinerea. The molecular docking simulation of LEX-K01 (10) with the SDH protein of B. cinerea displayed four hydrogen bonds with amino acid residues TYR144, ARG88, TRP81, and SER84, rationalizing a stronger affinity than boscalid. The scanning electron microscopy (SEM) characteristic revealed that it could cause an obvious collapse of B. cinerea mycelium. This work indicates that LEX-K01 (10) has the potential to be further explored as a new antifungal agent.

In Vivo Durability of Polyurethane Insulated Implantable Cardioverter Defibrillator (ICD) Leads.

The 6935M Sprint Quattro Secure S and 6947M Sprint Quattro Secure are high voltage leads designed to administer a maximum of 40 joules of energy for terminating ventricular tachycardia or ventricular fibrillation. Both leads utilize silicone insulation and a polyurethane outer coating. The inner coil is shielded with polytetrafluoroethylene (PTFE) tubing, while other conductors are enveloped in ethylene tetrafluoroethylene (ETFE), contributing to the structural integrity and functionality of these leads. Polyurethane is a preferred material for the outer insulation of cardiac leads due to its flexibility and biocompatibility, while silicone rubber ensures chemical stability within the body, minimizing inflammatory or rejection responses. Thirteen implantable cardioverter defibrillator (ICD) leads were obtained from the Wright State University Anatomical Gift Program. The as-received devices exhibited varied in vivo implantation durations ranging from less than a month to 89 months, with an average in vivo duration of 41 ± 27 months. Tests were conducted using the Test Resources Q series system, ensuring compliance with ASTM Standard D 1708-02a and ASTM Standard D 412-06a. During testing, a load was applied to the intact lead, with careful inspection for surface defects before each test. Results of load to failure, percentage elongation, percentage elongation at 5 N, ultimate tensile strength, and modulus of elasticity were calculated. The findings revealed no significant differences in these parameters across all in vivo exposure durations. The residual properties of these ICD leads demonstrated remarkable stability and performance over a wide range of in vivo exposure durations, with no statistically significant degradation or performance changes observed.

Global LEADR pivotal trial results.

BACKGROUND: Implantable cardioverter-defibrillators last longer, and interest in reliable leads with targeted lead placement is growing. The OmniaSecure™ defibrillation lead is a novel small-diameter, catheter-delivered lead designed for targeted placement, based on the established SelectSecure SureScan MRI Model 3830 lumenless pacing lead platform. OBJECTIVE: This trial assessed safety and efficacy of the OmniaSecure defibrillation lead. METHODS: The worldwide LEADR pivotal clinical trial enrolled patients indicated for de novo implantation of a primary or secondary prevention implantable cardioverter-defibrillator/cardiac resynchronization therapy defibrillator, all of whom received the study lead. The primary efficacy end point was successful defibrillation at implantation per protocol. The primary safety end point was freedom from study lead-related major complications at 6 months. The primary efficacy and safety objectives were met if the lower bound of the 2-sided 95% credible interval was >88% and >90%, respectively. RESULTS: In total, 643 patients successfully received the study lead, and 505 patients have completed 12-month follow-up. The lead was placed in the desired right ventricular location in 99.5% of patients. Defibrillation testing at implantation was completed in 119 patients, with success in 97.5%. The Kaplan-Meier estimated freedom from study lead-related major complications was 97.1% at 6 and 12 months. The trial exceeded the primary efficacy and safety objective thresholds. There were zero study lead fractures and electrical performance was stable throughout the mean follow-up of 12.7 ± 4.8 months (mean ± SD). CONCLUSION: The OmniaSecure lead exceeded prespecified primary end point performance goals for safety and efficacy, demonstrating high defibrillation success and a low occurrence of lead-related major complications with zero lead fractures.

Leads with the Cut Proximal Ends Migrated into the Heart and Vasculature: A Rare Phenomenon among 3847 Lead Extraction Procedures.

Background: The study aimed to describe the phenomenon of leads migrated (MPLE) into the cardiovascular system (CVS). Methods: Retrospective analysis of 3847 transvenous lead extractions (TLE). Results: Over a 17-year period, 72 (1.87%) MPLEs (median dwell time 137.5 months) were extracted, which included mainly ventricular leads (56.94%). Overall, 68.06% of MPLEs had their cut proximal ends in the venous system. Most of them were pacing (95.83%) and passive fixation (98.61%) leads. Independent risk factors for MPLE included abandoned leads (OR = 8.473; p < 0.001) and leads located on both sides of the chest (2.981; p = 0.045). The higher NYHA class lowered the probability of MPLE (OR = 0.380; p < 0.001). Procedure complexity was higher in the MPLE group (procedure duration, unexpected procedure difficulties, use of additional (advanced) tools and alternative venous approach). There were no more major complications in the MPLE group, but the rate of procedural success was lower due to more frequent retention of non-removable lead fragments. Extraction of MPLEs did not influence long-term survival. Conclusions: 1. Extraction of leads with MPLE is rare among other TLE procedures (1.9%), 2. risk factors include abandoned leads and presence of leads on both sides of the chest but a higher NYHA class lowers the probability of MPLE, 3. complexity of MPLE extraction is higher regarding procedure duration, unexpected procedure difficulties, use of advanced tools and techniques but rates of major complications are comparable, and 4. extraction of MPLEs did not influence long-term survival.

Lead with speed: Recasting the forensic laboratory product line and service delivery model.

Forensic laboratories face a multitude of challenges when striving to deliver services to the criminal justice system. While many of these issues change over time, one in particular seems to endure the test of time … the need for faster results. Law enforcement wants and needs quicker response times to access critical information required to investigate their cases. One answer to this persistent problem is evolving technology. Technology not only permits a much quicker response than forensic laboratories are currently delivering, it can open the door to solving previously unsolvable cases. Along with applying new technology, an evaluation of current forensic laboratory product lines, service delivery models, and mindset regarding the role of forensic science-based investigative leads (termed forensic leads) is warranted. Resources and strategic planning are needed to realize the full potential of evolving technologies and what forensic laboratories can do to provide actionable and timely forensic leads to our criminal justice partners as a normal course of action instead of as an exception. This proposal is to establish a permanent, designated Forensic Lead Program (FLP) that resides under the umbrella of an accredited forensic laboratory and is tasked with the development and release of forensic leads. The FLP involves a focused menu of services, defined personnel roles, strict protocols, short turnaround time, standardized expectations, and targeted training, combined with the sense of urgency needed for consistent delivery of timely and actionable forensic leads. A dedicated FLP will save time and money by providing critical information for more focused investigations. 'Speed is the need' … for quick identification of those that threaten public safety and for the equally quick elimination of those wrongfully accused. Programs at two large state forensic laboratories will demonstrate how these concepts could be implemented along with their learning experiences. A business case will also be included to demonstrate the cost benefit of the Forensic Lead Program for DNA (CODIS - Combined DNA Index System) and NIBIN (National Integrated Ballistic Information Network), however other section services are expected to see similar benefits. Improving the response time by one day saves $1677.75 per $1 spent [1]. The return on investment (ROI) for applying DNA to firearms evidence returns $47.88 per $1 spent, or an 4,788 % ROI. Applying NIBIN (National Integrated Ballistic Information Network) to firearms evidence to provide investigative leads is $502.19 per $1 spent, which is a 50,219 % ROI. Recasting the forensic laboratory product line and service delivery model to 'Lead with Speed' makes both economic and investigative sense.

Eudistomins Y-Inspired Design and Divergent Optimization of Heteroaryl Ketones for New Antifungal Leads.

The discovery of structurally distinct leads is imperative in modern agrochemical science. Inspired by eudistomins Y and the framework-related pharmaceuticals, aryl heteroaryl ketone was drawn as a common model intriguing the design and divergent synthesis of 14 kinds of heteroaryl ketones aligned with their oxime derivatives. Antifungal function-oriented phenotypical screen protruded benzothiazolyl-phenyl oxime 5a as a promising model, and the concomitant modification led to benzothiazolyl oxime 5am (EC50 = 5.17 µM) as a superior lead than fluoxastrobin (EC50 = 7.54 µM) against Sclerotinia sclerotiorum. Scaffold hopping of the phenyl subunit identified benzothiazolyl-pyridyl oxime as a novel antifungal scaffold accompanied by acquiring oxime 5bm with remarkable activity (EC50 = 3.57 µM) against Pyricularia oryzae. Molecular docking showed that candidate 5am could form more hydrogen bonds with the amino acid residues of actin than metrafenone. This compound also demonstrated better curative efficacy than that of fluoxastrobin and metrafenone in controlling the plant disease caused by S. sclerotiorum. These results rationalize the discovery of antifungal candidates based on aryl heteroaryl ketone.

Lead Break during Extraction: Predisposing Factors and Impact on Procedure Complexity and Outcome: Analysis of 3825 Procedures.

Background: Currently, there are no reports describing lead break (LB) during transvenous lead extraction (TLE). Methods: This study conducted a retrospective analysis of 3825 consecutive TLEs using mechanical sheaths. Results: Fracture of the lead, defined as LB, with a long lead fragment (LF) occurred in 2.48%, LB with a short LF in 1.20%, LB with the tip of the lead in 1.78%, and LB with loss of a free-floating LF in 0.57% of cases. In total, extractions with LB occurred in 6.04% of the cases studied. In cases in which the lead remnant comprises more than the tip only, there was a 50.31% chance of removing the lead fragment in its entirety and an 18.41% chance of significantly reducing its length (to less than 4 cm). Risk factors for LB are similar to those for major complications and increased procedure complexity, including long lead dwell time [OR = 1.018], a higher LV ejection fraction, multiple previous CIED-related procedures, and the extraction of passive fixation leads. The LECOM and LED scores also exhibit a high predictive value. All forms of LB were associated with increased procedure complexity and major complications (9.96 vs. 1.53%). There was no incidence of procedure-related death among such patients, and LB did not affect the survival statistics after TLE. Conclusions: LB during TLE occurs in 6.04% of procedures, and this predictable difficulty increases procedure complexity and the risk of major complications. Thus, the possibility of LB should be taken into account when planning the lead extraction strategy and its associated training.

Accurate detection of lead malfunction from ECG-derived bipolar pacing stimulus amplitude.

BACKGROUND: One common mode of lead failure is insulation breach, which may result in myopotential noise and device malfunction. "Pseudo-unipolarization" of bipolar pacing stimuli, as observed from a routine 12-lead electrocardiogram (ECG) due to stimulus current leak, has been observed with insulation breaches. OBJECTIVE: We sought to characterize this electrocardiographic finding to detect this type of lead malfunction. METHODS: A total of 138 transvenous leads were analyzed, including 88 with known malfunction and 50 normal leads. The amplitude of a bipolar pacing stimulus on the ECG was recorded and compared with a control data set of newly implanted leads with bipolar stimuli normalized for output. RESULTS: The malfunction group consisted of 61% right atrium and 39% right ventricle leads with mean pacing output of 2.74 V at 0.5 ms. There was a significant difference in ECG bipolar stimulus amplitudes at time of identification of failure (7.89 ± 7.56 mm/V; P < .001) compared with those of normal leads (0.86 ± 0.41 mm/V). Receiver operating characteristic curve for the prediction of lead malfunction based on absolute ECG amplitude displayed an area under the curve of 0.93 (95% CI, 0.891-0.969). When normalized for programmed stimulus output, a cutoff of 5 mm/V demonstrated a sensitivity of 91% and a specificity of 92% (area under the curve, 0.967; 95% CI, 0.938-0.996). CONCLUSION: The maximum amplitude of a bipolar pacing stimulus on the ECG is significantly lower in normal functioning leads compared with those with known malfunction. This simply derived variable demonstrated good accuracy at identifying lead failure due to insulation breach.

Tall R waves across the precordial leads.

We here present a case of tall R waves in V1-V3, with normal R waves in V4-V6, due to a rare clinical entity. The differential diagnosis of such condition is reviewed. ECG clues are provided to guide the diagnosis. A simple diagnostic test is ordered to confirm the diagnosis.

Safety of intracranial electrodes in an MRI environment: a technical report.

INTRODUCTION: Intracranial electroencephalography (iEEG) involves placing intracranial electrodes to localise seizures in patients with medically refractory epilepsy. While magnetic resonance imaging (MRI) enables visualisation of electrodes within patient-specific anatomy, the safety of these electrodes must be confirmed prior to routine clinical utilisation. Therefore, the purpose of this study was to evaluate the safety of iEEG electrodes from a particular manufacturer in a 3.0-Tesla (3.0T) MRI environment. METHODS: Measurements of magnetically induced displacement force and torque were determined for each of the 10 test articles using standardised techniques. Test articles were subsequently evaluated for radiofrequency-induced heating using a Perspex phantom in both open and 'fault' conditions. Additionally, we assessed radiofrequency (RF)-induced heating with all test articles placed into the phantom simultaneously to simulate an implantation, again in both open and 'fault' conditions. Finally, each test article was evaluated for MRI artefacts. RESULTS: The magnetically induced displacement force was found to be less than the force on the article due to gravity for all test articles. Similarly, the maximum magnetically induced torque was less than the worst-case torque due to gravity for all test articles apart from the 8-contact strip - for which it was 11% greater - and the depthalon cap. The maximum temperature change for any portion of any test article assessed individually was 1.7°C, or 1.2°C for any device component meant to be implanted intracranially. In the implantation configuration, the maximum recorded temperature change was 0.7°C. CONCLUSIONS: MRI may be safely performed for localising iEEG electrodes at 3.0T under certain conditions.

Optimization of Using Multiple Machine Learning Approaches in Atrial Fibrillation Detection Based on a Large-Scale Data Set of 12-Lead Electrocardiograms: Cross-Sectional Study.

BACKGROUND: Atrial fibrillation (AF) represents a hazardous cardiac arrhythmia that significantly elevates the risk of stroke and heart failure. Despite its severity, its diagnosis largely relies on the proficiency of health care professionals. At present, the real-time identification of paroxysmal AF is hindered by the lack of automated techniques. Consequently, a highly effective machine learning algorithm specifically designed for AF detection could offer substantial clinical benefits. We hypothesized that machine learning algorithms have the potential to identify and extract features of AF with a high degree of accuracy, given the intricate and distinctive patterns present in electrocardiogram (ECG) recordings of AF. OBJECTIVE: This study aims to develop a clinically valuable machine learning algorithm that can accurately detect AF and compare different leads' performances of AF detection. METHODS: We used 12-lead ECG recordings sourced from the 2020 PhysioNet Challenge data sets. The Welch method was used to extract power spectral features of the 12-lead ECGs within a frequency range of 0.083 to 24.92 Hz. Subsequently, various machine learning techniques were evaluated and optimized to classify sinus rhythm (SR) and AF based on these power spectral features. Furthermore, we compared the effects of different frequency subbands and different lead selections on machine learning performances. RESULTS: The light gradient boosting machine (LightGBM) was found to be the most effective in classifying AF and SR, achieving an average F1-score of 0.988 across all ECG leads. Among the frequency subbands, the 0.083 to 4.92 Hz range yielded the highest F1-score of 0.985. In interlead comparisons, aVR had the highest performance (F1=0.993), with minimal differences observed between leads. CONCLUSIONS: In conclusion, this study successfully used machine learning methodologies, particularly the LightGBM model, to differentiate SR and AF based on power spectral features derived from 12-lead ECGs. The performance marked by an average F1-score of 0.988 and minimal interlead variation underscores the potential of machine learning algorithms to bolster real-time AF detection. This advancement could significantly improve patient care in intensive care units as well as facilitate remote monitoring through wearable devices, ultimately enhancing clinical outcomes.

12-Lead ECG Reconstruction Based on Data From the First Limb Lead.

PURPOSE: Electrocardiogram (ECG) data obtained from 12 leads are the most common and informative source for analyzing the cardiovascular system's (CVS) condition in medical practice. However, the large number of electrodes, specific placements on the body, and the need for specialized equipment make the ECG acquisition procedure complex and cumbersome. This raises the challenge of reducing the number of ECG leads by reconstructing missing leads based on available data. METHODS: Most existing methods for reconstructing missing ECG leads rely on utilizing signals simultaneously from multiple known leads. This study proposes a method for reconstructing ECG data in 12 leads using signal data from the first lead, lead I. Such an approach can significantly simplify the ECG registration procedure. The study demonstrates the effectiveness of using unique models with a developed architecture of artificial neural networks (ANNs) to generate the reconstructed ECG signals. Fragments of ECG from lead I, with a duration of 128 samples and a sampling frequency of 100 Hz, are input to the models. ECG fragments can be extracted from the original signal at arbitrary time points. Each model generates an ECG signal of the same length at its output for the corresponding lead. RESULTS: Despite existing limitations, the proposed method surpasses known solutions regarding ECG generation quality when using a single lead. The study shows that introducing an additional feature of the direction of the electrical axis of the heart (EAH) as input to the ANN models enhances the generation quality. The quality of ECG generation by the proposed ANN models is found to be dependent on the presence of CVS diseases. CONCLUSIONS: The developed ECG reconstruction method holds significant potential for use in portable registration devices, screening procedures, and providing support for medical decision-making by healthcare specialists.

Mechanical Behavior of Polyurethane Insulation of CRT Leads in Cardiac Implantable Electronic Devices: A Comparative Analysis of In Vivo Exposure and Residual Properties.

Left ventricle leads are designed for the purpose of long-term pacing in the left ventricle. This study investigated the leads that use polyurethane as an outer insulator and SI-polyimide as an inner insulator. Polyurethane is commonly used for the outer insulation of cardiac leads due to its flexibility and biocompatibility. SI-polyimide (SI-PI) is a high-performance material known for its electrical insulation properties and is used for the inner insulation to maintain the integrity of the electrical pathways within the lead. Ten leads were received from the Wright State University Anatomical Gift Program. The duration of in vivo implantation varied for each lead, from less than a month to 108 months, with an average in vivo duration of 41 ± 31 months. We used the Test Resources Q series system for conducting our tests, as well as samples prepared to ensure compliance with the ASTM Standard D 1708-02a and the ASTM Standard D 412-06a. During the test, the load was applied to the intact lead. Before conducting individual tests, each lead was carefully inspected for surface defects. After conducting the tests, the load to failure, percentage of elongation, percentage of elongation at 5 N, ultimate tensile strength, and modulus of elasticity were calculated. There was no significant difference in load to failure, the percentage of elongation to failure, ultimate tensile strength, and modulus of elasticity (p-value = 0.82, p-value = 0.62, p-value = 0.82, and p-value = 0.12), respectively, when compared to in vivo exposure time. On the other hand, the percentage of elongation at 5 N force showed a significant difference (p-value = 0.0066) after 60 months in an in vivo environment. As the duration of in vivo exposure increased, the load to failure, percentage of elongation, ultimate tensile strength, and modulus of elasticity decreased insignificantly. The residual properties of these left ventricle leads remained relatively stable after 108 months of in vivo exposure duration, with no statistically significant degradation or changes in performance.

The Use of Image Guided Programming to Improve Deep Brain Stimulation Workflows with Directional Leads in Parkinson's Disease.

BACKGROUND: Deep brain stimulation (DBS) of the subthalamic nucleus (STN) is a preferred treatment for parkinsonian patients with severe motor fluctuations. Proper targeting of the STN sensorimotor segment appears to be a crucial factor for success of the procedure. The recent introduction of directional leads theoretically increases stimulation specificity in this challenging area but also requires more precise stimulation parameters. OBJECTIVE: We investigated whether commercially available software for image guided programming (IGP) could maximize the benefits of DBS by informing the clinical standard care (CSC) and improving programming workflows. METHODS: We prospectively analyzed 32 consecutive parkinsonian patients implanted with bilateral directional leads in the STN. Double blind stimulation parameters determined by CSC and IGP were assessed and compared at three months post-surgery. IGP was used to adjust stimulation parameters if further clinical refinement was required. Overall clinical efficacy was evaluated one-year post-surgery. RESULTS: We observed 78% concordance between the two electrode levels selected by the blinded IGP prediction and CSC assessments. In 64% of cases requiring refinement, IGP improved clinical efficacy or reduced mild side effects, predominantly by facilitating the use of directional stimulation (93% of refinements). CONCLUSIONS: The use of image guided programming saves time and assists clinical refinement, which may be beneficial to the clinical standard care for STN-DBS and further improve the outcomes of DBS for PD patients.

General Algorithm Applicability in Determining DBS Lead Orientation: Adapting 2D and 3D X-Ray Techniques for SenSightTM Leads.

INTRODUCTION: With recent advancements in deep brain stimulation (DBS), directional leads featuring segmented contacts have been introduced, allowing for targeted stimulation of specific brain regions. Given that manufacturers employ diverse markers for lead orientation, our investigation focuses on the adaptability of the 2017 techniques proposed by the Cologne research group for lead orientation determination. METHODS: We tailored the two separate 2D and 3D X-ray-based techniques published in 2017 and originally developed for C-shaped markers, to the dual-marker of the Medtronic SenSight™ lead. In a retrospective patient study, we evaluated their feasibility and consistency by comparing the degree of agreement between the two methods. RESULTS: The Bland-Altman plot showed favorable concordance without any noticeable systematic errors. The mean difference was 0.79°, with limits of agreement spanning from 21.4° to -19.8°. The algorithms demonstrated high reliability, evidenced by an intraclass correlation coefficient of 0.99 (p < 0.001). CONCLUSION: The 2D and 3D algorithms, initially formulated for discerning the circular orientation of a C-shaped marker, were adapted to the marker of the Medtronic SenSight™ lead. Statistical analyses revealed a significant level of agreement between the two methods. Our findings highlight the adaptability of these algorithms to different markers, achievable through both low-dose intraoperative 2D X-ray imaging and standard CT imaging.

Directional deep brain stimulation in the management of Parkinson's disease: efficacy and constraints-an analytical appraisal.

Deep brain stimulation (DBS) is a widely employed treatment for Parkinson's disease. However, conventional DBS utilizing ring-shaped leads can often result in undesirable side effects by stimulating nearby brain structures, thus limiting its effectiveness. To address this issue, a novel DBS electrode was developed to allow for directional stimulation, avoiding neighboring structures. This literature review aims to analyze the disparities between conventional and directional DBS and discuss the benefits and limitations associated with this innovative electrode design, focusing on the stimulation-induced side effects it can or cannot mitigate. A comprehensive search was conducted in MEDLINE/PubMed, ScienceDirect, and EBSCO databases using the Boolean search criteria: "Deep brain stimulation" AND "Parkinson" AND "Directional." Following the application of inclusion and exclusion criteria, the selected articles were downloaded for full-text reading. Subsequently, the results were organized and analyzed to compose this article. Numerous studies have demonstrated that directional DBS effectively reduces side effects associated with brain stimulation, prevents the stimulation of non-targeted structures, and expands the therapeutic window, among other advantages. However, it has been observed that directional DBS may be more challenging to program and requires higher energy consumption. Furthermore, there is a lack of standardization among different manufacturers of directional DBS electrodes. Various stimulation-induced side effects, including dysarthria, dyskinesia, paresthesias, and symptoms of pyramidal tract activation, have been shown to be mitigated with the use of directional DBS. Moreover, directional electrodes offer a wider therapeutic window and a reduced incidence of undesired effects, requiring the same or lower minimum current for symptom relief compared to conventional DBS. The utilization of directional leads in DBS offers numerous advantages over conventional electrodes without significant drawbacks for patients undergoing directional DBS therapy.