Predictors of venous obstruction following pacemaker or implantable cardioverter-defibrillator implantation: a contrast venographic study on 100 patients admitted for generator change, lead revision, or device upgrade

Successful left ventricular lead placement by way of an azygos vein for a patient performing cardiac resynchronization therapy implantation with an occluded left subclavian vein: A case report

Central venous obstruction following pacemaker implantation is not uncommon and can prove challenging in the case of a system upgrade to a cardiac resynchronization therapy pacemaker (CRT-P). We describe the case of a patient who underwent a successful upgrading procedure of a pacemaker to a CRT-P in the presence of an occluded left subclavian vein and superior vena cava, using collateral veins that drained into right atrium.

Long-term outcomes with abandoning versus extracting sterile leads: A 10-year population-based study

BACKGROUND

Long-term outcomes of sterile lead management strategies of lead abandonment (LA) or transvenous lead extraction (TLE) remain unclear.

METHODS

We performed a retrospective study of a population residing in southeastern Minnesota with follow-up at the Mayo Clinic and its health systems. Patients who underwent LA or TLE of sterile leads from January 1, 2000, to January 1, 2011, and had follow-up for at least 10 years or until their death were included.

RESULTS

A total of 172 patients were included in the study with 153 patients who underwent LA and 19 who underwent TLE for sterile leads. Indications for subsequent lead extraction arose in 9.1% (n = 14) of patients with initial LA and 5.3% (n = 1) in patients with initial TLE, after an average of 7 years. Moreover, 28.6% of patients in the LA cohort who required subsequent extraction did not proceed with the extraction, and among those who proceeded, 60% had clinical success and 40% had a clinical failure. Subsequent device upgrades or revisions were performed in 18.3% of patients in the LA group and 31.6% in the TLE group, with no significant differences in procedural challenges (5.2% vs. 5.3%). There was no difference in 10-year survival probability among the LA group and the TLE group (p = .64).

CONCLUSION

An initial lead abandonment strategy was associated with more complicated subsequent extraction procedures compared to patients with an initial transvenous lead extraction strategy. However, there was no difference in 10-year survival probability between both lead management approaches.

Multilevel Venous Obstruction in Patients with Cardiac Implantable Electronic Devices

Background and Objectives: The nature of multilevel lead-related venous stenosis/occlusion (MLVSO) and its influence on transvenous lead extraction (TLE) as well as long-term survival remains poorly understood. Materials and Methods: A total of 3002 venograms obtained before a TLE were analyzed to identify the risk factors for MLVSO, as well as the procedure effectiveness and long-term survival. Results: An older patient age at the first system implantation (OR = 1.015; p < 0.001), the number of leads in the heart (OR = 1.556; p < 0.001), the placement of the coronary sinus (CS) lead (OR = 1.270; p = 0.027), leads on both sides of the chest (OR = 7.203; p < 0.001), and a previous device upgrade or downgrade with lead abandonment (OR = 2.298; p < 0.001) were the strongest predictors of MLVSO. Conclusions: The presence of MLVSO predisposes patients with cardiac implantable electronic devices (CIED) to the development of infectious complications. Patients with multiple narrowed veins are likely to undergo longer and more complex procedures with complications, and the rates of clinical and procedural success are lower in this group. Long-term survival after a TLE is similar in patients with MLVSO and those without venous obstruction. MLVSO probably better depicts the severity of global venous obstruction than the degree of vein narrowing at only one point.

Leadless epicardial pacing at the left ventricular apex: an animal study

AIMS

State-of-the-art pacemaker implantation technique in infants and small children consists of pace/sense electrodes attached to the epicardium and a pulse generator in the abdominal wall with a significant rate of dysfunction during growth, mostly attributable to lead failure. In order to overcome lead-related problems, feasibility of epicardial implantation of a leadless pacemaker at the left ventricular apex in a growing animal model was studied.

METHODS AND RESULTS

Ten lambs (median body weight 26.8 kg) underwent epicardial implantation of a Micra transcatheter pacing system (TPS) pacemaker (Medtronic Inc., Minneapolis, USA). Using a subxyphoid access, the Micra was introduced through a short, thick-walled tube to increase tissue contact and to prevent tilting from the epicardial surface. The Micra's proprietary delivery system was firmly pressed against the heart, while the Micra was pushed forward out of the sheath allowing the tines to stick into the left ventricular apical epimyocardium. Pacemakers were programmed to VVI 30/min mode. Pacemaker function and integrity was followed for 4 months after implantation. After implantation, median intrinsic R-wave amplitude was 5 mV [interquartile range (IQR) 2.8-7.5], and median pacing impedance was 2235 Ω (IQR 1725-2500), while the median pacing threshold was 2.13 V (IQR 1.25-2.9) at 0.24 ms. During follow-up, 6/10 animals had a significant increase in pacing threshold with loss of capture at maximum output at 0.24 ms in 2/10 animals. After 4 months, median R-wave amplitude had dropped to 2.25 mV (IQR 1.2-3.6), median pacing impedance had decreased to 595 Ω (IQR 575-645), and median pacing threshold had increased to 3.3 V (IQR 1.8-4.5) at 0.24 ms. Explantation of one device revealed deep penetration of the Micra device into the myocardium.

CONCLUSION

Short-term results after epicardial implantation of the Micra TPS at the left ventricular apex in lambs were satisfying. During mid-term follow-up, however, pacing thresholds increased, resulting in loss of capture in 2/10 animals. Penetration of one device into the myocardium was of concern. The concept of epicardial leadless pacing seems very attractive, and the current shape of the Micra TPS makes the device unsuitable for epicardial placement in growing organisms.

Incidence, Treatment, and Outcomes of Symptomatic Device Lead-Related Venous Obstruction

BACKGROUND

The incidence and clinical impact of lead-related venous obstruction (LRVO) among patients with cardiovascular implantable electronic devices (CIEDs) is poorly defined.

OBJECTIVES

The objectives of this study were to determine the incidence of symptomatic LRVO after CIED implant; describe patterns in CIED extraction and revascularization; and quantify LRVO-related health care utilization based on each type of intervention.

METHODS

LRVO status was defined among Medicare beneficiaries after CIED implant from October 1, 2015, to December 31, 2020. Cumulative incidence functions of LRVO were estimated by Fine-Gray methods. LRVO predictors were identified using Cox regression. Incidence rates for LRVO-related health care visits were calculated with Poisson models.

RESULTS

Among 649,524 patients who underwent CIED implant, 28,214 developed LRVO, with 5.0% cumulative incidence at maximum follow-up of 5.2 years. Independent predictors of LRVO included CIEDs with >1 lead (HR: 1.09; 95% CI: 1.07-1.15), chronic kidney disease (HR: 1.17; 95% CI: 1.14-1.20), and malignancies (HR: 1.23; 95% CI: 1.20-1.27). Most patients with LRVO (85.2%) were managed conservatively. Among 4,186 (14.8%) patients undergoing intervention, 74.0% underwent CIED extraction and 26.0% percutaneous revascularization. Notably, 90% of the patients did not receive another CIED after extraction, with low use (2.2%) of leadless pacemakers. In adjusted models, extraction was associated with significant reductions in LRVO-related health care utilization (adjusted rate ratio: 0.58; 95% CI: 0.52-0.66) compared with conservative management.

CONCLUSIONS

In a large nationwide sample, the incidence of LRVO was substantial, affecting 1 of every 20 patients with CIEDs. Device extraction was the most common intervention and was associated with long-term reduction in recurrent health care utilization.

Prevalence, management, and prediction of venous access site occlusion in patients undergoing lead revision surgery

BACKGROUND

Implantable electronic cardiac devices (CIED) have emerged as an essential component in the treatment of cardiac arrhythmias and heart failure. Due to increased life expectancy, expanding indications and limited technical survival, an increasing number of revision procedures can be anticipated. Venous access site occlusion (VASO) is the main obstacle during revision surgery. In this retrospective study we evaluated the prevalence, predictive parameters and operative management of venous access site occlusion.

METHODS AND RESULTS

Between 01/2016 and 12/2020 304 patients underwent lead revision surgery of transvenous CIED in our department. Prevalence of VASO was 25.7% (n = 78), one patient was symptomatic. Independent predicting clinical parameters were male sex (2.86 (1.39-5.87), p < 0.01) and lead age (1.11 (1.05-1.18), p < 0.01)). Revision surgery despite VASO was successful in 97.4% (n = 76) without prolongation of the total surgery time or higher complication rates. Yet, lead extraction was possible in 92% of patients with VASO vs. 98.2% of patients without VASO (p 0.01).

CONCLUSION

VASO is a frequent condition in patients undergoing lead revision surgery, but successful revision is feasible in most cases without preceding lead extraction. However, the lower success rates of lead extractions may be prognostically relevant, especially for younger patients.

Electrical Stimulation for Low-Energy Termination of Cardiac Arrhythmias: a Review

Cardiac arrhythmias are a leading cause of morbidity and mortality in the developed world, estimated to be responsible for hundreds of thousands of deaths annually. Our understanding of the electrophysiological mechanisms of such arrhythmias has grown since they were formally characterized in the late nineteenth century, and this has led to the development of numerous devices and therapies that have markedly improved outcomes for patients affected by such conditions. Despite these advancements, the application of a single large shock remains the clinical standard for treating deadly tachyarrhythmias. Such defibrillating shocks are undoubtedly effective in terminating such arrhythmias; however, they are applied without forewarning, contributing to the patient's stress and anxiety; they can be intensely painful; and they can have adverse psychological and physiological effects on patients. In recent years, there has been interest in developing defibrillation protocols that can terminate arrhythmias without crossing the human pain threshold for energy delivery, generally estimated to be between 0.1 and 1 J. In this article, we review existing literature on the development of such low-energy defibrillation methods and their underlying mechanisms, in an attempt to broadly describe the current landscape of these technologies.

Leadless Cardiac Pacing: New Horizons

Since the introduction of transvenous cardiac pacing leads, pacemaker system design has remained similar for several decades. Progressive miniaturisation of electronic circuitry and batteries has enabled a smaller, single pacing unit comprising the intracardiac electrodes, generator and computer. This review explores the development of leadless pacing, the clinical trials comparing leadless to transvenous pacing in addition to the future developments of multi-chamber leadless pacing.

Retrograde venography to navigate an occluded subclavian vein to achieve cardiac resynchronization therapy upgrade via His bundle pacing: a case report

Background

Guidelines support upgrade to cardiac resynchronization therapy (CRT) through His-bundle pacing (HBP) in pacing-induced cardiomyopathy and moderate left ventricular systolic dysfunction (LVSD). Lead-related venous occlusion can represent an obstacle to upgrade procedures. We describe a technique to overcome venous occlusion through direct puncture of a collateral vein facilitating upgrade to HBP.

Case summary

An 84-year-old man with a right ventricular (RV) pacemaker was referred with New York Heart Association (NYHA) Class III breathlessness secondary to moderate LVSD (left ventricular ejection fraction [LVEF] 45%). Device interrogation revealed 100% RV pacing and AV-dyssynchrony. To optimize atrioventricular (AV) and interventricular (VV) synchrony a CRT upgrade with HBP was planned. Venography revealed an occluded left subclavian vein which was probed in a retrograde manner using a 6F MPA catheter from right femoral venous access. We were able to direct the catheter distal to the left brachio-cephalic vein and define the occlusion using contrast. A collateral branch was identified, a J-wire was left in this branch and venous access was secured at this medial subclavian site using the Seldinger technique. A right atrial lead was deployed and 69 cm ISI-1 His lead was deployed via a C315 sheath at the His-bundle. The resulted in non-selective HBP (Stim-QRS end 146 ms). There were no procedural complications. Two months later both symptoms and LV function (LVEF 55%) improved.

Discussion

Lead-related venous occlusion occurs frequently and can be probed in a retrograde manner from femoral venous access using contrast, facilitating direct percutaneous puncture of collateral venous branches to allow upgrade to CRT via HBP.

Severity and Extent of Lead-Related Venous Obstruction in More Than 3000 Patients Undergoing Transvenous Lead Extraction

Background

Lead-related venous stenosis/obstruction (LRVSO) may be a major challenge in patients with cardiac implantable electronic devices (CIED) when device upgrade, insertion of central lines, or creation of an arteriovenous fistula for hemodialysis is indicated. The aim of this study was to evaluate the extent and severity of LRVSO.

Methods

We performed a retrospective analysis of 3002 venograms from patients awaiting transvenous lead extraction (TLE) to assess the occurrence, severity, and extent of LRVSO.

Results

Mild LRVSO occurred in 19.9%, moderate in 20.7%, severe in 19.9% and total venous occlusion in 22.5% of the patients. Moderate/severe stenosis or total occlusion of the subclavian and brachiocephalic veins was found in 38.2% and 22.5% of the patients, respectively. LRSVO was not detected in 16.9% of the patients. Moderate and severe superior vena cava (SVC) obstruction and total SVC occlusion were rare (0.4%, 0.3%, and 0.3%, respectively). Lead insertion on the left side of the chest contributed to an increased risk of LRVSO compared to right-sided implantation. Major thoracic veins on the opposite side may be narrowed in varying degrees.

Conclusion

A total of 60% of the patients with pacemaker or high-voltage leads have an advanced form of LRVSO. Any attempt to insert new pacing leads, central lines, venous ports, or catheters for hemodialysis, or to create dialysis fistula on the same side as the existing lead should be preceded by venography. Furthermore, venography may provide useful information, if it is planned to implant the lead or the catheter on the opposite side of the chest.

Transvenous lead extraction in conduction system pacing

Conduction System Pacing (CSP) delivered by His Bundle Pacing (HBP) or Left Bundle Pacing (LBP) are exciting novel interventions in the field of Cardiac Resynchronization Therapy (CRT). As the evidence base for CSP grows, the volume of implants worldwide is projected to rise significantly in the coming years. As such, physicians will be confronted with increasingly prevalent and vital issues arising in long-term follow up, including the management of infected, malfunctioning, or redundant CSP leads. Transvenous lead extraction (TLE) is the first-line option for removal of pacing leads when indicated in these circumstances. The evidence base for TLE in the context of CSP is still in its infancy. In this article, we first provide a brief overview of TLE. We then examine the data on the long-term performance of HBP leads. Next, we describe the features of the Medtronic Select Secure 3,830 lead, and how experience of TLE of this lead in the paediatric population has informed our practice. Finally, we review the current evidence for TLE in HBP and LBP, and discuss how future studies can address gaps in our current knowledge.

Unguided temporary pacing via jugular/subclavian vein in an emergency department of a high-volume tertiary care hospital of India: its safety, efficacy, and practicability

Background

Temporary pacing is usually performed by cardiologists under fluoroscopic, echocardiographic, or ECG guidance. However, in the developing world, there are inadequate number of cardiologists, and C-arm, catheterization laboratories, or echocardiography are not available at primary or secondary healthcare facilities. In addition, in emergencies option of fluoroscopy and echocardiography is limited. So these patients are transferred to a facility where cardiologists and these facilities are available. Crucial time is lost in transit, which leads to increased mortality. In this study, we aimed to evaluate the safety, efficacy, and practicability of unguided temporary pacemaker insertion.

Results

A total of 1093 patients were enrolled in this study. After cannulating the internal jugular vein or subclavian vein, the pacing lead attached to the pulse generator was advanced blindly till ventricular pacing was achieved. Procedural success was taken as the primary endpoint. Secondary endpoints included the number of attempts taken for successful central venous puncture and procedural time. Complications and mortality were assessed for safety outcomes. Finally, the position of the pacing lead was assessed after the procedure on X-ray or fluoroscopy. The procedure was successful in all but one patient in whom a femoral vein approach was required because of brachiocephalic vein obstruction. Right internal jugular access was achieved in 981 (89.75%) patients. The mean number of attempts taken for achieving successful venous accesses was 1.54 ± 0.85; however, in 726 (66.42%) patients it was achieved in the first attempt. The mean procedural time was 11.5 ± 2.1 min. Overall, 117 (10.70%) patients developed complications; however, most of them were minor. Pneumothorax developed in 12 (1.1%) patients, of whom 2 needed an intercostal tube. Pericardial effusion was seen in 21 (1.92%) patients. Pacing lead tip was located in the right ventricular cavity abutting interventricular septum or free wall in 843 (77.20%) patients. No mortality attributable to procedure occurred.

Conclusions

Unguided temporary pacing via jugular or subclavian venous approach in an emergency setting is possible with high success and a low complication rate. Thus, it is a safe and effective procedure, and clinicians working at primary and secondary healthcare levels should be encouraged to perform this procedure.

Trial registration UMIN Clinical Trials Registry, UMIN000046771. Registered 28 January 2022—Retrospectively registered, https://center6.umin.ac.jp/cgi-open-bin/ctr_e/ctr_view.cgi?recptno=R000053348

New Insights in Central Venous Disorders. The Role of Transvenous Lead Extractions

Over the last decades, the implementation of new technology in cardiac pacemakers and defibrillators as well as the increasing life expectancy have been associated with a higher incidence of transvenous lead complications over time. Variable degrees of venous stenosis at the level of the subclavian vein, the innominate trunk and the superior vena cava are reported in up to 50% of implanted patients. Importantly, the number of implanted leads seems to be the main risk factor for such complications. Extraction of abandoned or dysfunctional leads is a potential solution to overcome venous stenosis in case of device upgrades requiring additional leads, but also, in addition to venous angioplasty and stenting, to reduce symptoms related to the venous stenosis itself, i.e., the superior vena cava syndrome. This review explores the role of transvenous lead extraction procedures as therapeutical option in case of central venous disorders related to transvenous cardiac leads. We also describe the different extraction techniques available and other clinical indications for lead extractions such as lead infections. Finally, we discuss the alternative therapeutic options for cardiac stimulation or defibrillation in case of chronic venous occlusions that preclude the implant of conventional transvenous cardiac devices.

Should they stay, or should they go: do we need to remove the old cardiac implantable electronic device if a new system is required on the contralateral side?

Background

Ipsilateral approach in patients requiring cardiac implantable electronic device (CIED) revision or upgrade may not be feasible, primarily due to vascular occlusion. If a new CIED is implanted on the contralateral side, a common practice is to explant the old CIED to avoid device interaction.

Objective

The purpose of this study was to assess a conservative approach of abandoning the old CIED after implanting a new contralateral device.

Methods

We used an artificial intelligence algorithm to analyze postimplant chest radiographs to identify those with multiple CIEDs. Outcomes of interest included device interaction, abandoned CIED elective replacement indicator (ERI) behavior, subsequent programming changes, and explant of abandoned CIED. Theoretical risk of infection with removal of abandoned CIED was estimated using a validated scoring system.

Results

Among 12,045 patients, we identified 40 patients with multiple CIEDs. Occluded veins were the most common indication for contralateral implantation (n = 27 [67.5%]). Fifteen abandoned CIEDs reached ERI, with 4 reverting to VVI 65. One patient underwent explant due to device interaction, and 2 required device reprogramming. Of 32 patients with an implantable cardioverter-defibrillator, 8 (25%) had treated ventricular arrhythmia. There were no failed or inappropriate therapies due to interaction. Eighteen patients (45%) had hypothetical >1% annual risk of hospitalization for device infection if the abandoned CIED had been explanted.

Conclusion

In patients requiring new CIED implant on the contralateral side, abandoning the old device is feasible. This approach may reduce the risk of infection and concerns regarding abandoned leads and magnetic resonance imaging scans. Knowledge of ERI behavior is essential to avoid device interactions.

Emerging Technologies in Electrophysiology: From Single Chamber to Biventricular Leadless Pacemakers

BACKGROUND

Transvenous pacemakers have been shown to improve quality of life and mortality in patients with bradycardia and cardiac conduction blocks. However, they possess inevitable drawbacks as they have a relatively high incidence of lead and device pocket-related complications. Therefore, leadless pacemakers have emerged as a solution to reduce the complications seen with conventional pacemakers. However, there have been no clinical trials to date comparing transvenous to leadless pacemakers.

SUMMARY

Currently, the Micra TPS or AV device has been approved for commercial use worldwide but is limited to single-chamber pacing with single or dual-chamber sensing. Although the leadless pacemaker, Nanostim, was initially promising, it has been recalled due to concerns of battery failures and is no longer approved in Europe. In addition, the lack of defibrillation capabilities with leadless pacemakers has been a limiting factor; therefore, a leadless pacemaker with the already approved subcutaneous cardioverter-defibrillator system is currently being studied in humans. Moreover, the WiSE-CRT device has been approved in Europe, with the capabilities for leadless cardiac resynchronization therapy (CRT), to provide CRT for patients with unsuitable coronary sinus anatomy. Furthermore, retrieval of leadless pacemakers has been an area of concern; however, clinic data has signaled towards safe extraction of these devices with minimal complications. Key messages: This review will encompass the current literature regarding clinical safety and outcomes of these novel leadless pacemakers and discuss the evolving technologies in the field of cardiac pacing.

Risk Factors for Lead-Related Venous Obstruction: A Study of 2909 Candidates for Lead Extraction

Background: our knowledge of lead-related venous stenosis/occlusion (LRVSO) remains limited and there is still controversy regarding the risk factors for LRVSO. Venography is mandatory before transvenous lead extraction (TLE). Methods: we performed a retrospective analysis of venograms in 2909 patients (39.43% females, average age 66.90 years) who underwent TLE between 2008 and 2021 at high-volume centers. Results: the severity of LRVSO was likely to be dependent on the number of leads in the system (OR = 1.345; p = 0.003), the number of abandoned leads (OR = 1.965; p < 0.001), the presence of coronary sinus leads (OR = 1.184; p = 0.056), male gender (OR = 1.349; p = 0.003) and patient age at first CIED implantation (OR = 1.008; p = 0.021). The presence of permanent atrial fibrillation (OR = 0.666; p < 0.001) and right ventricular diastolic diameter (OR = 0.978; p = 0.006) showed an inverse correlation with the degree of LRVSO. The combined three-model multivariate analysis provided better prediction of LRSVO using the above-mentioned factors than the CHA2DS2-VASc score. Conclusions: the severity of LRVSO is probably dependent on the mechanical impact of the implanted/abandoned leads on the vein wall, therefore the study has demonstrated the central role of system-/procedure-related risk factors. The thrombotic mechanism may be less important, especially long after implantation, and for this reason the combined prediction model for LRVSO in this study was more effective than the CHA2DS2-VASc score.

The Influence of Lead-Related Venous Obstruction on the Complexity and Outcomes of Transvenous Lead Extraction

Background: Little is known about lead-related venous stenosis/occlusion (LRVSO), and the influence of LRVSO on the complexity and outcomes of transvenous lead extraction (TLE) is debated in the literature. Methods: We performed a retrospective analysis of venograms from 2909 patients who underwent TLE between 2008 and 2021 at a high-volume center. Results: Advanced LRVSO was more common in elderly men with a high Charlson comorbidity index. Procedure duration, extraction of superfluous leads, occurrence of any technical difficulty, lead-to-lead binding, fracture of the lead being extracted, need to use alternative approach and lasso catheters or metal sheaths were found to be associated with LRVSO. The presence of LRVSO had no impact on the number of major complications including TLE-related tricuspid valve damage. The achievement of complete procedural or clinical success did not depend on the presence of LRVSO. Long-term mortality, in contrast to periprocedural and short-term mortality, was significantly worse in the groups with LRSVO. Conclusions: LRVSO can be considered as an additional TLE-related risk factor. The effect of LRVSO on major complications including periprocedural mortality and on short-term mortality has not been established. However, LRVSO has been associated with poor long-term survival.

Upper Extremity Deep Vein Thrombosis and Asymptomatic Vein Occlusion in Patients With Transvenous Leads: A Systematic Review and Meta-Analysis

Aims: The presence of transvenous leads for cardiac device therapy may increase the risk of venous thromboembolisms. The epidemiology of these complications has not yet been determined systematically. Therefore, this study aims to determine (I) the incidence of symptomatic upper extremity deep vein thrombosis (UEDVT) and (II) the prevalence of asymptomatic upper extremity vein occlusion in patients with transvenous leads, both after the initial 2 months following lead implantation.

Methods: PubMed, EMBASE, and Cochrane Library were searched until March 31, 2020 to identify studies reporting incidence of UEDVT and prevalence of asymptomatic vein occlusion after the initial 2 months after implantation in adult patients with transvenous leads. Incidence per 100 patient years of follow-up (PY) and proportions (%) were calculated to derive pooled estimates of incidence and prevalence.

Results: Search and selection yielded 20 and 24 studies reporting on UEDVT and asymptomatic vein occlusion, respectively. The overall pooled incidence of UEDVT was 0.9 (95% CI 0.5–1.4) per 100PY after 2 months after lead implantation. High statistical heterogeneity was present among studies (I² = 82.4%; P = < 0.001) and only three studies considered to be at low risk of bias. The overall pooled prevalence of asymptomatic upper extremity vein occlusion was 8.6% (95% CI 6.0–11.5) with high heterogeneity (I² = 81.4%; P = <0.001). Meta-regression analysis showed more leads to be associated with a higher risk of UEDVT.

Conclusion: Transvenous leads are an important risk factor for symptomatic UEDVT, which may occur up to multiple years after initial lead implantation. Existing data on UEDVT after lead implantation is mostly of poor quality, which emphasizes the need for high quality prospective research. Asymptomatic vein occlusion is present in a substantial proportion of patients and may complicate any future lead addition.

Clinical Trial Registration: (URL: https://www.crd.york.ac.uk/prospero/display_record.php?ID=CRD42020178136, Identifier: PROSPERO 2020 CRD42020178136).

Avoiding implant complications in cardiac implantable electronic devices: what works?

Nearly one in ten patients experience complications in relation to cardiac implantable electronic device (CIED) implantations. CIED complications have serious implications for the patients and for the healthcare system. In light of the rising rates of new implants and consistent rate of complications, primary prevention remains a major concern. To guide future efforts, we sought to review the evidence base underlying common preventive actions made during a primary CIED implantation.

"Retained wire femoral lead removal and fibroplasty" for obtaining venous access in patients with refractory venous obstruction

BACKGROUND

Patients with wire and catheter refractory venous occlusion are traditionally referred for pectoral transvenous lead extraction (TLE) to obtain venous access. TLE causes 1-2 mm circumferential mechanical or laser destruction of tissue surrounding the lead(s). This not only exposes the patient to the risk of major complications but also can damage nontargeted leads. We present a series of patients where retained wire femoral lead removal and fibroplasty was used to obtain venous access in patients with refractory obstruction.

METHODS

Between 2008 and 2021, we identified 17 patients where retained wire lead removal followed by fibroplasty was used to retain venous access. Demographic and procedural data were obtained by retrospective review of patient charts.

RESULTS

We were able to successfully obtain venous access in all 17 patients in whom this technique was attempted. In two patients the target lead was less than or equal to 1 year old. In the remaining 15 patients, the average dwell time of the target lead(s) was 6 years. There were no procedure-related complications, and no changes in the parameters of other leads were noted.

CONCLUSION

Retained wire femoral lead removal and fibroplasty is safe and highly efficacious at obtaining venous access in patients with refractory venous occlusion. If the target lead(s) is less than or equal to 1 year old, this technique can help obtain venous access at the time of the initial surgery, hence avoiding the need for TLE. Furthermore, in patients referred for TLE to obtain venous access, this technique by avoiding the use of TLE tools spares the patient of the associated risks.

Lead Abandonment and Subcutaneous Implantable Cardioverter-Defibrillator (S-ICD) Implantation in a Cohort of Patients With ICD Lead Malfunction

Background: When an implantable-cardioverter defibrillator (ICD) lead becomes non-functional, a recommendation currently exists for either lead abandonment or removal. Lead abandonment and subcutaneous ICD (S-ICD) implantation may represent an additional option for patients who do not require pacing. The aim of this study was to investigate the outcomes of a strategy of lead abandonment and S-ICD implantation in the setting of lead malfunction.

Methods: We analyzed all consecutive patients who underwent S-ICD implantation after abandonment of malfunctioning leads and compared their outcomes with those of patients who underwent extraction and subsequent reimplantation of a single-chamber transvenous ICD (T-ICD).

Results: Forty-three patients underwent S-ICD implantation after abandonment of malfunctioning leads, while 62 patients underwent extraction and subsequent reimplantation of a new T-ICD. The two groups were comparable. In the extraction group, no major complications occurred during extraction, while the procedure failed and an S-ICD was implanted in 4 patients. During a median follow-up of 21 months, 3 major complications or deaths occurred in the S-ICD group and 11 in the T-ICD group (HR 1.07; 95% CI 0.29–3.94; P = 0.912). Minor complications were 4 in the S-ICD group and 5 in the T-ICD group (HR 2.13; 95% CI 0.49–9.24; P = 0.238).

Conclusions: In the event of ICD lead malfunction, extraction avoids the potential long-term risks of abandoned leads. Nonetheless the strategy of lead abandonment and S-ICD implantation was feasible and safe, with no significant increase in adverse outcomes, and may represent an option in selected clinical settings. Further studies are needed to fully understand the potential risks of lead abandonment.

Clinical Trial Registration: URL: ClinicalTrials.gov Identifier: NCT02275637

Factors influencing the use of leadless or transvenous pacemakers: results of the European Heart Rhythm Association Prospective Survey

To study the proportion of leadless pacemaker (LL-PM) implants and the factors influencing the choice of LL-PM vs. transvenous pacemaker (TV-PM) across tertiary centres in Europe with routine availability of the LL-PM. A European Heart Rhythm Association (EHRA) prospective snapshot survey using electronically distributed questionnaire sent to participating centres. Participating tertiary cardiac pacing centres prospectively included consecutive patients implanted between November 2018 and January 2019. Questions covered standards of care and policies used for patient management, focusing particularly on the reasons for choosing LL-PM vs. TV-PM. Overall, 21 centres from four countries (France, Netherlands, Spain, and Italy) participated, with eventual data from 798 patients (n = 472, 59% male). With 69 implants, LL-PM represented only 9% of all implants and 36% of the single-chamber pacing group; double-chamber transvenous pacemakers were implanted in 528 patients and biventricular (cardiac resynchronization pacemaker) in 79. The two major reasons reported in favour of LL-PM implantation were an anticipated high risk of infection or low rate of ventricular pacing. Compared to TV-PM, LL-PM patients were more often male (74% vs. 54%, P = 0.009), with greater proportion of valvular heart disease (45% vs. 35%, P = 0.01) and atrial fibrillation (AF; 65% vs. 23%, P < 0.0001), with significantly more comorbidities (≥ one comorbidity, 66% vs. 52%, P = 0.02). This contemporary multicentre European survey shows that LL-PM constitutes a small proportion of all PM implants. Patients implanted with LL-PM were more likely to have AF and a high anticipated risk of infection.

Long-term incidence of upper extremity venous obstruction in implantable cardioverter defibrillator patients

BACKGROUND

Very little is known about the long-term prevalence of severe venous obstruction and occlusion in patients with transvenous implantable cardioverter-defibrillator leads. The objective of the current investigation was to elucidate the incidence and prevalence and to identify predisposing conditions in an ICD cohort over a long follow-up period.

METHODS

Based on a prospective database, we analyzed consecutive patients who received an ICD implantation in our hospital between 06/1988 and 2009 as well as all corresponding follow-up data until 02/2018. Cavographies were used for analysis, and all patients with at least one device replacement and one follow-up cavography were included.

RESULTS

Over a mean follow-up period of 94 ± 50 months, severe venous obstruction was found in 147 (33%) of 448 patients. Kaplan-Meier analysis shows a severe obstruction or occlusion in 50% of patients after a period of 14.3 years. The total number of leads (p < .001, HR 2.01, CI 2.000-2.022), an advanced age (p = .004, HR 1.023 per year, CI 1.022-1.024) and the presence of dilated cardiomyopathy (p = .035, HR 1.49, CI 1.47-1.51) were predictive of venous obstruction whereas the presence of anticoagulation was not.

CONCLUSION

Severe obstruction of the access veins after ICD implantation occurs frequently and its prevalence shows a nearly linear increase over long-time follow-up. Multiple leads, an advanced age and DCM as underlying disease are associated with an increased risk of venous obstruction while the role of anticoagulation to prevent venous obstruction in ICD patients is unclear.

Permanent pacemaker implantation in a hemodialysis patient with subclavian vein occlusion using the balloon-target puncture technique

The balloon-target puncture technique is an effective method to secure the subclavian vein access route of cardiovascular implantable electronic devices.

Cardiovascular implantable electronic devices and native arteriovenous fistula in hemodialysis patients: novel perspectives

The benefits from cardiovascular implantable electronic devices (CIED) implantation in hemodialysis (HD) patients are still far to be thoroughly defined, especially on primary prevention. In addition, CIED placement is not a risk-free procedure, because it could be followed by a not negligible burden of complications that could compromise the health and the vascular access of HD patients. In fact, the arteriovenous fistula (AVF) dysfunction following CIED implantation is usually due to a hemodynamically significant alteration of blood flow. This condition could lead to a potential decrease of dialysis efficacy and a raised risk of thrombosis of both the central vein and the efferent vein of the AVF.The pathological pathway that leads to AVF dysfunction after CIED implantation may involve the irritating actions of the CIED and their leads to the vascular wall in HD patients that are more prone to show previous vascular diseases.The aim of this review is to focus the physiopathology of the CIED-induced AVF dysfunction, the current treatment strategies and the novel perspectives that could be taken into consideration and offered to the HD population to preserve both their AVF and their quality of life.

Eligibility for subcutaneous implantable cardioverter-defibrillator in adults with congenital heart disease

Aims

Patients with adult congenital heart disease (ACHD) carry an increased risk for sudden cardiac death. Implantable cardioverter‐defibrillator (ICD) therapy may be challenging in these patients due to anatomical barriers, repeated cardiac surgery, or complicated transvenous access. Thus, the subcutaneous ICD (S‐ICD) can be a promising alternative in this patient population. Patients with ACHD show significant electrocardiogram (ECG) abnormalities, which could affect S‐ICD sensing because it depends on surface ECG.

Methods and results

One hundred patients with ACHD were screened for S‐ICD eligibility. Standard ECG‐based screening test and automated S‐ICD screening test were performed in all patients. Sixty‐six patients (66%) were male. Underlying congenital heart disease (CHD) was mainly CHD of great complexity (71%) and moderate complexity (29%), including repaired tetralogy of Fallot (20%), which was the most common entity. Thirty‐seven patients (37%) already had a pacemaker (23%) or ICD (14%) implanted. Automated screening test identified 83 patients (83%) eligible for S‐ICD implantation in either left parasternal position (78%) or right parasternal position (75%). Absence of sinus rhythm, QRS duration, and a paced QRS complex were associated with S‐ICD screening failure in univariate analysis. Receiver operating characteristic curve and multivariate analysis revealed a QRS duration ≥148 ms as the only independent predictor for S‐ICD screening failure.

Conclusions

Patients with ACHD show satisfactory eligibility rates (83%) for S‐ICD implantation utilizing the automated screening test, including patients with CHD of high complexity. S‐ICD therapy should be considered with caution in ACHD patients with a QRS duration ≥148 ms and/or need for ventricular pacing.

Comparing the safety of subcutaneous versus transvenous ICDs: a meta-analysis

PURPOSE

The use of transvenous implantable cardioverter defibrillators (TV-ICDs) is associated with multiple risks related to the presence of the defibrillator leads within the venous system and right side of the heart, including endocarditis, venous occlusion, tricuspid regurgitation, and potential lead failure. The emergence of subcutaneous ICDs (S-ICDs) may potentially overcome the aforementioned disadvantages. However, evidence validating the safety of S-ICDs relative to TV-ICDs is limited. The present study aimed to synthesize and analyze available data from published studies to comprehensively compare transvenous and subcutaneous ICDs.

METHODS

Different databases were searched for full-text publications with a direct comparison of TV- and S-ICDs. Fixed effect models were applied to pooled data, and no study-to-study heterogeneity was detected.

RESULTS

Data from 7 studies totaling 1666 patients were pooled together. Compared to S-ICDs, the risk of suffering device-related complications was higher in patients with TV-ICDs (OR = 1.71; 95% CI: 1.23-2.38). The number of patients with an S-ICD who suffered inappropriate shocks (IS) was not significantly different than patients with a TV-ICD (OR = 0.92; 95% CI: 0.65-1.30). Subgroup analysis indicated that the TV-ICD group had a higher risk of IS due to supraventricular oversensing (OR = 3.29; 95% CI: 1.92-5.63) while T-wave oversensing tending to cause IS in the S-ICD group (OR = 0.09; 95% CI: 0.03-0.23). The risk of device-related infection in the S-ICD group was not any lower than that in the TV-ICD group (OR = 1.57; 95% CI: 0.67-3.68). The survival rate without any complications during a 1-year follow-up period was similar between the 2 groups (HR = 1.23; 95% CI: 0.81-1.86), although it was assumed that the trend leaned toward more complications in patients with a TV-ICD.

CONCLUSION

The present study verified the safety of S-ICDs based on pooled data. Although there were no differences between TV- and S-ICDs in the short term, fewer adverse events were found in patients with S-ICDs during long-term follow-up.

Comparative Analysis of Procedural Outcomes and Complications Between De Novo and Upgraded Cardiac Resynchronization Therapy

OBJECTIVES

This study compared rates of procedural success and complications between de novo cardiac resynchronization therapy (CRT) implantation versus upgrade, including characterization of technical challenges.

BACKGROUND

CRT upgrade is common, but data are limited on the incidence of procedural success and complications as compared to de novo implantation.

METHODS

All patients who underwent a transvenous CRT procedure at a single institution between 2013 and 2018 were reviewed for procedure outcome, 90-day complications, reasons for unsuccessful left ventricular lead delivery, and the presence of venous occlusive disease (VOD) that required a modified implantation technique.

RESULTS

Among 1,496 patients, 947 (63%) underwent de novo implantation and 549 (37%) underwent device upgrade. Patients who received a device upgrade were older (70 ± 12 years vs. 68 ± 13 years; p < 0.01), with a male predominance (75% vs. 66%; p < 0.01) and greater prevalence of comorbidities. There was no difference in the rate of procedural success between de novo and upgrade CRT procedures (97% vs. 96%; p = 0.28) or 90-day complications (5.1% vs. 4.6%; p = 0.70). VOD was present in 23% of patients who received a device upgrade and was more common among patients with a dual-chamber versus a single-chamber device (26% vs. 9%; p < 0.001). Patients with and without VOD had a similar composite outcome of procedural failure or complication (8.0% vs. 7.8%; p = 1.0).

CONCLUSIONS

Rates of procedural success and complications were no different between de novo CRT implantations and upgrades. VOD frequently increased procedural complexity in upgrades, but alternative management strategies resulted in similar outcomes. Routine venography before CRT upgrade may aid in procedural planning and execution of these strategies.

Epicardial implantation of a leadless pacemaker in a lamb model

BACKGROUND

Pacemaker used in small children typically consist of an abdominally placed generator and epicardially affixed leads, making such a system prone to lead dysfunction during growth. Aim of this study was to investigate the feasibility of epicardial pacing with a leadless pacemaker in a lamb model.

ANIMALS AND METHODS

Seventeen lambs underwent epicardial implantation of a Micra transcatheter pacing system (TPS) (Medtronic, Minneapolis, MN, USA) via left-lateral thoracotomy to the left ventricle (LV) surface (n = 11/17) and to the left atrial appendage (n = 6). Ventricular devices were fixated with the tines within the pericardium, whereas the tines of the atrial devices penetrated the myocardium of the left atrial appendage. After 31 weeks, animals were sacrificed and hearts were explanted for histological analysis.

RESULTS

Following implantation, median P/R amplitude was 4.25/5.5 mV while median pacing threshold was 1.1/1.9 V at 0.24 ms. After 31 weeks, median P/R amplitude was 3.3/4.2 mV. Median atrial pacing threshold was 0.5/0.24 ms. Eight of 10 ventricular pacemakers had lost capture at standard impulse width even at maximum impulse amplitude. On explantation, firm adhesion of the device to the thoracic wall and dislodgement of the electrode tip was found in those ventricular devices.

CONCLUSIONS

Firm fixation of the Micra electrode to the epicardial surface as applied to the atrial devices resulted in excellent electrical properties during midterm follow up. Pericardial fixation as in the ventricular devices was associated with loss of capture. Therefore, it is important to embed the tines in the myocardium and to choose an alternative implantation site allowing for safe fixation of the Micra TPS in a position perpendicular to ventricular epimyocardium.

Is Venoplasty an Alternative to Lead Extraction for Patients With Venous Obstruction?

BACKGROUND

Indications for cardiovascular implantable electronic devices (CIEDs) have increased over time. Patients may require lead replacement or implantation due to lead failure or need for device upgrade. Venous obstruction is a common finding in these patients and often poses difficulties for operators. Venoplasty as an alternative to lead extraction emerges as an important intervention in the treatment of selected patients, particularly with a view to minimising procedural risk.

METHODS

Nine (9) patients with CIED related venous occlusion were treated with venoplasty at our institution between April 2006 and October 2019. Six (6) of nine patients were initially referred to our institution for consideration of transvenous lead extraction in the setting of venous occlusion. These patients are the subjects of the case series. Patient demographics, indication for venoplasty and procedural outcomes were examined.

RESULTS

We present a series of six patients in whom venoplasty has been performed at our centre as an alternative to lead extraction. Device and patient characteristics have been examined as well as radiation exposure and fluoroscopy time. The median age of our cohort was 64.5 years (range: 37-81 years) and 67% were female. Luminal calibre was improved in all patients allowing lead replacement, device upgrade or relief of symptoms. Procedural complications were not observed, and all patients remained free of symptoms related to venous occlusion at 3-month follow-up.

CONCLUSIONS

We present venoplasty as a viable alternative to lead extraction in high risk patients or in those who favour a less invasive approach.

Uso Racional dos Cabos-Eletrodos na Estimulação Cardíaca Artificial

Introdução: Os dispositivos cardíacos eletrônicos implantáveis (DCEIs) são terapia consagrada para o tratamento de bradiarritmias, prevenção de morte súbita ou insuficiência cardíaca. Desde o primeiro implante de marcapasso transvenoso há mais de 60 anos, ocorreram avanços tecnológicos dos dispositivos e melhorias nas técnicas cirúrgicas. No entanto esse tipo de terapia ainda está associado a complicações significativas, a maioria relacionada ao implante dos cabos-eletrodos transvenosos. Objetivo: apresentar uma reflexão sobre como praticar o uso racional do implante de cabos-eletrodos e propor estratégias e alternativas para postergá-lo ou evitá-lo, com base nos conhecimentos atuais nos diversos campos da estimulação cardíaca artificial. Métodos: Revisão da literatura que utilizou artigos de 1995 a 2019, de diversas plataformas e revistas. Conclusão:Há a expectativa de que nos próximos anos ocorram avanços tecnológicos e de conhecimento no campo da estimulação leadless, permitindo que esses dispositivos sejam incorporados na prática clínica de maneira rotineira. Atualmente, se o implante de eletrodos ventriculares nos casos de doença do nó sinusal com condução atrioventricular preservada for racionalizado, o implante de eletrodos atriais nos cardiodesfibriladores implantáveis (CDI) sem necessidade de estimulação antibradicardia ou dos eletrodos ventriculares nos casos sem a necessidade de estimulação antitaquicardia (ATP) considerando o implante de CDIs subcutâneos, este artigo terá cumprido o seu papel.

Rational Use of Leads in Artificial Cardiac Pacing

Introduction: Cardiovascular implantable electronic device (CIEDs) are a proven therapy for the treatment of bradyarrhythmias, prevention of sudden death or heart failure. Since the first transvenous pacemaker implantation more than 60 years ago, technological advances in devices and improvements in surgical techniques have occurred. However, this type of therapy is still associated with significant complications, most of them related to the implantation of transvenous leads. Objective: To present a reflection on how to practice the rational use of lead implantation and propose strategies and alternatives to delay or avoid it, based on the current knowledge in the various fields of artificial cardiac stimulation. Methods: Review of literature that used articles from 1995 to 2019, from several platforms and periodicals. Conclusion: There is an expectation that in the coming years there will be technological and knowledge advances in the field of leadless stimulation, allowing these devices to be incorporated into clinical practice in a routine manner. Currently, if the implantation of ventricular electrodes in cases of sinus node disease with preserved atrioventricular conduction is rationalized, the implantation of atrial electrodes in implantable cardioverter-defibrillators (ICD) without the necessity of antibradicardia stimulation or ventricular electrodes in cases without the necessity of antitachycardia stimulation (ATP) considering the subcutaneous ICD implantation, this article will have fulfilled its role.

Wire countertraction for sheath placement through stenotic and tortuous veins: The “body flossing” technique

Background

Innominate vein stenosis and venous tortuosity are common findings during cardiac implantable electronic device upgrades or replacements and present a challenge to the implanting physician. Various techniques have been described to facilitate lead placement, including serial dilation, balloon venoplasty, and percutaneous access medial to the stenosis, each with its own benefits and risks.

Objective

The purpose of this study was to assess the feasibility, safety, and efficacy of the wire countertraction (“body flossing”) technique to facilitate sheath placement through tortuous and stenotic vessels.

Methods

Patients undergoing cardiac implantable electronic device procedures requiring the body flossing technique due to inability to place vascular sheaths over the wire through stenoses or tortuosity were retrospectively analyzed. Clinical characteristics, procedural equipment, and outcomes were analyzed.

Results

Simultaneous countertraction was successful in all attempted cases, including 8 patients with stenoses and 2 with tortuosity. In 2 of the stenosis cases, venoplasty had previously failed. No complications occurred.

Conclusion

Simultaneous countertraction (body flossing) is an effective tool to overcome venous stenosis and tortuosity that are amenable to wire advancement but not to vascular sheaths. It seems to be a safe and effective alternative to other techniques used in these scenarios.

Narrow Escape: A Novel Approach to the Endovascular Treatment of Superior Vena Cava Syndrome Secondary to Pacemaker Leads with Excellent Long-term Outcomes

Pacemaker or defibrillator placement is a common procedure done in more and more patients due to increased longevity and the prominence of cardiac disease. With more indications for cardiac implantable electrode devices, the devices themselves have evolved into more complex structures with more leads. The mechanical stress, risk of infection, and decreased blood flow through the superior vena cava (SVC) put patients at risk for SVC obstruction. Herein, we present a rare case of complete SVC obstruction secondary to fibrosis due to pacemaker leads which was treated with venoplasty and showed excellent long-term results. We also review the current literature on different approaches to treating SVC obstruction in this group of patients.

State of the art: leadless ventricular pacing : A national expert consensus of the Austrian Society of Cardiology

Background

Cardiac pacing has been shown to improve quality of life and prognosis of patients with bradycardia for almost 60 years. The latest innovation in pacemaker therapy was miniaturization of generators to allow leadless pacing directly in the right ventricle. There is a long history and extensive experience of leadless ventricular pacing in Austria. However, no recommendations of national or international societies for indications and implantation of leadless opposed to transvenous pacing systems have been published so far.

Results

A national expert panel of skilled implanters gives an overview on the two utilized leadless cardiac pacing systems and highlights clinical advantages as well as current knowledge of performance and complication rates of leadless pacing. Furthermore, a national consensus for Austria is presented, based on recent studies and current know-how, specifically including indications for leadless pacing, management of infection, suggestions for qualification, and training of the operators and technical standards.

Conclusions

Leadless pacing systems can be implanted successfully with a low complication rate, if suggestions for indications and technical requirements are followed.

Condensed abstract

An overview of the two utilized leadless cardiac pacing systems is given, specifically highlighting clinical advantages as well as current knowledge of performance and complication rates. Furthermore, a national consensus for Austria is presented, specifically including indications for leadless pacing, management of infection, and suggestions for qualification and technical standards.

Unusual Venous Access for Device Implantation

Case series

Patient: Male, 80 • Female, 67 • Male, 48

Final Diagnosis: Management of difficult venous access for implantable cardiac devices

Symptoms: Heart failure

Medication: —

Clinical Procedure: —

Specialty: Cardiology

Hybrid venous recanalization and cardiac implantable electronic device lead revision procedures: A single-center retrospective analysis of 38 patients

PURPOSE

The purpose of this study was to describe the safety and efficacy of hybrid recanalization procedures in a series of patients with obstructed central veins requiring cardiac implantable electronic device (CIED) revision.

METHODS

Between 2008 and 2016, 38 consecutive patients (24 M; age 60.5 ± 16.2 years; range 25-87 years) with central venous obstruction underwent 42 recanalization interventions performed in conjunction with CIED revision or extraction. Fifty percent of patients (19/38) presented with veno-occlusive symptoms, and 13% (5/38) of patients had CIED leads with an ipsilateral upper extremity dialysis conduit.

RESULTS

Ninety-one percent (38/42) of all procedures resulted in successful recanalization and CIED revision. Twenty-four percent (9/38) of all patients required secondary procedures due to recurrent stenosis, and 78% (7/9) of those requiring secondary procedures had indwelling dialysis conduits and/or clinical symptoms related to venous occlusion before the initial procedure. There were complications in 2 patients related to recanalization, and in 3 related to CIED revision.

CONCLUSIONS

Recanalization of central venous stenosis/occlusion in patients with CIED can be technically challenging but is successful in most patients. Symptomatic patients and those with dialysis conduits often require more aggressive revascularization interventions and may be at increased risk of complication or need for secondary interventions.

A Novel Defibrillation Tool: Percutaneously Delivered, Partially Insulated Epicardial Defibrillation

INTRODUCTION

Epicardial defibrillation systems currently require surgical access. We aimed to develop a percutaneous defibrillation system with partially-insulated epicardial coils to focus electrical energy on the myocardium and prevent or minimize extra-cardiac stimulation.

METHODS

We tested 2 prototypes created for percutaneous introduction into the pericardial space via a steerable sheath. This included a partially-insulated defibrillation coil and a defibrillation mesh with a urethane balloon acting as an insulator to the face of the mesh not in contact with the epicardium. The average energy associated with a chance of successful defibrillation 75% of the time (ED75) was calculated for each experiment.

RESULTS

Of 16 animal experiments, 3 pig experiments had malfunctioning mesh prototypes such that results were unreliable; these were excluded. Therefore, 13 animal experiments were analyzed - 6 canines (29.8±4.0kg); 7 pigs (41.1±4.4kg). The overall ED75 was 12.8±6.7J (10.9±9.1J for canines; 14.4±3.9J in pigs [P=0.37]). The lowest ED75 obtained in canines was 2.5J while in pigs it was 9.5J. The lowest energy resulting in successful defibrillation was 2J in canines and 5J in pigs. There was no evidence of coronary vessel injury or trauma to extra-pericardial structures.

CONCLUSION

Percutaneous, epicardial defibrillation using a partially insulated coil is feasible and appears to be associated with low defibrillation thresholds. Focusing insulation may limit extra-cardiac stimulation and potentially lower energy requirements for efficient defibrillation.

Upper extremity deep venous thrombosis and stenosis after implantation of pacemakers and defibrillators; A prospective study

BACKGROUND

Obstruction of the access vein following cardiac pacemaker and defibrillator implantation is a common complication. However, the exact incidence and contributing risk factors are unknown. The aim of this study is to determine the incidence and analyze the contribution of each risk factor.

METHODS

57 consecutive patients candidate for their first transvenous pacemaker, implantable cardioverter-defibrillator (ICD), or cardiac resynchronization therapy device implantation were enrolled. After implantation, venography of the ipsilateral peripheral arm was performed. Patients underwent their second venography after the follow-up period of 3 to 6 months.

RESULTS

42 patients (13 females, mean age 59.71 ± 12.33) completed the study. The followup venography showed significant venous obstruction (more than 50%) in 9 (21%) patients, but in none of the individuals, venography revealed total occlusion of the veins. Patients with obstruction had more leads in their veins (2.56 ± 0.53 vs 1.58 ± 0.71, P = 0.001). Venous obstruction was significantly more prevalent in patients with implanted cardiac resynchronization therapy device compared with an ICD or pacemaker (p = 0. 01). Age, gender, diabetes mellitus, hypertension, ischemic heart disease and antiplatelet consumption did not reveal any other contribution to the risk of thrombosis. In multivariate analysis, total lead number was a positive predictor for venous occlusion (P = 0.015, OR:19.2, and CI: 1.7-207.1).

CONCLUSION

Venous obstruction is relatively frequent after pacemaker or ICD implantation. This study also shows that pacemaker and ICD leads have a similar risk for lead-related venous obstruction. However, patients with multiple leads are associated with an increased risk.

The role of transvenous lead extraction in the management of redundant or malfunctioning pacemaker and defibrillator leads post ELECTRa

Cardiac implantable electronic devices implantation rates have increased over the past decade due to broader indications and an ageing population. Similarly, device and lead complications have also risen. The management of pacemaker/defibrillator leads that are no longer required (redundant) or malfunctioning, can be contentious. There is a need to balance the risk of transvenous lead extraction (TLE) against those of lead abandonment. The recently published European Lead Extraction ConTRolled Registry (ELECTRa) study provides contemporary outcomes for TLE across Europe with important implications for the management of redundant and/or malfunctioning leads. This review article discusses the potential complications for each interventional approach when managing redundant or malfunctioning pacemaker leads.

Central Venous Stenosis after Hemodialysis: Case Reports and Relationships to Catheters and Cardiac Implantable Devices

The appropriate vascular access for hemodialysis in patients with cardiac implantable electronic devices (CIED) is undefined. We describe two cases of end-stage renal disease patients with CIED and tunneled central venous catheter (CVC) who developed venous cava stenosis: (1) a 70-year-old man with sinus node disease and pacemaker in 2013, CVC, and a Brescia-Cimino forearm fistula in 2015; (2) a 75-year-old woman with previous ventricular arrhythmia with implanted defibrillator in 2014 and CVC in 2016. In either case, after about 1 year from CVC insertion, patients developed superior vena cava (SVC) syndrome due to stenosis diagnosed by axial computerized tomography. In case 1, the patient was not treated by angioplasty of SVC and removed CVC with partial resolving of symptoms. In case 2, a percutaneous transluminal angioplasty with placement of a new CVC was required. To analyze these reports in the context of available literature, we systematically reviewed studies that have analyzed the presence of central venous stenosis associated with the simultaneous presence of CIED and CVC. Five studies were found; two indicated an increased incidence of central venous stenosis, while three did not find any association. While more studies are definitely needed, we suggest that these patients may benefit from epicardial cardiac devices and the insertion of devices directly into the ventriculus. If the new devices are unavailable or contraindicated, peritoneal dialysis or intensive conservative treatment in older patients may be proposed as alternative options.

Use of leadless pacemakers in Europe: results of the European Heart Rhythm Association survey

The purpose of this European Heart Rhythm Association (EHRA) survey is to provide an overview of the current use of leadless pacemakers (LLPM) across a broad range of European centres. An online questionnaire was sent to centres participating in the EHRA Electrophysiology Research Network. Questions dealt with standards of care and policies used for patient management, indications, and techniques of implantation of LLPM. In total, 52 centres participated in the survey. Most (86%) reported using LLPM, although 82% of these centres implanted <30 LLPM devices during the last 12 months. Non-availability (36%), lack of reimbursement (55%), and cost of the device (91%) were factors limiting the use of LLPM. The most commonly reported indications for LLPM were permanent atrial fibrillation (83%), a history of complicated conventional pacemaker (87%), or an anticipated difficult vascular access (91%). Implantation of LLPM is perceived as an easy-to-do and safe procedure by most implanters (64%), while difficult or risky in 28%, and comparable to conventional pacemakers by only a few (8%). Local vascular complications were the most frequently reported major problems (28%), but a significant number of respondents (36%) have never encountered any issue after LLPM implantation. Although cost and reimbursement issues strongly influence the use of LLPM, most respondents (72%) anticipate a significant increase in device utilization within next 2 years.

Predictors of venous stenosis or occlusion following first transvenous cardiac device implantation: Prospective observational study

INTRODUCTION

Venous stenosis or occlusion related to an intracardiac device is a well-known complication of that procedure. There are numerous studies tried to determine predictors of venous stenosis or occlusion; however, most of them investigate the venous system prior to device upgrade, generator replacement, or transvenous lead extraction. Therefore, we aimed to assess the prevalence and determine the predictors of venous stenosis or occlusion following first transevnous cardiac device implantation.

METHODS

Observational, prospective study included 71 consecutive patients admitted for first transvenous cardiac device implantation. All patients were followed up for 6 months after operation.

RESULTS

Implanted device systems comprised cardioverter defibrillator (n = 26), single-chamber or dual-chamber pacemakers (n = 34), and biventricular pacemakers (n = 11); 88.5% of implantable cardioverter defibrillator leads were single-coils and 11.5% were dual-coils. The incidence of venous stenosis or occlusion within 6-month follow-up was 21.1%. Multivariate logistic regression showed that only diabetes or prediabetes (p = 0.033, odds ratio: 0.17, 95% confidence interval: 0.04-0.87), prolonged procedure time (p = 0.046, odds ratio: 4.54, 95% confidence interval: 1.01-20.12), and perioperative complications (p = 0.021, odds ratio: 7.04, 95% confidence interval: 1.35-36.85) were predictors of venous stenosis or occlusion.

CONCLUSION

Prolonged implantation time (>60 min) and perioperative complications are associated with an increased risk of venous stenosis or occlusion, whereas diabetes and prediabetes significantly reduce the risk of venous stenosis or occlusion.