Venous Obstruction After Pacemaker Implantation

Cavoatrial junction stenting in vascular hemodialysis catheter malfunction

In patients undergoing hemodialytic treatment via intravascular catheters, stenosis or occlusion of central veins is common. Despite an extensive characterization of Superior Vena Cava Syndrome (SVCS) no data is available about CavoAtrial Junction (CAJ) stenosis. We report the case of two patients with a story of multiple catheter failures due to thrombosis or infection. Computed tomography (CT) showed radiological signs of CAJ stenosis confirmed at the following venography. In absence of other feasible options to place a vascular access, the two underwent stenting with Gore Viabahn VBX balloon expandable endoprosthesis (W.L. Gore & Associates, Flagstaff, AZ, USA) of the CAJ stenosis. Completion venography showed complete resolution of the stenosis in both patients. No complications occurred during the procedures. At a mean follow-up of 878 ± 559 days no signs of in-stent restenosis or recoil were found. The present cases emphasize the feasibility and safety of CAJ stenting, underlining the importance of preserving CAJ and upper veins patency in hemodialysis access.

Venous thoracic outlet syndrome, as a pitfall for cardiac implantable electronic device implantations

The subclavian vein is typically used in cardiovascular implantable electronic device (CIED) implantations. External stress on the subclavian vein can lead to lead-related complications. There are several causes of this stress, such as frequent upper extremity movements or external injury. Venous thoracic outlet syndrome (TOS) can also become the cause of external lead stress. However, the diagnosis of venous TOS can be challenging because subclavian venography can appear normal at first glance. We present a unique case of a device infection in a patient with venous TOS. A careful observation of the imaging studies is vital for diagnosing venous TOS and a leadless pacemaker implantation could be an alternative therapeutic option.

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.

Deep Vein Thrombosis in the Humeral Vein After Implantable Cardioverter-Defibrillator Implantation: A Family Physician's Perspective

Upper extremity deep vein thrombosis (DVT) is an uncommon, under-reported, and difficult-to-diagnose condition. Although the strong provoking risk factors of venous thromboembolism are well described in the literature, the majority of cases are provoked by weak risk factors or are even considered unprovoked. In this case report, we describe a rare case of a brachial DVT in a woman in her 40s following implantable cardioverter-defibrillator (ICD) implantation. In her first evaluation, slight left arm edema and brachialgia were noted, and physiotherapy was prescribed. One month later, the patient was reevaluated because her complaints did not resolve, and an upper extremity venous ultrasound was done to exclude complications due to ICD implantation. The ultrasound identified an old DVT, which had been completely recanalized. The patient was then referred to a vascular surgery specialty consultation, which confirmed the diagnosis, and an anticoagulant was prescribed for three months. The symptoms resolved, and the patient did not report any more pain.

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.

How does a CIED presence influence chances and safety of haemodialysis access? Conclusions from over 3000 thoracic venografies

Patients requiring temporal or permanent catheter or arterio-venous fistula (AVF) for haemodialysis may be in challenging situation, if they are cardiovascular implantable electronic devices (CIED) carriers.

MATERIALS AND METHODS

The authors analysed preoperative venogrphies of 3100 patients referred for transvenous lead extraction for a possible chance of safe haemodialysis catheter (HC) implantation or proper AVF function.

RESULTS

A chance of safe catheter implantation parallel to existing leads reaches 68.8% ipsilaterally to CIED. Contraindications for implantation have been found in less than 2% of cases contralaterally. Ipsilaterally proper AVF function chance has been found in 50.3% of the cases and almost 98% contralaterally. A bilateral chest electrodes location require the special attention. Abandoned lead, lead burden, bilateral leads, additional lead implantation or abandonment, and implant duration may have a significant influence on HC insertion or proper function of arteriovenous fistula.

CONCLUSION

(1) Obstruction of prominent thoracic veins is a frequent finding in CIED carriers and may impede or disable implantation haemodialysis accesses. (2) Implantation of temporary or permanent HC may be questionable ipsilaterally to the CIED in 31.2% and contralaterally in 2.0% of patients. Proper function of AVF is uncertain in 49.7% ipsilaterally and 2.1% contralaterally to CIED. (3) Pacing history and leads dwell time influence chances of success haemodialysis access even on the free-from CIED chest side. (4) Proper venous flow evaluation seems to be valuable in CIED carriers before an attempt of haemodialysis access formation, even contralaterally.

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.

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

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

Lead-Related Venous Obstruction in Patients With Implanted Cardiac Devices: JACC Review Topic of the Week

Cardiac implantable electronic device implantation rates have increased in recent decades. Venous obstruction of the subclavian, brachiocephalic, or superior vena cava veins represents an important complication of implanted leads. These forms of venous obstruction can result in significant symptoms as well as present a barrier to the implantation of additional device leads. The risk factors for the development of these complications remain poorly understood, and diagnosis relies on clinical recognition and cross-sectional imaging. Anticoagulation remains the mainstay of treatment, and thrombus debulking, lead extraction, venoplasty, and stenting are all important therapeutic interventions. This review provides a multidisciplinary-based approach to the evaluation and management of cardiac implantable electronic device lead-associated venous obstruction.

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).

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.

Endovascular Neuromodulation: Safety Profile and Future Directions

Endovascular neuromodulation is an emerging technology that represents a synthesis between interventional neurology and neural engineering. The prototypical endovascular neural interface is the Stentrode^TM, a stent-electrode array which can be implanted into the superior sagittal sinus via percutaneous catheter venography, and transmits signals through a transvenous lead to a receiver located subcutaneously in the chest. Whilst the Stentrode^TM has been conceptually validated in ovine models, questions remain about the long term viability and safety of this device in human recipients. Although technical precedence for venous sinus stenting already exists in the setting of idiopathic intracranial hypertension, long term implantation of a lead within the intracranial veins has never been previously achieved. Contrastingly, transvenous leads have been successfully employed for decades in the setting of implantable cardiac pacemakers and defibrillators. In the current absence of human data on the Stentrode^TM, the literature on these structurally comparable devices provides valuable lessons that can be translated to the setting of endovascular neuromodulation. This review will explore this literature in order to understand the potential risks of the Stentrode^TM and define avenues where further research and development are necessary in order to optimize this device for human application.

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.

Arteriovenous Fistula and Graft Construction in Patients with Implantable Cardiac Devices: Does Side Matter?

BACKGROUND

Limited reports have documented the effect cardiac implantable electronic devices (CIEDs) have on arteriovenous (AV) access patency. Current recommendations suggest placing the access on the contralateral side of the CIEDs, as there is concern for increased central venous stenosis and access failure. The goal of this study is to review our single-center AV access patency rates for dialysis patients with an ipsilateral or contralateral side CIED.

METHODS

A retrospective review was performed from 2008 to 2016 at a single institution identifying all patients who have received a CIED and the diagnosis of end-stage renal disease (ESRD). Medical records were queried to identify each patient's dialysis access and whether it was ipsilateral or contralateral to the CIED. Primary outcomes of study were primary and secondary patency rates.

RESULTS

A total of 44 patients were identified to have ESRD and CIED. Of these patients, 28 patients with fistulas or grafts (13 ipsilateral and 15 contralateral) had follow-up with regards to their AV access. There were 3 primary failures in both groups. For patients who had the CIED placed after already starting the dialysis, patency was based on when the cardiac device was implanted. Primary patency for ipsilateral and contralateral access was 20.2 and 22.2 months, respectively. With secondary interventions, ipsilateral and contralateral mean patency was 39 and 48.8 months, respectively. Six-month and 1-year primary patency for arteriovenous fistula or arteriovenous graft on patients with ipsilateral access was 69.2% and 53.8%, respectively. Ipsilateral 1-year cumulative patency was 39 months.

CONCLUSIONS

CIED may lead to stenosis or occlusion to one's AV access; however, primary assisted and secondary patency rates are still acceptable at 6 months and 1 year compared to Kidney Disease Outcomes Quality Initiative guidelines. Despite a CIED, a surgeon's algorithm should not lead to the abandonment of an ipsilateral access if the central venous system is patent.

Leadless multisite pacing: A feasibility study using wireless power transfer based on Langendorff rodent heart models

INTRODUCTION

Fifteen to thirty percent of patients with impaired cardiac function have ventricular dyssynchrony and warrant cardiac resynchronization therapy (CRT). While leadless pacemakers eliminate lead-related complications, their current form factor is limited to single-chamber pacing. In this study, we demonstrate the feasibility of multisite, simultaneous pacing using miniaturized pacing nodes powered through wireless power transfer (WPT).

METHODS

A wireless energy transfer system was developed based on resonant coupling at approximately 200 MHz to power multiple pacing nodes. The pacing node comprises circuitry to efficiently convert the harvested energy to output stimuli. To validate the use of these pacing nodes, ex vivo studies were carried out on Langendorff rodent heart models (n = 4). To mimic biventricular pacing, two beating Langendorff rodent heart models, kept 10 cm apart, were paced using two distinct pacing nodes, each attached on the ventricular epicardial surface of a given heart.

RESULTS

All ex vivo Langendorff heart models were successfully paced with a simple coil antenna at 2 to 3 cm from the pacing node. The coil was operated at 198 MHz and 0.3 W. Subsequently, simultaneous pacing of two Langendorff heart models 30 cm apart using an output power of 5 W was reliably demonstrated.

CONCLUSION

WPT provides a feasible option for multisite, wireless cardiac pacing. While the current system remains limited in design, it offers support and a conceptual framework for future iterations and eventual clinical utility.

Usefulness of preoperative venography in patients with cardiac implantable electronic devices submitted to lead replacement or device upgrade procedures

Background

Venous obstructions are common in patients with transvenous cardiac implantable electronic devices, but they rarely cause immediate clinical problems. The main consequence of these lesions is the difficulty in obtaining venous access for additional leads implantation.

Objectives

We aimed to assess the prevalence and predictor factors of venous lesions in patients referred to lead reoperations, and to define the role of preoperative venography in the planning of these procedures.

Methods

From April 2013 to July 2016, contrast venography was performed in 100 patients referred to device upgrade, revision and lead extraction. Venous lesions were classified as non-significant (< 50%), moderate stenosis (51-70%), severe stenosis (71-99%) or occlusion (100%). Collateral circulation was classified as absent, discrete, moderate or accentuated. The surgical strategy was defined according to the result of the preoperative venography. Univariate analysis was used to investigate predictor factors related to the occurrence of these lesions, with 5% of significance level.

Results

Moderate venous stenosis was observed in 23%, severe in 13% and occlusions in 11%. There were no significant differences in relation to the device side or the venous segment. The usefulness of the preoperative venography to define the operative tactic was proven, and in 99% of the cases, the established surgical strategy could be performed according to plan.

Conclusions

The prevalence of venous obstruction is high in CIED recipients referred to reoperations. Venography is highly indicated as a preoperative examination for allowing the adequate surgical planning of procedures involving previous transvenous leads.

Venous Obstruction in Cardiac Rhythm Device Therapy

PURPOSE OF REVIEW

A variety of complex vascular pathologies arise following the implantation of electronic cardiac devices. Pacemaker and defibrillator lead insertion may cause proximal venous obstruction, resulting in symptomatic venous congestion and the compromise of potential future access sites for cardiac rhythm lead management.

RECENT FINDINGS

Various innovative techniques to recanalize the vein and establish alternate venous access have been pioneered over the past few years. A collaborative team of electrophysiologists and vascular specialists strategically integrate the patient's vascular disease into the planning of electrophysiology procedures. When vascular complications occur after device implantation, the same team effectively manages both the resulting vascular sequelae and related cardiac rhythm device challenges. This review will outline the various vascular challenges related to device therapy and offer an effective strategy for their management.

Initial experience with the subcutaneous implantable cardioverter-defibrillator with the real costs of hospitalization analysis in a single Polish center

BACKGROUND

The recent introduction of an entirely subcutaneous implantable cardioverter-defibril-lator (S-ICD) represents an important progress in the defibrillation technology towards a less invasive approach. This is a single-center observational study of S-ICD implantations in Poland.

METHODS

The S-ICD was implanted in 11 patients with standard indications for an ICD. Patients in whom the device was implanted were evaluated for adverse events and device function at hospital discharge. All hospitalization costs were calculated and summed up for all patients. Costs were divided into following categories: medical materials, pharmaceuticals, operating theatre staff, cardiology depart-ment staff, laboratory tests, non-laboratory tests and additional non-medical costs.

RESULTS

The mean age of patients was 51.6 ± 16.4 years, 9 were men and 2 were women. Four pa-tients had atrial fibrillation as the basal rhythm, 1 patient had atrial flutter and 6 patients had sinus rhythm. All patients had at least one condition that precluded the use of a traditional ICD system or the S-ICD was preferred due to other conditions, i.e. a history complicated transvenous ICD therapy (18%), anticipated higher risk of infection (27%), lack or difficult vascular access (18%), young age and anticipated high cumulated risk of lifetime device therapy (36%). The mean duration of the im-plantation procedure was 2 h. One patient developed a postoperative pocket hematoma. Mean total time of hospitalization was 28 (6-92) days. Average cost of hospitalization per patient was 21,014.29 EUR (minimal = 19,332.71 EUR and maximal = 24,824.14 EUR).

CONCLUSIONS

S-ICD implantation appears to provide a viable alternative to transvenous ICD, espe-cially for patients without pacing requirements.

An Easy Technique for the Removal of a Hemodialysis Catheter Stuck in Central Veins

Background

Central venous catheters are currently used for long-term hemodialysis (HD) in a large number of patients. When the catheter needs to be removed, the removal is usually achieved without difficulty after dissection of the cuff from the tunnel. However, when the catheter is stuck in the central vein, the removal becomes complex or unsuccessful. Herein, a simple and easy technique is described for the removal of an HD catheter stuck in the central vein.

Case Report

Attempts were made to remove an HD catheter from a 65-year-old male by making an incision in the skin over the exit site of the catheter to dissect the cuff from the tunnel and by pulling the catheter, but without success because the catheter was stuck in the central vein. Through a second skin incision in the neck, the subcutaneous portion of the catheter was retrieved from the tunnel and then an introducer sheath was inserted over the catheter into the internal jugular vein while the catheter was held in place. The sheath was advanced around the catheter into the central vein. The catheter was then easily pulled out from the central vein.

Comment

The reported cases of stuck catheters in the literature were reviewed to acknowledge the difficulties encountered in the removal attempts. The technique described herein can be used for the removal of a variety of catheters and wires stuck in the central vein.

Coronary Venous Lead Extraction

The increasing number of cardiac resynchronization therapy devices implanted, coupled with the increasing incidence of cardiac implantable electronic device infection, has led to a greater need for extraction of coronary venous pacing leads. The objectives of this study were to review the indications, techniques and published results of coronary venous lead extraction. In this study, we searched PubMed using the search terms "lead extraction," "coronary sinus," "coronary venous," "pacing," and "cardiac resynchronization therapy" for relevant papers. The reference lists of relevant articles were also searched, and personal experience was drawn upon. Published success rates and complications were found to be similar to those reported for non-coronary venous leads in experienced centers. However, reimplantation success differs and can be limited by vessel occlusion postextraction. The available active fixation coronary sinus lead (Attain Starfix™; Medtronic, MN, USA) is a particularly complex lead to extract, whereas limited data on the newer active fixation leads (Attain Stability™, Medtronic, MN, USA) suggest that they are less challenging to remove. The study concluded that coronary venous lead extraction presents unique challenges, especially reimplantation, that require special consideration and planning to overcome.

Canadian Cardiovascular Society/Canadian Heart Rhythm Society 2016 Implantable Cardioverter-Defibrillator Guidelines

Sudden cardiac death is a major public health issue in Canada. However, despite the overwhelming evidence to support the use of implantable cardioverter defibrillators (ICDs) in the prevention of cardiac death there remains significant variability in implantation rates across Canada. Since the most recent Canadian Cardiovascular Society position statement on ICD use in Canada in 2005, there has been a plethora of new scientific information to assist physicians in their discussions with patients considered for ICD implantation to prevent sudden cardiac death due to ventricular arrhythmias. We have reviewed, critically appraised, and synthesized the pertinent evidence to develop recommendations regarding: (1) ICD implantation in the primary and secondary prevention of sudden cardiac death in patients with and without ischemic heart disease; (2) when it is reasonable to withhold ICD implantation on the basis of comorbidities; (3) ICD implantation in patients listed for heart transplantation; (4) implantation of a single- vs dual-chamber ICD; (5) implantation of single- vs dual-coil ICD leads; (6) the role of subcutaneous ICDs; and (7) ICD implantation infection prevention strategies. We expect that this document, in combination with the companion article that addresses the implementation of these guidelines, will assist all medical professionals with the care of patients who have had or at risk of sudden cardiac death.

Innovative pacing: Recent advances, emerging technologies, and future directions in cardiac pacing

The field of cardiovascular medicine is rapidly evolving as advancements in technology and engineering provide clinicians new and exciting ways to care for an aging population. Cardiac pacing, in particular, has seen a series of game-changing technologies emerge in the past several years spurred by low-power electronics, high density batteries, improved catheter delivery systems and innovative software design. We look at several of these emerging pacemaker technologies, discussing the rationale, current state and future directions of these pioneering developments in electrophysiology.

Prevalence and predictor factors of severe venous obstruction after cardiovascular electronic device implantation

AIMS

Despite not being uncommon, limited evidence exists about predisposing factors for venous obstruction in patients with implantable electronic devices. We aimed to assess the prevalence of severe venous obstruction in patients with intravenous devices and identify predictor factors.

METHODS AND RESULTS

A total of 184 patients underwent venography to detect venous obstruction associated with the inserted lead. Vessel obstruction was graded as venous occlusion (complete flow interruption), severe obstruction (narrowing >90%), or mild-moderate obstruction (narrowing 50-90%). Severe venous obstruction/occlusion prevalence was 11.4% (n = 21) and was always asymptomatic. Collateral circulation was found in 80.9% of patients with severe obstruction/occlusion. Twelve patients (6.5%) had 3 leads. The rates of patients with secondary prevention of sudden cardiac death as indication for implantable devices and of those of patients with 3 leads were significantly greater in the group with severe obstruction/occlusion than in the non-severe obstruction/occlusion group (respectively, P = 0.004 and P = 0.03). Logistic analysis adjusted for venous thromboembolic risk factors confirmed that secondary prevention of sudden cardiac death as indication for implantable devices [odds ratio (OR), 7.1; 95% confidence interval (CI): 1.4-35.3; P = 0.017] and the presence of 3 leads (OR, 8.5; 95% CI: 1.75-41.35; P = 0.008) were predictors of severe obstruction/occlusion.

CONCLUSION

In patients with implantable devices, severe venous obstruction prevalence is not negligible and the lack of symptoms does not exclude it. The presence of three leads and sudden cardiac death as indication for implantable devices seem to be associated with the presence of severe venous obstruction/occlusion.

Coronary Sinus Lead Extraction

Expanded indications for cardiac resynchronization therapy and the increasing incidence of cardiac implantable electronic device infection have led to an increased need for coronary sinus (CS) lead extraction. The CS presents unique anatomical obstacles to successful lead extraction. Training and facility requirements for CS lead extraction should mirror those for other leads. Here we review the indications, technique, and results of CS lead extraction. Published success rates and complications are similar to those reported for other leads, although multiple techniques may be required. Re-implantation options may be limited, which should be incorporated into pre-procedural decision making.

Percutaneous Implantation of an Entirely Intracardiac Leadless Pacemaker

BACKGROUND

Cardiac pacemakers are limited by device-related complications, notably infection and problems related to pacemaker leads. We studied a miniaturized, fully self-contained leadless pacemaker that is nonsurgically implanted in the right ventricle with the use of a catheter.

METHODS

In this multicenter study, we implanted an active-fixation leadless cardiac pacemaker in patients who required permanent single-chamber ventricular pacing. The primary efficacy end point was both an acceptable pacing threshold (≤2.0 V at 0.4 msec) and an acceptable sensing amplitude (R wave ≥5.0 mV, or a value equal to or greater than the value at implantation) through 6 months. The primary safety end point was freedom from device-related serious adverse events through 6 months. In this ongoing study, the prespecified analysis of the primary end points was performed on data from the first 300 patients who completed 6 months of follow-up (primary cohort). The rates of the efficacy end point and safety end point were compared with performance goals (based on historical data) of 85% and 86%, respectively. Additional outcomes were assessed in all 526 patients who were enrolled as of June 2015 (the total cohort).

RESULTS

The leadless pacemaker was successfully implanted in 504 of the 526 patients in the total cohort (95.8%). The intention-to-treat primary efficacy end point was met in 270 of the 300 patients in the primary cohort (90.0%; 95% confidence interval [CI], 86.0 to 93.2, P=0.007), and the primary safety end point was met in 280 of the 300 patients (93.3%; 95% CI, 89.9 to 95.9; P<0.001). At 6 months, device-related serious adverse events were observed in 6.7% of the patients; events included device dislodgement with percutaneous retrieval (in 1.7%), cardiac perforation (in 1.3%), and pacing-threshold elevation requiring percutaneous retrieval and device replacement (in 1.3%).

CONCLUSIONS

The leadless cardiac pacemaker met prespecified pacing and sensing requirements in the large majority of patients. Device-related serious adverse events occurred in approximately 1 in 15 patients. (Funded by St. Jude Medical; LEADLESS II ClinicalTrials.gov number, NCT02030418.).

The entirely subcutaneous defibrillator (s-icd): state of the art and selection of the ideal candidate

The traditional transvenous defibrillator has been one of the greatest advancement in Cardiology in the last 30 years and has demonstrated to reduce arrhythmic and total mortality in selected patients. However the traditional defibrillator can have a high price to pay in terms of complications, the "weakest link" being the transvenous/endocardial leads. The entirely subcutaneous defibrillator (S-ICD) has recently entered into the clinical scenario and represents a valid alternative to the transvenous device. S-ICD can provide substantial advantages, especially among some subgroups of patients (i.e. after device infection, in young patients and arrhythmogenic syndromes). However, given its characteristics, it is fundamental to choose patients that can benefit the most. In this review we will describe advantages and limitations of the SICD and point-out how to select the "ideal candidate" for the implantation.

Prevalence of venous occlusion in patients referred for lead extraction: implications for tool selection

AIMS

Data concerning the incidence of venous obstruction in patients referred for lead extraction is limited. Thus, we aimed to assess the incidence of venous obstruction in patients referred for lead extraction and the implications for tool selection.

METHODS AND RESULTS

Contrast venography of the access vein was obtained in 202 patients (147 men; mean age, 62.4 ± 14.5 years) scheduled for lead extraction. The indication for lead extraction included infection (n = 145, 72%) and other causes (n = 57, 28%). Two patients with device infection had superior vena caval occlusion. Access vein occlusion occurred in 6 (11%) patients without infection vs. 46 (32%) patients with infection [P = 0.002; odds ratio (OR) 3.94; 95% confidence interval (CI) 1.58-9.87]. No significant differences between occluded and non-occluded patients were seen for age, sex, device type, number of leads, time from implant of the initial lead, or anticoagulation therapy (all P>0.05). Procedural duration and fluoroscopy exposure time were significantly lower in the open group than in the occluded group (P < 0.05). Patients with venous occlusion required more advanced tools for lead extraction, such as dilator sheaths, evolution sheaths, and needle's eye snares (P = 0.019).

CONCLUSION

Both systemic and local infections are associated with increased risk of access vein occlusion. We found no support for the hypothesis that venous occlusion increases with the number of leads present. Lead extraction was more difficult in patients with venous occlusion, requiring advanced tools and more time.

Implanted endocardial lead characteristics and risk of stroke or transient ischemic attack

INTRODUCTION

Patent foramen ovale (PFO) has been recently implicated as a strong predictor of stroke or transient ischemic attack (TIA) in patients with implanted pacemaker or defibrillation leads. Leads in the right heart can form thrombi that embolize to the pulmonary circulation and raise pulmonary pressure. This increases right-to-left shunting through PFO or intrapulmonary shunts and can result in paradoxical embolism. We sought to determine whether certain lead characteristics confer a higher thrombogenic risk resulting in stroke/TIAs in patients either with or without a PFO.

METHODS

We retrospectively analyzed 5,646 patients (mean age 67.3 ± 16.3 years, 64 % male) who had endocardial device leads implanted in 2000-2010. We performed univariate and multivariate-adjusted proportional hazards models to determine association of lead characteristics with stroke/TIA during follow-up.

RESULTS

On univariate analysis, passively fixated tined leads were associated with more stroke/TIAs (HR 1.77, 95 % CI 1.27, 2.47; p<0.001), whereas presence of defibrillation coil was associated with fewer stroke/TIAs (HR 0.59, 95 % CI 0.42-0.84; p=0.003). Number of leads per patient, presence of atrial lead, maximum lead size, tip shape, and type of insulating material were not associated with stoke/TIA. On multivariate analyses adjusting for age, sex, diagnosis of PFO, and prior history of stroke/TIA, the presence of tined leads was associated with stroke/TIA (HR 1.41, 95 % CI 1.00-1.97; p=0.049). Defibrillation coils were no longer associated with lower stroke/TIA on multivariate analysis.

CONCLUSIONS

Most physical characteristics of contemporary leads do not impact rate of stroke/TIA among patients receiving implantable devices. The presence of a PFO is a major risk factor for stroke/TIA in patients with endovascular leads.

Automatic implantable cardiac defibrillator implantation may precipitate effort-induced thrombosis in young athletes: a case report and literature review

Upper extremity deep vein thrombosis (DVT) is a common finding after implantation of an automatic implantable cardiac defrillator (AICD). We describe the case of a patient who developed a left upper extremity DVT 4.5 months after implantation of an AICD and was found to have a lead-induced stenosis with possible underlying Paget-Schroetter syndrome (PSS) in the midbrachiocephalic vein on venography. While his symptoms resolved after the combination of pharmacomechanical thrombolysis, angioplasty, and anticoagulation, his long-term management is complicated by the presence of both PSS and lead-induced stenosis. Herein, we discuss his presentation, treatment, and future management options.

Complex cardiac pacing in the setting of a district general hospital: procedural success and complications

BACKGROUND AND PURPOSE

Complex cardiac pacing with either an implantable cardiovertor defibrillator (ICD) or a biventricular pacemaker with pacing only (CRT-P) or biventricular pacemaker with implantable cardiovertor defibrillator (CRT-D) plays an important role in the management of patients with heart failure. However, device implantation is associated with rare but significant complications which may limit the number of centres offering this treatment. The aim of this study is to define procedural success and complication rates associated with implantation of complex implantable cardiac devices in a district general hospital.

METHODS AND SUBJECTS

The pacing records of all the patients who underwent complex cardiac pacing (ICD, CRT-P and CRT-D) between January 2010 and December 2011 were reviewed. Information on clinical characteristics, pacing indications, venous access, implantation data, lead stability at follow-up, and procedure-related complications were obtained.

RESULTS

A total of 151 devices (60 CRT-Ds, 55 CRT-Ps and 36 ICDs), were implanted between January 2010 and December 2011 with a median follow-up of 12 months. Overall transvenous procedural success rate was 99.3%. 14 (9.3%) out of the 151 patients suffered a complication. There were no procedure-related deaths, and lead displacement (5.3%) was the most common complication. Other complications included pocket haematoma and phrenic nerve stimulation (1.3% and 3.4%, respectively). There were no cases of pneumothorax, cardiac tamponade, device-related infection, symptomatic venous thrombosis and stroke. Lead thresholds, in particular that of the left ventricular lead, remained stable during the follow-up period indicating persistent delivery of cardiac resynchronisation therapy in the group receiving CRT systems.

CONCLUSIONS

In the presence of necessary clinical expertise, complex cardiac devices can be implanted successfully and with a high degree of safety in the setting of a district general hospital.

Suitability for subcutaneous defibrillator implantation: results based on data from routine clinical practice

OBJECTIVE

To assess the proportion of current implantable cardioverter defibrillator (ICD) recipients who would be suitable for a subcutaneous lead ICD (S-ICD).

DESIGN

A retrospective cohort study.

SETTING

Tertiary care facility in the Netherlands.

PATIENTS

All patients who received a single- or dual-chamber ICD in the Leiden University Medical Center between 2002 and 2011. Patients with a pre-existent indication for cardiac pacing were excluded.

MAIN OUTCOME MEASURE

Suitability for an S-ICD defined as not reaching one of the following endpoints during follow-up: (1) an atrial and/or right ventricular pacing indication, (2) successful antitachycardia pacing without a subsequent shock or (3) an upgrade to a CRT-D device.

RESULTS

During a median follow-up of 3.4 years (IQR 1.7-5.7 years), 463 patients (34% of the total population of 1345 patients) reached an endpoint. The cumulative incidence of ICD recipients suitable for an initial S-ICD implantation was 55.5% (95% CI 52.0% to 59.0%) after 5 years. Significant predictors for the unsuitability of an S-ICD were: secondary prevention, severe heart failure and prolonged QRS duration.

CONCLUSIONS

After 5 years of follow-up, approximately 55% of the patients would have been suitable for an S-ICD implantation. Several baseline clinical characteristics were demonstrated to be useful in the selection of patients suitable for an S-ICD implantation.

Relationship between changes in selected thrombotic and inflammatory factors, echocardiographic parameters and the incidence of venous thrombosis after pacemaker implantation based on our own observations

INTRODUCTION

Thrombosis (VTh) is a rare dangerous complication of pacemaker implantation (PM). The aim of the study was to determine the dynamics of change in selected thrombotic and inflammatory factors after PM.

MATERIAL AND METHODS

The study involved 81 patients (30 female, mean age: 71.1 years) with PM, divided into two groups. Group A (71 patients) consisted of patients without VTh, whereas group B (10 patients) comprised the patients with VTh. A transthoracic echocardiogram (TTE) and a venous ultrasound (VU) examination were performed. The levels of D-dimers, fibrinogen, tissue factor (TF), factor VII, plasminogen activator inhibitor-1 (PAI-1), interleukin-6 (IL-6) and high-sensitivity C-reactive protein (hsCRP) were determined in the venous blood. After PM, the TTE and VU examinations were repeated at 6 and 12 months, and blood analyses were performed within 7 days after PM, and subsequently at 6 and 12 months.

RESULTS

In 10 patients of group B, symptomatic VTh occurred at a mean time of 13.06 months after PM. Initially, the levels of IL-6, hsCRP, D-dimers, fibrinogen, TF, VII factor and PAI-1 were considerably higher in group B than in group A. In all patients the levels of these factors kept on increasing for up to 7 days after the procedure. In group A they subsequently decreased, whereas in group B they continued to rise.

CONCLUSIONS

Increased levels of inflammatory and thrombotic factors were observed in patients with VTh before and after PM. The factors of highest risk of VTh occurrence were D-dimers, fibrinogen and TF.

Endovascular recanalization of central venous access to allow for pacemaker implantation or upgrade

BACKGROUND

Several patients undergoing permanent pacemaker (PPM) implantation/upgrade present with difficult access due to sub- or total central vein occlusion. Our institution has used the endovascular approach to recanalize central veins to allow for subsequent PPM implantation. Here we aim to describe the feasibility and safety of using this approach to allow for PPM implantation/upgrade.

METHODS

From October 2006 to November 2010, 50 consecutive patients who underwent central vein recanalization prior to PPM implantation were included in this analysis.

RESULTS

The population's mean age was 70 years, with a high rate of comorbidities including chronic renal failure (52.0%), congestive heart failure (64.0%), diabetes (33.3%) and peripheral vascular disease (36.0%). The endovascular recanalization procedure was performed via femoral access in all patients; however adjuvant brachial access was required in 13 cases and subclavian vein in one. Subclavian vein (74.5%) followed by innominate vein (21.6%) were the most common locations/target for recanalization. Successful vein recanalization followed by successful PPM implantation/upgrade was achieved in 48 patients (96.0%) without peri-procedural complications. Two patients died during the hospitalization, one due to severe respiratory failure and a second due to complicated end-stage renal disease, although neither was related to the endovascular procedure. No other event, including myocardial infarction, cerebral-vascular accident, bleeding/transfusion, or renal failure was identified.

CONCLUSIONS

This study proved the feasibility and safety of the endovascular approach to recanalize central veins in patients with poor vascular access to allow for further PPM implantation/upgrade.