Lead Placement In Patients Research Articles

Lead placement in extravascular ICD recipients: the first step to prevent P-wave oversensing

Abstract Background Extravascular (EV) implantable cardiac defibrillators (ICD) with substernal lead have recently proved to be a safe and effective alternative to conventional transvenous (TV) and subcutaneous defibrillators (S-ICDs) 1, owing to the possibility to deliver antitachycardia and asystole pacing while saving intravascular hardware. However, inappropriate shock delivery occurred in 9.7% of patients, and P-wave oversensing accounted for 42% of inappropriate shocks in the EV ICD Pivotal Study. Purpose to investigate the difference of lead placement in patients with and without P-wave oversensing. Method 17 patients undergoing implantation as part of the EV ICD Pivotal Study received the substernal lead placement based on computer tomography imaging (CT) and following the protocol recommendations. Lead placement beyond the left lateral sternum border was attempted whenever possible, based on CT guidance. P-wave detectability (P detected visually but non sensed by the device) on the sensing vector and P-wave oversensing by the device were investigated at each follow-up. The distance of sensing ring electrodes (R1 and R2) from the mid-spine line (line connecting the spinous processes from cervical to lumbar vertebral processes) was measured in each patient on the posterior-anterior chest radiogram. Results Mean age, BMI, NYHA class and left ventricular ejection fraction (LVEF) were respectively 53±9yrs, 25.3 ±6 kg/m2, 2 ±0.7, and 39±14%. The main aetiology was non-ischemic cardiomyopathy (12/17), including 3 arrhythmogenic cardiomyopathy patients and one with hypertrophic cardiomyopathy. The implantation was successful in 16 (6 females) out of 17 patients without any complication, with one implant failure due to inadequate sensing (0,5 mV) despite several attempts at tunnelling in different locations (rightward and leftward of the sternum). One patient with P-wave detectability had lead dislodgement after 2 weeks, and underwent repositioning to a more leftward location, where P-wave was not detectable. Only one patient had P-wave oversensing at follow-up, and received inappropriate shocks (Figure A); the remaining 15 patients neither had detectable P-wave on the sensing vector nor inappropriate shocks (Figure B). The median sensing amplitude at implantation was 2,7±1.4 mV and 2.6±1.2 mV along a 18±4 months follow-up, with R1-R2 being the final sensing vector chosen for 14/16 and R2-Can for 2/16 patients. The distance of R1 and R2 from the mid-spine line was significantly longer in patients with detectable P-wave compared to those without (37±13mm vs 18 mm and 30±15 vs 16 mm, respectively). Conclusions Placement of the EV ICD lead leftward to the left sternum border is safe, and prevents P-wave detection. The mid-spine line represents an easy landmark to guide lead placement during implantation. R1 distance ≥ 25 mm and R2 distance ≥ 20 mm from the mid-spine line provide a reliable marker of freedom from P-wave oversensing.Figure AFigure B

The usefulness of proximal anchor balloon technique during implantation of a cardiac resynchronization therapy device in a patient with complex coronary venous anatomy: a case report

BackgroundCardiac resynchronization therapy (CRT) is an accepted device treatment in stable heart failure (HF) patients. In recent years increased awareness of coronary anatomy and implantation techniques have significantly impacted this evolving therapy.Case presentationIn this article, we present a case describing the usefulness of the proximal balloon anchoring technique to enable initial coronary sinus (CS) cannulization and left ventricular (LV) lead placement in the tortuous coronary sinus during CRT implantation.ConclusionsThe proximal anchor balloon technique can easily enable coronary sinus cannulization and left ventricular lead placement in patients with complex venous anatomy.

Radionuclide imaging for feasibility of target left ventricular lead placement in patients with heart failure scheduled for cardiac resynchronization therapy

Aim. To assess the feasibility and effectiveness of target left ventricular (LV) lead placement using the radionuclide imaging and changes of myocardial perfusion (MP) and cardiac sympathetic neural activity (SNA) in patients with heart failure (HF) before and after cardiac resynchronization therapy (CRT). Material and methods . This prospective, observational study included 15 patients (9 men, 61 [58; 72] years old) with HF who were referred for CRT Patients underwent radionuclide imaging with assessment of MP and cardiac SNA with 123I -MIBG. All patients underwent implantation of CRT devices with target LV lead placement. Target LV lead placement was performed in accordance with preoperative data on 99m Tc-MIBI myocardial perfusion scintigraphy and intraoperative data on coronary sinus (CS) anatomy. After successful implantation, patients were assigned to the group 1 (target LV lead placement). In case of targeted placement inability, the LV lead was implanted into the available CS branches — group 2. The patients were followed up within period of 3-6 months after surgery. Results. Target LV lead placement was performed in 9 (60%) of 15 patients (group 1). In 6 (40%) of 15 patients, targeted implantation was not possible and LV lead was implanted anatomically (group 2). The follow-up period was 4 [3.5; 4.5] months. Patients from group 1 demonstrated a significant improvement of myocardial perfusion compared with preoperative data: summed stress score improved from 16,2±12,2 to 10,8±12,8 (p=0,007), summed rest score — from 15,2±12,5 to 9,8±12,9 (p=0,008), respectively. A significant change in the 123I -MIBG scintigraphy of cardiac SNA was also observed: an improvement in the delayed heart/mediastinum ratio from 1,4±0,2 to 1,63±0,1 (p=0,02) and an improvement in the washout rate from 13,2±5,6% to 7,8±4,7% (p=0,026), respectively. These parameters did not show any significant difference between the groups and within the anatomical positioning group. Conclusion. In patients with HF scheduled for CRT the target LV lead placement using radionuclide imaging results in an improvement of myocardial perfusion and cardiac SNA compared with baseline data and does not have differences compared to anatomical positioning. Further studies are needed to assess the role of radionuclide imaging in CRT.

Clinical outcomes of pallidal deep brain stimulation for dystonia implanted using intraoperative MRI.

Lead placement for deep brain stimulation (DBS) using intraoperative MRI (iMRI) relies solely on real-time intraoperative neuroimaging to guide electrode placement, without microelectrode recording (MER) or electrical stimulation. There is limited information, however, on outcomes after iMRI-guided DBS for dystonia. The authors evaluated clinical outcomes and targeting accuracy in patients with dystonia who underwent lead placement using an iMRI targeting platform. Patients with dystonia undergoing iMRI-guided lead placement in the globus pallidus pars internus (GPi) were identified. Patients with a prior ablative or MER-guided procedure were excluded from clinical outcomes analysis. Burke-Fahn-Marsden Dystonia Rating Scale (BFMDRS) scores and Toronto Western Spasmodic Torticollis Rating Scale (TWSTRS) scores were assessed preoperatively and at 6 and 12 months postoperatively. Other measures analyzed include lead accuracy, complications/adverse events, and stimulation parameters. A total of 60 leads were implanted in 30 patients. Stereotactic lead accuracy in the axial plane was 0.93 ± 0.12 mm from the intended target. Nineteen patients (idiopathic focal, n = 7; idiopathic segmental, n = 5; DYT1, n = 1; tardive, n = 2; other secondary, n = 4) were included in clinical outcomes analysis. The mean improvement in BFMDRS score was 51.9% ± 9.7% at 6 months and 63.4% ± 8.0% at 1 year. TWSTRS scores in patients with predominant cervical dystonia (n = 13) improved by 53.3% ± 10.5% at 6 months and 67.6% ± 9.0% at 1 year. Serious complications occurred in 6 patients (20%), involving 8 of 60 implanted leads (13.3%). The rate of serious complications across all patients undergoing iMRI-guided DBS at the authors' institution was further reviewed, including an additional 53 patients undergoing GPi-DBS for Parkinson disease. In this expanded cohort, serious complications occurred in 11 patients (13.3%) involving 15 leads (10.1%). Intraoperative MRI-guided lead placement in patients with dystonia showed improvement in clinical outcomes comparable to previously reported results using awake MER-guided lead placement. The accuracy of lead placement was high, and the procedure was well tolerated in the majority of patients. However, a number of patients experienced serious adverse events that were attributable to the introduction of a novel technique into a busy neurosurgical practice, and which led to the revision of protocols, product inserts, and on-site training.

Chapter 22 - Electrophysiologic mapping for deep brain stimulation for movement disorders

Electrophysiologic mapping remains an integral component of deep brain stimulation (DBS) surgical procedures, particularly in movement disorder cases where functional maps are used to guide DBS lead placement in patients with Parkinson's disease, dystonia, or tremor. Overall, the goal of the surgical procedure is to implant the distal end of a chronic, multicontact depth electrode into a specific brain region for the purpose of delivering therapeutic electrical stimulation. Regions that are currently targeted for patients with movement disorders include the subthalamic nucleus, the ventral intermediate nucleus of the thalamus, and the globus pallidus. Multiple imaging modalities are used initially to derive a stereotactic plan and guide the initial microelectrode trajectory. Changes in neuronal firing rate and pattern, both spontaneous and in response to somatosensory stimulation, are used to establish the location of the tip of the microelectrode(s), while acute stimulation can be used to estimate the proximity of neighboring brain regions. In this chapter, we will provide an overview of the microelectrode recording process as it is commonly applied to refine image-based targeting of lead placement for DBS surgery.

Surface electrogram-guided left ventricular lead placement improves response to cardiac resynchronization therapy.

ObjectiveFailure to select the optimal left ventricular (LV) segment for lead implantation is one of the most important causes of unresponsiveness to the cardiac resynchronization therapy (CRT). In our study, we aimed to investigate the echocardiographic and clinical benefits of LV lead implantation guided by an intraoperative 12-lead surface electrocardiogram (ECG) in patients with multiple target veins.MethodsWe included 80 [42 (62.5%) male] heart failure patients who successfully underwent CRT defibrillator (CRT-D) implantation. Patients were divided into two groups. In group 1, LV lead was positioned at the site with the shortest biventricular-paced (BiV-paced) QRS duration (QRSd), as intraprocedurally measured using surface ECG. In group 2 (control), we included patients who underwent the standard unguided CRT. ECG, echocardiogram, and functional status were evaluated before and 6 months after CRT implantation in all patients.ResultsIn group 1, BiV-paced QRSd measurements were successfully performed in 112 of 120 coronary sinus branches during CRT and an LV lead was successfully placed at the optimal site in all patients. Compared with group 2, group 1 had a significantly higher rate (85% vs. 50%, p=0.02) of response (>15% reduction in LV end-systolic volume) to CRT as well as a shorter QRSd (p<0.001) and a greater QRS shortening (∆QRS) associated with CRT compared with baseline (p<0.001). The mean New York Heart Association functional class was significantly improved in both groups, and no significant differences were found in clinical response to CRT (85% vs. 70%, p=0.181).ConclusionSurface ECG can be used to guide LV lead placement in patients with multiple target veins for improving response to CRT. Thus, it is a safe, feasible, and economic approach for CRT-D implantation.

Correlation of diffusion tensor tractography and intraoperative macrostimulation during deep brain stimulation for Parkinson disease.

The purpose of this study was to investigate whether diffusion tensor imaging (DTI) of the corticospinal tract (CST) is a reliable surrogate for intraoperative macrostimulation through the deep brain stimulation (DBS) leads. The authors hypothesized that the distance on MRI from the DBS lead to the CST as determined by DTI would correlate with intraoperative motor thresholds from macrostimulations through the same DBS lead. The authors retrospectively reviewed pre- and postoperative MRI studies and intraoperative macrostimulation recordings in 17 patients with Parkinson disease (PD) treated by DBS stimulation. Preoperative DTI tractography of the CST was coregistered with postoperative MRI studies showing the position of the DBS leads. The shortest distance and the angle from each contact of each DBS lead to the CST was automatically calculated using software-based analysis. The distance measurements calculated for each contact were evaluated with respect to the intraoperative voltage thresholds that elicited a motor response at each contact. There was a nonsignificant trend for voltage thresholds to increase when the distances between the DBS leads and the CST increased. There was a significant correlation between the angle and the voltage, but the correlation was weak (coefficient of correlation [R] = 0.36). Caution needs to be exercised when using DTI tractography information to guide DBS lead placement in patients with PD. Further studies are needed to compare DTI tractography measurements with other approaches such as microelectrode recordings and conventional intraoperative MRI-guided placement of DBS leads.

A novel approach to eliminate intraventricular lead placement in patients with congenital heart disease

We describe two patients with congenital heart disease who were referred for implantable cardioverter-defibrillator (ICD) placement. Both patients possessed factors causing the conventional transvenous approach to be undesirable. We therefore devised a technique which circumvented both intravascular ICD lead placement, as well as placement of leads across the tricuspid valve. For both patients, a bipolar pace-sense lead was successfully placed in a branch of the coronary sinus. A shocking coil was then tunneled from the posterolateral margin of the device pocket, being positioned posterior and inferior to the cardiac silhouette. Defibrillation testing was carried out with goal of a 10-J safety margin. We were able to successfully achieve ICD implantation in both patients with complex congenital heart disease without requirement for surgical thoracotomy or a lead across the AV valve. R waves in excess of 5 mV were obtained and acceptable defibrillation characteristics were achieved. Both patients are doing well after mid-term follow-up. A new implant approach is presented, which involves minimal intravascular hardware and eliminates passage across the atrioventricular valve for patients with congenital heart disease in whom conventional ICD implant techniques may be undesirable or not possible. This procedure is technically straightforward with proper technique and knowledge of the patient specific anatomy.

Left Ventricular Pacing in Right Ventricular Cardiomyopathy: Blessing or Blunder?

Arrhythmogenic right ventricular dysplasia (ARVD) predominantly involves the right ventricle, and myocardium is progressively replaced by fat and fibrous tissue in the apex, base, and outflow tract regions. This pathology, and the progressive nature of the disease, poses special challenges for implant and subsequent appropriate functioning of an implantable cardioverter-defibrillator. This case report describes a solution to problems during lead placement in patients with ARVD.

Characterization of the suitability of coronary venous anatomy for targeting left ventricular lead placement in patients undergoing cardiac resynchronization therapy

Recent studies suggest differences in coronary venous anatomy between patients with ischaemic (I) and non-ischaemic (N) cardiomyopathy. We hypothesize that these differences may affect the potential for left ventricular (LV) lead targeting in patients undergoing cardiac resynchronization therapy. The retrograde contrast venograms were retrospectively reviewed in 133 patients (age 68 +/- 9 years, 101 males). The quantity and distribution of veins were recorded as well as the final lead position. There were no major differences in the distribution of LV lead positions between I and N [posterior vein, 14.0% (I) vs. 15.8% (N); posterolateral vein, 21.1 vs. 18.4%; lateral vein, 59.7 vs. 50.0%; anterolateral vein, 3.5 vs. 13.2%; P= NS]. Excluding the middle and great cardiac veins, in total only 59 of 133 patients had more than one suitable vein as potential targets for LV lead placement (I, 36.8% vs. N, 50.0%; P = 0.16). Underlying aetiology does not affect the quantity and distribution of coronary veins available for LV lead placement. The limitations of venous anatomy restrict LV lead placement to a single vein with little scope for site selection in almost half of all the patients. Given these limitations, in many patients, prospective targeting of LV lead placement may require a direct surgical approach.

Epicardial versus Transvenous Left Ventricular Lead Placement in Patients Receiving Cardiac Resynchronization Therapy: Results from a Randomized Prospective Study

The aim of this prospective study was to determine the differences in left ventricular (LV) lead positioning for cardiac resynchronization therapy (CRT): comparing a percutaneous transvenous approach via the coronary sinus versus epimyocardial placement via a left lateral mini-thoracotomy. Eighty consecutive patients with symptomatic left ventricular dysfunction and an indication for CRT were randomized to receive either a transvenous (n = 40) or epicardial (n = 40) LV-lead placement. Postoperative follow-up included assessment of NYHA functional class, ECG and echocardiography. The transvenous group had a shorter ICU stay (0.66 vs. 3.8 days) and shorter ventilation times (0.34 vs. 3.2 h). The epicardial group had less exposure to radiation (7.4 vs. 23 min) and required less use of contrast medium (3.24 vs. 61 ml). At 6 months follow-up, no major differences in LV-lead parameters (threshold, sensing, and impedance) were observed. Both epicardial and transvenous LV-lead placement for CRT therapy are safe and effective. The transvenous approach is less invasive and should be considered the standard procedure for patients without renal insufficiency. However, in a case of difficult coronary venous anatomy with the inability to position the lead as desired, epicardial LV-lead placement remains an alternative option.

Percutaneous coronary venous stenting to facilitate placement of a left ventricular lead

Cardiac resynchronisation therapy (CRT) is increasingly utilised in the treatment of patients with advanced heart failure. In up to 10% of eligible patients device implantation is technically impossible due to an inability to site the left ventricular lead, one cause for which is focal venous stenosis. In such cases percutaneous coronary venoplasty is becoming an accepted technique [1], the standard alternative being epicardial lead placement. There are, however, few reports of stenting of the vein to facilitate lead access. Here we describe a case where percutaneous coronary venous stenting allowed optimal placement of the left ventricular (LV) lead in a patient with coronary venous stenoses that had not responded adequately to venoplasty. We also review the literature about coronary venous stenting to facilitate left ventricular lead placement in patients with unfavourable venous anatomy. 2. Case details

A novel technique for right ventricular lead placement in a patient with a persistent left superior vena cava

Persistent left superior vena cava is the most common venous anomaly of the thorax. If unrecognized, it could lead to catheter malplacement and even vascular injuries. We describe a novel use of a Worley sheath for the delivery of a right ventricular (RV) endocardial pacing lead in a 65-year-old male with a persistent left superior vena cava. After failed attempts with the standard stylets, use of the Worley sheath aided successful lead deployment. We conclude that when used appropriately, the Worley sheath is a tool that could be helpful in pacing lead placement in patients with persistent left superior vena cava.

Epicardial versus tranvenous approach for left ventricular lead placement in patients receiving CRT – a randomized prospective study

Aims: CRT is an effective treatment for patients with heart failure and intraventricular conduction delay. The aim of this study is to determine the most advantageous method of placing the left ventricular (LV) lead – transvenous intubation of the coronary sinus versus epimyocardial placement via a lateral mini-thoracotomy using a randomized prospective trial.

P2-95: Symptomatic and exercise capacity effects of right ventricular septal lead placement in patients with high degree atrioventricular block

A number of recent studies have demonstrated the potentially detrimental effects of right ventricular apical (RVA) pacing on left ventricular function and development of heart failure, but whether these effects can be mitigated by pacing from elsewhere in the RV remains unclear. We studied 58 unselected, consecutive patients with high-degree atrioventricular (AV) block (mean age 74.7±11.5 years, 36 male), randomised to receive a passive RVA lead (n = 26) or an active fixation RV septal (RVS) lead (n = 32). Follow-up was at 24 hours, 1, 6, 12 and 18 months. We measured exercise capacity using the 6 minute hall walk (6MHW, meters), and quality of life using the Minnesota Living With Heart Failure (MLWHF) score and the Cardiac Symptom Score (CSS). There were no differences between groups pre-implant with similar distribution of other cardiac conditions (hypertension, ischaemic heart disease, previous cardiac surgery, valve disease etc). At 1 month, RVA 6MHW was 259.5±81.3, RVS 289.3±110.9 [NS]) but at 18 months RVS patients showed greater 6MHW distance (RVA: 271.3±132.7 versus RVS: 336.9±124.6, p<0.05). MLWHF score showed no significant differences at 1 month (RVA: 16.64±14.27 versus RVS:17.50±19.22) or at 18 months (RVA: 19.16±17.19 versus RVS: 18.27±21.00) although RVS was better at 6 and 12 months. CSS showed no significant difference between groups at 18 months (RVA: 15.30+20.50 versus RVS: 12.67+14.52). No measurement showed any detrimental effect of RVS over RVA pacing at any time point or between groups.

Suitability of coronary sinus tributaries for left ventricular lead placement in patients undergoing cardiac resynchronization therapy

Suitability of coronary sinus tributaries for left ventricular lead placement in patients undergoing cardiac resynchronization therapy