Delayed Cardiac Perforation by Defibrillator Lead Placed in the Right Ventricular Outflow Tract Resulting in Massive Pericardial Effusion

A 76‐year‐old man received a dual‐chamber implantable cardioverter defibrillator (ICD), with the defibrillator lead positioned within the right ventricular outflow tract. The lead parameters at the time of implantation were satisfactory and the postprocedure chest X‐ray showed the leads were in place. The patient was cardioverted from atrial fibrillation during defibrillation threshold testing and commenced on anticoagulation immediately. One month post implantation, he experienced multiple ventricular tachycardia episodes all successfully treated with antitachycardia pacing and shocks by his ICD, but he fell and hit his chest against a hard surface during one of these attacks. He developed a massive pericardial effusion and computed tomography confirmed cardiac perforation by the defibrillator lead. Pericardiocentesis was performed and the defibrillator lead replaced with a different model positioned at the right ventricular apex. The patient made an uneventful recovery. The management and avoidance of delayed cardiac perforation by transvenous leads were discussed.     

Unsatisfying Results in Long-Term Atrial Pacing with a Bipolar Active Fixation Atrial Lead

A high dislodgment rate during long-term atrial pacing using the unipolar sickle-shaped active fixation lead was recently reported; therefore, the long-term results of atrial pacing in 118 consecutive patients with the bipolar sickle-shaped active fixation lead (Biotronik FH60-BP) were evaluated. Between January 1989 and September 1993, 87 leads (74%) were inserted for dual chamber pacing and 31 leads (26%) for atrial pacing only. At the time of implantation, the bipolar atrial electrogram had a mean voltage of 4.4 ± 1.6 mV, whereas the acute atrial threshold was 0.72 ± 0.38 V and 1.46 ± 0.67 ml at 0.5-msec pulse duration and mean resistance 506 ± 79 Ω. Early lead dislodgment (< 1 month after implantation) occurred in 9 patients (7.6%). During a mean follow-up of 21.8 months (median 20.9 months), late dislodgment (> 1 month after implantation) occurred in 6 patients (5.1%) after a mean interval of 7.9 months (range 3–14 months). Due to the unacceptably high late dislodgment rate, which to date remains unexplained, new implants of this lead are not recommended.     

ICD Lead Implantation Following Sharp Cannulation of a Blocked Superior Vena Cava

Blocked superior vena cava (SVC) presents a well‐recognized problem for the implantation of device leads. Implantable cardioverter defibrillator (ICD) leads pose a greater challenge than the pacing leads by requiring an adequate shock vector for successful defibrillation. We present here a novel technique of opening the blocked SVC to facilitate ICD lead implantation through the upper venous system. (PACE 2011; 34:e82–e84)     

Near‐Fatal ICD Lead Dysfunction with Implications for ICD Testing

A 31‐year‐old male patient with an implantable cardioverter defibrillator (ICD) experienced ventricular fibrillation. After resuscitation, no communication between the device and an ICD programmer was possible. The ICD was explanted, no signs of destruction were visible, and the ICD leads revealed normal values. A new ICD was implanted, interrogation values were stable. However, immediately after defibrillation testing the connection between programmer and ICD was interrupted and could not be established again. The device showed burn marks and a hole in the can. Analysis revealed an isolation defect of the ICD lead, which was not detectable with standard interrogation.     

Transvenous Extraction Performance of Expanded Polytetrafluoroethylene Covered ICD Leads in Comparison to Traditional ICD Leads in Humans

Background: In the Endotak Reliance G defibrillating leads (Guidant Corporation, St. Paul, MN, USA), coils are covered with expanded polytetrafluoroethylene (ePTFE) to prevent tissue ingrowth. The aim of the study was to evaluate transvenous extraction performance, outcomes, and fibrotic adherences rate of ePTFE defibrillating leads in comparison to traditional non‐ePTFE cardiac defibrillator (ICD) leads. Methods: Seventeen consecutive ICD recipients (ePTFE Group A, 16 men, mean age 66 ± 12 years) with 17 Endotak Reliance G dual‐coil ICD leads (mean implantation time 23 ± 26 months) underwent a transvenous removal procedure. They were compared with two control groups, including 20 Sprint Quattro 6944 (non‐ePTFE Group B; Medtronic Inc., Minneapolis, MN, USA) and 36 Riata 1570 ICD leads (non‐ePTFE Group C; St. Jude Medical, St. Paul, USA). The indication for lead extraction was local infection in 35 patients (48%), sepsis in 24 patients (33%), and lead malfunction in 14 patients (19%). Results: In all groups, all leads were successfully and completely removed without major complications. Overall manual traction was effective in six patients (8%) and more effective in the ePTFE Group (29%) compared to Group B (0%) and Group C (3%) (P = 0.001). Sixty‐seven leads (92%) required mechanical dilatation by the venous entry site approach, with a shorter extraction time in the ePTFE Group (5 ± 11 min) compared to Group B (21 ± 22 min) and Group C (16 ± 22 min) (P = 0.003). ePTFE leads showed a lower rate of fibrotic adherences at the superior vena cava level (P = 0.01) without statistically significant differences in the other sites. Conclusions: ePTFE‐covered leads may be removed more easily and quickly than non‐ePTFE leads, requiring less frequently mechanical dilatation. (PACE 2010; 1376–1381)     

Initial Experience with Transvenous Implantable Cardioverter Defibrillator Lead Systems: Operative Morbidity and Mortality

Introduction of non-thoracotomy lead systems™ (Medtronic, Inc.) for the implantable cardioverter defibrillator (ICD) has expanded the indications for use of this mode of therapy. Patients previously considered "too ill" to undergo a thoracotomy as well as patients who are at a high risk for developing sudden death but without previous cardiac arrest, are now considered candidates. The initial experience with the non-thoracotomy lead system at our institution was analyzed for morbidity and mortality. Thirty-four patients underwent attempted intravascular lead implantation, with 30 having initial successful implantation (88.2%). There were 23 males; average ejection fraction (EF) was 38.6%. Three patients developed pulmonary edema and low output immediately after the procedure. Three patients developed electromechanical dissociation during defibrillation threshold testing. A prolonged testing time for the non-thoracotomy lead system was noted when compared to the thoracotomy system (57.39 vs 32.30 min; P < 0.0000). There were more intraoperative morbidities with the non-thoracotomy leads than with the thoracotomy system. There were no perioperative deaths. The potential consequences of prolonged anesthesia time and extensive defibrillation threshold testing should be considered when choosing the route of ICD implant, the type of anesthesia, and the intraoperative testing protocol for each patient.     

Clinical Results with Electrophysiologist-Implanted Cardioverter-Defibrillators

With the advent of nonthoracotomy leads and smaller devices. implantation techniques for implantable cardioverters defibrillators (ICDs) have been simplified. We reviewed the outcome of pectoral ICD implantation by electrophysiologists in 51 consecutive patients, 47 males and 4 females, mean age 60 ± 12 years, presenting with aborted sudden cardiac death (14) and drug refractory hypotensive ventricular tachycardia (37). Patients were implanted with either the PCD Jewel^TM 7219D (37) or 72197C (14) Medtronic pectoral ICDs. The mean operative time was 98 ± 31 minutes. There was no operative mortality. Complications occurred in 2 (4%) patients: right ventricular lead dislodgement requiring lead repositioning occurred in 1 patient, and 1 patient treated with anticoagulants, who had received a subcutaneous patch lead, developed a hematoma not requiring surgical reintervention. The mean defibrillation threshold was 18.6 ± 5.5 J, but was significantly lower for the 7219C(14.1 ± 5.0 J) compared to the 7219D (20.6 ± 4.4J) device, P = 0.0001. A two-lead system consisting of a right ventricular electrode (RVA) and a superior vena caval lead (SVC) was utilized in 29, RVA/SVC-subcutaneous patch in 5 and active can in 17 patients, Patients were discharged after 4.3 ± 3 days. The procedure time was significantly shorter for the 7219C device (79.7 ± 18.9 vs 105.2 ± 32.8 minutes., P = 0.0035]. Over the fallow-up period of 8 ± 5 (range 1–20] months, 26% patients received appropriate therapy (95% antitachycardia pacing, 5% shock). Concomitant antiarrhythmic therapy was utilized in 41% of patients. Ninety-eight percent of patients are alive. One patient died of congestive heart failure. Clinical results with electrophysiologist-implanted pectoral ICDs demonstrate lou morbidity and no operative mortality in this clinical series and lower DFTs and shorter procedure times may be achieved with 7219C (active can) device.     

Implantation of a Dual Chamber Pacing and Sensing Single Pass Defibrillation Lead

GRADAUS, R., et al. : Implantation of a Dual Chamber Pacing and Sensing Single Pass Defibrillation Lead. Dual-chamber ICDs are increasingly used to avoid inappropriate shocks due to supraventricular tachycardias. Additionally, many ICD patients will probably benefit from dual chamber pacing. The purpose of this pilot study was to evaluate the intraoperative performance and short-term follow-up of an innovative single pass right ventricular defibrillation lead capable of bipolar sensing and pacing in the right atrium and ventricle. Implantation of this single pass right ventricular defibrillation lead was successful in all 13 patients (  age 63 ± 8 years  ; LVEF  0.44 ± 0.16  ; New York Heart Association [NYHA]  2.4 ± 0.4  , previous open heart surgery in all patients). The operation time was  79 ± 29  minutes, the fluoroscopy time  4.7 ± 3.1  minutes. No perioperative complications occurred. The intraoperative atrial sensing was  1.7 ± 0.5 mV  , the atrial pacing threshold product was  0.20 ± 0.14 V/ms  (  range 0.03–0.50 V/ms  ). The defibrillation threshold was  8.8 ± 2.7 J  . At prehospital discharge and at 1-month and 3-month follow-up, atrial sensing was  1.9 ± 0.9, 2.1 ± 0.5, and 2.7 ± 0.6 mV  , respectively, (  P = NS, P < 0.05, P < 0.05  to implant, respectively), the mean atrial threshold product  0.79, 1.65, and 1.29 V/ms  , respectively. In two patients, an intermittent exit block occurred in different body postures. All spontaneous and induced ventricular arrhythmias were detected and terminated appropriately. Thus, in a highly selected patient group, atrial and ventricular sensing and pacing with a single lead is possible under consideration of an atrial pacing dysfunction in 17% of patients.     

Survival of Transvenous ICD Leads in Young Patients

Background : In adults, transvenous implantable cardioverter defibrillator (ICD) lead failure rates are significant, and their occurrence increases with time from implant. There are limited data in children. The goal of this study was to assess lead survival in young patients undergoing ICD implantation at a single center. Methods : Records of patients under 21 years old with transvenous ICD leads implanted at our center from June 1997 to August 2007 were retrospectively reviewed. Age, weight, height, diagnosis, lead and generator model, venous access technique, generator position, pacing thresholds, lead impedance, and R wave size were recorded. “Lead failure” was defined as any lead problem requiring surgical intervention to restore proper function to the ICD system. Results : Seventy‐one transvenous leads were included (70 patients). Average age at implant was 14.8 years (range 5.7–19.5). All the devices were implanted by a single operator (HMS). Venous access was obtained via cephalic cutdown in 66/71. Mean follow‐up time was 2.8 years (range 0.2–7.8 years, median 2.3 years). There were no infections requiring explantation. There were four lead failures. Three were lead fractures, occurring 12, 13, and 19 months after implant. The fourth lead failed when an arrhythmia was not appropriately detected, and a second dedicated rate‐sensing lead was thus implanted. Univariate analysis did not identify any variable to be a significant predictor of lead failure. Kaplan–Meier survival analysis demonstrated 5‐year lead survival at 89.6%. Conclusions : ICD lead survival in children, when performed by an experienced operator, is similar to that found in adults. (PACE 2010; 33:186–191)     

Improved Sensing Signals After Endocardial Defibrillation with a Redesigned Integrated Sense Pace Defibrillation Lead

Adequate sensing is a basic requirement for appropriate therapy with ICDs. Integrated sense pace defibrillation leads, which facilitate ICD implantation, show a close proximity of sensing and defibrillation electrodes that might affect the sensing signal amplitude by the high currents of internal defibrillation. In 99 patients, we retrospectively examined two integrated sense pace defibrillation leads, eitherboth with a distance of 6 mm between the tip of the lead (sensing cathode) and the right ventricular defibrillation electrode (sensing anode) or one with a distance of 12 mm. Three seconds after a shock of 20 J, mean sensing signal amplitude during sinus rhythm (SR) decreased from 10.5 ± 4.3 mVto 5.1 ± 3.7 mV (P < 0.001) for the 6-mm lead, but showed no significant decrease for the 12-mm lead. The degree of signal reduction was inversely related to the time passed since defibrillation. Significant differences in reduction of sensing signal amplitude concerning monophasic and biphasic shocks could not be observed. Mean sensing signal amplitude of VF after shocks that failed to terminate it decreased in the same order as during SR (from 8.3 ± 4.1 mV to 4.1 ± 3.2 mV), but resulted in no failure of redetection during ongoing VF. DFTs did not differ for the 6-mm and the 12-mm lead. In conclusion, close proximity of the right ventricular defibrillation coil to the sensing tip of an integrated sense pace defibrillation lead causes energy and time related reductions in sensing signal amplitude after defibrillation, and might cause undersensing in the postshock period. A new lead design with a more proximal position of the right ventricular defibrillation coil avoids these problems without impairing DFTs.     

Nontraditional Implantable Cardioverter Defibrillator Placement in Adult Patients with Limited Venous Access: A Case Series

Background: Conventional transvenous approaches for implantable cardioverter defibrillator (ICD) lead placement are not possible in some patients with limited venous access or severe tricuspid valve dysfunction. Methods: We retrospectively identified six patients who underwent ICD placement or revision requiring nontraditional alternative surgical lead placement at our institution between November 2006 and August 2008. The baseline and operative patient characteristic data were accumulated and reviewed. Results: All the patients (mean age 71 ± 3.4 years) underwent nontraditional surgical placement of epicardial ICD leads and traditional placement of ventricular epicardial bipolar pacing/sensing leads. Five patients had the distal lead tip fixed to the anterior epicardium of the right ventricular outflow tract, which was then looped under and around the ventricles, forming a “sling,” and tunneled to a left subclavicular pocket. One patient had a single unipolar subcutaneous array lead fashioned into a “loop” and placed under the inferior aspect of the ventricles. The average procedure time was 311 ± 115 minutes with a mean defibrillatory threshold (DFT) of ≤ 22 + 3 J. Post‐procedure hospitalization was 9.3 ± 4.4 days and no device‐related complications were encountered. Mean device follow‐up of 451 + 330 days showed normal function and two appropriate successful ICD discharges. Conclusion: Nontraditional alternative surgical methods for the placement of ICD systems in adult patients with limited venous access or TV dysfunction can achieve results similar to those of conventionally placed endovascular leads with limited complications and comparable DFTs in short‐term follow‐up. (PACE 2010; 33:217–225)     

Comparison of a Unipolar Defibrillation System with a Dual Lead System Using an Enlarged Defibrillation Anode

The unipolar system for transvenous defibrillation, consisting of a single right ventricular lead as the cathode and the device shell as anode, has been shown to combine low de- fibrillation thresholds (DFTs) and simple implantation techniques. We compared the defibrillation efficacy of this system with the defibrillation efficacy of a dual lead system with a 12-cm long defibrillation anode placed in the left subclavian vein. The data of 38 consecutive patients were retrospectively analyzed. The implantation of an active can system was attempted in 20 patients (group 1), and of the dual lead system in 18 patients (group 2). Both groups had comparable demographic data, cardiac disease, ventricular function, or clinical arrhythmia. The criterion for successful implantation was a DFT of > 24 J. This criterion was met in all 18 patients of group 2, The active can system could not be inserted in 3 of the 20 group 1 patients because of a DFT > 24 J. In these patients, the implantation of one (n = 2) or two (n = 1) additional transvenous leads was necessary to achieve a DFT ≤ 24). The DFTs of the 17 successfully implanted group 1 patients were not significantly different from the 18 patients in group 2 (12.3 ± 5.7 f vs 10.8 ± 4.8 J). The defibrillation impedance was similar in both groups (50.1 ± 6.1 ± 48.9 ± 5.2 Ω). In group 1, both operation duration (66.8 ± 17 min vs 80.8 ± 11 min; P < 0.05) and fluoroscopy time (3.3 ± 2.1 min vs 5.7 ± 2.9 min; P < 0,05) were significantly shorter. Thus, the active can system allows reliable transvenous defibrillation and a marked reduction of operation duration and fluoroscopy time. The dual lead system, with an increased surface area defibrillation anode, seems to he a promising alternative for active can failures.     

1-year performance of a defibrillation lead with a small electrode surface for high impedance pacing: a randomized,controlled study

A small electrode surface reduces pacing current drain and can extend generator longevity. The study evaluated the performance of a tined, quadripolar defibrillation lead (model 6944) that has a small-surfaced, steroid-eluting electrode tip for high impedance pacing. In a prospective, controlled study, 34 patients with conventional ICD indications were randomized one to one to receive the high impedance model 6944 or a tined defibrillation lead with a conventional sized, steroid-eluting electrode tip model 6942. Lead performance was evaluated at implant, prior to hospital discharge, and 1, 3, 6, and 12 months thereafter. Baseline characteristics did not differ significantly between patients implanted with lead model 6942 (n = 16) or model 6944 (n = 17). One patient randomized to receive the model 6942 was excluded from the study and was implanted with an active-fixation lead after stable lead positioning was neither possible with the 6942 nor with the 6944 electrode. No other lead related adverse events were observed. At implant, there were no significant differences between pacing thresholds, sensing performance, defibrillation impedances, and defibrillation thresholds in both groups, but pacing impedance of the model 6944 (988.6 +/- 217.7 omega) was approximately twice as high as high as in the model 6942 (431.7 +/- 83.7 omega; P < 0.0001). This difference remained highly significant throughout the observation period of 12 months, while R wave amplitudes and pacing thresholds remained equal in both lead models. The use of a tined defibrillation lead with a small, steroid-eluting electrode tip appears safe and results in a high pacing impedance without compromising system performance.     

Preliminary Clinical Results of a Biphasic Waveform and an RV Lead System

Biphasic defibrillation waveforms have provided a reduction in defibrillation thresholds in transvenous ICD systems. Although a variety of biphasic waveforms have been tested, the optimal pulse durations and tilts have yet to be identified. A multicenter clinical study was conducted to evaluate the performance of a new ICD biphasic waveform and new RV active fixation steroid eluting lead system. Fifty-three patients were entered into the study. Mean age was 63 years with a mean ejection fraction of 36.8%. Primary indication for implantation was monomorphic ventricular tachycardia alone (54.7%). Forty-eight patients (90.6%) were implanted with an RV shocking lead and active can alone as the anodal contact. The ICD can was the cathode. In four cases (7.5%), an additional SVC or CS had was used due to a high DFT with the RV lead alone. In an additional case, a chronic SVC lead was used although the RV-Can DFT was acceptable. DFT for all cases at implant was 9.8 ± 3.7 J. Repeat testing at 3 months for a subset of patients showed a reduction in DFT (7.4 ± 3.0 J), P value = 0.03. Sensing and pacing characteristics of the RV lead system remained excellent during the study period (acute 0.047 ± 0.005 ms at 5.4 V and 9.9 ± 6.2 mV R wave; chronic 0.067 ± 0.11 ms at 5.4 V and 9.3 ± 5.4 mV R wave). It is concluded that this lead system provides good acute and chronic sensing and pacing characteristics with good DFT values in combination with this waveform.     

Lead implant duration does not always predict ease of extraction: extraction sheath may be required at < 1 year

Introduction: Lead implant duration is a predictor of extraction sheath (ES) use in transvenous lead extraction (TLE). Most operators agree that leads with short implant durations can be extracted easily but data regarding defibrillator (implantable cardioverter‐defibrillator [ICD]) leads and newer generation leads with backfilled coils are limited. Methods and Results: We performed a retrospective study of consecutive patients undergoing TLE of leads with implant durations of ≤ 2 years at a single, high‐volume center. Patient and lead characteristics, indications, and ES use were analyzed. Between January 2000 and January 2011, 139 patients underwent TLE meeting inclusion criteria. Mean implant duration was 13.2 ± 6.4 months. The cohort was 67% male with a mean age of 63 years (16–93) and left ventricular ejection fraction of 36 ± 17%. Indications for extraction included infection (51%), lead malfunction (27%), device upgrade (13%), and other indications (venous occlusion, severe chronic pain at site of device or lead, advisory leads, etc., 9%). Extraction was achieved with simple traction alone in 68% of the 239 leads removed. ES assistance with laser or femoral sheaths was employed in 32% of cases. ES use increased significantly with longer implant duration (P = 0.0004). In multivariate analysis, young age, the presence of an ICD, and increasing implant duration were the strongest predictors of the need for ES assistance for successful lead removal. There was no statistically significant difference in ES use between older and newer generation ICD leads (P = 0.68). Conclusions: While leads with short implant durations may be extracted easily, the need for ES assistance is significant and frequently unpredictable even with newer generation ICD leads. Thus, operators should be fully prepared to use all available methods of extraction in every case regardless of implant duration. (PACE 2011; 34:1615–1620)     

Fluoroscopic and Electrical Assessment of a Series of Defibrillation Leads: Prevalence of Externalized Conductors

Introduction : Insulation defects with externalized conductors have been reported in the St. Jude Riata^® family of defibrillation leads (St. Jude Medical, Sylmar, CA, USA). The objective of the Northern Ireland Riata^® lead screening program was to identify insulation defects and externalized conductors by systematic fluoroscopic and electrical assessment in a prospectively defined cohort of patients. We sought to estimate the prevalence, identify risk factors, and determine the natural history of this abnormality. Methods : All patients with a Riata^® lead under follow‐up at the Royal Victoria Hospital were invited for fluoroscopic imaging and implantable cardioverter‐defibrillator lead parameter checks. Fluoroscopic images were read independently by two cardiologists and the presence of externalized conductors was classified as positive, negative, or borderline. Results: One hundred and sixty‐five of 212 patients with a Riata lead were evaluated by fluoroscopy and lead parameter measurements. The mean duration after implantation was 3.98+/?1.43 years. After screening 25 (15%) patients were classified as positive, 137 (83%) negative, and three (1.8%) borderline. Time since implantation (P = 0.001), presence of a single coil lead (P = 0.042), and patient age (P = 0.034) were significantly associated with externalized conductors. The observed rate of externalized conductors was 26.9% for 8‐French and 4.7% for 7‐French leads. No leads that were identified prospectively with externalized conductors had electrical abnormalities. Seven of 25 (28%) patients had a defective lead extracted by the end of this screening period. Conclusion: A significant proportion (15%) of patients with a Riata lead had an insulation breach 4 years after implantation. High‐resolution fluoroscopic imaging in at least two orthogonal views is required to identify this abnormality. (PACE 2012;35:1498–1504)     

Update on small-diameter implantable cardioverter-defibrillator leads performance

Background: The performance of small diameter implantable cardioverter defibrillator (ICD) leads is questionable. However, data on performance during long‐term follow‐up are scarce. The aim of this study is to provide an update for the lead failure and cardiac perforation rate of Medtronic's Sprint Fidelis ICD lead (Medtronic Inc., Minneapolis, MN, USA) and St. Jude Medical's Riata ICD lead (St. Jude Medical Inc., St. Paul, MN, USA). Methods: Since 1996, all ICD system implantations at the Leiden University Medical Center, the Netherlands, are registered. For this study, data up to February 2011 on 396 Sprint Fidelis leads (follow‐up 3.4 ± 1.5 years), 165 8‐French (F) Riata leads (follow‐up 4.6 ± 2.6 years), and 30 7‐F Riata leads (follow‐up 2.9 ± 1.3 years) were compared with a benchmark cohort of 1,602 ICD leads (follow‐up 3.4 ± 2.7 years) and assessed for the occurrence of lead failure and cardiac perforation. Results: During follow‐up, the yearly lead failure rate of the Sprint Fidelis lead, 7‐F Riata lead, 8‐F Riata lead, and the benchmark cohort was 3.54%, 2.28%, 0.78%, and 1.14%, respectively. In comparison to the benchmark cohort, the adjusted hazard ratio of lead failure was 3.7 (95% confidence interval [CI] 2.4–5.7, P < 0.001) for the Sprint Fidelis lead and 4.2 (95% CI 1.0–18.0, P < 0.05) for the 7‐F Riata lead. One cardiac perforation was observed (3.3%) in the 7‐F Riata group versus none in the 8‐F Riata and Sprint Fidelis lead population. Conclusion: The current update demonstrates that the risk of lead failure during long‐term follow‐up is significantly increased for both the Sprint Fidelis and the 7‐F Riata lead in comparison to the benchmark cohort. Only one cardiac perforation occurred. (PACE 2012; 35:652–658)     

Intracardiac Emergency Defibrillation for Refractory Ventricular Fibrillation During Implantation of Cardioverter Defibrillators with Nonthoracotomy Lead Systems

Implantable cardioverter defibrillators (ICDs) are being implanted in increasing numbers. At inlraoperative defibrillation threshold tests refractory ventricular fibrillation (VF) requiring emergency open chest resuscitation is a major concern during impiantation of nonthoracotomy ICD lead systems. A new method of high energy endocardial/extrathoracic defibrillotion via the implanted ICD transvenous defibrillation electrode (TDE) was used to terminate refractory VF. During implantation of ICD with TDE in 20 patients refractory VF occurred in two patients. The arrhythmia was terminated with endocardial/extrathoracic defibrillation in both cases, and no complications were observed.     

Effectiveness of excimer laser-assisted pacing and ICD lead extraction in children and young adults

BACKGROUND: High capture thresholds, decreased electrical sensing, and lead fractures continue to be a problem in children undergoing transvenous pacing. The clinician must therefore decide at the time of pacing system revision to either abandon chronically implanted transvenous pacing leads or extract them. METHODS: We report our experience using an excimer laser-assisted (LA) strategy for removing chronically implanted pacing (36) and implantable cardioverter/defibrillator (ICD) (7) leads in children and young adults. The study population consisted of 25 patients, in whom 29 procedures were performed. The patients ranged in age from 8.4 to 39.9 years, median age was 13.9 years, at the time of the extraction procedure. In all procedures, a Spectranectics locking stylet and excimer laser sheath were used to assist in lead extraction. RESULTS: Lead removal was complete for 39 (91%) leads, and partial for four leads. In two patients, the pacing lead tip was retained and in two, the ring electrode from a bipolar pacing lead was left in situ. All ICD leads were removed completely. Two major complications occurred--cardiac perforation and tamponade (1), and thrombosis of the left subclavian/innominate vein (1). LA extraction facilitated the implantation of new pacing or ICD leads in three patients with obstructed venous access. CONCLUSIONS: Removal of pacing and ICD leads using an excimer LA technique was highly successful. Lead removal was complete in 91%. The most common indication for lead removal in our study was lead fracture. Complications were few, but may be significant.     

The azygos defibrillator lead for elevated defibrillation thresholds: implant technique, lead stability, and patient series

Background: Conventional insertion of implantable cardioverter‐defibrillator (ICD) includes an evaluation of the defibrillation threshold (DFT). Implanting an ancillary defibrillation lead in the azygos vein has been introduced as a therapeutic option in patients with “high” DFT. This study reports the efficacy and stability of azygos defibrillation coils implanted for elevated DFTs. Methods: This is a retrospective review of seven consecutive patients with right and left pectoral, single‐ and dual‐chamber, and biventricular ICDs and elevated DFTs, in whom an azygos defibrillation coil was introduced. Results: Addition of an azygos defibrillator lead achieved a satisfactory safety margin during single energy defibrillation efficacy testing in four out of seven patients, with success at maximum device output in two patients. No satisfactory safety margin was achieved in the remaining patient, despite the further addition of a subcutaneous defibrillation coil. No change in lead position was observed over a mean radiographic follow‐up of 8 months. No complications were noted during a mean follow‐up of 14 months, including no deaths, and no ICD shocks. Conclusion: Implanting a defibrillation coil into the azygos vein is feasible and safe. In a majority of patients with failed defibrillation efficacy testing, adding an azygos coil achieves success on repeat testing. Therefore, this technique is one option for lowering the defibrillation threshold in patients who fail DFT testing of their ICD.