"Add-on pacing lead": An effective and safe alternative to lead replacement in ICD pacing failure

Despite recent advances in implantable cardioverter defibrillator (ICD) technology, the long-term reliability of ICD leads remains a significant problem. Lead failures constitute a major risk for patients with an implantable cardioverter defibrillator. There is no clear consensus on treatment strategy of ICD lead failure and decision should be individualized. We report a pacing-dependent elderly male with ICD lead pacing failure secondary to insulation break resulting in recurrent syncope. We emphasize the technique of "Add-on pacing lead implantation" could be an effective and alternative to ICD lead replacement.     

High voltage lead failure diagnosed at upgrade of single-chamber ICD to dual-chamber ICD with CRT.

We describe a case of defibrillation lead damage which was detected only during an upgrade procedure from single-chamber ICD to dual-chamber ICD with biventricular pacing. The damage was not detected during routine checks in the ICD clinic.     

Early failure of a small-diameter high-voltage implantable cardioverter-defibrillator lead

BACKGROUND: We have observed a higher than expected rate of Sprint Fidelis model 6949 lead failures in our practice. OBJECTIVE: The aim of this study was to assess the performance of small-diameter Sprint Fidelis high-voltage ICD leads. METHODS: The actuarial survival of Sprint Fidelis model 6949 leads implanted at our center was compared with that of the Sprint Quattro Secure model 6947. The United States Food and Drug Administration Manufacturers and User Facility Device Experience (MAUDE) database was searched for Sprint Fidelis models. RESULTS: The survival of 583 Sprint Fidelis 6949 leads implanted at our center between September 2004 and February 2007 was significantly less than 285 Sprint Quattro Secure model 6947 leads implanted by us between November 2001 and February 2007 (P = .005). Six patients presented with Sprint Fidelis lead failure 4-23 months after implant. Five of the six patients experienced multiple inappropriate shocks associated with pace-sense conductor and coil fractures; the sixth patient had a fixation mechanism failure. The MAUDE search rendered reports for 679 Sprint Fidelis leads. The most frequent complaints or observations were inappropriate shocks (33%), high impedance (33%), and fracture (35%). Of 125 leads analyzed by the manufacturer, 62 involved fracture of the pace-sense conductor or coil and the high-voltage (defibrillation) conductor. CONCLUSIONS: The Sprint Fidelis high-voltage lead appears to be prone to early failure. Its use should be limited until the failure mechanism is identified and corrected. Patients should be evaluated quarterly, and automatic lead test features should be enabled. While more data are needed, routine prophylactic replacement of intact, normally functioning Sprint Fidelis leads does not appear justified.     

Patient Alert to detect ICD lead failure: efficacy, limitations, and implications for future algorithms.

AIMS: An algorithm that alerts implantable cardioverter-defibrillator (ICD) patients, in case of abnormal lead impedance (Patient Alerttrade mark, Medtronic), may help to recognize lead dysfunction. We aimed to determine the utility of Patient Alert for ICD lead-failure detection in a prospective study. METHODS AND RESULTS: Three hundred and sixty ICD patients were followed for 22+/-14 months. Patient Alert was active for pacing impedance <200 and >2000-3000 Omega, and high-voltage conductor impedance <10-20 and >200 Omega. Ten alert events and a total of 29 severe system complications occurred. Patient Alert detected three of 10 ICD lead failures, with a positive predictive value (PPV) of 77.8% for any severe system complication. Retrospective analysis identified 23 patients with a sensing integrity counter (SIC) >300 and revealed an additional four prior undetected lead defects. SIC detected ICD lead failure with 92.9% sensitivity and a PPV of 59.1%. Eight of nine patients with a false-positive SIC had an integrated bipolar lead. Patient Alert combined with SIC detected all ICD lead failures and 71.4% of all severe lead complications. CONCLUSIONS: Patient Alert, based on daily lead-impedance measurement, detected one-third of all ICD lead failures. Combined use with continuous lead integrity monitoring (SIC) increased sensitivity to 100%. Integrated bipolar leads may yield a false-positive SIC. Incorporating SIC and automated pace/sense threshold measurement may improve Patient Alert sensitivity for severe lead complications.     

植入型心律转复除颤器导线故障分析

目的总结分析我院植入型心律转复除颤器（ICD）起搏除颤导线故障病例特点。方法对2005年10月至2009年12月62例在我院新植入ICD导线患者进行随访分析,所有导线植入均以锁骨下静脉作为入路。随访中出现以下1项或多项异常考虑导线故障：（1）起搏阻抗永久性或间歇性〉2000n或〈250Q;（2）除颤高压阻抗〉200n;（3）心内电图证实除颤导线感知非生理性高频噪声导致误放电。结果中位数随访时间28（10～46）个月,4例患者（6．5％）诊断ICD导线故障,导线寿命18～38个月;临床均以ICD误放电至医院就诊,同时程控发现ICD导线起搏阻抗异常。其中1例患者放电前闻及ICD导线阻抗报警,4例患者均重新植入新的起搏感知导线。结论ICD导线故障是一个值得重视的临床问题。ICD导线阻抗报警功能可能有助于早期发现导线故障。如程控发现仅仅除颤导线起搏阻抗异常,植入新的起搏感知导线可以作为首选的故障处理方法。     

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

AIM: Venous obstruction following transvenous device implantation rarely cause immediate clinical problems. When lead revision or device upgrade is indicated, venous obstruction become a significant challenge. The aim of this study was to determine the predictors of venous obstruction after transvenous device implantation, and to asess likely effects of antiplatelet/anticoagulant drugs in preventing venous thrombosis. METHODS AND RESULTS: Between March 2005 and July 2006, contrast venography was performed in 100 patients who were candidates for generator change, lead revision, or device upgrade. Vessel patency was graded as either completely obstructed, partially obstructed (>70%), or patent. The incidence of venous obstruction was 26%, with 9% of patients having total obstruction and 17% of patients exhibiting partial obstruction. No statistically significant differences between obstructed and non-obstructed patients were seen for age, sex, indication for device implantation, atrial fibrillation, cardiothoracic ratio, insulation material, operative technique, device type, and manufacturer (all Ps > 0.05). In a univariate analysis, multiple leads (P = 0.033), and presence of dilated cardiomyopathy (P = 0.036) were associated with higher risk of venous obstruction, whereas anticoagulant/antiplatelet therapy (P = 0.047) significantly reduced incidence of venous obstruction. Multivariate logistic regression analysis showed that only number of the leads (P = 0.039, OR: 2.22, and 95% CI: 1.03-4.76) and antiplatelet/anticoagulant therapy (P = 0.044, OR: 2.79, and 95% CI: 0.98-7.96) were predictors of venous obstruction. CONCLUSION: Total or partial obstruction of the access veins occurs relatively frequently after pacemaker or ICD implantation. Multiple pacing or ICD leads are associated with an increased risk of venous obstruction, whereas antiplatelet/anticoagulant therapy appears to have a preventive effect on development of access vein thrombosis.     

Implantable defibrillator lead extraction with optimized standard extraction techniques

Background Implantable cardioverter-defibrillator (ICD) leads might not be extracted especially in developing countries because of the high cost and lack of specialized tools. We aimed to evaluate transvenous extraction of ICD leads using optimized standard techniques. Methods We prospectively analyzed clinical characteristics, optimized extraction techniques and the feasibility of extraction for 40 patients (33 males; mean age 47.9 ? 16.1 years) with 42 ICD leads. Results Complete procedural success rate was 95.2% (40/42), and the clinical success rate was 97.6% (41/42). One ICD lead required cardiothoracic surgery. Minor complications occurred in three cases (7.5%), and no major complications or death occurred. Locking stylets were used to extract most leads (34, 81.0%) and almost half of the leads (20, 47.6%) required mechanical dilatation to free fibrotic adhesions; these leads had been implanted for a longer period of time than the others (43.7 ± 18.2 vs. 18.4 ± 13.4 months, P < 0.05). Three-quarters of the leads (30, 71.4%) were extracted with locking stylets plus manual traction (12, 28.6%), or mechanical dilatation with counter-traction (18, 42.8%) by the superior vena cava approach and one-quarter of the leads (11, 26.2%) were removed by optimized snare techniques using the femoral vein approach. Median extraction time was 20 min (range 2–68 min) per lead. Linear regression analysis showed that the extraction time was significantly correlated with implant duration (r = 0.70, P < 0.001). Median follow-up was 14.5 months (range 1–58 months), no infection, or procedure-related death occurred in our series. Conclusions Our optimized procedure for transvenous extraction of ICD leads provides a practical and low-cost method for standard procedures.     

Development and testing of an algorithm to detect implantable cardioverter-defibrillator lead failure

BACKGROUND: Implantable cardioverter-defibrillator (ICD) lead failures often present as inappropriate shock therapy. An algorithm that can reliably discriminate between ventricular tachyarrhythmias and noise due to lead failure may prevent patient discomfort and anxiety and avoid device-induced proarrhythmia by preventing inappropriate ICD shocks. OBJECTIVES: The goal of this analysis was to test an ICD tachycardia detection algorithm that differentiates noise due to lead failure from ventricular tachyarrhythmias. METHODS: We tested an algorithm that uses a measure of the ventricular intracardiac electrogram baseline to discriminate the sinus rhythm isoelectric line from the right ventricular coil-can (i.e., far-field) electrogram during oversensing of noise caused by a lead failure. The baseline measure was defined as the product of the sum (mV) and standard deviation (mV) of the voltage samples for a 188-ms window centered on each sensed electrogram. If the minimum baseline measure of the last 12 beats was <0.35 mV-mV, then the detected rhythm was considered noise due to a lead failure. The first ICD-detected episode of lead failure and inappropriate detection from 24 ICD patients with a pace/sense lead failure and all ventricular arrhythmias from 56 ICD patients without a lead failure were selected. The stored data were analyzed to determine the sensitivity and specificity of the algorithm to detect lead failures. RESULTS: The minimum baseline measure for the 24 lead failure episodes (0.28 +/- 0.34 mV-mV) was smaller than the 135 ventricular tachycardia (40.8 +/- 43.0 mV-mV, P <.0001) and 55 ventricular fibrillation episodes (19.1 +/- 22.8 mV-mV, P <.05). A minimum baseline <0.35 mV-mV threshold had a sensitivity of 83% (20/24) with a 100% (190/190) specificity. CONCLUSION: A baseline measure of the far-field electrogram had a high sensitivity and specificity to detect lead failure noise compared with ventricular tachycardia or fibrillation.