Sensing failure associated with the Medtronic Sprint Fidelis defibrillator lead.
ABSTRACT The diameter of implantable cardioverter-defibrillator (ICD) leads has become progressively smaller over time. However, the long-term performance characteristics of these smaller ICD leads are unknown.
We retrospectively evaluated 357 patients who underwent implantation of a Medtronic Sprint Fidelis defibrillating lead at two separate centers between September 2004 and October 2006. Lead characteristics were measured at implant, at early follow-up (1-4 days post implant), and every 3-6 months thereafter.
During the study period, 357 patients underwent implantation of the Medtronic Sprint Fidelis lead. The mean R-wave measured at implant through the device was not different (P = NS) when compared with that measured at first follow-up (10.5 +/- 5.0 mV vs 10.7 +/- 5.1 mV). Forty-one patients (13%) had an R-wave amplitude <or= 5 mV measured through the device at implant. Of those patients with an R-wave amplitude <or= 5 mV at implant measured through the device, 63% (n = 26) remained <or= 5 mV for the duration of follow-up. The mean time to R-wave amplitude <or= 5 mV was 96.2 +/- 123 days. During follow-up, 65 (18%) patients developed R-wave <or= 5 mV. Overall 10 lead revisions (2.8%) were performed during the first year of follow-up.
Abnormal R-wave sensing is frequently observed during follow-up with the Medtronic Fidelis ICD lead. Lead revision was necessary in 2.8% of the patients, most often (8 of 10) due to abnormal R-wave sensing along with elevated pacing threshold. Whether this issue is limited to this lead or reflects a potential problem with all downsized ICD leads merits further investigation.
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ABSTRACT: The Medtronic Sprint Fidelis (Medtronic Inc., Minneapolis, MN, USA) lead family is associated with an unacceptable incidence of premature lead failure. There are limited data on risk factors for lead fracture. We hypothesized that factors leading to potential increased forces on the lead related to device implantation or technique may be associated with premature lead failure. We reviewed the implant data from our group and identified 176 patients who received active fixation Medtronic Fidelis (Model 6931, single coil and Model 6949, dual coil) leads. Implant data, including age, sex, venous access site, implant side, implant location, and number of venous leads were reviewed. Hospital, pacemaker clinic, and Medtronic registration databases were reviewed for evidence of lead failure, replacement, or abandonment. Data was evaluated in univariate and multivariate regression analyses. Of the 176 leads implanted, 10 (5.7%) were noted to develop malfunction. This presented as inappropriate shocks from sensed noise or elevated impedance measurements. Of the above noted implant features, only right-sided (vs left-sided) implant (hazard ratio [HR] 18.8, 95% confidence intervals [CI] 3.8, 93.3), and subpectoral implant (vs prepectoral; HR 14.31, 95% CI 3.2, 64.0) were predictive of lead failure in maximally adjusted models. We have identified both right-sided implantation and subpectoral generator positioning as factors associated with premature lead malfunction in Fidelis active fixation leads. Clinical decisions regarding patient management should incorporate these findings in regard to lead replacement in high-risk patients.Pacing and Clinical Electrophysiology 04/2012; 35(6):659-64. DOI:10.1111/j.1540-8159.2012.03357.x · 1.75 Impact Factor
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ABSTRACT: Clinical Performance of the St. Jude Medical Riata Defibrillation Lead in a Large Patient Population. Objective: The purpose of this large multicenter study was to evaluate the long-term reliability of an implantable cardioverter defibrillator (ICD) lead to determine the incidence of adverse events (AEs).Background: A recent concern has been the performance of cardiac defibrillator leads. There have been conflicting reports regarding the rate of lead perforation and other AEs.Methods: Medical records from patients implanted from 6-1-2001 to 11-27-2007 with the St. Jude Medical Riata family of RV leads at 23 US (N = 12,969) and 5 German (N = 2,418) centers were reviewed for chronic lead-related AEs. These included perforation, dislodgment, conductor fracture and insulation damage. The mean follow-up period was 18.0 months. AEs were defined as those that required Riata lead revision, extraction, or replacement.Results: The incidence of lead AEs was <1% for each AE type. Perforation occurred in 0.38%, dislodgement in 0.93%, conductor fracture in 0.18%, and insulation damage in 0.21% of patients studied.Conclusions: During the follow-up of the 15,387 patients with Riata leads, the incidence of AEs which included perforation, dislodgement, conductor fraction and insulation damage was low and within the range of what is considered clinically acceptable. (J Cardiovasc Electrophysiol, Vol. 21, pp. 551-556, May 2010)Journal of Cardiovascular Electrophysiology 04/2010; 21(5):551 - 556. DOI:10.1111/j.1540-8167.2009.01651.x · 3.48 Impact Factor
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ABSTRACT: Background The structures composing implantable cardioverter-defibrillator (ICD) leads have become more complicated and thinner with technological advances. Silicon insulation defects with and without clinically manifested electrical abnormalities have been reported in Riata leads (St. Jude Medical). Objective The aim of this study was to assess the incidence and clinical implications of insulation defects in Riata leads implanted at our hospital. Methods The subjects included 10 consecutive patients who received 8-French Riata ICD leads with dual-coil conductors (model 1580 or 1581) between 2006 and 2010 at our hospital. Operative records, chest X-rays and interrogation data were reviewed. Results In all cases, Atlas+ (St. Jude Medical) was used as an ICD generator and the Riata leads were implanted transvenously and fixed to the right ventricular apex. During a mean follow-up period of 52±9 (36-70) months, chest X-rays revealed insulation defects in Riata leads and conductor wires projecting from the bodies of the Riata leads in two of 10 (20%) patients. One of the patients received inappropriate ICD therapies due to T-wave oversensing based on attenuation of R waves and augmentation of T waves 41 months after implantation. In the other patient, an insulation defect without any clinically manifested electrical troubles was detected 50 months after implantation. Conclusion Riata leads have a high incidence of insulation defects, which may be occasionally accompanied by inappropriate ICD discharges. For patients with Riata leads, careful observation of any changes in the lead-electrical measurements and a routine chest X-ray follow-up are necessary.Internal Medicine 01/2012; 51(19):2689-94. DOI:10.2169/internalmedicine.51.7805 · 0.97 Impact Factor