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Pulse Generator Replacement (pulse + generator_replacement)
Selected AbstractsStimulation Parameters After Vagus Nerve Stimulator ReplacementNEUROMODULATION, Issue 2 2008Douglas Labar MD ABSTRACT Objectives., This study aims to assess tolerability and efficacy of stimulation parameters after vagus nerve stimulator (VNS) pulse generator replacement. Materials and Methods., We carried out an observational, retrospective study, reviewing our experience with VNS generator replacements in 28 epilepsy patients. Results., Seven patients had actual end of battery life (EOBL) (with symptoms), and 21 patients had asymptomatic projected EOBL. When we reprogrammed stimulation parameters postoperatively, 17 of the 28 patients could not tolerate the preoperative baseline current settings, even one year later. There were no differences in pre- vs. postoperative seizure rates between patients who did or did not return to baseline settings. Failure to return to baseline current was not related to previous VNS duration, same- vs. different-battery generator replacements, or antiepileptic medication changes. Conclusions., After VNS generator replacement, patients' common inability to tolerate preoperative current settings does not lead to more seizures. A chronic modification of the vagus nerve system's sensitivity to stimulation changes may be hypothesized. [source] Complication Risk with Pulse Generator Change: Implications When Reacting to a Device Advisory or RecallPACING AND CLINICAL ELECTROPHYSIOLOGY, Issue 6 2007SURAJ KAPA M.D. Background:Recent advisories and recalls of pacemakers and implantable cardioverter-defibrillators (ICDs) have highlighted the need for evidence-based recommendations regarding management of patients with advisory devices. In order to better facilitate decision-making when weighing the relative risks and benefits of performing generator changes in these patients, we conducted a review to assess operative complication rates. Methods:We reviewed generator changes performed between 2000 and 2005 at the Mayo Clinic-Rochester, including a total of 732 change-outs consisting of 570 done for elective replacement indicators (ERI) and 162 for manufacturer advisories or recalls. Complications included all those requiring reoperation, occurring within a 60-day period postoperatively and directly attributable to the generator change. These included infection requiring device excision, hematoma requiring evacuation, and incisional dehiscence requiring reclosure. Results:Operation-associated complications requiring intervention were noted in 9 patients, or 1.24% of our population. Of these nine complications, eight occurred among patients receiving pulse generator replacement for ERI (1.40%) and one occurred in a patient receiving replacement for a manufacturer advisory or recall (0.62%). Complications included 5 infections, 3 hematomas, and 1 incisional dehiscence. Conclusions:Generator replacement is not a benign procedure and associated risks must be weighed in the context of other variables when making management choices in patients with advisory or recall devices. [source] Variability in Implantable Cardioverter Defibrillator Pulse Generator Longevity Between ManufacturersPACING AND CLINICAL ELECTROPHYSIOLOGY, Issue 1p1 2003PATRICK T. ELLINOR ELLINOR, P.T., et al.: Variability in Implantable Cardioverter Defibrillator Pulse Generator Longevity Between Manufacturers.ICDs are used frequently to treat malignant ventricular arrhythmias. Despite the expanding role of these devices, little is known about the manufacturer variability in the performance of ICD generators. The purpose of this study is to explore the indications for ICD pulse generator replacement and to examine performance differences between the three major manufacturers of ICDs in the United States. The authors performed a retrospective review of ICD pulse generators that were implanted and replaced at Massachusetts General Hospital between February 1998 and March 2002. During the study period, 50 (7%) of the 707 devices in the study cohort were replaced. The most common indication for pulse generator replacement was related to battery performance followed by device recall, upgrade to a dual chamber device, and pulse generator malfunction. After exclusion of the recalled devices, a significantly higher number of pulse generators manufactured by St. Jude Medical (14/229) required replacement for battery depletion or prolonged charge times during the study period compared with devices from Guidant (2/220) or Medtronic (0/273),P = 0.003andP < 0.0001, respectively. This difference was attributable to reduced longevity in the Angstrom series of defibrillators. (PACE 2003; 26[Pt. I]:71,75) [source] Compatibility of Automatic Threshold Tracking Pacemakers with Previously Implanted Pacing Leads in ChildrenPACING AND CLINICAL ELECTROPHYSIOLOGY, Issue 11 2002OSMAN KUCUKOSMANOGLU KUCUKOSMANOGLU, O., et al.: Compatibility of Automatic Threshold Tracking Pacemakers with Previously Implanted Pacing Leads in Children. The Autocapture function controls and optimizes the amplitude of the pacing pulse and saves energy. The manufacturer recommends using a special low polarization, low threshold bipolar Pacesetter lead for the Autocapture function. The purpose of this study was to evaluate the compatibility of Autocapture with previously implanted pacing leads. The study included 15 patients (mean age 13.6 ± 3.4 years) who needed pulse generator replacement and received the VVIR pacemaker Regency SR+ or the DDDR pacemakers Affinity DR or Integrity DR with the Autocapture function. The new pulse generators connected to previously implanted ventricular leads. At the time of implantation the pacing threshold was 1.0 ± 0.35 V at 0.5 ms, the lead impedance was 580 ± 80 ,, and the spontaneous R wave amplitude was 7.89 ± 4.89 mV. The polarization signal (PS) was 3.8 ± 3.04 mV, and evoked response (ER) was 8.15 ± 4.57 mV at the predischarge testing. Follow-up telemetry was done at months 1, 3, 6, 12, and 18. The follow-up duration was 9.4 ± 5 months (range 1,18 months). If the results of PS and ER measurements were acceptable for Autocapture, it turned on at the 1-month visit. In six (40%) patients the results were found acceptable for Autocapture function. Age, lead impedance, pacing threshold, intrinsic R wave measurement, lead age, fixation mechanism, and ER measurements were not statistically different in Autocapture suitable and not suitable groups. The main reason not to activate Autocapture had been increased PS. Any significant fluctuations were not observed in pacing threshold, lead impedance, ER, and PS during follow-up. In conclusion, previously implanted pacing leads may be compatible with the Autocapture function. [source] Criteria for Pacemaker Explant in Patients Without a Precise Indication for Pacemaker ImplantationPACING AND CLINICAL ELECTROPHYSIOLOGY, Issue 3 2002MARTINO MARTINELLI MARTINELLI, M., et al.: Criteria for Pacemaker Explant in Patients Without a Precise Indication for Pacemaker Implantation. Unnecessary pacemaker implantation may cause significant social and psychological consequences, the inconvenience of periodic office visits, and the expense of pulse generator replacement. Establishing adequate criteria for explanting pacemakers is crucial and has not yet been described. This study presents the results of a study protocol for explanting the pacemaker in patients without a clear indication for pacemaker implantation. Seventy pacemaker users without a clear reason for the implantation were included in the study conducted from August 1986 to November 1998 and were prospectively followed. The investigation consisted of clinical and neurological evaluations, echocardiogram, exercise testing, and tilt table testing. When these tests were negative, the pulse generator energy and stimulation rates were reprogrammed to the lowest values. Periodic Holter monitoring was conducted during follow-up. When asymptomatic for 1 year, patients underwent an electrophysiological evaluation of sinus and atrioventricular junction function and ventricular vulnerability. When the electrophysiological study was negative, pacemaker explantation was performed. Of the 70 patients, 35 had their pacemaker explanted; 3 were excluded due to a positive tilt table test and electrophysiological study, and 3 are waiting for pacemaker explantation. Mean follow-up after pacemaker explantation was 30.3 months, and all patients remained asymptomatic, except for one patient who died of a noncardiac cause. Critical analysis of pacemaker users without a well-established indication is justified because it may allow pacemaker explant in a significant proportion of these patients, and it may bring considerable social, economic, and psychological benefits. [source] Runaway Pulse Generator Malfunction Resulting from Undetected Battery DepletionPACING AND CLINICAL ELECTROPHYSIOLOGY, Issue 2 2002PUGAZHENDHI VIJAYARAMAN VIJAYARAMAN, P., et al.: Runaway Pulse Generator Malfunction Resulting from Undetected Battery Depletion. Runaway pacemaker is an uncommon, potentially lethal circuit malfunction characterized by sudden onset of erratic pacing at rapid nonphysiological rates. Two patients with a single chamber pacemaker (Medtronic ST 8331 and 8419) presented with episodic dizziness. ECG revealed recurrent decrescendo amplitude episodes of runaway stimuli at 2,400 and 2,600 ppm, approximately 3 seconds in duration, separated by pacing at 62.5 and 65 ppm, respectively. Fortunately the runaway stimuli were subthreshold and did not result in capture of the ventricle. Emergency pulse generator replacement was uneventful. Both leads were normal and both pulse generators had low battery voltages at 1.488 and 1.78 V, respectively. 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