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Lead System (lead + system)
Selected AbstractsThe use of light-emitting diode therapy in the treatment of photoaged skinJOURNAL OF COSMETIC DERMATOLOGY, Issue 3 2007FACCS, FRACGP, Fabien Baez MBBS, MAACS, MCPSA Summary Background, Light-emitting diode (LED) therapy is an increasingly popular methodology for the treatment of sun damage. Combination use of light wavelengths reported to stimulate collagen synthesis and accelerate fibroblast,myofibroblast transformation may display a composite rejuvenative effect. Objective, To clinically assess reduction in sun damage signs following a 5-week course of LED therapy and to assess subject's perception of the treatment. Methods, Thirteen subjects with wrinkles or fine lines in the periorbital and nasolabial region and those presenting Glogau scale photodamage grade II,III received nine 20-min duration light treatments using the OmniluxÔ LED system. The treatments combined wavelengths of 633 and 830 nm at fluences of 126 and 66 J/cm2, respectively. Sun-damage reduction was assessed at 6, 9, and 12 weeks by clinical photography and patient satisfaction scores. Results, The majority of subjects displayed "moderate" (50%) or "slight" (25%) response to treatment at investigator assessment. Treatment of the periorbital region was reported more effective than the nasolabial region. At 12-week follow-up, 91% of subjects reported improved skin tone, and 82% reported enhanced smoothness of skin in the treatment area. Conclusion, Good response to LED therapy has been shown in this modest sample. Larger trials are needed to assess optimum frequency of light treatments and overall treatment time. [source] In vitro and in vivo comparison of two different light sources for topical photodynamic therapyBRITISH JOURNAL OF DERMATOLOGY, Issue 4 2006P. Babilas Summary Background, Photodynamic therapy (PDT) with 5-aminolaevulinic acid (ALA) is an effective and safe treatment option for the treatment of actinic keratosis (AK). Incoherent lamps are often used, matching the absorption maxima of ALA. Objectives, A comparative trial was performed to evaluate the efficacy of recently developed light-emitting diodes (LEDs). Methods, Human epidermal keratinocytes were incubated for 24 h with ALA (100, 200, 300, 400 or 500 ,mol L,1) and irradiated consecutively using either an incoherent halogen lamp (,em = 580,750 nm; 24 J cm,2; 40 mW cm,2) or an LED system (,em = 633 ± 3 nm; 3, 6, 12 or 24 J cm,2; 40 mW cm,2). Topical ALA-PDT was performed on 40 patients with AK (n = 584) in a symmetrical distribution suitable for two-sided comparison. After incubation with ALA (20% in cream base) irradiation was performed with the incoherent lamp (100 J cm,2; 160 mW cm,2) on one side and the LED system (40 J cm,2; 80 mW cm,2) on the opposite side followed by re-evaluation up to 6 months. Results, No significant differences between the LED system (3, 6, 12 or 24 J cm,2) and the incoherent light source (24 J cm,2) regarding cytotoxicity was found in vitro. The complete remission rate yielded in the in vivo investigation was also not significantly different at 6 weeks (P = 0·95), 3 months (P = 0·75) and 6 months (P = 0·61) following therapy. Six weeks following therapy complete remission rates of 84·3% (LED system) and 82·8% (incoherent lamp) were achieved. There was also no significant difference between both light sources regarding pain during light treatment (P = 0·67), patient satisfaction (P = 1·0) or cosmesis (P = 1·0) following therapy. Conclusions, These results show the efficacy of an LED system for ALA-PDT both in vitro and in vivo. ALA-PDT with the LED system showed a noninferiority regarding the clinical outcome in the treatment of AK compared with the incoherent lamp. [source] Initial Experience of Pacing with a Lumenless Lead System in Patients with Congenital Heart DiseasePACING AND CLINICAL ELECTROPHYSIOLOGY, Issue 11 2009SANTABHANU CHAKRABARTI M.D. Background: Long-term pacing is frequently necessary in patients with congenital heart disease (CHD). Preservation of ventricular function and avoidance of venous occlusion is important in these patients. Site-selective pacing with a smaller diameter lead is achievable with the model 3830 lead (SelectSecure®, Medtronic Inc., Minneapolis, MN, USA), which was specifically designed to target these complications. We describe our initial experience with the Model 3830 lead in patients with CHD. Methods: Retrospective analysis of all patients undergoing site-selective implantation of a Model 3830 lead(s) from two congenital heart centers (Bristol, UK, and Dublin, Ireland) from October 2004 until February 2008. Results: We implanted 139 SelectSecure® leads (atrial n = 70; ventricular n = 69) in 90 patients (57 male) with CHD. Median age at implantation: 13.4 years (1.1,59.2 years), median weight: 43 kg. Sixty-nine patients (76%) were children (<18 years). Indications for lead implantation included atrioventricular block (n = 55), sinus node disease (n = 18), implantable cardiac defibrillator (n = 12), antitachycardia pacing (n = 4), and cardiac resynchronization (n = 1). Twenty-two patients underwent pre-existing lead extraction during the same procedure. All the attempted procedures resulted in successful pacing. One patient had a significantly raised threshold at implantation. There was no procedural mortality. There were two procedural complications. Three patients required lead repositioning for increasing thresholds early postprocedure (<6 weeks). Four leads (2.9%) had displaced on median follow-up of 21.8 months (0.5,42 months). Conclusions: The Model 3830 lead is safe and effective in patients with CHD. This is a technically challenging patient group yet procedural complication and lead displacement rates are acceptable. [source] Clinical Predictors of Defibrillation Thresholds with an Active Pectoral Pulse Generator Lead SystemPACING AND CLINICAL ELECTROPHYSIOLOGY, Issue 4 2002DENICE M. HODGSON HODGSON, D.M., et al.: Clinical Predictors of Defibrillation Thresholds with an Active Pectoral Pulse Generator Lead System. Active pectoral pulse generators are used routinely for initial ICD placement because they reduce DFTs and simplify the implantation procedure. Despite the common use of these systems, little is known regarding the clinical predictors of defibrillation efficacy with active pulse generator lead configurations. Such predictors would be helpful to identify patients likely to require higher output devices or more complicated implantations. This was a prospective evaluation of DFT using a uniform testing protocol in 102 consecutive patients with an active pectoral can and dual coil transvenous lead. For each patient, the DFT was measured with a step-down protocol. In addition, 34 parameters were assessed including standard clinical echocardiographic and radiographic measures. Multivariate stepwise regression analysis was performed to identify independent predictors of the DFT. The mean DFT was 9.3 ± 4.6 J and 93% (95/102) of patients had a DFT , 15 J. The QRS duration, interventricular septum thickness, left ventricular mass, and mass index were significant but weak (R < 0.3) univariate predictors of DFT. The left ventricular mass was the only independent predictor by multivariate analysis, but this parameter accounted for < 5% of the variability of DFT measured (adjusted R2= 0.047, P = 0.017). The authors concluded that an acceptable DFT (< 15 J) is observed in > 90% of patients with this dual coil and active pectoral can lead system. Clinical factors are of limited use for predicting DFTs and identifying those patients who will have high thresholds. [source] Subcutaneous Array to Transvenous Proximal Coil Defibrillation as a Solution to High Defibrillation Thresholds with Implantable Cardioverter Defibrillator Distal Coil FailureJOURNAL OF CARDIOVASCULAR ELECTROPHYSIOLOGY, Issue 3 2003BOAZ AVITALL, Ph.D. Implantation of a subcutaneous array to improve the defibrillation threshold of an existing transvenous defibrillation lead system without the need for lead extraction is discussed.(J Cardiovasc Electrophysiol, Vol. 14, pp. 314-315, March 2003) [source] Initial Experience with an Active-Fixation Defibrillation Electrode and the Presence of Nonphysiological SensingPACING AND CLINICAL ELECTROPHYSIOLOGY, Issue 12 2001RAHUL N. DOSHI DOSHI, R.N., et al.: Initial Experience with an Active-Fixation Defibrillation Electrode and the Presence of Nonphysiological Sensing. Nonphysiological sensing by a pacing and defibrillation electrode may result in inappropriate defibrillator discharges and/or inhibition of pacing. Active-fixation electrodes may be more likely to sense diaphragmatic myopotentials because of the protrusion of the screw for fixation. In addition, the movement of the fixation screw in an integrated bipolar lead system could also result in inappropriate sensing. This may be increasingly important in patients who are pacemaker dependent because the dynamic range of the autogain feature of these devices is much more narrow. Five of 15 consecutive patients who received a CPI model 0154 or 0155 active-fixation defibrillation electrode with an ICD system (CPI Ventak AV3DR model 1831 or CPI Ventak VR model 1774 defibrillator) are described. In 2 of the 15 patients, nonphysiological sensing appearing to be diaphragmatic myopotentials resulted in inappropriate defibrillator discharges. Both patients were pacemaker dependent. Changes in the sensitivity from nominal to less sensitive prevented inappropriate discharges. In one patient, discreet nonphysiological sensed events with the electrogram suggestive of ventricular activation was noted at the time of implantation. This was completely eliminated by redeployment of the active-fixation lead in the interventricular septum. In two other patients, discreet nonphysiological sensed events resulted in intermittent inhibition of ventricular pacing after implantation. These were still seen in the least sensitive autogain mode for ventricular amplitude. These were not seen on subsequent interrogation 1 month after implantation. Increased awareness of nonphysiological sensing is recommended. The CPI 0154 and 0155 leads seem to be particularly prone to this abnormality. Particular attention should be made when deploying an active-fixation screw for an integrated bipolar lead. This increased awareness is more important when a given individual is pacemaker dependent, which may warrant DFT testing in a least or less sensitive mode in these patients. [source] Would Different Routine Precordial Electrode Positions Be More Useful?CLINICAL CARDIOLOGY, Issue 2 2009Answer: Not Likely Abstract There are reasons to wonder if the current precordial electrode positions are the best ones to study the electrical forces of the heart. Theoretically, more horizontal electrode positions and several superior and inferior electrode positions that are perpendicular to the horizontally placed electrode positions should make a superior lead system. A study was designed to determine if that was true. The result of the study indicated that such a system did not solve all of the problems that were posed by the current system. Although the new system was easier to use, the findings did not justify a change from the presently used system of precordial electrode placement. Copyright © 2009 Wiley Periodicals, Inc. [source] Induction Ovens and Electromagnetic Interference:PACING AND CLINICAL ELECTROPHYSIOLOGY, Issue 7p1 2003What is the Risk for Patients with Implanted Pacemakers? Electromagnetic fields may interfere with normal pacemaker function. Despite the introduction of modern pacemakers and bipolar lead systems, electromagnetic interference (EMI) still remains to be a concern during daily lives when patients are exposed to cellular phones, electronic security systems, and several household appliances. The aim of this study was to evaluate potential EMI risk of induction ovens, which are increasingly used in private households. The study included 40 consecutive patients (22 men, 18 women; age73 ± 11 years) with implanted DDD, VVI, VDD, and AAI pacemaker systems. The pacemakers were programmed to unipolar sensing and pacing. Sensitivity remained unchanged, if the measured sensing threshold was more than twice the programmed value; otherwise, it was set at half of the measured sensing threshold. Patients were placed in a sitting position at the closest possible distance of about 20 cm between two cooking pots and pacemaker bending the upper part of the body slightly over the induction oven. The energy was increased stepwise to the maximum. One pot was removed and placed again at the highest oven level. Potential interference was monitored continuously. The study showed no incidence of pacemaker malfunction during the entire test while the patients with intrinsic cardiac rhythms were exposed to the induction oven at varying energy strengths. Likewise, there was no external interference when the patients were paced at heart rates of 10,15 beats/min above their heart rates. The programmed parameters remained unchanged after the study. In conclusion, this study shows no EMI risk of an induction oven in patients with bipolar or right-sided unipolar pacemakers. (PACE 2003; 26[Pt. I]:1494,1497) [source] | ||||||||||||||||||||||