Ebook Implantable cardioverter - Defibrillators step by step: Part 2
➤ Gửi thông báo lỗi ⚠️ Báo cáo tài liệu vi phạmNội dung chi tiết: Ebook Implantable cardioverter - Defibrillators step by step: Part 2
Ebook Implantable cardioverter - Defibrillators step by step: Part 2
ICD TROUBLESHOOTING :TESTING FOR LEAD PROBLEMS Ị1Comparing near-held and far-fiold EGMs can help determine which conductor Is affected. Noise only on Ebook Implantable cardioverter - Defibrillators step by step: Part 2 the far-field EGM suggests that the defect involves the shocking lead and not the sensing lead.Look for abnormalities with changes in body position, deep respiration, coughing, movement of the ipsilateral arm. pocket manipulation and Valsalva maneuver. Differentiate myopotentials from false signals Ebook Implantable cardioverter - Defibrillators step by step: Part 2 but the two may coexistA slight decrease in sensitivity (0.3 to 0.45 mV) may eliminate myopotentials but Is unlikely to eliminate false signals.NoteEbook Implantable cardioverter - Defibrillators step by step: Part 2
that an insulation defect may set the stage for oversenslng pectoral myopotentials.Noise in more than one lead (AEGM A VEGM) suggests EMI.aVerify the ICD TROUBLESHOOTING :TESTING FOR LEAD PROBLEMS Ị1Comparing near-held and far-fiold EGMs can help determine which conductor Is affected. Noise only on Ebook Implantable cardioverter - Defibrillators step by step: Part 2 is always recorded when a shock Is delivered. A high value indicates a fracture, a low value an insulation defect In the past this was determined by deliberate delivery of a small shock. In contemporary devices, it is a painless measurement with a small test pulse. In some ICDs. these painless puls Ebook Implantable cardioverter - Defibrillators step by step: Part 2es are delivered periodically to construct a trend plot.The pacing Impedance Is related to lead design. Values lower than 200 ohms indicate an insulatEbook Implantable cardioverter - Defibrillators step by step: Part 2
ion defect, while values higher than 2000 ohms Indicate a fracture, a loose set screw or a defective adapter (More that high impedance leads do not caICD TROUBLESHOOTING :TESTING FOR LEAD PROBLEMS Ị1Comparing near-held and far-fiold EGMs can help determine which conductor Is affected. Noise only on Ebook Implantable cardioverter - Defibrillators step by step: Part 2 useful in the diagnosis of fracture.Occasionally a lead problem is associated with a normal impedance.j Remember’ Numerous aborted shocks duo to oversonsing suggest a lead problem.•Multiple shocks without prior symptoms may also be caused by lead problems.•Ineffectual shocks for VT/VF may occur if Ebook Implantable cardioverter - Defibrillators step by step: Part 2the problem involves the shocking electrode.•Audible “Patient Alert" system may be activated by a lead problem.ABBREVIATIONS : At GM • Xnol clodrogiimEbook Implantable cardioverter - Defibrillators step by step: Part 2
tv I ■ ctodrcniognctc. VEGM • vortncu'4' ooctrvợaT.vf ■ ventricular 'tjtiluUx'. VT ■ vootncuuã tadrycardu. HV ■ high .vilaguFigure 11.03PACING IMPEDAICD TROUBLESHOOTING :TESTING FOR LEAD PROBLEMS Ị1Comparing near-held and far-fiold EGMs can help determine which conductor Is affected. Noise only on Ebook Implantable cardioverter - Defibrillators step by step: Part 2NORMALPACING IMPEDANCE ca 500 ftLEAD FRACTURE >2000 ftAll impedances are measured according Ohm’s law. However different voltages are used between the different electrodes !'(B/ HIGH VOLTAGE IMPEDANCESHOCKING IMPEDANCE (lend + tissue)R _ Shocking voltage Shocking current laINSULATION DEFECT <20 ftNO Ebook Implantable cardioverter - Defibrillators step by step: Part 2RMAL PACING IMPEDANCE 20- 100 0LEAD FRACTURE > 100 ftNote:In older systems, the shocking impedance was measured while delivering a real shock to the hEbook Implantable cardioverter - Defibrillators step by step: Part 2
eart In contemporary systems a painless reduced voltage (Vs) Is used (altough higher than the pacing voltage).Figure 11.04ICD TROUBLESHOOTING :TESTING FOR LEAD PROBLEMS Ị1Comparing near-held and far-fiold EGMs can help determine which conductor Is affected. Noise only on ICD TROUBLESHOOTING :TESTING FOR LEAD PROBLEMS Ị1Comparing near-held and far-fiold EGMs can help determine which conductor Is affected. Noise only onGọi ngay
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