1 / 57

Components of Pacing Leads: Design and Performance Factors

Components of Pacing Leads: Design and Performance Factors. Pacing Lead Activity. 70 bpm 100,000 beats / day 37,000,000 beats / year. Pacing Lead Components. Objectives Be awareness of how leads play a critical role in the reliability of a pacing system -- A lead is not “just a wire”.

andrew
Télécharger la présentation

Components of Pacing Leads: Design and Performance Factors

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Components of Pacing Leads:Design and Performance Factors

  2. Pacing Lead Activity • 70 bpm • 100,000 beats / day • 37,000,000 beats / year

  3. Pacing Lead Components Objectives • Be awareness of how leads play a critical role inthe reliability of a pacing system -- A lead is not“just a wire”. • Demonstrate an understanding of design and technology that influence potential performance and reliability of a lead -- All leads are not created equal. • Demonstrate an understanding of lead assembly process

  4. Pacing Lead Components • Conductor • Connector Pin • Insulation • Electrode • Lead Assembly Tip Electrode Conductor Insulation Connector Pin

  5. Conductor • Purpose • Deliver electrical impulses from IPG to electrode • Return sensed intracardiac signals to IPG Conductor

  6. Conductor -- Types • Types • Unifilar • Multifilar • Cable

  7. Conductor -- Construction • Unipolar Construction

  8. Unipolar lead 1 pacing conductor IPG case (“can”)for sensing Conductor -- Unipolar Construction

  9. Conductor -- Unipolar Construction • Unipolar Lead Characteristics • Larger pacing spikes on EKG • Small diameter lead body • Less rigid lead body • More susceptible to oversensing • May produce muscle and nerve stimulation

  10. Conductor -- Construction • Bipolar Construction • Co-axial • Co-radial Tip electrode coil Indifferent electrode coil Outer insulation Tip electrode coil Indifferent electrode coil Integral insulation

  11. Conductor -- Construction • Bipolar Construction • Parallel Coils • Coil / Cables

  12. Bipolar 1 pacing conductor 1 sensing conductor Conductor -- Bipolar Construction

  13. Conductor -- Bipolar Construction • Bipolar Lead Characteristics • Larger diameter lead body • Tend to be stiffer • Less susceptible to oversensing • Unipolar programmable • Less likely to produce muscle and nerve stimulation

  14. Conductor -- Material • Typical Conductor Materials • MP35N (nickel alloy) • MP35N silver cored

  15. Connector • Purpose • Connects lead to IPG, and provides a conduit to: • Deliver current from IPG to lead • Return sensed cardiac signals to IPG Connector

  16. Connector -- IS-1 Standard • IS-1 Standard Connectors • Sizes Prior to IS-1 Standard • 3.2 mm low-profile connectors • 5/6 mm connectors

  17. Insulation • Purpose: • Contain electrical current • Prevent corrosion Insulation

  18. Insulation -- Properties • Properties of Insulation Materials • Tensile strength • Elongation • Tear strength • Abrasion • Compression set • Crush (cyclic compression) • Creep

  19. Insulation -- Type • Insulation Types • Silicone • Polyurethane • Fluoropolymers (PTFE, ETFE)

  20. Insulation -- Type • Silicone • Advantages • Inert • Biocompatible • Biostable

  21. Insulation -- Type • Silicone • Disadvantages • High friction coefficient (sticky) • Handling damage • Size (for some types of silicone)

  22. Insulation -- Type • Polyurethane • Advantages • Biocompatible • High tear strength • Low friction coefficient • Less fibrotic • Small lead diameter

  23. Insulation -- Type • Polyurethane Disadvantages • Environmental Stress Cracking (ESC) Crazing or cracking of the polyurethane due to exposure to the in-vivo environment and internal material stresses • Metal Ion Oxidation (MIO) Oxidative degradation of the polyurethane insulation

  24. Insulation -- Small Size New Insulation Materials Facilitate the Benefits of Smaller Lead Diameters • Smaller introducer size • Easier insertion/passage through smaller veins • More flexible lead bodies • Two leads through one introducer • Less intrusive

  25. Electrodes • Purpose • Deliver a stimulus to myocardium • Detect (sense) intracardiac signals Tip Electrode Ring Electrode

  26. Electrodes • Optimal Performance Factors • Low, Stable Thresholds • High Pacing Impedance • Low Source Impedance • Good Sensing

  27. Electrodes • Characteristics and Design Factors that Impact Electrical Performance • Fixation mechanism • Polarity • Surface material • Size • Surface structure • Steroid elution

  28. Electrodes -- Fixation Mechanism • Passive Fixation Mechanism – Endocardial • Tined • Finned • Canted/curved

  29. Electrodes -- Fixation Mechanism • Passive Fixation Applications – Endocardial • Trabeculated ventricle • Atrial appendage present • Traditional pacing sites

  30. Electrodes – Fixation Mechanism • Active Fixation Mechanism – Endocardial • Fixed screw • Extendible/retractable

  31. Electrodes -- Fixation Mechanism • Active Fixation Applications -- Endocardial • Smooth ventricular walls • Atrial appendage is missing/malformed • Alternate pacing site

  32. Electrodes -- Fixation/Visualization Fluoroscopic Visual Quality of Passive Fixation Leads CapSure® CapSure SP® Novus CapSure Z® Novus

  33. Electrodes -- Fixation/Visualization Fluoroscopic Visual Quality of Active Fixation Leads space Extended Retracted Fixed Screw SureFix CapSureFix®

  34. Electrodes -- Fixation Mechanism • Fixation Mechanism – Myocardial / Epicardial • Stab-in • Screw-in • Suture-on

  35. Electrodes -- Polarity • Characteristics and Design Factors that Impact Electrical Performance • Fixation mechanism • Polarity • Surface material • Size • Surface structure • Steroid elution

  36. Electrodes -- Surface Material • Characteristics and Design Factors that ImpactElectrical Performance • Fixation mechanism • Polarity • Surface material • Size • Surface structure • Steroid elution

  37. Electrodes -- Surface Material • Surface Material • Polished platinum • Activated carbon • Platinized metal

  38. Electrodes -- Surface Material • Surface Material Characteristics • Corrosion Resistant • Biocompatible • Reduced Polarization

  39. Electrodes -- Size • Characteristics and Design Factors that Impact Electrical Performance • Fixation mechanism • Polarity • Surface material • Size • Surface structure • Steroid elution

  40. Electrodes -- Size • Reducing Electrode Size • Increases Impedance • Reduces Current Drain • Increases Longevity

  41. Electrodes -- Size/Impedance 1500 Size = Impedance 1000 Pacing Impedance (Ohms) 500 0 0 1 2 3 4 5.5 6 Geometric Tip Electrode Surface Area (mm2)

  42. Electrodes -- Size/Current Drain • Reducing electrode size • Increased impedance • Lower outputs, reduces current drain • Increases longevity Increasedimpedance at thetip electrode Smaller current drain (less current doessame amount of work) Largercurrentdrain

  43. Electrodes -- Size/Longevity • Impact of Pacing Impedance on Longevity Medtronic.Kappa™ DR Model KDR701 Total Pulse Width 0.4 ms in both chambers Lead A = 3.5 V A = 2.5 V A = 2.5 V Impedance V = 3.5 V V = 2.5 V V = 1.5 V 500  6.3 Yr 7.7 Yr 8.1 Yr 600  6.6 Yr 8.0 Yr 8.3 Yr 1000  7.7 Yr 8.6 Yr 8.8 Yr 1200  8.0 Yr 8.8 Yr 9.0 Yr 100% pacing at 60 ppm

  44. Electrodes -- Size/Polarization • Reducing Electrode Size • Increases polarization

  45. + - - + + - + + + Current Tissue - Current + + - + + + + - - Electrodes -- Size/Polarization • Polarization Layering Effect

  46. Electrodes -- Surface Structure • Characteristics and Design Factors that ImpactElectrical Performance • Fixation mechanism • Polarity • Surface material • Size • Surface structure • Steroid elution

  47. Electrodes -- Surface Structure • Porous Electrode Surface 15KV x2500 12.0V Medt CapSure® 8.0 mm2Porous Electrode CapSure® SP Novus 5.8 mm2 Platinized Porous Electrode CapSure® Z Novus 1.2 mm2 Platinized Porous Electrode

  48. Electrodes -- Surface Structure • Benefits of a Porous Electrode Surface • Reduces Polarization • Improves Sensing • Promotes Tissue In-Growth

  49. Electrodes -- Size and Surface Structure Increased Porosity Smaller Size Increases electrode tissue impedance Reduces polarization Decreased current drain Longevity Increases!

  50. Electrodes -- Steroid Elution • Characteristics and Design Factors that ImpactElectrical Performance • Fixation mechanism • Polarity • Surface material • Size • Surface structure • Steroid elution

More Related