Current of injury predicts adequate active lead fixation in permanent pacemaker/defibrillation leads

Abstract

The development of a COI indicates that within 10 min of fixation, pacing threshold will return to an acceptable range even if the initial measurement is high. Conversely, without a COI, lead fixation is not adequate and the lead should be repositioned.

High-Confidence Medical Device Software Development

“…It happens when two leads are close to each other or pacing signal in the other chamber is too strong. It is common that the ventricular lead is placed in the right ventricle outflow tract, which is close to the atrium (Saxonhouse et al [2005]). Fig.…”

Foreseeable variation in parameters measured at implant and follow-up of permanent pacemaker active fixation electrodes

“…11,12 Other methods can also be incorporated to confirm good contact and fixation of the electrode, such as the injury current in the intracavitary electrogram. 13 In the human heart, the tissue enveloping the electrode tip is associated to an increase in impedance, and it is more likely for this to happen in the right atrium, while penetration is more likely in the right ventricle, and manifests in the form of a decrease in measured impedance. 8 During the electrode fixation process, impedance is the parameter showing the greatest variation, and this is inherent to the electrode design.…”

HRS Policy Statement: Clinical Cardiac Electrophysiology Fellowship Curriculum: Update 2011

“…135 Understanding pacing system technology Leads (including electrode configuration, fixation, insulation, conductors, and connectors)Pulse generators (including batteries, circuitry, sensors, and function, including monitoring)Biophysics of pacing, including strength duration curvesElectronics; sensing/stimulation/defibrillation Basic quantities (ampere, charge, coulomb, ohm, volt, hertz)Derived quantities (resistance, capacitance, battery capacity) and Ohm’s LawKnowledge of timing cycles, blanking and refractory periodsSensors (motion/activity and minute ventilation)Mode switching algorithmsEmerging pacing energy sources, devices, diagnostics and other functionality Temporary pacing 130 IndicationsTechniques Permanent pacemaker indications 130 Permanent pacemaker implantation (training program should provide sufficient experience and resources to enable fellows to perform pacemaker implantation, troubleshooting and interrogation) Pre procedure planning, including decisions on conscious sedation, periprocedural anticoagulation 136 and antimicrobial agents 137 Anatomic considerations, including normal and abnormal cardiac and great vessel variations, and selection of subcutaneous or subpectoral pocket locationsVenous access approaches including cephalic, subclavian or axillary veins, and unusual situations requiring the internal jugular or iliac veinsTechniques to deal with limited venous access Upsizing sheaths in cases of venous stenosis, consideration of balloon angioplasty or lead explantation to enable lead deliveryTunnelingUsing existing leads to provide access into central veins 138 Interpreting electrograms from pacing system analyzers 139 Evaluation of sensing, pacing parameters and impedancesRadiation safetyKnowledge of alternatives to transvenous lead placement in congenital heart disease, including epicardial and transatrial approachesIntra-operative complication recognition and management Radiology Fluoroscopic views and lead locationsPost operative X-ray evaluation and identification of complications Immediate post-procedure care; recognition and management of complications Permanent pacemaker follow-up and troubleshooting 140 Comprehensive knowledge of specific device and lead parameters, and which are most applicable to specific clinical scenarios12-Lead ECG recognition of device function, malfunction and pacing siteExperience of various follow-up approaches, including clinic-based interrogation, familiarity with transtelephonic follow-up, and remote monitoring data from various manufacturers 141 Monitoring and application of adaptive algorithms such as auto capture, minimization of ventricular pacing, selection of AV intervalsOptimization of AV and VV timing by use of device-based algorithms and modalities such as echocardiographyDetermination of when to replace a pacemaker with another cardiac implanted electronic device Lead extraction …”