title: Management of functional Sprint Fidelis leads at cardiac resynchronization therapy-defibrillator generator replacement: a novel option for preventing inappropriate shocks from lead failure in fragile patients with high risk of sudden death.
abstract: OBJECTIVE
  In patients with a functional Sprint Fidelis lead at generator replacement, the manufacturer recommended to either continue to use the existing lead or replace it with a new lead. For those patients who continue to use a functional Fidelis lead, the risk of inappropriate shocks remains present if the lead fails in the future. We evaluated the feasibility of an alternative approach at the time of cardiac resynchronization therapy-defibrillator (CRT-D) generator replacement in patients with a functional bipolar left ventricular (LV) lead for prevention of inappropriate shocks from future Fidelis lead failure.
  
  
  RESULTS
  During the procedure, the pace/sense IS-1 connection pin of the functional Fidelis lead was intentionally inserted into the LV port of the new CRT-D generator, while the existing bipolar LV lead IS-1 connection pin was inserted into the right ventricular (RV) pace/sense port. After such switching, the existing bipolar LV lead was used for functional LV pacing/sensing, while the Fidelis lead was used for functional RV pacing and high voltage shock only and could no longer be used for the purpose of sensing and detecting. This approach precluded oversensing and inappropriate shocks should the functional Fidelis lead fail in the future. Six fragile patients, who were not considered suitable candidates for lead replacement, underwent the alternative approach. During a follow-up of 35 ± 23 months, the CRT-D system functioned normally in five patients. The Fidelis lead fractured in one patient 7 months after generator replacement. The malfunction was detected promptly and the defected lead was replaced. No inappropriate detections or shock was triggered.
  
  
  CONCLUSIONS
  In CRT-D patients with a functional Fidelis lead and a bipolar LV lead, switching of the Fidelis lead pace/sense IS-1 pin with the bipolar LV lead IS-1 pin at generator replacement did not affect normal system function. This novel approach may be valuable in fragile patients with high risk of sudden death for prevention of inappropriate shocks triggered by oversensing from a malfunctioning Fidelis lead.
authors.affiliation: Regions Hospital, St. Paul, MN 55101, USA.|HealthPartners Medical Group, Bloomington, MN, USA.|University of Minnesota Medical School, Minneapolis, MN, USA.
authors.forename: Dennis W X
authors.initials: DWX
authors.lastname: Zhu
authors.affiliation: Regions Hospital, St. Paul, MN 55101, USA.
authors.forename: Matthew M
authors.initials: MM
authors.lastname: Chu
authors.affiliation: Regions Hospital, St. Paul, MN 55101, USA.|HealthPartners Medical Group, Bloomington, MN, USA.
authors.forename: Chad M
authors.initials: CM
authors.lastname: House
mesh_terms: D000367:Age Factors; D000368:Aged; D000369:Aged, 80 and over; D058406:Cardiac Resynchronization Therapy / Q000009:adverse effects / Q000401:mortality; D058409:Cardiac Resynchronization Therapy Devices; D015897:Comorbidity; D016757:Death, Sudden, Cardiac / Q000209:etiology / Q000517:prevention & control*; D017147:Defibrillators, Implantable; D020878:Device Removal / Q000009:adverse effects / Q000379:methods* / Q000401:mortality; D004554:Electric Countershock / Q000009:adverse effects / Q000295:instrumentation* / Q000401:mortality; D011211:Electric Power Supplies; D004558:Electric Stimulation; D004562:Electrocardiography; D022062:Electrophysiologic Techniques, Cardiac; D005240:Feasibility Studies; D005260:Female; D006801:Humans; D008297:Male; D011474:Prosthesis Design; D011475:Prosthesis Failure; D012189:Retrospective Studies; D018570:Risk Assessment; D012307:Risk Factors; D013997:Time Factors; D016896:Treatment Outcome; D016277:Ventricular Function, Left; D016278:Ventricular Function, Right
keywords: Cardioac resyncronization therapy; Implantable cardioverter-defibrillator; Inappropriate shock; Sprint Fidelis lead; Sudden death