title: Spectrum of issues detected by an ICD diagnostic alert that utilizes far-field electrograms: Clinical implications.
abstract: BACKGROUND
  Implantable cardioverter-defibrillator (ICD) lead failure is one of the major causes of inappropriate shocks. Algorithms have been developed by manufacturers to identify ICD lead failure and avoid inappropriate shocks. The SecureSense RV Lead Noise Discrimination (St Jude Medical, St Paul, MN) algorithm is designed to differentiate oversensing due to lead failure from ventricular arrhythmias and withhold inappropriate therapies. Several non-lead failure-related issues can trigger the SecureSense automated algorithm.
  
  
  OBJECTIVE
  Our objective was to explain the SecureSense algorithm in a detailed fashion, highlighting examples of SecureSense alerts triggered by non-lead failure-related issues.
  
  
  METHODS
  This is a nonrandomized observational case series. SecureSense-triggered alerts from 3 ICD device clinics were analyzed, and representative examples of SecureSense triggers due to non-lead failure-related issues were chosen to explain the function and malfunction of this algorithm.
  
  
  RESULTS
  The series includes 8 cases of SecureSense alerts triggered by non-lead failure-related issues---myopotential oversensing (1), P-wave oversensing (1), T-wave oversensing (1), loss of capture (1), R-wave undersensing (1), timing cycle issues (2), and cross talk (1)---and 1 case of failure of the algorithm to appropriately identify lead failure and prevent ICD shocks.
  
  
  CONCLUSIONS
  Lead failure detection algorithms such as the one assessed in this study have an inherent risk of false-positive and false-negative detections. The latter might have fatal consequences. The true accuracy of these algorithms needs to be evaluated in large-scale real-life prospective clinical studies.
authors: Cardiac Electrophysiology, Division of Cardiology, Virginia Commonwealth University, Richmond, Virginia. Electronic address: jkoneru@mcvh-vcu.edu.
authors: Jayanthi N
authors: JN
authors: Koneru
authors: The Hunter Holmes McGuire VA Hospital and Virginia Commonwealth University, Richmond, Virginia.
authors: Karoly
authors: K
authors: Kaszala
authors: Haut Leveque Hospital, LIRYC Institute, Pessac, France.
authors: Pierre
authors: P
authors: Bordachar
authors: Cedars-Sinai Heart Institute and David Geffen School of Medicine at UCLA, Los Angeles, California.
authors: Michael
authors: M
authors: Shehata
authors: Cedars-Sinai Heart Institute and David Geffen School of Medicine at UCLA, Los Angeles, California.
authors: Charles
authors: C
authors: Swerdlow
authors: Cardiac Electrophysiology, Division of Cardiology, Virginia Commonwealth University, Richmond, Virginia.
authors: Kenneth A
authors: KA
authors: Ellenbogen
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000465:Algorithms; D001145:Arrhythmias, Cardiac / Q000175:diagnosis / Q000209:etiology / Q000503:physiopathology / Q000628:therapy; D053840:Brugada Syndrome; D000075224:Cardiac Conduction System Disease; D017147:Defibrillators, Implantable / Q000009:adverse effects*; D004554:Electric Countershock / Q000009:adverse effects / Q000379:methods; D004562:Electrocardiography / Q000379:methods; D004868:Equipment Failure; D004869:Equipment Safety; D005260:Female; D006329:Heart Conduction System / Q000002:abnormalities* / Q000503:physiopathology; D006333:Heart Failure / Q000150:complications / Q000503:physiopathology / Q000628:therapy; D006801:Humans; D008297:Male; D008875:Middle Aged; D019233:Retreatment / Q000295:instrumentation / Q000379:methods; D016896:Treatment Outcome
keywords: Automated ICD algorithm; ICD; ICD lead failure; Implantable cardioverter-defibrillator; Inappropriate shocks; Lead failure; Lead fracture