title: Clinical efficacy and safety of an implantable cardioverter-defibrillator lead with a floating atrial sensing dipole.
abstract: BACKGROUND
  The concept of a single-lead implantable cardioverter-defibrillator (ICD), with a floating dipole, has been proven safe and functional.
  
  
  RESULTS
  The studied active-fixation, steroid-eluting lead (Linox(smart) S DX, BIOTRONIK SE & Co KG, Berlin, Germany) is one French thinner than its predecessor and coated with lubricious SilGlide to improve lead handling. A dedicated ICD device has a self-adaptive atrial input stage including a fourfold amplifier. The amplification, filtering, and adapted atrial input stage are located in the Lumax 540 VR-T DX (BIOTRONIK). The Linox(smart) S DX ICD lead delivers only the signal. The lead was evaluated during implantation; at predischarge; and 1-, 3-, and 6-month follow-up examinations. The primary endpoint (efficacy) was the rate of appropriate atrial sensing tests. The secondary endpoint (safety) was freedom from lead-related invasive reinterventions. Both safety and efficacy were expected to be significantly higher than 90%. The study enrolled 116 patients at 25 clinical sites. Skin-to-skin operation time was 52.4 ± 26.2 minutes. The investigators graded lead insertion as "easy" in 87% of patients. Mean P-wave amplitudes (preamplified) varied from 5.0 to 6.1 mV in different body positions. Both primary and secondary endpoints were met, as 93.8% (364/388; P = 0.005) of specific sensing tests indicated appropriate atrial sensing, and 94.8% (110/116; P = 0.048) of patients were free from reinterventions (lead dislodgement). Analysis of arrhythmia episodes stored in ICDs and elective 24-hour Holter electrocardiogram tests raised no concerns about lead functionality.
  
  
  CONCLUSIONS
  The studied ICD lead with a floating atrial sensing dipole met the predefined safety expectation and demonstrated appropriate atrial sensing performance.
authors.affiliation: Charité Campus Benjamin Franklin, Medical Clinic II, Berlin, Germany. erdal.safak@charite.de
authors.forename: Erdal
authors.initials: E
authors.lastname: Safak
authors.forename: Dietmar
authors.initials: D
authors.lastname: Schmitz
authors.forename: Thomas
authors.initials: T
authors.lastname: Konorza
authors.forename: Christian
authors.initials: C
authors.lastname: Wende
authors.forename: Jose Olague
authors.initials: JO
authors.lastname: De Ros
authors.forename: Alexander
authors.initials: A
authors.lastname: Schirdewan
mesh_terms: D001281:Atrial Fibrillation / Q000453:epidemiology* / Q000517:prevention & control*; D017147:Defibrillators, Implantable / Q000706:statistics & numerical data*; D004562:Electrocardiography / Q000295:instrumentation* / Q000706:statistics & numerical data*; D004567:Electrodes, Implanted / Q000706:statistics & numerical data*; D004867:Equipment Design; D004868:Equipment Failure / Q000706:statistics & numerical data; D019544:Equipment Failure Analysis; D004869:Equipment Safety / Q000706:statistics & numerical data*; D005060:Europe / Q000453:epidemiology; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D015995:Prevalence; D016896:Treatment Outcome
keywords: atrial sensing; complications; defibrillation lead; floating atrial sensing dipole; implantable cardioverter-defibrillator; lead handling