title: Long-term performance of modern coronary sinus leads in cardiac resynchronization therapy.
abstract: BACKGROUND
  Cardiac resynchronization therapy (CRT) has become an important pillar of contemporary heart failure therapy. The efficacy of CRT, however, critically relies on proper LV lead placement and performance, which is why data regarding the long-term performance of CS leads are of considerable interest. Available studies are limited by a restricted variety of lead vendors, earlier lead models and / or very short follow-up periods. In the current study, we therefore investigated the long-term performance of modern LV leads in a large "real world" cohort of patients undergoing CRT implantation.
  
  
  RESULTS
  All 193 patients who had successfullyundergone CRT implantation at the University Hospital Zurich between September 2003 and January 2010 were included in the study. An overall stable course of stimulation energy was observed over time; neither ischemic etiology, lead configuration, or severely reduced EF had an influence on the evolution of energy thresholds over time. Interestingly, patients with a high energy threshold at baseline experienced a significant reduction during follow-up. In contrast, a significant drop in impedance was seen following implantation, followed by a steady course for the rest of the observation period. Only 15 patients (9.7%) showed an impedance > 1000 Ohm at any time during their follow-up. Seven lead dislocations were observed during follow up.
  
  
  CONCLUSIONS
  The current comprehensive analysis of long-term performance of modern coronary sinus leads demonstrates excellent stability, performance and safety. These data may have important implications for physicians involved in biventricular pacemaker implantations and in the follow-up care of these patients.
authors.affiliation: Department of Cardiology, University Hospital Zurich.
authors.forename: Jan
authors.initials: J
authors.lastname: Steffel
authors.affiliation: Department of Cardiology, University Hospital Zurich.
authors.forename: Anja
authors.initials: A
authors.lastname: Hurlimann
authors.affiliation: Department of Cardiac Surgery, University Hospital Zurich.
authors.forename: Christoph
authors.initials: C
authors.lastname: Starck
authors.affiliation: Department of Cardiology, University Hospital Zurich.
authors.forename: Nazmi
authors.initials: N
authors.lastname: Krasniqi
authors.affiliation: Department of Cardiology, University Hospital Zurich.
authors.forename: Susann
authors.initials: S
authors.lastname: Schmidt
authors.affiliation: Department of Cardiology, University Hospital Zurich.
authors.forename: Thomas F
authors.initials: TF
authors.lastname: Luscher
authors.affiliation: Department of Cardiology, University Hospital Zurich.
authors.forename: Firat
authors.initials: F
authors.lastname: Duru
authors.affiliation: Department of Cardiology, University Hospital Zurich.
authors.forename: Frank
authors.initials: F
authors.lastname: Ruschitzka
authors.affiliation: Department of Cardiology, University Hospital Zurich.
authors.forename: Johannes
authors.initials: J
authors.lastname: Holzmeister
authors.affiliation: Department of Cardiology, University Hospital Zurich.
authors.forename: David
authors.initials: D
authors.lastname: Hurlimann
keywords: Cardiac Resynchronization Therapy; Coronary Sinus Leads