Financial support for this study was provided by Medtronic Inc.
Effect of Insulation Material in Aging Pacing Leads: Comparison of Impedance and Other Electricals
Time-dependent pacemaker insulation changes
Article first published online: 5 OCT 2011
©2011, The Authors. Journal compilation ©2011 Wiley Periodicals, Inc.
Pacing and Clinical Electrophysiology
Volume 35, Issue 1, pages 51–57, January 2012
How to Cite
JOHNSON, W. B., BRALY, A., COBIAN, K., CRAIG, M. B., VOEGTLIN, L., HADDAD, T. and McVENES, R. (2012), Effect of Insulation Material in Aging Pacing Leads: Comparison of Impedance and Other Electricals. Pacing and Clinical Electrophysiology, 35: 51–57. doi: 10.1111/j.1540-8159.2011.03230.x
- Issue published online: 12 JAN 2012
- Article first published online: 5 OCT 2011
- Received July 22, 2010; revised July 15, 2011; accepted August 1, 2011.
- random effects model
Background: There has been concern over declining bipolar (BP) impedance (Z) in aging polyurethane (PU) cardiac pacing leads. Subsequently, a prospective study was conducted comparing BP Z, threshold (Th), and R-wave sensing amplitude of 55D PU-insulated (Model 4024, Medtronic, Inc., Minneapolis, MN, USA) and silicone-insulated (Model 5024) leads.
Methods: This study was initiated by The Iowa Heart Center. Patients with Model 4024 (N = 162) or 5024 (N = 120) pacing leads with at least 6 years implant time were enrolled and followed for an additional 5 years.
Results: There was a significant drop in the mean BP Z for the Model 4024 population, between enrollment (6 years) and the final endpoint (11 years), which was in contrast to the Model 5024 which did not see a significant drop in its mean BP Z for this same period. The trend difference seen in the means between the two models was statistically significant (P < 0.0001). In addition, a statistically significant relationship was found between dropping BP Z and rising Th (P < 0.0001). The analysis showed that if BP Z dropped below 200 ohms, the probability of having a >3X increase over baseline, in Th at 2.5 V, increases from approximately 3–7% to as high as 30%.
Conclusions: A significant drop in BP Z observed in the PU-insulated Model 4024 lead was not present in the silicone-insulated Model 5024 lead. The statistically significant relationship between dropping BP Z and rising Th helps to understand how to better manage patients with aging leads. (PACE 2012; 35:51–57)