TITLE:
Leadless Cardiac Pacemaker: Does Anatomical Position at Implant Affect Long-Term Electrical Performance?
AUTHORS:
John Ip, Abdul R. Safadi, Randy Ip, Matthew Gaskill, Rajesh Banker, Derek Exner, Srinivas Dukkipati, Mayer Rashtian, Imran Niazi
KEYWORDS:
Pacing Lead Location, Leadless Pacing, Lead Impedance, Pacing Threshold, R-Wave Amplitude
JOURNAL NAME:
Journal of Biomedical Science and Engineering,
Vol.10 No.11,
November
29,
2017
ABSTRACT: Background: The Nanostim {trade mark, serif} Leadless Cardiac Pacemaker (LCP) has been shown to be safe and effective in human clinical trials. Since there is little information on the effect of implant location on LCP performance, the aim of this study was to determine whether anatomic position affects the long-term pacing performance of the LCP. Methods: Patients who enrolled in the Leadless II IDE Clinical Trial and had finished 6 months follow up (n = 479) were selected for the study. The implanting investigators determined the LCP final position under fluoroscope, which was categorized into three groups: RV apex (RVA, n = 174), RV apical septum (RVAS, n = 101), and RV septum (RVS, n = 204) (Figure 1). Data on capture threshold (at a 0.4 ms pulse width), R-wave amplitude and impedance were analyzed at implant, hospital discharge and 2 weeks, 6 weeks, 3 months and 6 months post-implant. Results: At implant, the mean capture thresholds in the RVA, RVAS and RVS were 0.77 ± 0.45, 0.81 ± 0.61 and 0.78 ± 0.59 volts, respectively. R-wave amplitudes were 8.0 ± 3.0 mV, 7.7 ± 2.9 mV and 7.6 ± 2.9 mV, respectively. Impedance values were 727 ± 311, 765 ± 333, and 677 ± 227 respectively. There were no differences among the 3 implant locations in capture threshold or R-wave amplitudes at 6 months (P > 0.06); however, all 3 performance parameters significantly improved over time (P