The time course of current of injury from onset to resolution was significantly correlated with the force needed to detach the active-fixation pacing lead from the myocardium in rabbits (r = 0.72, p<0.001).
Does the time course of current of injury correlate with acute stability of active-fixation pacing leads in rabbits?
In a rabbit model, the persistence of the current of injury after active-fixation pacing lead placement correlates with acute lead stability, suggesting dynamic monitoring may be superior to a single assessment.
Effect estimate: r = 0.72
p-value: p=<0.001
BACKGROUND: Magnitude of current of injury (COI) consequent to pacemaker lead fixation is recognized as a predictor of acute lead stability. It is unclear whether dynamic monitoring of COI after lead fixation provides additional information beyond a single assessment performed at the time of fixation. OBJECTIVES: This study was aimed to test the hypothesis that the time course of COI is related to acute lead stability. METHODS AND RESULTS: Active fixation leads with fixed screw were anchored to either Langendorff-perfused rabbit hearts endocardially or in vivo hearts epicardially in manners of contact the helix with no rotation, half rotation and full rotation, respectively. Intracardiac electrogram (EGM) was monitored dynamically from onset to resolution of COI, and magnitudes of intrinsic R wave and COI, including ST-segment elevation, ST/R and intracardiac EGM duration (IED), were measured. A digital force gauge was applied to assess lead stability. In vitro, COI in contacted leads was significantly smaller than those in half rotated (p<0.05) and fully rotated leads (p<0.05), and presented most precipitous recovery to baseline (1.5±1.1 min, p<0.05). Half-rotated and fully rotated leads manifested the same magnitude of COI right after placement. However, the time course of COI was significantly longer in fully rotated leads than that in half rotated leads (26.5±2.8 min vs. 5.6±2.0 min, p<0.05). Similar findings were observed in vivo. The time course of COI was significantly correlated with the force needed to detach the lead from myocardium (r = 0. 72, n = 48, p<0.001). CONCLUSIONS: Time course of COI is related to acute lead stability in rabbits. One might be misled by a single assessment of COI magnitude right after lead placement, whereas persistence of COI is likely to be a useful indicator of adequate lead stability.
Shali et al. (Tue,) conducted a other in Pacemaker lead implantation (n=24). Active-fixation pacing leads with different rotation patterns vs. Contact vs half rotation vs full rotation was evaluated on Correlation between time course of current of injury (COI) and force needed to detach the lead from myocardium (r = 0.72, p=<0.001). The time course of current of injury from onset to resolution was significantly correlated with the force needed to detach the active-fixation pacing lead from the myocardium in rabbits (r = 0.72, p<0.001).