Comparison of the Thresholds and the Lead Impedances between Right Ventricular Septal and Apical Pacing in Three-Year Follow Up

Abstract

Background: In recent years right ventricular septal (RVS) pacing has been performed instead of right ventricular apical (RVA) pacing because of the detrimental effects on the ventricular function associated with the latter type of pacing. Though we generally implant tined lead for RVA and screw-in lead for RVS in Japan, little information was available about comparison of the different pacing leads for those pacing positions. Purpose: In this study, we investigated the differences in the thresholds and the lead impedances between two pacing positions in those 2 groups of patients in whom a permanent pacemaker was implanted. Methods: In 39 patients, we positioned tined lead in the RVA for 20 patients and screwed-in lead in the RVS for 19 patients randomly. In each pacing position, we calculated the thresholds and the lead impedances over three years. Results: The threshold showed no remarkable changes between the RVA and the RVS (acute phase: 0.7±0.15 vs. 0.5±0.03 V, p=0.2538, 3 years: 0.8±0.07 vs. 0.9±0.09 V, p=0.2980). On the other hand, the lead impedance was significantly greater in the RVA in comparison to the RVS (acute phase: 784.5±19.8 vs. 564.6±28.2Ω, p<0.0001, 3 years: 612.9±17.2 vs. 450.3±15.8Ω, p<0.0001). Conclusions: The difference of the lead impedance between the RVA and RVS pacing was suggested to be owing to the speculations of each pacing lead. A careful follow-up for RVS pacing would be needed to preserve the life of a battery.