Lead outcome of upgrades
The pacemaker parameters including threshold, sensed R wave and impedance were recorded after a median follow-up period of 8.9 months (Table 3). The threshold of HPSP did not increased significantly (1.18±0.76 mv@0.4ms vs 1.26±0.70mv @ 0.4ms, P=0.581) (Figure 1D). Sensed R (4.85±2.08 vs. 4.56±1.94, P=0.148) and lead impedance (616.76±148.89 vs. 493.09±118.85, P=0.108) were remain relatively stable during follow-up duration.