3.3 Capture threshold at baseline and follow-up
Despite the difference in follow-up time, our study did not show the same situation as HBP6, the capture threshold did not increase with longer follow-up time, and there was no statistically significant difference between the postoperative capture threshold and the follow-up threshold ( P =0.95, I2 = 91%, Figure 4).
3.4R-waveamplitude at baseline and follow-up
After aggregating all studies that recorded R-wave amplitude with relevant follow-up data, we found a significant trend of elevated R-wave amplitude which was statistically significant when comparing the data collected after surgery and at follow-up(12.17±5.24mv VS 14.22±5.47mv ,P =0.003, I2 = 50%, Figure 5).
3.5 Impedance at baseline and follow-up
The data revealed a clear trend of decreasing pacing impedance at follow-up and a statistically significant correlation between the postoperative and the follow-up, which may be related to the remission of edema and the formation of fibrous scarring at the electrode fixation site. (684.51±134.15Ω vs 532.15±104.24Ω P<0.00001, I2 =85%, Figure 6)