“…4,17 There are also concerns regarding electrode perforation particularly with the atrial lead, 18,19 although the chronic use of active-fixation leads in the atrium is well established. 2,20,21 Previous studies examining the performance of active-fixation leads have not reported on acute changes in stimulation thresholds during the op-erative period. 2,4,7,22,23 The results of lead testing during implantation are critically important in determining whether lead repositioning is required.…”