3.4 Reproducibility of RR interval variability of VT
Overall, in 47 episodes in 14 patients, ATP therapy was administered more than once per episode. Of those, 30 episodes included a higher proportion of regular VTs (12 patients), and 17 episodes included a higher proportion of irregular VTs (8 patients). The reproducibility of VT variability within an episode was 89% with an SD of 19 (regular VT, 94%; SD, 15; irregular VT, 80%; SD, 21). Additionally, 27 patients had more than two VT episodes. The reproducibility of RR interval variability of VT in individuals was 73%, with an SD of 18 (ischemic vs. non-ischemic, 71%, SD: 17 vs. 75%, SD: 18).