Intra-QT Spectral Coherence as a Possible Noninvasive Marker of Sustained Ventricular Tachycardia

Table 2

Short-term (5-minute) ECG derived data in the two study groups.

Variables	VT group; 𝑁: 27	No-VT; 𝑁: 97	P values
QT𝑒 mean, ms	391 ± 56	381 ± 73	Ns
QT𝑒 variance, ms^2	46 [59]	43 [49]	Ns
QT𝑝 mean, ms	293 ± 52	304 ± 48	Ns
QT𝑝 variance, ms^2	47 [54]	35 [52]	Ns
𝑇𝑒 mean, ms	91 ± 39	88 ± 25	Ns
𝑇𝑒 variance, ms	99 [76]	86 [93]	Ns
RR mean, ms	961 ± 142	966 ± 137	ns
RR variance, ms^2	707 [879]	729 [962]	ns
QT𝑒 variability index	−0.46 [1.17]	−0.35 [0.80]	ns
QT𝑝 variability index	−0.21 [1.22]	−0.16 [0.84]	ns
𝑇𝑒 variability index	1.17 0 [1.26]	1.28 [0.79]	ns

Values are expressed as mean ± SD (compared with unpaired 𝑡-test) or median [interquartile range 75th percentile–25th percentile] (Mann-Whitney U test).