Table 1.

QT and RR Variables Grouped for Low and High Sympathetic Activity at Baseline and After Pacing-Induced CHF

	Baseline		CHF
Variables	Low Sympathetic Activity (<50th Percentile of iSGNA) (n = 18)	High Sympathetic Activity (≥50th Percentile of iSGNA) (n = 18)	Low Sympathetic Activity (<50th Percentile of iSGNA) (n = 18)	High Sympathetic Activity (≥50th Percentile of iSGNA) (n = 18)
RRm, s	0.995 ± 0.300*	0.696 ± 0.071	0.795 ± 0.120	0.727 ± 0.109
	<0.001		0.104
RRv, ms2	120,444 (369,936)*	62,000 (14,844)*	45,004 (26,511)	40,845 (15,110)
	<0.05		<0.05
QTm, s	0.291 ± 0.107	0.218 ± 0.013†	0.231 ± 0.013	0.241 ± 0.009
	<0.001		<0.05
QTv, ms2	38 (56)	35 (21)	28 (10)	61 (12)
	0.798		<0.001
QTcBazett	0.290 ± 0.053	0.262 ± 0.012†	0.260 ± 0.013	0.283 ± 0.014
	0.162		<0.001
QTcFridericia	0.289 ± 0.069	0.246 ± 0.010†	0.250 ± 0.009	0.268 ± 0.012
	0.098		<0.001
QTcTabo	0.289 ± 0.063	0.252 ± 0.011†	0.253 ± 0.010	0.273 ± 0.012
	0.112		<0.001
QTcVan de Water	0.292 ± 0.075	0.245 ± 0.010†	0.249 ± 0.009	0.265 ± 0.009
	0.165		<0.001
QTcFramingham	0.292 ± 0.053	0.265 ± 0.010†	0.262 ± 0.013	0.283 ± 0.011
	0.089		<0.001
300 s iSGNA, mV	53 ± 21	140 ± 49	57 ± 13	147 ± 57
	<0.0001		<0.0001
300 s iVNA, mV	45 ± 18	33 ± 12	40 ± 10	39 ± 19
	0.463		0.865

^*p<0.05 baseline versus congestive heart failure (CHF);

^†p < 0.001 baseline versus CHF. Bold values indicate a statistical significance.

iSGNA = integrated stellate ganglion nerve activity; iVNA = integrated vagal nerve activity; QTc = corrected QT interval; QT_m = mean QT interval; QT_v = QT variance; RR_m = reduced RR interval; RR_v = RR-interval variance.