. 2010 May 24;3:43–54. doi: 10.4137/cmamd.s4940

Table 6.

Correlation between HRV parameters and arrhythmia parameters in systemic sclerosis patients.

Parameter	PVCS ≥ 10/h		Total PVCs		SVT
Parameter	r	P	r	P	r	P
Mean RR (ms)	−0.36	0.007	−0.49	0.0005	−0.42	0.003
SDNN (ms)	−0.28	0.033	−0.37	0.007	−0.29	0.030
SDANN (ms)	−0.40	0.005	−0.39	0.005	−0.33	0.010
SDNNi (ms)	−0.31	0.025	−0.50	0.0004	−0.39	0.005
rMSSD (ms)	−0.52	0.0004	−0.60	0.0003	−0.47	0.0005
pNN50 (%)	−0.61	0.0003	−0.55	0.0004	−0.49	0.0005
TP (ms²)^″	−0.66	0.0003	−0.70	0.0002	−0.70	0.0002
VLF (ms²)	−0.38	0.006	−0.29	0.030	−0.28	0.033
LF (ms²)	−0.26	0.050	−0.36	0.008	−0.40	0.005
HF (ms²)	−0.88	0.0002	−0.51	0.0004	−0.55	0.0004
LF/HF	0.54	0.0004	0.72	0.0002	0.81	0.0002

Abbreviations: PVC, premature ventricular contractions; SVT, supravetricular tachycardia, SDANN, standard deviation of the mean of normal RR intervals for each 5-min period of the 24 hr ECG recording; SDNNi, mean of the standard deviation of all normal RR intervals for all 5-min segments of a 24-hr ECG recording; rMSSD, root mean square successive difference between adjacent normal RR intervals over the entire 24-hr ECG recording; pNN50, percent of difference between adjacent normal RR intervals greater than 50 ms calculated over the entire 24-hr ECG recording; TP, variance of all NN intervals; VLF, power in the very low frequency range; LF, power in the low frequency range; HF, power in the high frequency range; LF/HF, ratio of LF (ms²) to HF (ms²).