Sensitivity, specificity and predictive values of linear and nonlinear indices of heart rate variability in stable angina patients

Table 2 HRV indices in no CAD and CAD groups

Index	No DAC (n = 21)	DAC (n=43)	p
RR (ms)	896±136	914±139	0.6191
SDNN (ms)	39.71±18.7	29.95±13.6	0.0209 *
RMSSD (ms)	32.38±18.1	22.99±11.9	0.0303 **
NN50 (count)	135.48±146.28	59.42±80.9	0.0476 **
VLF (ms ² )	323.67±420.49	220.56±242.8	0.2058
LF (ms ² )	332.48±420.78	179.12±175.08	0.0641
HF (ms ² )	233.10±241.7	87.72±81.04	0.0073 **
SD1 (ms)	23.21±12.9	16.52±16.52	0.0282 *
SD2 (ms)	67.19±25.9	52.75±25.6	0.0387 *
SD1/SD2	0.33±0.1	0.34±0.1	0.6269
α1	0.93±0.2	1±0.3	0.2189
α2	0.9±0.2	0.91±0.1	0.5577
Lyapunov exponent (LE)	0.91±0.1	0.89±0.1	0.4416
Hurst exponent (HE)	0.21±0.1	0.22±0.1	0.6294
-ApEn	0.388±0.09	0.343±0.08	0.0368 **

* = p <0.05 with area under ROC curve < 0.65; ** = p <0.05 with area under ROC curve ≥ 0.65.