Table 2.

Time domain heart rate variability (HRV) parameters of patients with coronary slow flow and controls

HRV parameters	Group A (n = 8)	Group B (n = 25)	Control (n = 19)
Heart rate (beat/min)	72 ± 13	71 ± 12	74 ± 15
SDNN (ms)a,b	103.0 ± 19.5	136.3 ± 44.7	170.4 ± 38.9
SDANN (ms)c,d,e	92.4 ± 12.8	121.3 ± 29.6	143.7 ± 24.4
RMSSD (ms)f	21.9 ± 9.5	28.3 ± 8.6	34.8 ± 12.1
SDNN index (ms)c,d,e	40.8 ± 13.8	70.1 ± 29.2	90.3 ± 18.0
PNN 50 (%)d,g	13.3 ± 5.7	18.4 ± 6.9	27.1 ± 8.9
Triangular indexa,b	18.5 ± 9.6	24.8 ± 8.3	33.7 ± 9.3

^aP < 0.001 (group A vs. control); ^bP < 0.05 (group B vs. control); ^cP < 0.05 (group A vs. group B); ^dP < 0.0001 (group A vs. control), ^eP < 0.05 (group B vs. control), ^fP < 0.05 (group A vs. control), ^gP < 0.001 (group B vs. control).