Table 2 Heart rate variability parameters; frequency, linear and non-linear, across three different QRS groups
QRS duration (ms) | p-value | ||||||
|---|---|---|---|---|---|---|---|
80–100 (n = 115) | >100–120 (n = 69) | >120 (n = 16) | |||||
n | Mean (SD) | n | Mean (SD) | n | Mean (SD) | ||
Frequency domain, mean (SD) | |||||||
Total power (ms2) | 102 | 1222.9 (781.7) | 62 | 1302.4 (793.9) | 14 | 1233.3 (591.7) | 0.81 |
HF (ms2) | 92 | 192.2 (134.7) | 59 | 181.7 (125.3) | 14 | 2229.8 (145) | 0.47 |
LF (ms2) | 95 | 264.9 (178) | 62 | 300.4 (194.7) | 15 | 312.6 (229.4) | 0.42 |
HF In | 100 | 5.3 (1.1) | 52 | 5.3 (1.0) | 11 | 5.6 (0.8) | 0.73 |
LF In | 99 | 5.6 (0.9) | 52 | 5.7 (0.8) | 11 | 5.9 (0.9) | 0.59 |
HF norm (v) | 115 | 44.3 (18.2) | 69 | 42.2 (18.1) | 15 | 42.3 (23.0) | 0.73 |
LF norm (v) | 115 | 55.1 (18.1) | 68 | 58.1 (18.5) | 16 | 51.5 (23.3) | 0.37 |
LF/HF ratio | 101 | 1.3 (0.8) | 60 | 1.5 (0.9) | 13 | 1.2 (0.9) | 0.36 |
Time domain, mean (SD) | |||||||
SDNN (ms) | 108 | 38.9 (13.7) | 65 | 38.9 (13.2) | 14 | 38.7 (12) | 1.00 |
RMSDD (ms) | 103 | 25.7 (10.4) | 63 | 24.7 (10.3) | 15 | 29.1 (11.8) | 0.34 |
Nonlinear analysis | |||||||
DFA α1 | 115 | 1.0 (0.2) | 69 | 1.1 (0.3) | 16 | 1.1 (0.4) | 0.43 |
DFA α2 | 111 | 1.0 (0.2) | 67 | 1.0 (0.2) | 16 | 0.9 (0.2) | 0.60 |
DFA 32 | 0 | 0 | 0 | ||||
ApEN | 110 | 1.3 (0.2) | 69 | 1.2 (0.2) | 16 | 1.2 (0.2) | 0.093 |