TABLE 4. The Mean and Standard Deviation of Time-Domain HRV, Frequency-Domain HRV, Poincaré Plot, DFA, and MMCA Measures at Different Stages of Breathing Exercise (I: E = 1:2; Breathing Rate was Guided as Slowly as Possible).
| Stage | p-Value | ||||
|---|---|---|---|---|---|
| Pre | Dur | Post | Dur Vs Pre | Post Vs Pre | |
| Time Domain | |||||
| MeanRR | 804.0(92.5) | 803.2(80.9) | 807.0(94.3) | ||
| SDRR | 46.1(13.1) | 65.0(18.9) | 53.8(17.5) | *** | *** |
| RMSSD | 29.9(11.6) | 36.5(13.7) | 28.4(11.7) | *** | |
| pNN50 | 10.4(9.5) | 15.0(10.7) | 8.1(9.6) | *** | * |
| Frequency domain | |||||
| VLF | 909.2(581.1) | 1084.2(722.5) | 1528.8(1389.5) | ** | |
| LF | 792.7(602.8) | 3050.0(2067.3) | 1232.1(990.8) | *** | ** |
| HF | 461.2(406.9) | 374.7(286.0) | 353.5(361.1) | * | |
| Tpower | 1362.2(248.7) | 4578.8(2494.7) | 3202.6(2105.7) | *** | *** |
| LFn | 0.576(0.201) | 0.892(0.131) | 0.709(0.161) | *** | *** |
| HFn | 0.329(0.179) | 0.115(0.055) | 0.238(0.145) | *** | ** |
| LF/HF | 3.397(4.159) | 9.581(4.508) | 5.296(5.414) | *** | ** |
| Poincaré plot | |||||
| SD1 | 21.1(8.2) | 25.8(9.7) | 20.1(8.3) | *** | |
| SD2 | 61.4(17.5) | 88.2(25.2) | 73.3(23.9) | *** | *** |
| SDRatio | 0.346(0.104) | 0.288(0.046) | 0.277(0.073) | ** | *** |
| DFA | |||||
 |
1.241(0.258) | 1.621(0.093) | 1.440(0.191) | *** | *** |
 |
0.888(0.172) | 0.602(0.152) | 0.887(0.198) | *** | |
| MMCA parameters | |||||
| CPercent | 43.2(26.4) | 54.3(24.4) | 34.3(27.7) | * | |
| RSA | 364.1(294.6) | 1234.3(1129.2) | 564.3(493.8) | *** | ** |