TABLE 3. 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 = 1:1; Breathing Rate = 6 bpm).
| Stage | p-Value | ||||
|---|---|---|---|---|---|
| Pre | Dur | Post | Dur vs Pre | Post vs Pre | |
| Time Domain | |||||
| MeanRR | 803.8(86.1) | 802.5(79.0) | 803.0(84.5) | ||
| SDRR | 50.1(21.6) | 72.7(23.4) | 54.5(21.2) | *** | |
| RMSSD | 30.4(13.7) | 39.3(15.0) | 30.1(12.9) | *** | |
| pNN50 | 10.0(11.6) | 16.2(12.3) | 9.7(9.6) | ** | |
| Frequency domain | |||||
| VLF | 1039.3(887.2) | 1056.0(713.5) | 1584.8(1484.5) | ||
| LF | 1326.2(2199.4) | 4388.4(3237.4) | 1218.7(1451.8) | *** | |
| HF | 498.7(549.9) | 337.4(239.6) | 448.9(455.2) | ||
| Tpower | 2967.7(2929.5) | 5826.9(3660.0) | 3414.4(2680.6) | *** | |
| LFn | 0.598(0.214) | 0.916(0.053) | 0.640(0.186) | *** | |
| HFn | 0.327(0.182) | 0.078(0.033) | 0.277(0.171) | *** | |
| LF/HF | 3.890(5.547) | 15.233(9.581) | 5.311(7.465) | *** | |
| Poincaré plot | |||||
| SD1 | 21.5(9.7) | 27.8(10.6) | 21.3(9.1) | *** | |
| SD2 | 67.3(29.4) | 99.0(31.6) | 73.8(29.3) | *** | *** |
| SDRatio | 0.327(0.082) | 0.276(0.035) | 0.300(0.092) | ** | * |
| DFA | |||||
 |
1.293(0.275) | 1.672(0.079) | 1.381(0.222) | *** | |
 |
0.826(0.226) | 0.516(0.147) | 0.867(0.216) | *** | |
| MMCA parameters | |||||
| CPercent | 37.3(25.6) | 63.3(23.3) | 33.6(24.2) | *** | |
| RSA | 601.8(1055.3) | 1464.0(1440.3) | 549.0(729.3) | * | |