TABLE 2. 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 = 6 bpm).
| Stage | p-Value | ||||
|---|---|---|---|---|---|
| Pre | Dur | Post | Pre vs Dur | Pre vs Post | |
| Time Domain | |||||
| MeanRR | 802.8(93.44) | 800.9(72.7) | 797.8(76.3) | ||
| SDRR | 45.1(11.1) | 68.8(50.2) | 50.1(18.6) | *** | |
| RMSSD | 29.4(9.9) | 37.8(14.3) | 29.6(14.1) | *** | |
| pNN50 | 9.2(9.9) | 14.0(10.2) | 10.1(11.7) | *** | |
| Frequency domain | |||||
| VLF | 827.3(481.2) | 1127.9(762.0) | 1145.9(1091.9) | * | |
| LF | 798.7(629.3) | 3574.8(2484.1) | 1141.7(1156.3) | *** | |
| HF | 437.6(359.9) | 404.5(337.8) | 456.7(483.4) | ||
| Tpower | 2157.4(1046.5) | 5154.6(3250.9) | 2859.0(2278.2) | *** | * |
| LFn | 0.575(0.208) | 0.895(0.084) | 0.636(0.201) | *** | * |
| HFn | 0.343(0.177) | 0.101(0.040) | 0.302(0.183) | *** | |
| LF/HF | 3.495(5.446) | 10.626(4.907) | 4.741(6.033) | *** | |
| Poincaré plot | |||||
| SD1 | 20.8(7.0) | 26.8(10.1) | 21.0(10.0) | *** | |
| SD2 | 14.7(2.7) | 93.4(27.9) | 67.5(25.1) | *** | * |
| SDRatio | 0.347(0.082) | 0.282(0.043) | 0.313(0.092) | *** | * |
| DFA | |||||
 |
1.243(0.290) | 1.644(0.099) | 1.336(0.276) | *** | * |
 |
0.837(0.208) | 0.564(0.129) | 0.871(0.194) | *** | |
| MMCA parameters | |||||
| CPercent | 50.1(26.9) | 61.8(23.7) | 46.5(25.3) | ||
| RSA | 361.6(327.6) | 1335.3(247.7) | 534.2(651.1) | *** | |