Table 2.
HRV Spectral Power Values
| NEC (−) N = 61 | NEC (+) N = 9 | Group Difference |
|||||
|---|---|---|---|---|---|---|---|
| Variable | Mean | SD | SEM | Mean | SD | SEM | P value |
| Mean HR (bpm) | 145.80 | 11.15 | 2.19 | 163.40 | 4.98 | 2.49 | 0.005+ |
| Mean IBI (msec) | 413.84 | 31.83 | 6.24 | 367.65 | 11.17 | 5.59 | <0.001+ |
| LF Power (ms2) | 87.37 | 107.33 | 13.74 | 16.23 | 10.89 | 3.63 | <0.001* |
| HF Power (ms2) | 21.53 | 21.60 | 2.76 | 3.99 | 12.44 | 0.81 | <0.001* |
| Total Power (ms2) | 108.90 | 123.80 | 15.85 | 20.22 | 13.17 | 4.39 | <0.001* |
| nLF (%) | 75.27 | 12.11 | 1.55 | 79.90 | 5.14 | 1.71 | 0.263+ |
| nHF (%) | 24.73 | 12.11 | 1.55 | 20.09 | 5.14 | 1.71 | 0.263+ |
| nLF/nHF Ratio | 4.32 | 3.41 | 0.437 | 4.28 | 1.40 | 0.47 | 0.971+ |
NEC = necrotizing enterocolitis; HR = heart rate; IBI = interbeat interval; LF = low frequency; HF = high frequency; nLF = normalized low frequency; nHF = normalized high frequency
Summary of the HRV spectral power values at postnatal day 5-8 for infants who remained healthy during hospitalization (NEC (−); N = 61) and those infants who were later diagnosed with NEC (NEC (+); N = 9).
+
Independent samples t test
*
Non-parametric, Mann Whitney U