Table 5.
Heart rate and HRV in the Fontan patients and control subjects.
| Variables | Fontan Patients (n = 30) | Controls (n = 30) | p-Value |
|---|---|---|---|
| Heart rate, bpm | 69.1 (10.4) | 80.5 (6.5) | <0.001 |
| Mean NN, ms | 922.0 (157.9) | 771.57 (59.4) | <0.001 |
| SDNN, ms | 121.8 (29.6) | 152.74 (23.94) | <0.001 |
| SDANN, ms | 111.9 (31.6) | 133.63 (25.2) | <0.001 |
| rMSSD, ms | 16.5 (10.9–33.5) | 32.65 (27.4–43.7) | <0.001 |
| pNN50, ms | 6.75 (2.7–13.0) | 11.8 (7.2–13.2) | 0.018 |
| HRV triangular index, ms | 34.5 (11.3) | 45.7 (7.8) | <0.001 |
| Very low frequency (ms2) | 301.6 (13.1–491.2) | 491.8 (256.2–71.2) | 0.030 |
| Low frequency (ms2) | 332.8 (93.4–551.2) | 712.3 (538.3–1129.1) | <0.001 |
| High frequency (ms2) | 140.1 (46.1–303.2) | 289.0 (156.7–370) | 0.019 |
| Total power (ms2) | 861.1 (1.0–1738.0) | 1618.7 (957.4–2031) | 0.003 |
| Low frequency/high frequency ratio | 3.5 (2.5) | 4.2 (1.5) | 0.190 |
Continuous data are presented as mean (SD) or median (Q1–Q3). Abbreviations: HRV, heart rate variability; NN, normal-to-normal interval; pNN50, percentage difference between adjacent NN intervals of >50 ms duration; rMSSD, root mean square of the differences of successive NN intervals; SDANN, standard deviation of the averages of NN intervals in all 5-min segments of the entire recording; SDNN, standard deviation of all NN intervals.