Table 4.
Heart rate variability in severe secondary hyperparathyroidism patients before and after parathyroidectomy
| Variable in Two Subgroups | Baseline | After PTX | Mean Difference | P |
|---|---|---|---|---|
| Successful PTX follow-up (n=17)a | ||||
| Mean 24-h heart rate (beats/min) | 87.1±10.7 | 76.8±8.1 | −10.4±8.2 | <0.001 |
| Time domain measures | ||||
| Mean NN (ms) | 699.7±91.5 | 790.9±83.0 | 91.2±74.5 | <0.001 |
| SDNN (ms) | 67.8±24.6 | 84.2±28.6 | 16.4±19.0 | 0.003 |
| SDANN (ms) | 57.9±25.4 | 73.3±29.7 | 15.4±18.6 | 0.004 |
| rMSSD (ms) | 19.5±9.9 | 23.5±9.2 | 3.9±10.9 | 0.16 |
| pNN50% | 3.7±6.5 | 5.8±7.9 | 2.1±9.7 | 0.40 |
| Frequency domain measures | ||||
| ln VLF [ln(ms2)] | 5.4±0.9 | 5.9±0.7 | 0.5±0.7 | 0.008 |
| ln LF [ln(ms2)] | 4.4±1.0 | 3.7±1.7 | −0.7±1.7 | 0.09 |
| ln HF [ln(ms2)] | 3.4±1.1 | 1.7±2.8 | −1.8±2.8 | 0.02 |
| ln LF/HF | 1.0±0.8 | 2.0±1.4 | 1.0±1.4 | 0.008 |
| Unsuccessful PTX follow-up (n=4)b | ||||
| Mean 24-h heart rate (beats/min) | 73.0±8.1 | 73.5±12.4 | 0.5±5.8 | 0.87 |
| Time domain measures | ||||
| Mean NN (ms) | 833.0±91.5 | 844.3±138.7 | 11.3±60.3 | 0.73 |
| SDNN (ms) | 94.0±27.0 | 93.3±11.8 | −0.8±19.3 | 0.94 |
| SDANN (ms) | 81.0±28.1 | 82.5±7.5 | 1.5±21.1 | 0.90 |
| rMSSD (ms) | 18.0±5.7 | 17.8±5.9 | −0.3±4.4 | 0.92 |
| pNN50% | 1.7±1.7 | 2.5±2.4 | 0.8±2.0 | 0.51 |
| Frequency domain measures | ||||
| ln VLF [ln(ms2)] | 6.1±1.1 | 5.7±1.0 | −0.3±0.4 | 0.17 |
| ln LF [ln(ms2)] | 4.0±2.1 | 3.4±1.5 | −0.6±3.3 | 0.73 |
| ln HF [ln(ms2)] | 2.4±2.4 | 2.3±2.6 | −0.2±4.5 | 0.95 |
| ln LF/HF | 1.6±1.6 | 1.1±1.9 | −0.5±1.2 | 0.51 |
Data are mean ± SD. PTX, parathyroidectomy; mean NN, mean normal-to-normal R–R intervals; SDNN, SD of normal-to-normal R–R intervals; SDANN, SD of 5-minute average of normal R–R intervals; rMSSD, root mean square of differences between adjacent normal R–R intervals; pNN50%, proportion of adjacent R–R intervals differing by >50 ms over 24 hours; VLF, very low frequency; LF, low frequency; HF, high frequency.
a
Patients were followed up for a median period of 5.0 months.
b
Patients were followed up for a median period of 2.3 months.