Table 4.

Heart rate variability in severe secondary hyperparathyroidism patients before and after parathyroidectomy

Variable in Two SubgroupsBaselineAfter PTXMean DifferenceP
Successful PTX follow-up (n=17)a
 Mean 24-h heart rate (beats/min)87.1±10.776.8±8.1−10.4±8.2<0.001
 Time domain measures
  Mean NN (ms)699.7±91.5790.9±83.091.2±74.5<0.001
  SDNN (ms)67.8±24.684.2±28.616.4±19.00.003
  SDANN (ms)57.9±25.473.3±29.715.4±18.60.004
  rMSSD (ms)19.5±9.923.5±9.23.9±10.90.16
  pNN50%3.7±6.55.8±7.92.1±9.70.40
 Frequency domain measures
  ln VLF [ln(ms2)]5.4±0.95.9±0.70.5±0.70.008
  ln LF [ln(ms2)]4.4±1.03.7±1.7−0.7±1.70.09
  ln HF [ln(ms2)]3.4±1.11.7±2.8−1.8±2.80.02
  ln LF/HF1.0±0.82.0±1.41.0±1.40.008
Unsuccessful PTX follow-up (n=4)b
 Mean 24-h heart rate (beats/min)73.0±8.173.5±12.40.5±5.80.87
 Time domain measures
  Mean NN (ms)833.0±91.5844.3±138.711.3±60.30.73
  SDNN (ms)94.0±27.093.3±11.8−0.8±19.30.94
  SDANN (ms)81.0±28.182.5±7.51.5±21.10.90
  rMSSD (ms)18.0±5.717.8±5.9−0.3±4.40.92
  pNN50%1.7±1.72.5±2.40.8±2.00.51
 Frequency domain measures
  ln VLF [ln(ms2)]6.1±1.15.7±1.0−0.3±0.40.17
  ln LF [ln(ms2)]4.0±2.13.4±1.5−0.6±3.30.73
  ln HF [ln(ms2)]2.4±2.42.3±2.6−0.2±4.50.95
  ln LF/HF1.6±1.61.1±1.9−0.5±1.20.51
  • 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.