title: Heart rate variability in overactive bladder experimental model.
abstract: BACKGROUND
  TWO MAIN PATHOPHYSIOLOGICAL CONCEPTS OF OVERACTIVE BLADDER (OAB) ARE POSTULATED: the neurogenic and myogenic theories. Autonomic nervous system (ANS) dysfunction is also involved in OAB pathophysiology. The purpose of our study was to estimate ANS activity by heart rate variability (HRV) assessment in two OAB experimental models evoked by cyclophosphamide administration: acute (AOAB) and chronic (COAB) overactive ones.
  
  
  METHODS
  In the AOAB model, an i.p. dose of cyclophosphamide was administered (200 mg/kg body weight) while the COAB model received 4 times the i.p. administration of cyclophosphamide (75 mg/kg body weight). In each subject, after urethane anaesthesia (1.2 g/kg body weight), 20-minute ECG recordings (PowerLab) were performed with subsequent HRV analysis.
  
  
  RESULTS
  Most of the differences in time domain analysis parameters were insignificant, except those concerning SDNN and rMSSD (p < 0.05). In frequency analysis, a power decrease of all standard spectral components was revealed in both OAB groups. In AOAB, TP (1.43 ±1.21 vs. 7.92 ±6.22 in control; p < 0.05) and VLF (0.95 ±1.08 vs. 6.97 ±5.99 in control; p < 0.05) showed significant power decrease, whereas the COAB group was mostly characterized by LF (0.09 ±0.15 vs. 0.34 ±0.33 in control; p < 0.05) and HF (0.25 ±0.29 vs. 0.60 ±0.41 in control; p < 0.05) decrease.
  
  
  CONCLUSIONS
  The ANS disturbances, found as standard spectral parameter abnormalities, were demonstrated in both AOAB and COAB. When this finding is analysed, together with the lack of statistically significant differences in normalized nLF and nHF powers, the VLF changes seem to play an essential role, probably reflecting the progression in bladder inflammatory changes.
authors.affiliation: Pathophysiology Department, Jagiellonian University, Medical College, Cracow, Poland.
authors.forename: Lukasz
authors.initials: L
authors.lastname: Dobrek
authors.forename: Piotr
authors.initials: P
authors.lastname: Thor
keywords: autonomic nervous system; heart rate variability; overactive bladder