title: Comparative effect of bisoprolol and losartan in the treatment of essential hypertension.
abstract: OBJECTIVE
  We investigated the effects of bisoprolol and losartan on subjects with essential hypertension, by conducting heart rate variability (HRV) analysis of ECG signals. Our intention was to establish the set of linear and nonlinear heart rate variability parameters, which could be used as a noninvasive markers in the treatment of hypertension.
  
  
  METHODS
  Sixty subjects with essential hypertension included in this study were divided in two groups. During the four weeks medical treatment, the first group was administered with daily oral dose of 5 mg of bisoprolol and the second with daily oral dose of 50 mg of losartan. We recorded ECG signals, and performed HRV analysis of consecutive RR time intervals, before and after a month of pharmacological therapy.
  
  
  RESULTS
  IN THE CASE OF BISOPROLOL, STATISTICALLY THE MOST SIGNIFICANT CHANGES OF HRV PARAMETERS WERE: TP (1814.1 ± 1731.3 ms(2) vs. 761.3 ± 725.0 ms(2), P < 0.0001), RR (870.2 ± 105.7 ms vs. 1027.2 ± 150.0 ms, P < 0.0001), HR (70.81 ± 8.42 bp/min vs. 60.10 ± 9.52 bp/min, P < 0.0001). In the case of losartan, the most significant changes were: SDNN (43.16 ± 17.27 ms vs. 237.98 ± 118.54 ms, P = 0.002), rmSDD (27.09 ± 18.27 ms vs. 46.82 ± 37.71 ms, P = 0.003), SD2 (55.18 ± 20.6 vs. 70.67 ± 26.12, P < 0.019) and DF2 (0.69 ± 0.21 vs. 0.86 ± 0.25, P < 0.014).
  
  
  CONCLUSIONS
  Effects of bisoprolol and losartan were especially manifested among the set of linear HRV parameters. As a consequence of effect of losartan, we singled out the nonlinear parameters SD2 and DF2.
authors.affiliation: Laboratory of Radiation and Environmental Protection, Vinća Institute of Nuclear Sciences, University of Belgrade, Serbia.
authors.forename: Goran
authors.initials: G
authors.lastname: Keković
authors.forename: Branislav
authors.initials: B
authors.lastname: Milovanović
authors.forename: Dragomir
authors.initials: D
authors.lastname: Davidović
authors.forename: Dejan
authors.initials: D
authors.lastname: Raković
authors.forename: Milka
authors.initials: M
authors.lastname: Culić
keywords: Bisoprolol; heart rate variability; hypertension; losartan