title: Carvedilol recovers normal blood pressure variability in rats with myocardial infarction.
abstract: BACKGROUND
  The aim of this study was to investigate the effects of chronic treatment with carvedilol in blood pressure (BPV) and heart rate (HRV) variability of rats with myocardial infarction (MI).
  
  
  METHODS
  MI was produced in male rats by ligature of anterior interventricular branch of left coronary artery. Control rats were submitted to a sham surgery (SO). MI and SO rats were randomized to receive for 30 days placebo (Plac 0.5% metilcelulose) or carvedilol (Carv, 2mg/Kg body weight/day, drinking water): SO-Plac (N = 10), SO-Carv (N = 10), MI-Plac (N = 12), MI-Carv (N = 13). Blood pressure (BP) was directly recorded in the awake animals and BPV was determined, in time (variance, mmhg(2)) and frequency domains by the autoregressive method. Statistical significance was set in P<0.05. Data are median and interquartile range.
  
  
  RESULTS
  No significant changes in HRV was observed in MI rats, while BPV showed significant decreasing of blood pressure variance (SO-Plac = 42.08 (39.21) mmHg(2) vs. MI-Plac = 21.67 (12.58) mmHg(2), P<0.05), reversed by the Carv treatment (MI-Plac = 21.67 (12.58) vs. MI-Carv = 38.64 (29.25), P<0.05). In the frequency domain analyses, MI reduced absolute and normalized LF component (LF (mmHg(2)): SO-Plac = 8.98 (14.84) vs. MI-Plac = 2.08 (4.84), P<0.05; LF(nu): SO-Plac = 79.48 (45.03) nu vs. MI-Plac = 24.25 (40.67) nu, P<0.05) and increased the normalized HF component of the BPV (SO-Plac = 20.51 (39.18) vs. MI-Plac = 60.51 (39.73). Carv treatment significantly attenuated the LF component fall.
  
  
  CONCLUSIONS
  Chronic treatment with carvedilol restored the variance of BPV altered by the MI.
authors.affiliation: Department of Physiological Sciences, Federal University of Espírito Santo, Av. Marechal Campos 1468, Maruípe, Vitória - ES, 29042-751, Brazil. Electronic address: edantas9@hotmail.com.
authors.forename: Eduardo Miranda
authors.initials: EM
authors.lastname: Dantas
authors.forename: Enildo Broetto
authors.initials: EB
authors.lastname: Pimentel
authors.forename: Rodrigo Varejão
authors.initials: RV
authors.lastname: Andreão
authors.forename: Bruna Sgaria
authors.initials: BS
authors.lastname: Cichoni
authors.forename: Christine Pereira
authors.initials: CP
authors.lastname: Gonçalves
authors.forename: Divanei Dos Anjos
authors.initials: Ddos A
authors.lastname: Zaniqueli
authors.forename: Marcelo Perim
authors.initials: MP
authors.lastname: Baldo
authors.forename: Sérgio Lamêgo
authors.initials: SL
authors.lastname: Rodrigues
authors.forename: José Geraldo
authors.initials: JG
authors.lastname: Mill
mesh_terms: D058668:Adrenergic alpha-1 Receptor Antagonists / Q000494:pharmacology / Q000627:therapeutic use; D000319:Adrenergic beta-Antagonists / Q000494:pharmacology / Q000627:therapeutic use; D000818:Animals; D001794:Blood Pressure / Q000187:drug effects* / Q000502:physiology; D002227:Carbazoles / Q000494:pharmacology* / Q000627:therapeutic use*; D000077261:Carvedilol; D006339:Heart Rate / Q000187:drug effects / Q000502:physiology; D008297:Male; D009203:Myocardial Infarction / Q000188:drug therapy* / Q000503:physiopathology; D011412:Propanolamines / Q000494:pharmacology* / Q000627:therapeutic use*; D011897:Random Allocation; D051381:Rats; D017208:Rats, Wistar; D020127:Recovery of Function / Q000187:drug effects* / Q000502:physiology
chemical_list: D058668:Adrenergic alpha-1 Receptor Antagonists; D000319:Adrenergic beta-Antagonists; D002227:Carbazoles; D011412:Propanolamines; D000077261:Carvedilol
keywords: Arterial blood pressure; Autonomic nervous system; BPV; Beta-blocker therapy; Carv; HF; HRV; LF; MI; Plac; Power spectral analysis; SO; VLF; blood pressure variability; carvedilol; heart rate variability; high frequency; low frequency; myocardial infarct; placebo; sham operated; very low frequency