title: Impact of myocardial infarction on cardiac autonomic function in diabetic rats.
abstract: OBJECTIVE
  We evaluated autonomic and hemodynamic parameters and maximal oxygen consumption (VO(2)max) as possible determinants of mortality in streptozotocin (STZ) diabetic rats after myocardial infarction (MI).
  
  
  METHODS
  Male Wistar rats were divided into (n=8 of each): control sham (CS), diabetes sham (DS), MI (I), and diabetes+MI (DI). MI was induced 15 days after STZ induction. VO(2)max was measured at 3 (basal), 30, 60, and 91 days after MI. Hemodynamic and autonomic parameters were evaluated 92 days after MI.
  
  
  RESULTS
  MI area was similar in infarcted groups (~44%). Mortality rate increased in the DI (70%) compared with I (53%) group. Cardiopulmonary baroreflex, sympathetic (48%) and vagal (33%) tonus, low frequency (LF) band (57%), and LF/high frequency (HF) band ratio (53%) were reduced in DI compared with I animals. Furthermore, cardiac output (CO), peripheral vascular resistance (PVR) impairment, and VO(2)max reductions were observed in the DI compared with the I group.
  
  
  CONCLUSIONS
  Our data suggest that the CO and PVR changes as well as VO(2)max reduction were probably associated with additional cardiac autonomic control impairment, and, consequently, increased mortality rate in diabetic rats after a chronic myocardial infarction.
authors.affiliation: Human Movement Laboratory, São Judas Tadeu University, São Paulo, Brazil. bruno.rodrigues@incor.usp.br
authors.forename: Bruno
authors.initials: B
authors.lastname: Rodrigues
authors.forename: Cristiano T
authors.initials: CT
authors.lastname: Mostarda
authors.forename: Luciana
authors.initials: L
authors.lastname: Jorge
authors.forename: Catarina A
authors.initials: CA
authors.lastname: Barboza
authors.forename: Camilla F
authors.initials: CF
authors.lastname: Grans
authors.forename: Kátia
authors.initials: K
authors.lastname: De Angelis
authors.forename: Maria Cláudia
authors.initials: MC
authors.lastname: Irigoyen
mesh_terms: D000818:Animals; D001341:Autonomic Nervous System / Q000503:physiopathology*; D017704:Baroreflex / Q000502:physiology; D002302:Cardiac Output / Q000502:physiology; D003921:Diabetes Mellitus, Experimental / Q000139:chemically induced / Q000150:complications / Q000401:mortality / Q000503:physiopathology*; D003925:Diabetic Angiopathies / Q000401:mortality / Q000503:physiopathology; D006321:Heart / Q000503:physiopathology*; D006339:Heart Rate / Q000502:physiology; D006439:Hemodynamics / Q000502:physiology; D008297:Male; D009203:Myocardial Infarction / Q000150:complications / Q000401:mortality / Q000503:physiopathology*; D010101:Oxygen Consumption / Q000502:physiology; D051381:Rats; D017208:Rats, Wistar