title: Central sleep apnea is associated with blunted baroreflex sensitivity in patients with myocardial infarction.
abstract: OBJECTIVE
  The purpose of this study was to investigate the association of central sleep apnea (CSA) and baroreflex sensitivity (BRS) after acute myocardial infarction.
  
  
  BACKGROUND
  Both, CSA and blunted BRS have been shown to be independent predictors for cardiovascular mortality in patients with heart failure. But in contrast to BRS, which has been extensively studied in the setting of AMI, the incidence of CSA in patients recovering from AMI is thus far unknown. As previous reports suggested a potential role of sleep apnoea in augmenting reflex autonomic modulation, we hypothesized that there is a strong interrelation between CSA and BRS.
  
  
  METHODS
  Seventeen male patients in the subacute phase of a first uncomplicated ST-segment elevation AMI and eight healthy male controls without evidence of coronary artery disease underwent polysomnography with simultaneous beat-to-beat ECG- and blood-pressure recordings. Sleep stage specific spontaneous BRS was calculated from blood pressure and RR-interval fluctuations by using the time domain sequential technique.
  
  
  RESULTS
  AMI patients revealed to have a higher incidence and longer duration of central apnoeas in all sleep stages, light sleep, deep sleep and dream sleep. There were no significant sleep stage specific differences regarding BRS between groups, however, AMI patients with central sleep apnea exhibited blunted BRS which was inversely correlated to incidences of central apnea in all sleep stages.
  
  
  CONCLUSIONS
  Our findings suggest a direct relationship between impaired BRS and repetitive occurrence of CSA by inverse correlation in all sleep stages in the subacute phase of AMI. Thus, reflex cardiac autonomic nervous control, being represented by the BRS, may be the link between CSA and prognosis.
authors.affiliation: Medizinische Klinik III, Universitätsklinikum Schleswig-Holstein Campus Lübeck, Lübeck, Germany.
authors.forename: Alan
authors.initials: A
authors.lastname: Strassburg
authors.forename: Benina
authors.initials: B
authors.lastname: Majunke
authors.forename: Jana K
authors.initials: JK
authors.lastname: Nötges
authors.forename: Jasmin
authors.initials: J
authors.lastname: Ortak
authors.forename: Henning
authors.initials: H
authors.lastname: Kothe
authors.forename: Gunther
authors.initials: G
authors.lastname: Weitz
authors.forename: Heribert
authors.initials: H
authors.lastname: Schunkert
authors.forename: Hendrik
authors.initials: H
authors.lastname: Bonnemeier
mesh_terms: D000328:Adult; D000368:Aged; D017704:Baroreflex; D001784:Blood Gas Analysis; D001795:Blood Pressure Determination; D016022:Case-Control Studies; D016009:Chi-Square Distribution; D004562:Electrocardiography; D006801:Humans; D008297:Male; D008875:Middle Aged; D009203:Myocardial Infarction / Q000150:complications* / Q000175:diagnosis; D010100:Oxygen / Q000097:blood*; D010101:Oxygen Consumption / Q000502:physiology; D017286:Polysomnography; D011336:Probability; D012016:Reference Values; D012680:Sensitivity and Specificity; D012720:Severity of Illness Index; D020182:Sleep Apnea, Central / Q000150:complications* / Q000175:diagnosis; D013318:Stroke Volume / Q000502:physiology
chemical_list: D010100:Oxygen