title: Impact of diabetes on QT dynamicity in patients with and without myocardial infarction: The KORA Family Heart Study.
abstract: BACKGROUND
  Patients with diabetes mellitus (DM) have an unfavorable prognosis after myocardial infarction (MI), partially due to a higher risk of sudden cardiac death (SCD). QT dynamicity is an independent predictor of SCD in post-MI patients. However, the effects of diabetes on QT dynamicity in patients with MI have not been described.
  
  
  METHODS
  We studied 468 survivors of MI (67 with DM) from the population-based MONICA registry (KORA Family Heart Study), Augsburg, Germany, by standardized questionnaire, anthropometry, electrocardiogram (ECG), 30-minute-Holter-ECG-recordings and echocardiography. In addition, 422 siblings without prior MI (22 with DM) were studied by the same protocol.
  
  
  RESULTS
  Among post-MI patients, the QT/RR slope was significantly steeper in diabetics than in nondiabetics (0.096 +/- 0.057 vs 0.077 +/- 0.045; P = 0.002). Likewise, among siblings without MI, the QT/RR slope was steeper in diabetics than in nondiabetics (0.104 +/- 0.053 vs 0.080 +/- 0.042; P = 0.008). The association of DM with steeper QT/RR slope remained significant in multivariate models in post-MI patients (beta: -0.14; P = 0.004) as well as in individuals without MI (beta: -0.10; P = 0.047).
  
  
  CONCLUSIONS
  In a large population of survivors of MI and unaffected siblings, patients and siblings presenting with DM exhibited an abnormal QT rate-dependence, compared with individuals without DM in both groups. Thus, diabetes itself may be a major determinant of ventricular arrhythmias, independently of a previous MI. These observations might in part explain the higher incidence of sudden cardiac death and ventricular arrhythmias in patients with DM.
authors.affiliation: Medizinische Klinik 2, Universitatsklinikum Schleswig-Holstein, Campus Lubeck, Lubeck, Germany.
authors.forename: Wolfgang
authors.initials: W
authors.lastname: Lieb
authors.forename: Christian
authors.initials: C
authors.lastname: Voss
authors.forename: Jasmin
authors.initials: J
authors.lastname: Ortak
authors.forename: Melanie
authors.initials: M
authors.lastname: Barantke
authors.forename: Christian
authors.initials: C
authors.lastname: Hengstenberg
authors.forename: Hannelore
authors.initials: H
authors.lastname: Loewel
authors.forename: Stephan
authors.initials: S
authors.lastname: Holmer
authors.forename: Jeanette
authors.initials: J
authors.lastname: Erdmann
authors.forename: Heribert
authors.initials: H
authors.lastname: Schunkert
authors.forename: Hendrik
authors.initials: H
authors.lastname: Bonnemeier
mesh_terms: D000368:Aged; D001145:Arrhythmias, Cardiac / Q000503:physiopathology*; D016022:Case-Control Studies; D016757:Death, Sudden, Cardiac / Q000209:etiology; D048909:Diabetes Complications; D003920:Diabetes Mellitus / Q000235:genetics / Q000503:physiopathology*; D004452:Echocardiography; D004562:Electrocardiography; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009203:Myocardial Infarction / Q000235:genetics / Q000503:physiopathology*; D035781:Siblings; D017741:Survivors