title: QT-interval dispersion in type 2 diabetic and non-diabetic patients with post-myocardial infarction.
abstract: OBJECTIVE
  QT-interval dispersion (QTD), which reflects spatial ventricular repolarization inhomogeneity, has been reported to increase and to have a prognostic value in patients with either myocardial infarction or diabetes. Our aim was to compare increases in QTD in type 2 diabetic and non-diabetic patients following post-myocardial infarction (post-MI). We also compared QTD in type 2 diabetic patients with post-MI treated with insulin, sulfonylurea, or diet alone.
  
  
  RESULTS
  We determined the rate corrected QT-interval (QTc) dispersion (QTcD) in 178 consecutive post-MI patients, including 48 type 2 diabetic and 130 non-diabetic patients. The QTcD, measured with software (QTD-1), was defined as the difference in the minimum and maximum QTc in any of the 12 standard electrocardiographic leads. There were no significant differences in age, gender, left ventricular end-diastolic diameter, ejection fraction, or minimum QTc between type 2 diabetic and non-diabetic patients with post-MI. Compared with post-MI patients without diabetes, those with type 2 diabetes had higher maximum QTc (481+/-37 vs. 459+/-43ms, P<0.05) and QTcD (67+/-18 vs. 58+/-16ms, P<0.05). Among type 2 diabetic patients with post-MI treated with insulin, sulfonylurea, or diet alone, the QTcD (81+/-18 vs. 64+/-16 vs. 62+/-17ms, P<0.05, respectively) was significantly greater and the R-R interval was shorter in the insulin therapy group.
  
  
  CONCLUSIONS
  Type 2 diabetes is associated with an additional increase in the QTD in post-MI patients. This additional increase in spatial repolarization inhomogeneity might be implicated in the increased mortality risk in post-MI patients with type 2 diabetes. These findings were thought to be more striking in the insulin therapy group.
authors.affiliation: Department of Cardiology and Clinical Research, National Hospital Organization, Zentsuji National Hospital, 2-1-1, Senyu-cho, Zentsuji, Kagawa 765-0001, Japan.
authors.forename: Koichi
authors.initials: K
authors.lastname: Sakabe
authors.forename: Nobuo
authors.initials: N
authors.lastname: Fukuda
authors.forename: Yamato
authors.initials: Y
authors.lastname: Fukuda
authors.forename: Katsunori
authors.initials: K
authors.lastname: Wakayama
authors.forename: Teru
authors.initials: T
authors.lastname: Nada
authors.forename: Satofumi
authors.initials: S
authors.lastname: Morishita
authors.forename: Hisanori
authors.initials: H
authors.lastname: Shinohara
authors.forename: Yoshiyuki
authors.initials: Y
authors.lastname: Tamura
mesh_terms: D000200:Action Potentials; D000368:Aged; D000369:Aged, 80 and over; D016022:Case-Control Studies; D003924:Diabetes Mellitus, Type 2 / Q000150:complications / Q000178:diet therapy / Q000188:drug therapy / Q000503:physiopathology*; D004562:Electrocardiography; D005260:Female; D006329:Heart Conduction System / Q000187:drug effects / Q000503:physiopathology*; D006801:Humans; D007004:Hypoglycemic Agents / Q000494:pharmacology / Q000627:therapeutic use; D007328:Insulin / Q000494:pharmacology / Q000627:therapeutic use; D008297:Male; D008875:Middle Aged; D009203:Myocardial Infarction / Q000150:complications / Q000503:physiopathology*; D013453:Sulfonylurea Compounds / Q000494:pharmacology / Q000627:therapeutic use; D013997:Time Factors
chemical_list: D007004:Hypoglycemic Agents; D007328:Insulin; D013453:Sulfonylurea Compounds