title: Comparison between QT Interval Parameters in Type 2 Diabetic and Nondiabetic Patients with Non-ST Elevation Myocardial Infarction.
abstract: BACKGROUND
  QT interval parameters have been suggested as a predictor of lethal arrhythmia and mortality in patients with myocardial infarction. The aim of the present study was to compare the value of QT interval indices in patients presenting with non-ST-segment elevation myocardial infarction (NSTEMI) between a group of patients with type 2 diabetes mellitus and a nondiabetic group of patients.
  
  
  METHODS
  This case-control study evaluated QT interval parameters in 115 patients (47 diabetic and 68 nondiabetic patients) diagnosed with NSTEMI between September 2011 and July 2012. The following QT interval indices were analyzed: maximum (max) and minimum (min) QT interval; max and min corrected QT interval (QTc); QT dispersion (QTd); and corrected QT dispersion (QTcd). All the patients were observed for ventricular arrhythmia during their hospital course and underwent coronary angiography. They were selected to undergo coronary artery bypass surgery (CABG) or percutaneous coronary angioplasty (PCI) based on their coronary anatomy.
  
  
  RESULTS
  The mean age of the patients was 60.8 ± 11.4 years. The patients were 40.0% female and 60.0% male. There were no significant differences in clinical characters between type 2 diabetic and nondiabetic patients with NSTEMI. Compared with post-myocardial infarction patients without diabetes, those with type 2 diabetes had higher QTc max, QTd and QTcd (p value < 0.05). There was a significant difference in QTd and QTcd in the patients needing coronary revascularization with diabetes as opposed to the nondiabetics (p value = 0.035 and p value = 0.025, respectively) as well as those who had ventricular arrhythmia with diabetes (p value = 0.018 and p value = 0.003, respectively). QTcd was higher in the patients who had higher in-hospital mortality (p value = 0.047). The QTc max, QTd and QTcd were significantly (all p values < 0.05) associated with ventricular arrhythmia, QTcd with need for revascularization and QTc max with in-hospital mortality in the diabetic patients.
  
  
  CONCLUSIONS
  Based on the findings of this study, it seems that type 2 diabetics with NSTEMI have greater QTc max, QTd, and QTcd and these QT parameters may have a relationship with worse cardiac outcomes and poorer prognoses.
authors: Heshmat Cardiovascular Medical Center, Guilan University of Medical Sciences, Rasht, Iran.
authors: Hamid Reza
authors: HR
authors: Bonakdar
authors: Heshmat Cardiovascular Medical Center, Guilan University of Medical Sciences, Rasht, Iran.
authors: Masoumeh
authors: M
authors: Aslanpour
authors: Cardiovascular Research Center, Guilan University of Medical Sciences, Rasht, Iran.
authors: Hassan
authors: H
authors: Moladoust
authors: Heshmat Cardiovascular Medical Center, Guilan University of Medical Sciences, Rasht, Iran.
authors: Parham
authors: P
authors: Sadeghipour
authors: Razi General Hospital, Guilan University of Medical Sciences, Rasht, Iran.
authors: Fereshteh
authors: F
authors: Mohamadi
authors: Heshmat Cardiovascular Medical Center, Guilan University of Medical Sciences, Rasht, Iran.
authors: Mohammad Assadian
authors: MA
authors: Rad
authors: Heshmat Cardiovascular Medical Center, Guilan University of Medical Sciences, Rasht, Iran.
authors: Jalal
authors: J
authors: Kheirkhah
keywords: Diabetes mellitus, type 2; Electrocardiography; Myocardial infarction