title: The influence of type 2 diabetes and gender on ventricular repolarization dispersion in patients with sub-clinic left ventricular diastolic dysfunction.
abstract: OBJECTIVE
  To assess the influence of type 2 DM and gender, on the QT dispersion, Tpeak-Tend dispersion of ventricular repolarization, in patients with sub-clinic left ventricular diastolic dysfunction of the heart.
  
  
  BACKGROUND
  QT dispersion, that reflects spatial inhomogeneity in ventricular repolarization, Tpeak-Tend dispersion, this on the other hand reflects transmural inhomogeneity in ventricular repolarization, that is increased in an early stage of cardiomyopathy, and in patients with left ventricular diastolic dysfunction, as well. The left ventricular diastolic dysfunction, a basic characteristic of diabetic heart disease (diabetic cardiomyopathy), that developes earlier than systolic dysfunction, suggests that diastolic markers might be sensitive for early cardiac injury. It is also demonstrated that gender has complex influence on indices of myocardial repolarization abnormalities such as QT interval and QT dispersion.
  
  
  METHODS
  We performed an observational study including 300 diabetic patients with similar epidemiological-demographic characteristics recruited in our institution from May 2009 to July 2014, divided into two groups. Demographic and laboratory echocardiographic data were obtained, twelve lead resting electrocardiography, QT, QTc, Tpeak-Tend-intervals and dispersion, were determined manually, and were compared between various groups. For statistical analysis a t-test, X(2) test, and logistic regression are used according to the type of variables. A p value <0.05 was considered statistically significant for a confidence interval of 95%.
  
  
  RESULTS
  QTc max. interval, QTc dispersion and Tpeak-Tend dispersion, were significantly higher in diabetic group with subclinical LV (left ventricular) diastolic dysfunction, than in diabetic group with normal left ventricular diastolic function (445.24±14.7 ms vs. 433.55±14.4 ms, P<0.000; 44.98±18.78 ms vs. 32.05±17.9 ms, P<0.000; 32.60±1.6 ms vs. 17.46±2.0 ms, P<0.02. Prolonged QTc max. interval was found in 33% of patients, indiabetic group with subclinical left ventricular diastolic dysfunction vs. 13.3% of patients in diabetic group with normal left ventricular diastolic function, (Chi-square: 16.77, P<0.0001). A prolonged QTc dispersion, was found in 40.6% of patients, in diabetic group with subclinical left ventricular diastolic dysfunction vs. 20% of patients in diabetic group with normal left ventricular diastolic function Chi-square: 14.11, P<0.0002). A prolonged dispersion of Tpeak-Tend interval was found in 24% of patients in diabetic group with subclinical left ventricular diastolic dysfunction vs. 13.3% of patients in diabetic group with normal left ventricular diastolic function (Chi-square: 12.00, P<0.005). Females in diabetic group with subclinical left ventricular diastolic dysfunction in comparison with males in diabetic group with subclinical left ventricular diastolic dysfunction, have a significantly prolonged: mean QTc max. interval (23.3% vs. 10%, Chisquare: 12.0, P<0.005), mean QTc dispersion (27.3% vs. 13.3%, Chi-square: 10.24, P<0.001), mean Tpeak-Tend interval (10% vs. 3.3%, Chi-square: 5.77, P<0.01), mean Tpek-Tend dispersion (16.6% vs. 6.6%, Chi-square: 8.39, P<0.003).
  
  
  CONCLUSIONS
  The present study has shown that influences of type 2 diabetes and gender in diabetics with sub-clinical left-ventricular diastolic dysfunction are reflected in a set of electrophysiological parameters that indicate a prolonged and more heterogeneous repolarization than in diabetic patients with normal diastolic function. In addition, it demonstrates that there exist differences between diabetic females with sub-clinic LV dysfunction and those with diabetes and normal LV function in the prevalence of increased set of electrophysiological parameters that indicate a prolonged and more heterogeneous repolarization.
authors.affiliation: Private Health Institute "Heart Diagnostica" Debar, Republic of Macedonia.
authors.forename: Ylber
authors.initials: Y
authors.lastname: Jani
authors.affiliation: Department of Cardiology Faculty of Medicine, "Mother Teresa" University Tirana, Republic of Albania.
authors.forename: Ahmet
authors.initials: A
authors.lastname: Kamberi
authors.affiliation: Department of Cardiology Medical Center Dures, Republic of Albania.
authors.forename: Sotir
authors.initials: S
authors.lastname: Xhunga
authors.affiliation: Department of Cardiology Faculty of Medicine, "Ss Kiril and Metodij" University Skopje, Republic of Macedonia.
authors.forename: Bekim
authors.initials: B
authors.lastname: Pocesta
authors.affiliation: Department of Internal Medicine Faculty of Medicine Tetovo, Republic of Macedonia.
authors.forename: Fatmir
authors.initials: F
authors.lastname: Ferati
authors.affiliation: Private Health Institute of Family Medicine "Florenc" Tetovo, Republic of Macedonija.
authors.forename: Dali
authors.initials: D
authors.lastname: Lala
authors.affiliation: Department of Internal Medicine, General Hospital "DR Ferit Murat" Gostivar, Republic of Macedonia.
authors.forename: Agim
authors.initials: A
authors.lastname: Zeqiri
authors.affiliation: Department of Internal Medicine Faculty of Medicine Tetovo, Republic of Macedonia.
authors.forename: Atila
authors.initials: A
authors.lastname: Rexhepi
keywords: Type 2 diabetes; dispersion of ventricular repolarization; gender