title: Effect of hyperlipidemia on QT dispersion in patients without ischemic heart disease.
abstract: BACKGROUND
  Lipoproteins are known to exert direct and indirect effects on cardiovascular function, but their effects on ventricular repolarization have not yet been clearly elucidated.
  
  
  OBJECTIVE
  To assess the effect of hyperlipidemia on the longest QT interval (QTmax) of the 12-lead surface electrocardiogram (ECG) and on QT dispersion (QTd) in type IIb hyperlipidemic patients without myocardial ischemia, and to compare these patients with healthy control subjects.
  
  
  METHODS
  Ninety-six hyperlipidemic patients (44 men and 52 women; mean age 53+/-13 years) and 101 healthy control subjects (43 men and 58 women; mean age 46+/-16 years) were examined. Total cholesterol, high density lipoprotein cholesterol, low density lipoprotein cholesterol (LDL-C), triglyceride, apolipoprotein (apo) A1, apo B, lipoprotein(a), QTmax and QTd were measured. According to heart rate, corrected QTmax and corrected QTd were also determined.
  
  
  RESULTS
  A significant difference was observed between the two groups of subjects with respect to serum cholesterol, LDL-C, triglyceride, apo B, QTmax, corrected QTmax, QTd and corrected QTd. A positive significant correlation was found between cholesterol, triglyceride, LDL-C and all of the studied ECG parameters, between high density lipoprotein cholesterol and QTmax, apo B and QTd, and between body mass index and all of the studied ECG markers.
  
  
  CONCLUSIONS
  Hyperlipidemia may have a direct effect on the studied ECG markers.
authors.affiliation: First Department of Medicine, Medical and Health Science Centre, University of Debrecen, Debrecen, Hungary. Szaboz@internal.med.unideb.hu
authors.forename: Zoltán
authors.initials: Z
authors.lastname: Szabó
authors.forename: Mariann
authors.initials: M
authors.lastname: Harangi
authors.forename: István
authors.initials: I
authors.lastname: Lörincz
authors.forename: Ildikó
authors.initials: I
authors.lastname: Seres
authors.forename: Evelin
authors.initials: E
authors.lastname: Katona
authors.forename: Zsolt
authors.initials: Z
authors.lastname: Karányi
authors.forename: György
authors.initials: G
authors.lastname: Paragh
mesh_terms: D000328:Adult; D017677:Age Distribution; D000368:Aged; D001774:Blood Chemical Analysis; D016022:Case-Control Studies; D002784:Cholesterol / Q000097:blood; D004562:Electrocardiography; D005260:Female; D006439:Hemodynamics / Q000502:physiology*; D006801:Humans; D006949:Hyperlipidemias / Q000175:diagnosis* / Q000453:epidemiology; D015994:Incidence; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D017202:Myocardial Ischemia / Q000175:diagnosis* / Q000453:epidemiology; D011336:Probability; D011379:Prognosis; D012016:Reference Values; D012307:Risk Factors; D012720:Severity of Illness Index; D017678:Sex Distribution; D018709:Statistics, Nonparametric
chemical_list: D002784:Cholesterol