title: Lack of diurnal variation of P-wave and QT dispersions in patients with heart failure.
abstract: BACKGROUND
  P-wave dispersion (PWD) is a new parameter for the assessment of risk of atrial fibrillation and has been reported to be increased in heart failure. Diurnal variation of the PWD has been reported in patients with coronary artery disease (CAD). QT dispersion (QTD) has also a circadian variation. In this study we aimed to search diurnal variation of PWD and QTD in patients with heart failure.
  
  
  METHODS
  Fifty-three clinical heart failure patients having left ventricular ejection fraction (LVEF) <40% were divided into two groups according to presence of CAD. Twelve-lead ECGs were obtained in the morning (07:00-08:00 hours), at noon (12:00-14:00 hours), and at night (22:00-24:00 hours).
  
  
  RESULTS
  All the patients were in New York Heart Association class II except one in class I. beta-blocker and angiotensin-converting enzyme inhibitor or angiotensin receptor blocker usage was over 80% and spiranolactone usage was around 75% in the study group. PWD and QTD were not significantly different between patients with (n = 27) and without (n = 26) CAD. There was no significant diurnal variation of P wave and QT parameters.
  
  
  CONCLUSIONS
  We found that PWD and QTD do not show diurnal variation in patients having either ischemic or nonischemic origin of heart failure treated with optimal drug therapy.
authors.affiliation: Cardiology Department, Faculty of Medicine, Yuzuncu Yil University, Van, Turkey. yilmazleman@yahoo.com
authors.forename: Yilmaz
authors.initials: Y
authors.lastname: Gunes
authors.forename: Mustafa
authors.initials: M
authors.lastname: Tuncer
authors.forename: Unal
authors.initials: U
authors.lastname: Guntekin
authors.forename: Serkan
authors.initials: S
authors.lastname: Akdag
authors.forename: Hasan A
authors.initials: HA
authors.lastname: Gumrukcuoglu
mesh_terms: D000368:Aged; D002940:Circadian Rhythm; D004562:Electrocardiography / Q000379:methods; D005260:Female; D006329:Heart Conduction System / Q000503:physiopathology*; D006333:Heart Failure / Q000175:diagnosis* / Q000209:etiology / Q000503:physiopathology*; D006339:Heart Rate; D006801:Humans; D008297:Male; D008875:Middle Aged; D017202:Myocardial Ischemia / Q000150:complications / Q000175:diagnosis* / Q000503:physiopathology*