title: Determinants of heart rate turbulence after ventricular premature beats in healthy volunteers.
abstract: BACKGROUND
  A decline in the acceleration of the heart rate (HR, heart rate turbulence, HRT) after a ventricular premature capture is associated with increased mortality in patients suffering from coronary artery disease. The physiological properties of HRT have not been evaluated in a large human cohort.
  
  
  METHODS
  In 95 healthy individuals, HRT parameters onset (TO) and slope (TS) as well as the turbulence timing (TT) were calculated from 24-hour Holter ECGs. With the help of a simple, linear, weighted regression model, gender specific differences of TO and TS were compared. A multiple linear regression model served to evaluate the influence of age and the basic HR preceding the ventricular premature contraction (VPC) on HRT.
  
  
  RESULTS
  The median of TT is present in regression line #5. We discovered that, in men and women, TO is reduced as basic HR rises (p<0.01). In contrast, analysis of TS showed a divergence: in men, TS declines as basic HR increases. However, basic HR modifies TS in women to some extent (p<0.01). A multiple, linear regression model revealed a decrease of HRT with increasing age in men.
  
  
  CONCLUSIONS
  The acceleration of HR after a ventricular premature beat occurred within the first 11 beats in more than 75% of our healthy individuals. An increased HR prior to VPC affects HRT in men. Increasing age leads to an attenuation of HRT in men and to a reduction of TO in women. These results emphasise the significance of the physiological properties of HRT when using HRT for risk stratification, especially in elderly patients.
authors.affiliation: Department of Medicine-Cardiology, University of Bonn, Germany. joerg.schwab@ukb.uni-bonn.de
authors.forename: Jörg Otto
authors.initials: JO
authors.lastname: Schwab
authors.forename: Gerrit
authors.initials: G
authors.lastname: Eichner
authors.forename: Osman
authors.initials: O
authors.lastname: Balta
authors.forename: Berndt
authors.initials: B
authors.lastname: Lüderitz
mesh_terms: D000222:Adaptation, Physiological; D000328:Adult; D000367:Age Factors; D015331:Cohort Studies; D004562:Electrocardiography; D015716:Electrocardiography, Ambulatory / Q000379:methods*; D005260:Female; D006339:Heart Rate / Q000502:physiology*; D006801:Humans; D016014:Linear Models; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D011336:Probability; D012016:Reference Values; D018570:Risk Assessment; D012737:Sex Factors; D018879:Ventricular Premature Complexes / Q000175:diagnosis* / Q000401:mortality