title: Restoration of heart rate turbulence by titrated beta-blocker therapy in patients with advanced congestive heart failure: positive correlation with enhanced vagal modulation of heart rate.
abstract: BACKGROUND
  Heart rate turbulence (HRT) is a powerful novel predictor for cardiovascular mortality. Chronic congestive heart failure is associated with abnormal HRT. Whether antiadrenergic beta-blocker therapy can restore control of HRT in patients with chronic congestive heart failure is unknown.
  
  
  RESULTS
  A 24-hour Holter ECG recording was obtained before and 1 and 3 months after titrated addition of atenolol therapy in 10 consecutive patients with advanced congestive heart failure. Two parameters derived from HRT, turbulence slope (TS) and turbulence onset (TO), and time- and frequency-domain heart rate variability (HRV) parameters (SDNN, RMSSD, VLF, LF, HF) from 24-hour ECG were compared before and after beta-blocker therapy, together with the same parameters in age-matched normal control. Results showed that TS (3.1 +/- 2.2 vs 6.2 +/- 3.0; P = 0.001) and all HRV parameters were increased after 3 months of atenolol treatment. No changes in TO were evident (0.6 +/- 0.5 vs -0.2 +/- 1.3; P = 0.13). The improvement of TS and the vagally mediated parameters of mean R-R interval, RMSSD, and the HF component of HRV were positively correlated.
  
  
  CONCLUSIONS
  Abnormal HRT caused by chronic congestive heart failure can be restored by beta-blocker therapy. The evolution of TS was positively correlated with measures of vagal modulation of heart rate.
authors.affiliation: Division of Cardiology, Department of Internal Medicine, National Taiwan University College of Medicine and National Taiwan University Hospital, Taipei, Taiwan.
authors.forename: Lian-Yu
authors.initials: LY
authors.lastname: Lin
authors.forename: Juey-Jen
authors.initials: JJ
authors.lastname: Hwang
authors.forename: Ling-Ping
authors.initials: LP
authors.lastname: Lai
authors.forename: Hsiao-Lung
authors.initials: HL
authors.lastname: Chan
authors.forename: Chao-Cheng
authors.initials: CC
authors.lastname: Du
authors.forename: Yung-Zu
authors.initials: YZ
authors.lastname: Tseng
authors.forename: Jiunn-Lee
authors.initials: JL
authors.lastname: Lin
mesh_terms: D000319:Adrenergic beta-Antagonists / Q000627:therapeutic use*; D000368:Aged; D000704:Analysis of Variance; D001262:Atenolol / Q000627:therapeutic use*; D016022:Case-Control Studies; D016009:Chi-Square Distribution; D015716:Electrocardiography, Ambulatory; D005260:Female; D006333:Heart Failure / Q000188:drug therapy* / Q000503:physiopathology*; D006339:Heart Rate / Q000187:drug effects*; D006801:Humans; D016014:Linear Models; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D016896:Treatment Outcome
chemical_list: D000319:Adrenergic beta-Antagonists; D001262:Atenolol