title: Ivabradine improves heart rate variability in patients with nonischemic dilated cardiomyopathy.
abstract: BACKGROUND
  Ivabradine is a novel specific heart rate (HR)-lowering agent that improves event-free survival in patients with heart failure (HF).
  
  
  OBJECTIVE
  We aimed to evaluate the effect of ivabradine on time domain indices of heart rate variability (HRV) in patients with HF.
  
  
  METHODS
  Forty-eight patients with compensated HF of nonischemic origin were included. Ivabradine treatment was initiated according to the latest HF guidelines. For HRV analysis, 24-h Holter recording was obtained from each patient before and after 8 weeks of treatment with ivabradine.
  
  
  RESULTS
  The mean RR interval, standard deviation of all normal to normal RR intervals (SDNN), the standard deviation of 5-min mean RR intervals (SDANN), the mean of the standard deviation of all normal-to-normal RR intervals for all 5-min segments (SDNN index), the percentage of successive normal RR intervals exceeding 50 ms (pNN50), and the square root of the mean of the squares of the differences between successive normal to normal RR intervals (RMSSD) were low at baseline before treatment with ivabradine. After 8 weeks of treatment with ivabradine, the mean HR (83.6 ± 8.0 and 64.6 ± 5.8, p < 0.0001), mean RR interval (713 ± 74 and 943 ± 101 ms, p < 0.0001), SDNN (56.2 ± 15.7 and 87.9 ± 19.4 ms, p < 0.0001), SDANN (49.5 ± 14.7 and 76.4 ± 19.5 ms, p < 0.0001), SDNN index (24.7 ± 8.8 and 38.3 ± 13.1 ms, p < 0.0001), pNN50 (2.4 ± 1.6 and 3.2 ± 2.2 %, p < 0.0001), and RMSSD (13.5 ± 4.6 and 17.8 ± 5.4 ms, p < 0.0001) substantially improved, which sustained during both when awake and while asleep.
  
  
  CONCLUSIONS
  Our findings suggest that treatment with ivabradine improves HRV in nonischemic patients with HF.
authors.affiliation: Department of Cardiology, Malatya State Hospital, Malatya, Turkey.
authors.forename: Ertugrul
authors.initials: E
authors.lastname: Kurtoglu
authors.affiliation: Department of Cardiology, Eskisehir Military Hospital, Eskisehir, Turkey.
authors.forename: Sevket
authors.initials: S
authors.lastname: Balta
authors.affiliation: Department of Cardiology, Malatya State Hospital, Malatya, Turkey.
authors.forename: Yasin
authors.initials: Y
authors.lastname: Karakus
authors.affiliation: Department of Cardiology, Malatya State Hospital, Malatya, Turkey.
authors.forename: Erdogan
authors.initials: E
authors.lastname: Yasar
authors.affiliation: Department of Cardiology, Malatya State Hospital, Malatya, Turkey.
authors.forename: Bilal
authors.initials: B
authors.lastname: Cuglan
authors.affiliation: Department of Cardiology, Malatya State Hospital, Malatya, Turkey.
authors.forename: Ozgur
authors.initials: O
authors.lastname: Kaplan
authors.affiliation: Department of Cardiology, Malatya State Hospital, Malatya, Turkey.
authors.forename: Gokhan
authors.initials: G
authors.lastname: Gozubuyuk
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D001552:Benzazepines / Q000494:pharmacology / Q000627:therapeutic use*; D002311:Cardiomyopathy, Dilated / Q000188:drug therapy* / Q000503:physiopathology; D002316:Cardiotonic Agents / Q000494:pharmacology / Q000627:therapeutic use*; D015716:Electrocardiography, Ambulatory; D005260:Female; D006333:Heart Failure / Q000188:drug therapy / Q000503:physiopathology; D006339:Heart Rate / Q000187:drug effects* / Q000502:physiology; D006801:Humans; D000077550:Ivabradine; D008297:Male; D008875:Middle Aged; D018709:Statistics, Nonparametric; D013997:Time Factors; D016896:Treatment Outcome
chemical_list: D001552:Benzazepines; D002316:Cardiotonic Agents; D000077550:Ivabradine