title: Long-term outcomes of ivabradine in inappropriate sinus tachycardia patients: appropriate efficacy or inappropriate patients.
abstract: BACKGROUND
  Inappropriate sinus tachycardia (IST) is characterized by persistent and disproportional elevation of heart rate (HR). Ivabradine has been successfully used in some patients.
  
  
  METHODS
  Twenty-four patients (18 women, 41 ± 13 year olds) were diagnosed with IST according to current guidelines criteria. Patients were treated with 5-7.5 mg of ivabradine twice a day. Twenty-four-hour Holter recordings and the SF-36 Health Survey were performed at 6 months to evaluate both HR control and clinical status.
  
  
  RESULTS
  Holter recordings before and after 6 months on treatment showed a significant reduction in the average maximal HR of 155 ± 18 beats/min versus 132 ± 16 beats/min, mean HR of 97 ± 6 beats/min versus 79 ± 8 beats/min (mean daytime HR of 103 ± 8 beats/min vs 84 ± 10 beats/min) and minimal HR of 58 ± 12 beats/min versus 48 ± 7 beats/min (Wilcoxon analysis, P < 0.05). The SF-36 mean score showed a significant improvement on ivabradine treatment (57 ± 23 vs 76 ± 20), with a better physical and mental status scores (56 ± 25 vs 74 ± 22 and 58 ± 24 vs 78 ± 18, respectively) (Wilcoxon analysis, P < 0.001). Mean dose of ivabradine was 5.8 ± 1.4 mg. No episodes of severe bradycardia or syncope were reported. After 1 year, patients were asked to stop treatment to reevaluate the situation. Twenty patients were on treatment and only 10 patients accepted to stop ivabradine. Only two patients (20%) remained on IST criteria.
  
  
  CONCLUSIONS
  IST patients treated with ivabradine showed both HR normalization and quality-of-life improvement maintained in the long-term follow-up. Stopping ivabradine after 1 year unexpectedly showed that HR remained in the normal limits in 80% of the patients.
authors.affiliation: Department of Cardiology, Fundacion Jimenez Diaz-Capio, Universidad Autonoma de Madrid, Madrid, Spain. jbenezet@yahoo.es
authors.forename: Juan
authors.initials: J
authors.lastname: Benezet-Mazuecos
authors.forename: José M
authors.initials: JM
authors.lastname: Rubio
authors.forename: Jerónimo
authors.initials: J
authors.lastname: Farré
authors.forename: Miguel Á
authors.initials: MÁ
authors.lastname: Quiñones
authors.forename: Pepa
authors.initials: P
authors.lastname: Sanchez-Borque
authors.forename: Ester
authors.initials: E
authors.lastname: Macía
mesh_terms: D000328:Adult; D001552:Benzazepines / Q000627:therapeutic use*; D002316:Cardiotonic Agents / Q000627:therapeutic use; D005260:Female; D006801:Humans; D000077550:Ivabradine; D008137:Longitudinal Studies; D008297:Male; D017060:Patient Satisfaction; D011788:Quality of Life; D013616:Tachycardia, Sinus / Q000175:diagnosis* / Q000188:drug therapy*; D016896:Treatment Outcome
chemical_list: D001552:Benzazepines; D002316:Cardiotonic Agents; D000077550:Ivabradine
keywords: diagnosis; inappropriate sinus tachycardia; ivabradine; tachyarrhythmias