title: Association of heart rate with blood pressure variability: implications for blood pressure measurement.
abstract: BACKGROUND
  Antihypertensive β-blocker use is associated with greater intervisit blood pressure variability (BPV) and with less favorable outcomes compared to other antihypertensive agents. A theoretical model demonstrated that accuracy and precision of BP measurement are affected by heart rate (HR) at a constant cuff deflation rate. We aimed to examine the empirical relationship between HR and BPV in a clinical setting.
  
  
  METHODS
  Intratracing variability in ambulatory BP monitoring (ABPM) were analyzed in search of a link between BPV and HR. BPV was expressed as standard deviation (s.d.), coefficient of variation (CV), and variability independent of the mean (VIM).
  
  
  RESULTS
  In a dataset of 4,693 subjects, HR was inversely associated with BPV and independently explained 1.3% of between-subject variation in s.d. of awake systolic BP (1.5% of CV and VIM). Linear regression suggested 0.5 mm Hg increase in s.d. of systolic BP per 10 beats per minute (bpm) decrease in HR. In a subset of 1,019 patients with available data on medications, HR was independently and inversely related with awake systolic BPV (P < 0.0001), more so in diuretic (P < 0.050) and renin-angiotensin system antagonists-treated (P < 0.050) patients. Associations of β-blockade with increased BPV were abolished by model-adjustment for HR. In another subset of patients who were monitored twice (n = 635), HR had a mild (0.6%) but significant (P < 0.05) inverse contribution to the change in awake systolic BPV between repeated monitoring.
  
  
  CONCLUSIONS
  Ambulatory BPV is inversely related to HR and is not increased in referred patients treated with β-blockers after correction for HR.
authors.affiliation: Department of Medicine, Hadassah-Hebrew University Medical Center, Jerusalem, Israel. amosc@hadassah.org.il
authors.forename: Amos
authors.initials: A
authors.lastname: Cahan
authors.forename: Iddo Z
authors.initials: IZ
authors.lastname: Ben-Dov
authors.forename: Michael
authors.initials: M
authors.lastname: Bursztyn
mesh_terms: D000319:Adrenergic beta-Antagonists / Q000494:pharmacology* / Q000627:therapeutic use; D000328:Adult; D000368:Aged; D000959:Antihypertensive Agents / Q000494:pharmacology* / Q000627:therapeutic use; D001794:Blood Pressure / Q000187:drug effects*; D001795:Blood Pressure Determination / Q000379:methods*; D018660:Blood Pressure Monitoring, Ambulatory / Q000379:methods*; D005260:Female; D006339:Heart Rate / Q000187:drug effects*; D006801:Humans; D006973:Hypertension / Q000188:drug therapy; D008297:Male; D008875:Middle Aged
chemical_list: D000319:Adrenergic beta-Antagonists; D000959:Antihypertensive Agents