title: Attenuation of heart rate recovery after exercise in hypertensive patients with blunting of the nighttime blood pressure fall.
abstract: OBJECTIVE
  To evaluate whether hypertensive patients with attenuation of nighttime blood pressure (BP) fall exhibit a delay of the recovery of heart rate (HR) after exercise as an index of a general decrease in the vagal tone.
  
  
  METHODS
  Mild-moderate hypertensive patients (n = 219, age 55 +/- 3, 77% men) underwent a maximal exercise test (Bruce > 85% heart rate limited) in whom we calculated the recovery of HR as the percent decrease of HR from peak to 1 min after stopping exercise (%HR fall-1 min), a 24-h ambulatory BP monitoring, calculating the percent decrease of nighttime vs. daytime BP (% night SBP fall). Left ventricular mass index (LVMI) was measured by echo and aortic stiffness by pulse wave velocity (PWV). Sixty percent were on antihypertensive drugs (not on beta-blockers nor on non-dihydropiridine calcium blockers); 12 subjects were type 2 diabetics.
  
  
  RESULTS
  The "% night SBP fall" ranged from - 6.3% to 38.9% and the "%HR fall-1 min" ranged from 3.3% to 43.7%. There was a significant positive correlation between these two variables (r = 0.594, p < 0.001). Population was divided into five groups according to quintiles of values for the "% night SBP fall". For similar daytime BP and age, the lowest quintile for % night SBP fall (- 6.3% to 7.2%) showed the lower "%HR fall-1 min" (3.1 +/- 0.5%), and the higher LVMI (92 +/- 3 g/m(2)) and PWV (12.1 +/- 0.4 m/s) values comparing to the other quintiles (p < 0.02).
  
  
  CONCLUSIONS
  In hypertensives, blunting of the nocturnal fall of BP is associated with a delayed recovery in heart rate after graded maximal exercise and with greater aortic stiffness and ventricular mass. This may indicate that in non-dipper subjects a relative general decrease of parasympathetic reactivation after exercise is linked to the failure of nighttime fall of BP, both of which might contribute to target-organs deterioration.
authors.affiliation: Centro Clínico MOSS do Porto, Faculdade Ciências da Saude, Universidade Fernando Pessoa, Porto, Portugal.. jjpolonia@mail.telepac.pt
authors.forename: Jorge
authors.initials: J
authors.lastname: Polónia
authors.forename: Cristina
authors.initials: C
authors.lastname: Amaral
authors.forename: Susana
authors.initials: S
authors.lastname: Bertoquini
authors.forename: Luis
authors.initials: L
authors.lastname: Martins
mesh_terms: D000704:Analysis of Variance; D018660:Blood Pressure Monitoring, Ambulatory; D002940:Circadian Rhythm; D003430:Cross-Sectional Studies; D004452:Echocardiography; D005080:Exercise Test; D005260:Female; D006339:Heart Rate / Q000502:physiology*; D006801:Humans; D006973:Hypertension / Q000503:physiopathology*; D008297:Male; D008875:Middle Aged; D011674:Pulse