title: The relationship between resting heart rate and peak VO2: A comparison of atrial fibrillation and sinus rhythm.
abstract: Resting heart rate is a surrogate marker associated with achieved exercise capacity, which has been observed in patients with sinus rhythm. The aim of this study was to examine and compare the relationships between resting heart rate and peak oxygen consumption in atrial fibrillation and sinus rhythm.
  
  
  
  A total of 2160 consecutive patients undergoing cardiopulmonary exercise testing in our single-hospital cohort were divided into two groups according to rhythm status: an atrial fibrillation group (N = 320) and a sinus rhythm group (N = 1840). In the total cohort and sinus rhythm group, resting heart rate was negatively correlated with percentage of predicted peak oxygen consumption (Ptrend < 0.0001); in atrial fibrillation patients, this correlation was apparently positive (Ptrend = 0.032). Multivariate analysis of the total cohort showed a significant interaction between resting heart rate and rhythm status for peak oxygen consumption after adjustments for age, sex, ejection fraction, structural heart diseases and heart rate-lowering drugs. In the sinus rhythm group, resting heart rate was an independent, negative contributing factor for peak oxygen consumption, even after the adjustments for patient background. However, in the atrial fibrillation group, resting heart rate was a weak positive or non-independent contributing factor for peak oxygen consumption after the same adjustments.
  
  
  
  The impact of resting heart rate on exercise capacity differed completely between atrial fibrillation and sinus rhythm, suggesting that heart rate control may need to be managed differently for atrial fibrillation and sinus rhythm, in light of exercise capacity that is related to quality of life and prognosis.
authors.affiliation: Department of Cardiovascular Medicine, The Cardiovascular Institute, Japan kimuchi@nms.ac.jp.
authors.forename: Yuko
authors.initials: Y
authors.lastname: Kato
authors.affiliation: Department of Cardiovascular Medicine, The Cardiovascular Institute, Japan.
authors.forename: Shinya
authors.initials: S
authors.lastname: Suzuki
authors.affiliation: Department of Cardiovascular Medicine, The Cardiovascular Institute, Japan.
authors.forename: Tokuhisa
authors.initials: T
authors.lastname: Uejima
authors.affiliation: Department of Cardiovascular Medicine, The Cardiovascular Institute, Japan.
authors.forename: Hiroaki
authors.initials: H
authors.lastname: Semba
authors.affiliation: Department of Clinical laboratory, The Cardiovascular Institute, Japan.
authors.forename: Osamu
authors.initials: O
authors.lastname: Nagayama
authors.affiliation: Department of Clinical laboratory, The Cardiovascular Institute, Japan.
authors.forename: Etsuko
authors.initials: E
authors.lastname: Hayama
authors.affiliation: Department of Cardiovascular Medicine, The Cardiovascular Institute, Japan.
authors.forename: Takeshi
authors.initials: T
authors.lastname: Yamashita
mesh_terms: D001281:Atrial Fibrillation / Q000378:metabolism / Q000503:physiopathology*; D005080:Exercise Test; D017079:Exercise Tolerance / Q000502:physiology*; D005260:Female; D005500:Follow-Up Studies; D006339:Heart Rate / Q000502:physiology*; D006801:Humans; D008297:Male; D008875:Middle Aged; D010100:Oxygen / Q000378:metabolism*; D010101:Oxygen Consumption / Q000502:physiology*; D012146:Rest / Q000502:physiology*; D012189:Retrospective Studies
chemical_list: D010100:Oxygen
keywords: Resting HR; atrial fibrillation; exercise capacity; peak oxygen consumption; sinus rhythm