title: Cardiovascular magnetic resonance measurement of coronary arterial blood flow at rest and after submaximal exercise.
abstract: OBJECTIVE
  Because most daily activities are conducted at submaximal exercise level, treatments are implemented to improve submaximal coronary artery blood flow (CABF). We sought to validate the reproducibility of cardiovascular magnetic resonance imaging measurements of submaximal CABF.
  
  
  METHODS
  We measured CABF in the left anterior descending artery in 11 healthy postmenopausal women at rest and after submaximal bike exercise on 2 occasions 8 to 16 weeks apart.
  
  
  RESULTS
  After exercise, CABF increased by 42% and 47% on the first and second examination, respectively. These changes in CABF in the 2 examinations were highly correlated (r=0.86).
  
  
  CONCLUSIONS
  These data indicate that cardiovascular magnetic resonance assessments of CABF before and after submaximal exercise are feasible, reproducible, and consistent with those obtained invasively. In future studies, 24 patients would be needed per group to detect a 20% change of submaximal exercise blood flow at 80% power.
authors.affiliation: Department of Internal Medicine, Wake Forest University School of Medicine, Winston-Salem, NC 27157-1045, USA.
authors.forename: Erica
authors.initials: E
authors.lastname: Dall'Armellina
authors.forename: Miranda B
authors.initials: MB
authors.lastname: Baugh
authors.forename: Timothy M
authors.initials: TM
authors.lastname: Morgan
authors.forename: Craig A
authors.initials: CA
authors.lastname: Hamilton
authors.forename: Ping
authors.initials: P
authors.lastname: Tan
authors.forename: David M
authors.initials: DM
authors.lastname: Herrington
authors.forename: Kerry M
authors.initials: KM
authors.lastname: Link
authors.forename: W Gregory
authors.initials: WG
authors.lastname: Hundley
mesh_terms: D003326:Coronary Circulation / Q000502:physiology*; D015444:Exercise / Q000502:physiology*; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008875:Middle Aged; D015203:Reproducibility of Results; D012146:Rest