title: Improved Accuracy of Automated Estimation of Cardiac Output Using Circulation Time in Patients with Heart Failure.
abstract: BACKGROUND
  Lung-to-finger circulation time of oxygenated blood during nocturnal periodic breathing in heart failure patients measured using polysomnography correlates negatively with cardiac function but possesses limited accuracy for cardiac output (CO) estimation.
  
  
  RESULTS
  CO was recalculated from lung-to-finger circulation time using a multivariable linear model with information on age and average overnight heart rate in 25 patients who underwent evaluation of heart failure. The multivariable model decreased the percentage error to 22.3% relative to invasive CO measured during cardiac catheterization.
  
  
  CONCLUSIONS
  This improved automated noninvasive CO estimation using multiple variables meets a recently proposed performance criterion for clinical acceptability of noninvasive CO estimation, and compares very favorably with other available methods.
authors.affiliation: School of Electrical Engineering and Computer Science, University of Ottawa, Ottawa, Canada. Electronic address: hdajani@eecs.uottawa.ca.
authors.forename: Hilmi R
authors.initials: HR
authors.lastname: Dajani
authors.affiliation: Department of Cardiovascular Medicine, Kyushu University Hospital, Fukuoka, Japan.
authors.forename: Kazuya
authors.initials: K
authors.lastname: Hosokawa
authors.affiliation: Sleep Apnea Center, Kyushu University Hospital, Fukuoka, Japan.
authors.forename: Shin-Ichi
authors.initials: SI
authors.lastname: Ando
mesh_terms: D000368:Aged; D001331:Automation / Q000379:methods*; D001776:Blood Circulation Time / Q000379:methods; D001783:Blood Flow Velocity; D006328:Cardiac Catheterization / Q000379:methods; D002302:Cardiac Output / Q000502:physiology*; D015331:Cohort Studies; D005260:Female; D006333:Heart Failure / Q000175:diagnosis*; D006801:Humans; D016014:Linear Models; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D010101:Oxygen Consumption / Q000502:physiology*; D017286:Polysomnography / Q000379:methods; D011237:Predictive Value of Tests; D011446:Prospective Studies; D058996:Quality Improvement; D012720:Severity of Illness Index
keywords: Cardiac output estimation; heart failure; sleep apnea