title: [Validation during exercise of a new device for cardiac output measurement using pulse wave transit time (comparison EsCCO(®) vs. Physioflow(®))].
abstract: OBJECTIVE
  EsCCO is a novel non-invasive continuous cardiac output monitoring system based on pulse wave transit time already validated at rest. The aim of our study was to compare cardiac output measurements obtained simultaneously by EsCCO(®) (Q˙cOP) and impedance cardiography (Physioflow(®) ; Q˙cIMP), in healthy subjects.
  
  
  METHODS
  Eight healthy subjects (age: 31±9 years, weight: 76±10kg, height: 179±5cm) realized two exercise tests: an incremental ergocycle test performed until exertion (Pmax=269±48W) and a constant load exercise (P=163±27W). Comparison between measurements (Q˙cOP versus Q˙cIMP) obtained during the first test allowed to evaluate the accuracy of the device. Reliability was determined on three repeated measures during the second test, realized at ventilatory threshold.
  
  
  RESULTS
  Correlation coefficient between both methods is 0.88 (P<0.01). Mean difference is 0.04±1.49L/min (95 % limits of agreement: +2.94 to -3.00L/min) and only 3/74 measures are not included between the limits of agreement. At high intensity and for cardiac output over than 15 L/min, Q˙cOP signal is lost in almost half the time. Concerning reliability, reproducibility coefficient is 0.87 (P<0.05), only 1.8 % of this variability is due to the method.
  
  
  CONCLUSIONS
  EsCCO(®) measurements are accurate, reliable and allow a good estimation of cardiac output on healthy subjects. The signal lost observed for high cardiac output levels (>15L/min) can limit its utilization during very high intensity exercise.
authors.affiliation: Service de médecine du sport et des explorations fonctionnelles, hôpital G.-Montpied, CHRU de Clermont-Ferrand, 58, rue Montalembert, 63003 Clermont-Ferrand cedex, France; INRA, UMR 1019, 63000 Clermont-Ferrand, France.
authors.forename: A
authors.initials: A
authors.lastname: Stalter
authors.affiliation: Service de médecine du sport et des explorations fonctionnelles, hôpital G.-Montpied, CHRU de Clermont-Ferrand, 58, rue Montalembert, 63003 Clermont-Ferrand cedex, France.
authors.forename: N
authors.initials: N
authors.lastname: Lanot
authors.affiliation: Service de médecine du sport et des explorations fonctionnelles, hôpital G.-Montpied, CHRU de Clermont-Ferrand, 58, rue Montalembert, 63003 Clermont-Ferrand cedex, France.
authors.forename: G
authors.initials: G
authors.lastname: Bridon
authors.affiliation: Service de médecine du sport et des explorations fonctionnelles, hôpital G.-Montpied, CHRU de Clermont-Ferrand, 58, rue Montalembert, 63003 Clermont-Ferrand cedex, France.
authors.forename: V
authors.initials: V
authors.lastname: Julian
authors.affiliation: Unité de biostatistiques (DRCI), CHRU de Clermont-Ferrand, 63000 Clermont-Ferrand, France.
authors.forename: B
authors.initials: B
authors.lastname: Péreira
authors.affiliation: Service de médecine du sport et des explorations fonctionnelles, hôpital G.-Montpied, CHRU de Clermont-Ferrand, 58, rue Montalembert, 63003 Clermont-Ferrand cedex, France; INRA, UMR 1019, 63000 Clermont-Ferrand, France. Electronic address: rrichard@chu-clermontferrand.fr.
authors.forename: R
authors.initials: R
authors.lastname: Richard
mesh_terms: D000328:Adult; D002302:Cardiac Output; D002307:Cardiography, Impedance / Q000295:instrumentation*; D005080:Exercise Test; D064368:Healthy Volunteers; D006801:Humans; D008875:Middle Aged; D008991:Monitoring, Physiologic / Q000295:instrumentation*; D063177:Pulse Wave Analysis; D015203:Reproducibility of Results
keywords: Cardiac output; Débit cardiaque; Exercice; Exercise; Healthy subjects; Onde de pouls; Pulse wave; Sujets sains