title: Noninvasive cardiac output measurement by transthoracic electrical bioimpedence: influence of age and gender.
abstract: BACKGROUND
  Thoracic electrical bioimpedance (TEB) as a method of measuring cardiac output (CO) is being explored increasingly over the last two decades, as a non-invasive alternative to the pulmonary artery catheter. The objective of this study was to establish normative data for measurement of CO by TEB and define the effect of age and gender on CO.
  
  
  METHODS
  Stroke volume (SV) of 397 normal individuals (203 men, 194 women) in the age range of 10-77 years was determined using Kubisek and Bernstein formulae by TEB method. Derived cardiac parameters including CO, cardiac index (CI), systemic vascular resistance and resistance index were calculated and analyzed.
  
  
  RESULTS
  We found significant difference in CO among age groups and between gender. CO between Kubicek formula and Bernstein formula correlated well, but their means differed significantly. Cardiac indices peak in the third and seventh decade and were comparable between genders.
  
  
  CONCLUSIONS
  A comprehensive data set of normalized values expressed as 95% confidence interval and mean +/- SD in different age groups and different gender was possible for cardiac parameters using TEB.
authors.affiliation: NIMHANS, Bangalore, India. drsathyaprabha@gmail.com
authors.forename: Talakad N
authors.initials: TN
authors.lastname: Sathyaprabha
authors.forename: Cauchy
authors.initials: C
authors.lastname: Pradhan
authors.forename: G
authors.initials: G
authors.lastname: Rashmi
authors.forename: Kandavel
authors.initials: K
authors.lastname: Thennarasu
authors.forename: Trichur R
authors.initials: TR
authors.lastname: Raju
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000375:Aging / Q000502:physiology*; D002302:Cardiac Output / Q000502:physiology*; D002307:Cardiography, Impedance / Q000379:methods*; D002648:Child; D003936:Diagnosis, Computer-Assisted / Q000379:methods*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D012737:Sex Factors; D013318:Stroke Volume / Q000502:physiology*; D055815:Young Adult