title: The characteristics of the spectra of superior venae cavae in patients with right heart failure.
abstract: BACKGROUND
  Aimed to elucidate the characteristics of the spectra of superior venae cavae (SVC) in respiratory cycles in patients with right heart failure.
  
  
  METHODS
  The spectra of SVC of 30 patients with right heart failure and 30 paired healthy subjects were recorded through right supraclavicular fossa view. The profiles of spectra of superior venae cavae were observed, and peak velocity and velocity time integral (VTI) of every wave of SVC under spontaneous respiration were measured for statistical analysis.
  
  
  RESULTS
  In healthy subjects, the peak velocities and VTI of S wave and D wave increased in inspiratory phase and diminished in expiratory phase, and which of S wave were larger than which of D wave in whole respiratory cycle. In patients with right heart failure, spectral variations of SVC could be classified into three patterns: Pattern I: peak velocities and VTI of S wave were larger than that of D wave in early inspiratory phase, but peak velocities and VTI of D wave were larger than those of S wave in late inspiratory phase and early expiratory phase [Pattern I-1], even in whole respiratory cycle [Pattern I-2]; Pattern II: the S wave disappeared and was substituted by inverse wave with low amplitude in whole respiratory cycle. Pattern III: the profiles of the spectra of SVC in patients were similar to those of healthy subjects. In the whole, the respiratory variation ratios of peak velocities and VTI of S wave and D wave were diminished in patients compared with those in healthy subjects.
  
  
  CONCLUSIONS
  The spectra of superior venae cavae in patients with right heart failure were abnormal, and these characteristics could be used as signs in evaluating right heart failure.
authors.affiliation: Tangdu Hospital, The Fourth Military Medical University, Xi an, Shaanxi province, China. jiahuaping@yahoo.com.cn
authors.forename: Hua-Ping
authors.initials: HP
authors.lastname: Jia
authors.forename: Yun-You
authors.initials: YY
authors.lastname: Duan
authors.forename: Tie-Sheng
authors.initials: TS
authors.lastname: Cao
authors.forename: Li-Jun
authors.initials: LJ
authors.lastname: Yuan
authors.forename: Juan
authors.initials: J
authors.lastname: Li
mesh_terms: D001783:Blood Flow Velocity; D005260:Female; D006333:Heart Failure / Q000503:physiopathology*; D006801:Humans; D008297:Male; D008875:Middle Aged; D012119:Respiration; D014683:Vena Cava, Superior