The characteristics of the spectra of superior venae cavae in patients with right heart failure

Table 3 Peak velocities and VTI of VR wave and their respiratory variation ratios ( ± s).

	Patients		Health subjects
	Peak velocity (cm/s)	VTI(mm)	Peak velocity (cm/s)	VTI(mm)
Inspiration	17.15 ± 6.27	0.0159 ± 0.0110	12.77 ± 3.34	0.0080 ± 0.0043
Expiration	19.74 ± 6.71	0.0192 ± 0.0157	15.13 ± 3.90	0.0098 ± 0.0049
Inspiratory variation ratio (%)	16.47 ± 5.51	21.55 ± 12.79	15.75 ± 8.90	17.69 ± 17.08
Expiratory variation ratio (%)	20.21 ± 7.94	27.68 ± 18.19	20.10 ± 14.45	28.25 ± 34.71

The peak velocities and VTI of VR wave were larger in the patient group than in the control group in whole respiratory cycle (P < 0.05), but there were no differences in their respiratory variation ratios.

ISSN: 1476-7120