Carotid-femoral pulse wave velocity

Method

Aortic pulse wave velocity derived from the carotid-to-femoral transit time and the surface path length between those two recording sites, by applanation tonometry or a validated oscillometric device. The path-length convention (direct, subtracted, or 0.8 x direct) is recorded on the edge -- the three conventions differ by up to 20 percent on the same subject.

The method is part of the endpoint identity. Studies measuring the same quantity by a different method are held as separate endpoints.

Notes

The reference-standard regional arterial stiffness measure. Will be confused with augmentation index, reported from the same tonometry session and described in the same sentence as arterial stiffness: AIx is a wave-reflection index in percent that depends strongly on heart rate and height, whereas this is a direct transit-time measurement in m/s. Also distinct from the segment-unspecified velocity node, which exists precisely because an unlabelled PWV cannot be assumed aortic. SIGN INVERSION HAZARD against flow-mediated dilation, reported alongside it as vascular function: FMD improves by RISING while this improves by FALLING.