Carotid-Femoral Pulse Wave Velocity: Impact of Different Arterial Path Length Measurements.

BACKGROUND: Carotid-femoral pulse wave velocity (PWV) is the most established index of arterial stiffness. Yet there is no consensus on the methodology in regard to the arterial path length measurements conducted on the body surface. Currently, it is not known to what extent the differences in the arterial path length measurements affect absolute PWV values. METHODS: Two hundred fifty apparently healthy adults (127 men and 123 women, 19-79 years) were studied. Carotid-femoral PWV was calculated using (1) the straight distance between carotid and femoral sites (PWV(car-fem)), (2) the straight distance between suprasternal notch and femoral site minus carotid arterial length (PWV((ssn-fem)-(ssn-car))), (3) the straight distance between carotid and femoral sites minus carotid arterial length (PWV((car-fem)-(ssn-car))), and (4) the combined distance from carotid site to the umbilicus and from the umbilicus to femoral site minus carotid arterial length (PWV((ssn-umb-fem)-(ssn-car))). RESULTS: All the calculated PWV were significantly correlated with each other (r=0.966-0.995). PWV accounting for carotid arterial length were 16-31% lower than PWV(car-fem). PWV(car-fem) value of 12 m/sec corresponded to 8.3 m/sec for PWV((ssn-fem)-(ssn-car)), 10.0 m/sec for PWV((car-fem)-(ssn-car)), and 8.9 m/sec for PWV((ssn-umb-fem)-(ssn-car)). CONCLUSION: Different body surface measurements used to estimate arterial path length would produce substantial variations in absolute PWV values.