title: Simultaneous measurement of beat-to-beat carotid diameter and pressure changes to assess arterial mechanical properties.
abstract: Use of local arterial distensibility measurements by change in carotid artery diameter divided by pulse pressure has limitations because blood pressure is often taken in a vessel distant or at a time different from where and when change in diameter is taken. In 92 subjects (23 to 91 years of age), carotid artery diameter was continuously measured ecographically, whereas blood pressure was continuously measured simultaneously tonometrically on the contralateral artery, the 2 signals being synchronized via 2 EKGs. Within each cardiac cycle, there was a linear relationship between the changes in vessel diameter and the changes in blood pressure during either the protomesosystole or the diastole after the dicrotic notch. The diastolic slope was displaced upward and steeper than the systolic slope, the pressure-diameter loop showing a hysteresis. Both slopes showed a high reproducibility when data were averaged over a several-second period. There were small differences between consecutive cardiac cycles, suggesting that modulation of arterial mechanical response to continuous changes in intravascular pressure may undergo physiological variations. In the 92 subjects, systolic and diastolic slopes correlated significantly with distensibility values obtained by Reneman formula and exhibited a close inverse relationship with each subject's age and systolic blood pressure, thereby showing the ability to reflect age- and pressure-dependent large artery stiffening. This method may allow precise assessment of man's arterial mechanical properties within each cardiac cycle. This highly dynamic assessment may help to collect information on properties of normal and altered large elastic arteries and the mechanisms involved in disease.
authors.affiliation: Clinica Medica, University of Milano-Bicocca and S. Gerardo Hospital, Monza, Milano, Italy.
authors.forename: Cristina
authors.initials: C
authors.lastname: Giannattasio
authors.forename: Paolo
authors.initials: P
authors.lastname: Salvi
authors.forename: Filippo
authors.initials: F
authors.lastname: Valbusa
authors.forename: Anna
authors.initials: A
authors.lastname: Kearney-Schwartz
authors.forename: Anna
authors.initials: A
authors.lastname: Capra
authors.forename: Maria
authors.initials: M
authors.lastname: Amigoni
authors.forename: Monica
authors.initials: M
authors.lastname: Failla
authors.forename: Lucia
authors.initials: L
authors.lastname: Boffi
authors.forename: Fabiana
authors.initials: F
authors.lastname: Madotto
authors.forename: Athanasios
authors.initials: A
authors.lastname: Benetos
authors.forename: Giuseppe
authors.initials: G
authors.lastname: Mancia
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000375:Aging / Q000502:physiology; D001696:Biomechanical Phenomena; D001794:Blood Pressure / Q000502:physiology*; D002339:Carotid Arteries / Q000000981:diagnostic imaging* / Q000502:physiology*; D003971:Diastole / Q000502:physiology; D015150:Echocardiography, Doppler / Q000379:methods*; D004548:Elasticity; D004562:Electrocardiography; D005260:Female; D006801:Humans; D008297:Male; D008365:Manometry / Q000379:methods*; D008875:Middle Aged; D009200:Myocardial Contraction / Q000502:physiology*; D013599:Systole / Q000502:physiology