Copyright © Lippincott Williams & Wilkins. Unauthorized reproduction of this article is prohibited. Noninvasive assessment of carotid-femoral pulse wave velocity: the influence of body side and body contours Jelle Bossuyt a , Sandrien Van De Velde a , Majda Azermai a , Sebastian J. Vermeersch a,b , Tine L.M. De Backer a , Daniel G. Devos c , Catherine Heyse c , Jan Filipovsky d , Patrick Segers b , and Luc M. Van Bortel a Background: Recently, an expert group advised to measure carotid-femoral (cf) pulse wave velocity (PWV) on the right side of the body, and to use a sliding caliper when tape measure distance cannot be obtained in a straight line. The present study investigates the evidence for this advice by comparing the real travelled cf path lengths (RTPLs) at both body sides and comparing the straight distance (as can be obtained with a sliding caliper) with the tape measure distance. Methods: RTPLs were measured with MRI in 98 individuals (49 men, age 21–76 years). Path lengths from the aortic arch to the carotid (AA-CA) and femoral (AA-FA) sites were determined. RTPL was calculated as (AA-FA) - (AA- CA) and compared between both sides. RTPLs were compared with 80% of the direct cf distance using a tape measure and the straight cf distance obtained from MRI images. Results: RTPL was slightly longer [11 mm (12), P < 0.001] at the right side. The 80%-rule overestimated RTPLs with 0.5% at the right and 2.7% at the left side. Straight MRI distance tended (P ¼ 0.09) to perform slightly better than tape measure distance. Conclusion: The travelled cf path is slightly longer at the right than at the left body side and the straight MRI distance tends to perform better than tape measure distance. The present study supports the advice of the expert consensus group to measure cf-PWV at the right body side using a sliding caliper when tape measure distance cannot be obtained in a straight line. Keywords: arterial stiffness, body contours, body side, carotid-femoral pulse wave velocity, distance standardization Abbreviations: bpm, beats per minute; cf, carotid- femoral; CI, confidence interval; ESC, European Society of Cardiology; ESH, European Society of Hypertension; PWV, pulse wave velocity; SD, standard deviation INTRODUCTION L arge artery stiffness is an independent predictor of cardiovascular mortality and morbidity [1 – 3]. Accord- ing to the 2007 Guidelines for the Management of Arterial Hypertension of the European Society of Hypertension (ESH) and of the European Society of Cardio- logy (ESC), measurement of carotid-femoral pulse wave velocity (cf-PWV) can be considered the ‘gold standard’ method for noninvasive assessment of aortic stiffness [4]. PWV is the velocity at which a pulse wave travels along a certain segment of the arterial tree [5] and is calculated as the ratio of the distance and the time delay of a pulse wave travelling between two measurement sites. Although the time delay can be accurately estimated with many methods [6], measurement of the travelled distance appears to be less straightforward. Obviously, estimating the real intraarterial distance travelled by the pulse wave for assessment of cf- PWV by means of a measurement on the body surface provides a serious challenge. Recently, several distances measured on the body surface have been compared with the real travelled distance measured with MRI [7]. Three methods of distance measurement [7–9] revealed carotid- femoral distances that do not significantly differ from the real travelled carotid-femoral path length at the right body side. Of these three, the 80% of the direct tape measure distance from carotid to femoral was the most accurate in approaching the real travelled distance [7]. In a recent consensus document [10], it has been proposed to uniformly use this 80% rule for estimation of the travelled distance between carotid and femoral artery by tape measurement. However, this 80% rule was tested for measurements at the right carotid and femoral arteries only, and has not been validated on the left side of the body. A substantial difference in anatomy exists between the left and right common carotid artery [11]. In addition, with the common iliac bifurcation located slightly to the left of the midline of the body, it follows that the distance from this point to the measurement site at the left femoral artery will Journal of Hypertension 2013, 31:946–951 a Heymans Institute of Pharmacology, b Institute Biomedical Technology, bioMMeda, Ghent University, c Department of Cardiovascular Radiology and Magnetic Resonance Imaging, Ghent University Hospital, Ghent, Belgium and d Faculty of Medicine, Charles University, Pilsen, Czech Republic Correspondence to Jelle Bossuyt, Heymans Institute of Pharmacology, Ghent Univer- sity Hospital, De Pintelaan 185, B-9000 Ghent, Belgium. Tel: +32 9 332 00 42; fax: +32 9 332 88 00; e-mail: Jelle.Bossuyt@ugent.be Received 19 November 2012 Revised 15 January 2013 Accepted 13 February 2013 J Hypertens 31:946–951 ß 2013 Wolters Kluwer Health | Lippincott Williams & Wilkins. DOI:10.1097/HJH.0b013e328360275d 946 www.jhypertension.com Volume 31  Number 5  May 2013 Original Article