MEASUREMENT OF REGIONAL ELASTIC PROPERTIES OF THE HUMAN AORTA - A NEW APPLICATION OF TRANSESOPHAGEAL ECHOCARDIOGRAPHY WITH AUTOMATED BORDER DETECTION AND CALIBRATED SUBCLAVIAN PULSE TRACINGS

Article

关键词: AGE-RELATED CHANGES;    ESSENTIAL-HYPERTENSION;    PRESSURE MEASUREMENTS;    BOUNDARY DETECTION;    BRACHIAL-ARTERY;    CONSCIOUS DOGS;    BLOOD-FLOW;    DIAMETER;    STIFFNESS;    DISTENSIBILITY;   

DOI  :  10.1161/01.CIR.90.4.1875

来源: SCIE

【 摘 要 】

Background Evaluation of regional aortic elastic properties in humans has been hampered by the need for invasive techniques to access instantaneous aortic pressure, wall thickness, and cross-sectional area or diameter. In this study, a new noninvasive method is presented for quantification of regional aortic elastic properties. Methods and Results Twenty-five patients were studied during transesophageal echocardiographic procedures. Measurements of instantaneous aortic cross-sectional area were obtained with an automated border detection algorithm applied to short-axis transesophageal two-dimensional echocardiographic images of the proximal descending thoracic aorta. Instantaneous aortic wall thickness was derived from combined two-dimensional targeted M-mode end-diastolic wall thickness and instantaneous aortic area measurements. Instantaneous aortic pressures were estimated from calibrated subclavian pulse tracings recorded simultaneously. Data were digitized to generate aortic area-pressure loops. Regional aortic mechanical properties were quantified in terms of compliance per unit length (C is the slope of the area-pressure regression), aortic midwall radius (R(m)), and incremental elastic modulus of the aortic wall (E(inc)). To assess the independent effect of age, R(m) and E(inc) values were compared at a common level of aortic midwall stress (0.666x10(6) dynes/cm(2)). Mean values (+/-SD) for C, R(m) and E(inc) were 0.01+/-0.004 cm(2)/mm Hg, 1.14+/-0.17 cm, and 7.059+/-4.091x10(6) dynes/cm(2), respectively. An inverse linear correlation was found between aortic compliance per unit length and age (r=-.68, P<.0007). Incremental elastic modulus was related to age (r=+.80, P<.00003) in a nonlinear fashion such that it increased sharply after the age of 60 years. Finally, midwall radius was less tightly correlated with age (r=+.45, P<.05). Values for C, R(m), and E(inc) as well as the age dependency of these properties are similar to those reported previously when invasive techniques were used. Conclusions This methodology constitutes a new tool to improve the clinical evaluation of regional aortic elastic properties in multiple disease states.

【 授权许可】

Free