Sex difference in the mechanical properties of the abdominal aorta in human beings  Björn Sonesson, MD, Toste Länne, MD, PhD, Einar Vernersson, MD, PhD, Flemming Hansen, MD  Journal of Vascular Surgery  Volume 20, Issue 6, Pages 959-969 (December 1994) DOI: 10.1016/0741-5214(94)90234-8 Copyright © 1994 Society for Vascular Surgery and International Society for Cardiovascular Surgery, North American Chapter Terms and Conditions

Fig. 1 Ultrasonic longitudinal image of abdominal aorta with cursors locked to luminar interface of echo image of anterior and posterior wall of abdominal aorta. Tip of pressure catheter can be seen in aortic lumen. Journal of Vascular Surgery 1994 20, 959-969DOI: (10.1016/0741-5214(94)90234-8) Copyright © 1994 Society for Vascular Surgery and International Society for Cardiovascular Surgery, North American Chapter Terms and Conditions

Fig. 2 Schematic drawing of experimental set-up for simultaneous measurement of aortic diameter and pressure. Journal of Vascular Surgery 1994 20, 959-969DOI: (10.1016/0741-5214(94)90234-8) Copyright © 1994 Society for Vascular Surgery and International Society for Cardiovascular Surgery, North American Chapter Terms and Conditions

Fig. 3 A, Original tracing of mean pressure curve (upper tracing) and corresponding mean diameter curve (lower tracing) in abdominal aorta based on 10 consecutive cardiac cycles in 24-year-old man. Notice similarity in pressure and diameter curves and dicrotic wave in diastole. B, Original tracing of mean pressure curve (upper tracing) and corresponding mean diameter curve (lower tracing) in abdominal aorta based on 11 consecutive cardiac cycles in 69-year-old man. Compared with 24-year-old man's curves, dicrotic wave in diastole is absent, and, instead, an augmentation of late systole is seen. Although similarities in pressure and diameter curves of young and elderly predominate small differences do exist. Pressure and diameter have been given same maximum amplitude for sake of comparison. It can be seen that, during systole, amplitudes of diameter and pressure are same, and during diastole, when change in pressure is slower, diameter exceeds pressure amplitude. Journal of Vascular Surgery 1994 20, 959-969DOI: (10.1016/0741-5214(94)90234-8) Copyright © 1994 Society for Vascular Surgery and International Society for Cardiovascular Surgery, North American Chapter Terms and Conditions

Fig. 3 A, Original tracing of mean pressure curve (upper tracing) and corresponding mean diameter curve (lower tracing) in abdominal aorta based on 10 consecutive cardiac cycles in 24-year-old man. Notice similarity in pressure and diameter curves and dicrotic wave in diastole. B, Original tracing of mean pressure curve (upper tracing) and corresponding mean diameter curve (lower tracing) in abdominal aorta based on 11 consecutive cardiac cycles in 69-year-old man. Compared with 24-year-old man's curves, dicrotic wave in diastole is absent, and, instead, an augmentation of late systole is seen. Although similarities in pressure and diameter curves of young and elderly predominate small differences do exist. Pressure and diameter have been given same maximum amplitude for sake of comparison. It can be seen that, during systole, amplitudes of diameter and pressure are same, and during diastole, when change in pressure is slower, diameter exceeds pressure amplitude. Journal of Vascular Surgery 1994 20, 959-969DOI: (10.1016/0741-5214(94)90234-8) Copyright © 1994 Society for Vascular Surgery and International Society for Cardiovascular Surgery, North American Chapter Terms and Conditions

Fig. 4 Original tracing of P-D curve in abdominal aorta in 24-year-old man. That diameter is smaller during expansion than during retraction can be ascribed to viscoelastic properties of vessel wall and accounts for hysteresis of curves. Furthermore, P-D relation is nonlinear, revealing that aortic wall is more distensible at lower than at higher pressures. Journal of Vascular Surgery 1994 20, 959-969DOI: (10.1016/0741-5214(94)90234-8) Copyright © 1994 Society for Vascular Surgery and International Society for Cardiovascular Surgery, North American Chapter Terms and Conditions

Fig. 5 Original tracings of P-D curves in abdominal aorta in three representative women, 23, 53, and 69 years old. With increasing age steepness of P-D curve decreases, indicating that aorta becomes less distensible. Journal of Vascular Surgery 1994 20, 959-969DOI: (10.1016/0741-5214(94)90234-8) Copyright © 1994 Society for Vascular Surgery and International Society for Cardiovascular Surgery, North American Chapter Terms and Conditions

Fig. 6 P-D curves in abdominal aorta compiled from men in three different age groups, young, middle-aged, and elderly. With increasing age, P-D curve becomes less steep, aortic diameter increases, and nonlinear behavior becomes less obvious. Journal of Vascular Surgery 1994 20, 959-969DOI: (10.1016/0741-5214(94)90234-8) Copyright © 1994 Society for Vascular Surgery and International Society for Cardiovascular Surgery, North American Chapter Terms and Conditions

Fig. 7 This figure illustrates difference in P-D relationship in abdominal aorta between sexes compiled from male (solid line) and female (broken line) subjects at different ages. It shows that steepness of P-D curves decreases with increasing age in both sexes and that this occurs earlier in life in men. Thus middle-aged men have less distensible aorta than corresponding female age group, indicating that degenerative aortic wall changes appear earlier in men. Journal of Vascular Surgery 1994 20, 959-969DOI: (10.1016/0741-5214(94)90234-8) Copyright © 1994 Society for Vascular Surgery and International Society for Cardiovascular Surgery, North American Chapter Terms and Conditions

Fig. 7 This figure illustrates difference in P-D relationship in abdominal aorta between sexes compiled from male (solid line) and female (broken line) subjects at different ages. It shows that steepness of P-D curves decreases with increasing age in both sexes and that this occurs earlier in life in men. Thus middle-aged men have less distensible aorta than corresponding female age group, indicating that degenerative aortic wall changes appear earlier in men. Journal of Vascular Surgery 1994 20, 959-969DOI: (10.1016/0741-5214(94)90234-8) Copyright © 1994 Society for Vascular Surgery and International Society for Cardiovascular Surgery, North American Chapter Terms and Conditions

Fig. 7 This figure illustrates difference in P-D relationship in abdominal aorta between sexes compiled from male (solid line) and female (broken line) subjects at different ages. It shows that steepness of P-D curves decreases with increasing age in both sexes and that this occurs earlier in life in men. Thus middle-aged men have less distensible aorta than corresponding female age group, indicating that degenerative aortic wall changes appear earlier in men. Journal of Vascular Surgery 1994 20, 959-969DOI: (10.1016/0741-5214(94)90234-8) Copyright © 1994 Society for Vascular Surgery and International Society for Cardiovascular Surgery, North American Chapter Terms and Conditions

Fig. 8 This figure shows differences in P-D relations in abdominal aorta between sexes adjusted for smaller diameter of aorta in women (solid line represents data from men, broken line represents data from women). Increase in diameter with pressure is expressed as percent increase of mean diastolic diameter in corresponding age- and sex-matched group. Steepness of curves decreases with increasing age in both sexes and this occurs earlier in life in men. This indicates that degenerative aortic wall changes appear earlier in life in men. Journal of Vascular Surgery 1994 20, 959-969DOI: (10.1016/0741-5214(94)90234-8) Copyright © 1994 Society for Vascular Surgery and International Society for Cardiovascular Surgery, North American Chapter Terms and Conditions