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Abdominal aortic hemodynamic conditions in healthy subjects aged 50–70 at rest and during lower limb exercise: in vivo quantification using MRI

      Abstract

      The prevalence of atherosclerosis in the abdominal aorta increases with age and is hypothesized to be related to adverse hemodynamic conditions including flow recirculation and low wall shear stress. Exercise has been shown to modulate these adverse conditions observed in the infrarenal aorta of healthy young subjects at rest. A custom magnetic resonance (MR)-compatible stationary cycle, an open MRI, and custom image processing software were used to quantify hemodynamic conditions in the abdominal aorta at rest and during cycling exercise in healthy subjects aged 50–70 years. The subjects increased their heart rate from 63±8 bpm at rest to 95±12 bpm during cycling exercise. Supraceliac blood flow increased from 2.3±0.4 to 6.0±1.4 l/min (P<0.001) and infrarenal flow increased from 0.9±0.3 to 4.9±1.7 l/min (P<0.001) from rest to exercise. Wall shear stress increased from 2.0±0.7 to 7.3±2.4 dynes/cm2 at the supraceliac level (P<0.001) and 1.4±0.8 to 16.5±5.1 dynes/cm2 at the infrarenal level (P<0.001) from rest to exercise. Flow and shear oscillations present at rest were eliminated during exercise. At rest, these older subjects experienced lower mean wall shear stress at the supraceliac level of the aorta and greater oscillations in wall shear stress as compared to a group of younger subjects (23.6±2.2 years). Compared to the younger subjects, the older subjects also experienced greater increases in mean wall shear stress and greater decreases in wall shear stress oscillations from rest to exercise.

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      References

      1. AHA. Risk factors and coronary heart disease. 2000; American Heart Association.

      2. AHA. Heart and stroke statistical update. 2002; American Heart Association.

        • Zicrler R.E.
        • Strandness D.E.
        Moore W.S. Hemodynamics for the vascular surgeon, in vascular surgery: a comprehensive review. W.B. Saunders Company, Philadelphia1993: 186
      3. Zarins C, Glagov S. Pathophysiology of human atherosclerosis, In: Vascular surgery. McGraw-Hill Book Company, 1986. p. 23–41.

        • Tschudi M.R.
        • Barton M.
        • Bersinger N.A.
        • Moreau P.
        • Cosentino F.
        • Noll G.
        • Malinski T.
        • Luscher T.F.
        Effect of age on kinetics of nitric oxide release in rat aorta and pulmonary artery.
        J. Clin. Invest. 1996; 98: 899-905
        • Berne R.M.
        • Levy M.N.
        Cardiovascular physiology. 7th ed. Mosby-Year Book, St. Louis1997: 139-140
        • Lazarus M.
        • Dang T.
        • Gardin J.M.
        • Allfie A.
        • Henry W.L.
        Evaluation of age, gender, heart rate and blood pressure changes and exercise conditioning on doppler measured aortic blood flow acceleration and velocity daring upright treadmill testing.
        Am. J. Cardiol. 1988; 62: 439-443
        • Imura T.
        • Yamamoto K.
        • Kanamori K.
        • Mikami T.
        • Yasvda H.
        Non-invasive ultrasonic measurement of the elastic properties of the human abdominal aorta.
        Cardiovasc. Res. 1986; 20: 208
        • Caro C.G.
        • Fitz-Gerald J.M.
        • Schroter R.C.
        Atheroma and arterial wall shear: observation, correlation and proposal of a shear dependent mass transfer mechanism for atherogenesis.
        Proc. R. Soc. Lond. Ser. B: Biol. Sci. 1971; 177: 109-159
        • Ku D.
        • Giddens D.
        • Zarins C.
        • Glagov S.
        Pulsatile flow and atherosclerosis in the human carotid bifurcation: positive correlation between plaque location and low oscillating shear stress.
        Arteriosclerosis. 1985; 5: 293-302
        • Friedman M.H.
        • Hutchins G.M.
        • Bargeron C.B.
        Correlation between intimal thickness and fluid shear in human arteries.
        Atherosclerosis. 1981; 39: 425
        • Zarins C.K.
        • Giddens D.P.
        • Bharadvaj B.K.
        • Sottiurai V.S.
        • Mabon R.F.
        • Glagov S.
        Carotid bifurcation atherosclerosis: quantitative correlation of plaque localization with flow velocity profiles and wall shear stress.
        Circ. Res. 1983; 53: 502-514
        • Zarins C.K.
        • Bomberger R.A.
        • Glagov S.
        Local effects of stenoses: increased flow velocity inhibits atherogenesis.
        Circulation. 1981; 64: II-221-II-227
        • Taylor C.A.
        • Cheng C.P.
        • Espinosa L.A.
        • Tang B.T.
        • Parker D.
        • Herfkens R.J.
        In vivo quantification of blood flow and wall shear stress in the human abdominal aorta during lower limb exercise.
        Ann. Biomed. Eng. 2002; 30: 402-408
        • Sessa W.
        • Pritchard K.
        • Seydi N.
        • Wang J.
        • Hintze T.
        Chronic exercise in dogs increases coronary vascular nitric oxide production and endothelial cell nitric oxide synthase gene expression.
        Circ. Res. 1994; 74: 349-353
        • Cybulsky M.I.
        • Gimbrone Jr., M.A.
        Endothelial expression of a mononuclear leukocyte adhesion molecule during atherogenesis.
        Science. 1991; 251: 788-791
        • Nobutaka I.
        • Ramasamy S.
        • Fukai T.
        • Neren R.
        • Harrison D.G.
        Shear stress modulates expression of Cu/Zn superoxide dismutase in human aortic endothelial cells.
        Circ. Res. 1996; 79: 32-37
        • Glagov S.
        • Rowley D.A.
        • Kohut R.
        Atherosclerosis of human aorta and its coronary and renal arteries.
        Arch. Pathol. Lab. Med. 1961; 72: 558
        • Roberts J.C.
        • Moses C.
        • Wilkins R.H.
        Autopsy studies in atherosclerosis: distribution and severity of atherosclerosis in patients dying without any morphologic evidence of atherosclerotic catastrophe.
        Circulation. 1959; 20: 511-519
        • Pelc N.J.
        • Sommer F.G.
        • Li K.C.
        • Brosnan T.J.
        • Herfkens R.J.
        • Enzmann D.R.
        Quantitative magnetic resonance flow imaging.
        Magn. Resonance Q. 1994; 10: 125-147
        • Pollock M.L.
        • Wilmore J.H.
        Exercise in health and disease: evaluation and prescription for prevention and rehabilitation. W.B. Saunders, Philadelphia1990
        • Fredrickson J.O.
        • Wegmuller H.
        • Herfkens R.J.
        • Pelc N.J.
        Simultaneous temporal resolution of cardiac and respiratory motion in MR imaging.
        Radiology. 1995; 195: 169-175
        • Sethian J.A.
        Level set methods and fast marching methods. Cambridge University Press, Cambridge, England1999
        • Wang K.
        • Dutton R.
        • Taylor C.
        Geometric image segmentation and image-based model construction for computational hemodynamics.
        IEEE Eng. Med. Biol. 1999; 18: 33-39
        • Bernstein M.A.
        • Zhou X.J.
        • Polzin J.A.
        • King K.F.
        • Ganin A.
        • Pelc N.J.
        • et al.
        Concomitant gradient terms in phase contrast MR: analysis and correction.
        Magn. Resonance Med. 1998; 39: 300-308
        • Pelc L.R.
        • Pelc N.J.
        • Rayhill S.C.
        • Castro L.J.
        • Glover G.H.
        • Herfkens R.J.
        • et al.
        Arterial and venous blood flow: noninvasive quantitation with MR imaging.
        Radiology. 1992; 185: 809-812
        • Cheng CP
        • Parker D
        • Taylor CA.
        Quantification of wall shear stress in large blood vessels using Lagrangian interpolation functions with cine PC-MRI.
        Ann Biomed Eng. 2002; 30: 1020-1032
        • He X.
        • Ku D.
        Pulsatile flow in the human left coronary artery bifurcation: average conditions.
        J. Biomech. Eng. 1996; 118: 74-82
        • Womersley J.
        Method for the calculation of velocity, rate of flow and viscous drag in arteries when the pressure gradient is known.
        J. Physiol. 1955; 127: 553-563
        • Moore J.
        • Ku D.
        Pulsatile velocity measurements in a model of the human abdominal aorta under simulated exercise and postprandial conditions.
        J. Biomech. Eng. 1994; 116: 107-111
        • Pedersen F.
        • Kozerke S.
        • Ringgaard S.
        • Scheidegger M.B.
        • Boesiger P.
        Quantitative abdominal aortic flow measurements at controlled levels of ergometer exercise.
        Magn. Resonance Imag. 1999; 17: 489-494
        • Schalet B.
        • Taylor C.
        • Harris E.
        • Herfkens R.
        • Zarins C.
        Quantitative assessment of human aortic blood flow during exercise.
        Surg. Forum. 1997; XLVIII: 359-362
        • Taylor C.A.
        • Hughes T.J.R.
        • Zarins C.K.
        Effect of exercise on hemodynamic conditions in the abdominal aorta.
        J. Vasc. Surg. 1999; 29: 1077-1089
        • Goldstone J.
        Aneurysms of the aorta and iliac arteries.
        in: Moore W.S. Vascular surgery: a comprehensive review. W.B. Saunders Company, Philadelphia1993: 401-422
        • Glagov S.
        • Vito R.
        • Giddens D.P.
        • Zarins C.K.
        Micro-architecture and composition of artery walls: relationship to location, diameter and the distribution of mechanical stress.
        J. Hyperten. 1992; 10: S101-S104
        • Halloran B.G.
        • Davis V.A.
        • McManus B.M.
        • Lynch T.G.
        • Baxter B.T.
        Localization of aortic disease is associated with intrinsic differences in aortic structure.
        J. Surg. Res. 1995; 59: 17-22
        • Womersley J.R.
        An elastic tube theory of pulse transmission and oscillatory flow in mammalian arteries. Aeronautical Research Laboratory, Wright-Patterson Air Force Base, Ohio1957