Stefanadis C, Dernellis J, Toutouzas P
Department of Cardiology, Hippokration Hospital, University of Athens, Greece.
Pathol Biol (Paris). 1999 Sep;47(7):696-704.
Elastic properties of the aorta represent an important determinant of left ventricular function and coronary blood flow. Aortic pressure-diameter relation provides insights into the mechanism, involved in the alterations of the elastic properties of the aorta. Recently, we described a new method to obtain aortic pressure-diameter relation in conscious humans. Aortic strain, distensibility, pressure-diameter relation, stiffness constant, augmentation index and aortic energy loss are indexes of aortic elastic properties derived by this method. Coronary artery disease is a potent independent factor associated with aortic elastic performance. Smoking produced an acute decrease of the elastic properties of the aorta in habitual smokers. Passive smoking has a similar unfavourable effect on aortic elastic properties. Elastic properties of the aorta are deteriorated in hypertensive patients compared to normotensive subjects and energy loss due to aortic wall viscosity is increased in the first group. Tachycardia induced by ventricular pacing produces an acute increase of the aortic distensibility in humans. Intravenous 17 beta-estradiol produces an improvement of the elastic properties of the aorta in menopausal women both with and without coronary artery disease. A decrease of aortic stiffness is demonstrated during intraaortic balloon pumping, associated with significant increase of the cardiac index and significant reduction of myocardial oxygen consumption. Thus, therapeutic interventions alter the elastic properties of the aorta and improvement of the elastic properties of the aorta may be beneficial in altering the natural history of diseases.
主动脉的弹性特性是左心室功能和冠状动脉血流的重要决定因素。主动脉压力-直径关系有助于深入了解主动脉弹性特性改变所涉及的机制。最近，我们描述了一种在清醒人体中获取主动脉压力-直径关系的新方法。主动脉应变、扩张性、压力-直径关系、刚度常数、增强指数和主动脉能量损失是通过该方法得出的主动脉弹性特性指标。冠状动脉疾病是与主动脉弹性性能相关的一个强有力的独立因素。吸烟会使习惯性吸烟者的主动脉弹性特性急性下降。被动吸烟对主动脉弹性特性也有类似的不利影响。与血压正常的受试者相比，高血压患者的主动脉弹性特性会恶化，且第一组中由于主动脉壁粘性导致的能量损失会增加。心室起搏诱发的心动过速会使人体主动脉扩张性急性增加。静脉注射17β-雌二醇可改善绝经后女性（无论有无冠状动脉疾病）的主动脉弹性特性。主动脉内球囊反搏期间主动脉僵硬度降低，同时心指数显著增加，心肌耗氧量显著降低。因此，治疗干预会改变主动脉的弹性特性，而改善主动脉弹性特性可能有利于改变疾病的自然病程。
