Cheitlin Melvin D
University of California at San Francisco, Former Chief of Cardiology, San Francisco General Hospital, San Francisco, CA 94110, USA.
Am J Geriatr Cardiol. 2003 Jan-Feb;12(1):9-13. doi: 10.1111/j.1076-7460.2003.01751.x.
With aging there are changes in the cardiovascular system, which result in alterations in cardiovascular physiology. The changes in cardiovascular physiology must be differentiated from the effects of pathology, such as coronary artery disease, that occur with increasing frequency as age increases. The changes with age occur in everyone but not necessarily at the same rate, therefore accounting for the difference seen in some people between chronologic age and physiologic age. The changes in the cardiovascular system associated with aging are a decrease in elasticity and an increase in stiffness of the arterial system. This results in increased afterload on the left ventricle, an increase in systolic blood pressure, and left ventricular hypertrophy, as well as other changes in the left ventricular wall that prolong relaxation of the left ventricle in diastole. There is a dropout of atrial pacemaker cells resulting in a decrease in intrinsic heart rate. With fibrosis of the cardiac skeleton there is calcification at the base of the aortic valve and damage to the His bundle as it perforates the right fibrous trigone. Finally there is decreased responsiveness to beta adrenergic receptor stimulation, a decreased reactivity to baroreceptors and chemoreceptors, and an increase in circulating catecholamines. These changes set the stage for isolated systolic hypertension, diastolic dysfunction and heart failure, atrioventricular conduction defects, and aortic valve calcification, all diseases seen in the elderly.
随着年龄增长，心血管系统会发生变化，从而导致心血管生理功能的改变。心血管生理功能的变化必须与病理影响区分开来，比如冠状动脉疾病，随着年龄增长其发病率会不断上升。年龄相关的变化在每个人身上都会发生，但速率不一定相同，因此这就解释了为何有些人的实际年龄和生理年龄存在差异。与衰老相关的心血管系统变化包括动脉系统弹性降低和硬度增加。这会导致左心室后负荷增加、收缩压升高以及左心室肥厚，同时左心室壁也会出现其他变化，从而延长舒张期左心室的松弛时间。心房起搏细胞减少会导致固有心率下降。随着心脏骨骼纤维化，主动脉瓣基部会出现钙化，希氏束在穿过右纤维三角区时也会受损。最后，对β肾上腺素能受体刺激的反应性降低，对压力感受器和化学感受器的反应性降低，循环儿茶酚胺增加。这些变化为单纯收缩期高血压、舒张功能障碍和心力衰竭、房室传导缺陷以及主动脉瓣钙化埋下了隐患，这些都是老年人常见的疾病。
