内科学中的高血压.pptVIP

Define hypertension Hypertension is a vascular disease with blood pressure elevations .It has two clinical forms :essential (primary)hypertension and secondary hypertension. 原发性高血压以血压升高（收缩压≥ 140mmHg和（或）舒张压≥ 90mmHg）为主要临床表现的综合征，简称高血压病 病 因(pathogeny) 发病机制(mechanisms of essential hypertension)-1 BP = cardiac output x peripheral vascular resistance 交感神经系统活性亢进(Increased sympathetic nervous system activity)：情绪,应激等刺激神经中枢系统,交感神经系统活性亢进，儿茶酚胺浓度升高，阻力小动脉收缩增强,同时影响肾素分泌，升高血压（heightened vascular reactivity to alpha-adrenergic agonists by causing arteriolar and venous constriction or by altering the normalrenal pressure –volume relationship) 肾性水钠潴留(Renal Retention of Sodium)：各种病因引起的肾性水钠潴留，组织过渡灌注，全身阻力小动脉收缩( increased total body sodium and extracellular fluid volume in renal dysfuntion) 发病机制(mechanisms of essential hypertension)-2 肾素－血管紧张素－醛固酮系统(Renin-Angiotensin Aldosterone System (RAAS)激活：血管紧张素II为主要效应物质，作用于AT1受体，使小动脉收缩，并刺激醛固酮和促进交感神经系统激活（ALL functions of renin are mediated through the synthesis of angiotensin II. It will stimulate the secretion of aldosterone and hence mediates responses to varying sodium intake and volume load also Increased sympathetic nervous system activity) 发病机制(mechanisms of essential hypertension)-3 血管重建 (Vascular structural remodeling ) 多种因素的参与，血压对血管壁的冲击，血管内皮受损，水钠储留（multiple factors can cause both functional contraction and structural remodeling and Hypertrophy) 内皮细胞功能受损(Endothelial Cell Dysfunction） 舒张血管因子减少（NO,PGI2);收缩血管因子增加（ENDOTHELIN TXA2) –promote abnormal Vascular structural remodeling . 胰岛素抵抗(insulin resistance):机制不明,可能与继发高胰岛素血症有关(内皮细胞功能受损,钠储留等） 病 理 功能-------结构 心脏：左心室肥厚和扩大；冠状动脉粥样硬化（Left Ventricular Hypertrophy, coronary atherosclerotic heart disease) 脑：脑血管缺血和变性，易形成微动脉瘤，发生脑出血；脑动脉粥样硬化，发生脑血栓形成；脑小动脉闭塞性病变，引起腔隙性脑梗塞(ischemic stroke and intracerebral hemorrhage) 肾脏：肾小球纤维化、萎缩，以及肾动脉硬化导致肾功能减退(nephrosclerosis-renal dysfunction) 临床表现 症状:symptoms 大多起病缓慢、渐进，一般缺乏特异性临床表现 约1/5患者在测量血压和发生并发症时才发现 头晕、头痛、心悸,失眠等(dizzy