内科学课件心力衰竭_2

心力衰竭 Heart Failure 北京大学第一医院心内科 心力衰竭的基本概念 l心力衰竭是一组复杂的临床综合征，由于任何 心脏的异常导致心室射血功能减退，心排血量 减少：心脏不能排出静脉回心的血液体循环，肺循环淤血 肺水肿，周围水肿 组织灌注不良不能满足机体代谢所需的血液供应 呼吸困难及运动耐力下降 l心力衰竭呈进展性，预后不良，易发生猝死。 l发病率：美国：病例总数 4.8million, 40-70万新病例/年， 死亡病例25万/年。 心脏病和心力衰竭 l心力衰竭是在心脏病基础上产生的一 组综合征； l心脏病不等于心力衰竭，心脏病有一 定的功能代偿期； l心脏病的表现在心脏；心力衰竭的表 现多在心脏外。 心脏负荷和心力衰竭 l前负荷(preload)：舒张末期心室内的容量或压力 测定CVP (RAP) , PWP l后负荷(afterload)： ：心室射血时遇到的阻力 根据SVR, PVR及BP l心力衰竭是指心脏有足够的前负荷，但心排血 量减少，不能满足机体的需要； l心外原因引起的前负荷不足（脱水，失血或静 脉阻塞）所致的心排血量减低不是心力衰竭。 心力衰竭的病因 心力衰竭的原因主要包括心肌的损害及心脏负荷过重 l心肌损害： 缺血性：冠心病，占60-70%； 非缺血性：有明确原因：高血压、甲亢、酒精性及心肌炎； 不明原因：心肌病。 l负荷过重： 压力负荷过重：高血压病、主动脉瓣狭窄。 容量负荷过重：返流及分流性疾病. 。 l心室充盈受限： 机械性或心肌病变所致。 心力衰竭的诱因 l感染：呼吸道感染，心内膜炎，心脏炎 l心律失常：房颤及各种快速心律失常 l风湿热 l水电解质紊乱 l环境气候的急剧变化，过劳，精神压力及情绪激动等 l治疗不当：洋地黄中毒，利尿剂过量等 l肺栓塞 l贫血，妊娠，甲亢 心脏代偿期 失代偿 病因心力衰竭 诱因 心 力 衰 竭 的 病 理 生 理 心力衰竭的发病机理 l血流动力学异常： 泵功能衰竭, (CO、VEDP) 外周循环阻力 （SVR, PVR) 终末器官异常 l神经内分泌的激活： 交感神经系统； 肾素-血管紧张素-醛固酮系统； 精氨酸-血管加压素系统 l心肌损害和心室重构(remodeling) 心力衰竭的发病机理 l能量产生和利用障碍 l内皮功能异常 l心肌受体功能异常：受体密度降低， cAMP l前列腺素合成异常 l心房肽等分泌增加 心力衰竭的临床类型 l根据心衰发生的速度：急性，慢性； l根据部位：左心衰，右心衰，全心衰； l根据功能的异常：收缩性，舒张性； 舒张性心衰的机制：左室松弛受损，心肌细胞内Ca2+水平降低； 心肌肥厚，舒张期心肌扩张能力减弱 l根据心排血量：高心排，低心排； l前向性和后向性心衰； l无症状性心力衰竭及充血性心力衰竭。 心功能分级 New York Heart Association(NYHA) lClass I: Patients with cardiac disease but without resulting limitations of physical activity. lClass II: Patients with cardiac disease resulting in slight limitation of physical activity. They are comfortable at rest. Ordinary physical activity result in fatigue, palpitation, dyspnea or anginal pain. 心功能分级 New York Heart Association(NYHA) lClass III: Patients with cardiac disease resulting in marked limitation of physical activity.They are comfortable at rest. Less than ordinary physical activity result in fatigue, palpitation, dyspnea or anginal pain. lClass IV: Patients with cardiac disease resulting in inability to carry on any physical activity without discomfort. 心功能分级 CANADIAN CARDIOVASCULAR SOCIETY lClass I: Ordinary physical activity, such as walking and climbing stairs, does not cause angina. Angina with strenuous or rapid or prolonged exertion at work or recreation. 心功能分级 CANADIAN CARDIOVASCULAR SOCIETY lClass II: Slight limitation of ordinary activity.Walking or climbing stairs rapidly, walking uphill, walking or stair climbing after meals, in cold, in wind, or when under emotional stress, or only during the few hours after awakening. Walking more than two blocks on the level and climbing more than one flight of ordinary stairs at a normal pace and in normal conditions. 心功能分级 CANADIAN CARDIOVASCULAR SOCIETY lClassIII: Marked limitation of ordinary physical activity. Walking one to two blocks on the level and climbing more than one flight in normal conditions. lClass IV: Inability to carry on any physical activity without discomfort-angin syndrome may be present at rest. 心力衰竭的临床表现 l左心衰竭：肺淤血和心排血量降低 疲乏、呼吸困难、咳嗽 肺内湿性罗音、奔马律 l右心衰竭：体循环淤血 上腔：颈静脉怒张 下腔：周围水肿 门脉：肝大、腹水、食欲减退 l全心衰竭：二者表现并存 全心衰时，左心衰的症状可能减轻 辅助检查 l超声心动图(Echo): -确定病变的部位；收缩/舒张功能； -左室射血分数(LVEF); -心脏形态，厚度，室壁运动，瓣膜等 l同位素检查-心腔大小，室壁运动 l胸部X光检查-心脏大小，肺淤血情况，肺疾病 l心电图检查 l运动耐量试验 辅助检查-血流动力学检查 l左心功能不全： LVEDP (MS除外） 左房压力及容量 PCWP SVR HR CO，CI l右心功能不全： RVEDP CVP PVR HR CO，CI 正常值：PWP 6-12mmH， CI 2.6-4.0L/minm2 心力衰竭的诊断88:107 Management of Heart Failure Strategies for the prevention of HF lPrevention of initial injury - coronary heart disease - hypertention lPrevention of further injury lPrevention of post-injury deterioration Management of Heart Failure Strategies for the prevention of HF lControl coronary risk factors: hypertention, hyperlipidemia and smoking lUse reperfusion strategies and ACEI / -blocker in patients with AMI lUse ACEI / -blocker in patients with LV dysfunction Treatment of heart Failure general measures-1 lDecrease the risk of a new cardiac injury 1) cessation of smoking 2) weight reduction in obese patients 3) control of hypertention, hyperlipidemia and DM 4) discontinuation of alcohol use lMaintain fluid balance lPhysical condition lPrevention of infections Treatment of heart Failure general measures-2 lIn patients with atrial fibrillation - restore sinus rhythm or control the ventricular rate: digitalis, -blocker - anticoagutions lCoronary intervention in patients with angina or silent ischemia Treatment of heart Failure general measures-3 Avoided: luse of anti-arrhythmic agents for asymptomatic ventricular arrhythmias luse of most antagonists luse of nonsteroidal anti-inflammatory agents Not recommended: lnutritional supplements: coenzyme Q10, Vit. lhormone: growth hormone Treatment of heart Failure Approved Drugs Recommended Diuretics lDiuretics acts on the kidney to promote excretion of sodium and water. lThree main group of diuretics used clinically: - Loop diuretics: furosemide(lasix),bumetanide - Thiazides: hydrochlorothiazide, chlorothalidone - Potassium-sparing diuretics: spironolactone, triamterene Approved Drugs Recommended Diuretics lDiuretics produce symptomatic benefits more rapidly than any other drugs for HF; lDiuretics are the only drugs that can adequately control the fluid retention of HF; lAppropriate use of diuretics is a key element in the success of other drugs used for the treatment of HF; ldiuretics should not be used as monotherapy, should generally be combined with an ACEI and a -blocker. Approved Drugs Recommended Diuretics l注意水，电解质紊乱； l注意低血压； l根据病情选择制剂； l根据病人的肾功能选择应用； l根据病人的治疗反应调整剂量； l注意药物的相互作用； l注意药物对代谢的影响。 Approved Drugs Recommended Angiotensin-Converting Enzyme Inhibitors l作用机制： - 作用于ATI及ATII/缓激肽/前列腺素系统； - 兼有扩张动脉/ 静脉的作用； - 保K+. Mg2+, 纠正水，电解质紊乱； - 抗自由基，抗血小板； - 预防心脏的 remodeling, 增加 LVEF. Approved Drugs Recommended Angiotensin-Converting Enzyme Inhibitors l作用 - 改善临床症状,减少住院率； - 增加运动耐量； - 提高生活质量； - 改善血管的收缩状态，增加CO，降低心脏 的充盈压（LVEDP）； - 减少心律失常； - 减少利尿剂的使用剂量； - 提高生存率。 Approved Drugs Recommended Angiotensin-Converting Enzyme Inhibitors lACEI have been approved for the treatment of CHF by FDA: captopril, enalapril, lisinopril, quinapril, fosinopril. lRamipril is approved for the treatment of heart failure after AMI(HOPE study) 。 Approved Drugs Recommended Angiotensin-Converting Enzyme Inhibitors l通常于利尿剂合用，有时与洋地黄类或-阻滞剂合用 ； lACEI可以降低左室收缩功能异常但无临床症状病人发 生心力衰竭的危险； lACEI应尽早应用 l应从极小剂量开始，以后逐渐加量。 Captopril: 6.25 mg bid-tid Enalapril: 2.5 mg bid Lisinopril: 2.5-5 mg Qd l用药1-2周查一次肾功能及血K+ Vasodilator l改善心脏的做功环境，降低前后负荷，减少心 肌耗氧量，改善心室功能，提高生存率； l根据病人的血流动力学选择合适的血管扩张剂 l小剂量开始，逐渐加量； l急性期以静脉用药为主，慢性期以口服药为主 ； l避免过量引起的低血压，反射性心动过速及心 排血量降低； l常用药物：硝酸酯类，硝普钠，1受体阻滞剂 等。 血管扩张剂的分类和作用 Approved Drugs Recommended DIGITALIS lMechanism of action: - Inhibit the cell membrane Na+-K+-ATPase, intracellular Ca2+ increase myocardial contraction. - The inotropic effect of digitalis is present in both normal and failing myocardium and results in increased stroke work for a given volume. Approved Drugs Recommended DIGITALIS lImprove the clinical status of patients with HF due to LV systolic dysfunction, and HF with rapid atrial fibrillation; lShould be used in conjunction with ACEI, diuretics and -blocker. Approved Drugs Recommended DIGITALIS lNo data to recommend the use of digitalis in Patients with Asy LV systolic dysfunction; lDigitalis increases cardiac output, improves symptoms and hemodynamics in pts with HF, reduces hospitalization and deaths from worsening HF; l overall mortality is not affected. Approved Drugs Recommended DIGITALIS lContraindications: - WPW with atrial fibrillation; - SSS; - Significant sinus or A-V block; - Hypertrophic obstructive cardiomyopathy; - Mitral stenosis with sinus rhythm but no right heart failure; - Acute myocardial infarction. Approved Drugs Recommended DIGITALIS lDose of digoxin: - common dose: 0.25 mg/d - lower dose: 0.125 mg/d or 0.125 mg Qod in patients with age 70 y or impaired renal function lSerum level of digoxin: 0.52.0 ng/ml Approved Drugs Recommended DIGITALIS lAdverse effects - Cardiac arrhythmias; - Gastrointestinal symptoms; - Neurologic complaints. lDrugs interactions - Increased serum level: atropine, amiodarone, quinidine, diltizem, verapamil, cimitidine, spironolactone - Decreased serum level: antacids. Other Inotropic Drugs 1 2 1 Dopamine lIsoproterenol + + 0 0 lEpinephrine + + + 0 lNorepinephr