心力衰竭ppt课件

1、Heart Failure(心力衰竭心力衰竭)Department of Pathophysiology 临床医学本、医学检验本、医学影像学本适用Concept (概念概念)Heart failure(pump failure) may be defined as the condition in which the heart is no longer able to pump an adequate supply of blood for the metabolic needs of the body,provided there is adequate veneous blood.Con

2、cept(概念概念)Myocardial failure(心肌衰竭心肌衰竭) refers to the heart failure which is caused by a defect in myocardium itself. Congestive heart failure(充血性心衰充血性心衰) has a chronic course with an abnormal accumulation of fluid,which results in the expansion of intravascular blood volumeCardiac insufficiency(心功能不

3、全心功能不全) Causes of Heart Failure (心衰的病因心衰的病因) Dysfunction of myocardium (心肌构造破坏) diffuse myocardial damage: myocardial infarction;cardiopathies; myocarditi; myocardial ischemia and hypoxia: coronary heart disease;severe anemia;hypotension;shock;myocardial hypertrophy;vitamin B1 deficiency Causes of H

4、eart failure(心衰的心衰的病因病因) Overload for myocardium (心脏负荷过重心脏负荷过重) Pressure overload(afterload): systemic hypertension;pulmonary hypertension;aortic stenosis;pulmonary stenosis; Volume overload(preload): mitral and aortic regurgitation for left ventricles;tricuspid and pulmonary regurgitation for right

5、 ventriclesCauses of heart failure (心衰的病因心衰的病因) Conditions that restrict ventricular filling (心室充盈受限心室充盈受限) mitral stenosis,constrictive pericarditis, restrictive cardiomyopathy Precipitating factors (诱因诱因) Infection arrhythmias pulmonary embolism pregnancy water,eletrolytes disturbances acid-base d

6、isturbances emotionInfectionfevertachycardiahypoxiatoxinemiaIncreased demandsArrhythmias(心律失常心律失常) Reduce the time period available for ventricular filling and coronary perfusion increase the demand for myocardial oxygen the dissociation between atrial and ventricular contractions Acidosis and heart

7、 failure (酸中毒和心力衰竭酸中毒和心力衰竭) Compete with Ca2+ for combination of troponin Influence the Ca2+ trigger mechanism-reduce the sensitivity of the sarcoplasmic reticulum to the local concentrations of Ca2+; result in a reduced release of Ca2+ from the SRCompensatory mechanism in heart failure (心衰的代偿机制心衰的代

8、偿机制)1. The Frank-starling mechanism(tonogenic dilatation)2. Increased release of catecholamines 3. Myocardial hypertrophy4. Increase of blood volume and redistribution of blood flow 1.The Frank-starling mechanismSarcomere length(micron)Tension2.2Relationship between myofilament length andtension dev

9、elopment in cardiac muscle 3.652.Increased release of catecholamines (儿茶酚胺释放添加儿茶酚胺释放添加) Augment myocardial contractility(the positive inotropic effect) increase heart rate(the positive chrotropic effect) elevate the peripheral vascular resistance pressure receptor,volume receptor,chemical receptor 3

10、.Myocardial hypertrophy (心肌肥大心肌肥大) Volume overload eccentric hypertrophy Pressure overload concentric hypertrophyMyocardial hypertyophy heart failure Increased formation of a myosin isozyme,V3 uptake and release of Ca2+ by SR may be imparied diminished activity of sympathetic nervous system prolifer

11、ation of mitochondria and capillaries myofilament proliferation increased collagen in hypertrophic myocardium can lead to a reduced ventricular compliance and interfere with the filling of ventricles ?4.increase of blood volume and redistribution of blood flow (血容量添加和血流重分布血容量添加和血流重分布)Water and sodiu

12、m retensionRedistribution of blood flowClassification of heart failure (心力衰竭的分类心力衰竭的分类) Right-sided versus left-sided heart failure acute versus chronic heart failure high-output versus low-output heart failure high out-put heart failure:hyperthyrodism, anemia,arterioveneous fistulas and beriberi(an

13、y other factors that decrease the total resistance chronically will also increase the cardiac output)beriberi Lack of this vitamin causes diminished ability of the tissues to utilize cellular neutrients,which in turn causes marked peripheral vasodilation.The total peripheral resistance decreases som

14、etimes to as little as one-half normal.consequently,the long time level of cardiac output also increases to as much as 2 times normal.Pathogenesis of heart failure (心力衰竭的发活力制心力衰竭的发活力制)SarcomereThick filamentThin filamentMyosinActinTropomyosinTroponinBasic structure of sarcomereTnCTnITnTMyosinTroponi

15、nActinTropomyosinMyocardial filament slidingPathogenesis of heart failure (心力衰竭的发活力制心力衰竭的发活力制) Depressed myocardial contractility altered diastolic properties of ventricles asymmetry and asynchronism in ventricular contraction and relaxation1.Depressed myocardial contractility (心肌收缩功能降低心肌收缩功能降低) Myo

16、cardial cellular injuries Myocardial metabolic dysfunction Dysfunction of excitation-contraction coupling Alterations of the adrenergic nervous system in the failing myocardiumThe relationship between ventricular dysfunction and prognosisMyocardial infarted sizeCardiacindexMortality5-10% Normal 2%10

17、-20% Slightly decreased 10%20-40% Decreased 22%40% Markedly decreased 60%Energy liberation(ischemia) energy storageenergy utilization(hypertrophy)Myocardial metabolic dysfunction (心肌代谢妨碍心肌代谢妨碍) Disorders in liberation of energy ischemic heart disease;shock;severe anemia;hypoxia Disorders in utilizat

18、ion of energy myocardial hypertrophyDysfunction of excitation-contraction coupling (兴奋和收缩偶联妨碍兴奋和收缩偶联妨碍) Reduced uptake and release of Ca2+ by sarcoplasmic reticulum(SR) Mitochondria Ca2+ is greatly increased Extracellular Ca2+ inward movement Diturbed combination with troponinAlterations of the adre

19、nergic nervous system in the failing myocadium (交感神经系统变化交感神经系统变化) Norepinephrine depletion Dowmregulation of belta 1-receptors Uncoupling of belta 2-receptors Receptor-operated channels2.Altered diastolic properties of ventricles(舒张功能改动舒张功能改动) Dysfunction of ventricular relaxation-increased cytosol

20、Ca2+ concentration; low levels of ATP Reduced ventricular compliance- Myocardialhypertrophy;inflammation; edema;fiberosis3.Asymmetry and asynchronism in ventricular contraction and relaxation(心肌收缩舒张不协调心肌收缩舒张不协调) Hypokinesis or akinesis dyskinesis asynchronismFunctional and metabolic alterations in h

21、eart failure (功能代谢变化功能代谢变化)1.Alterations in cardiac function2.Blood pressure change3.Respiratory distressAlterations in cardiac function1. Decreased cardiac output and cardiac index(CI) 2. Decreased ejection fraction(EF): stroke volume/end diastolic volume3. Increased intracardiac pressure: LVEDP-PC

22、WP;RVEDP-CVP4. Alterations in myocardial contractility and its diastolic properties: Vmax and dp/dt max5. Blood pressure change Respiratory distress(呼吸困难呼吸困难) Dyspnea- exertional dyspnea Orthopnea- reduced pooling of fluid in the extremities and abdomen;elevation of diaphragm Paroxysmal nocturnal dyspnea- reduced adrenergic drive to the left ventricle during sleep;elevation of thracic blood volume during recunbency;normal nocturnal depression of the respiratory center;elevation of diaphragm病例病例 患者，女，36岁。主诉心慌，气闷，浮肿，腹胀三月余。患者有风湿性心脏病十年病史。近三月来又出现心慌气闷加重，不能平卧而住院治疗。检查：重病容，半卧位，颈静脉怒张，呼吸36