心力衰竭ppt課件

1、Heart Failure(心力衰竭心力衰竭)Department of Pathophysiology 臨床醫(yī)學(xué)本、醫(yī)學(xué)檢驗本、醫(yī)學(xué)影像學(xué)本適用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 (心肌構(gòu)造破壞) 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 (心臟負荷過重心臟負荷過重) 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 (誘因誘因) 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 (心衰的代償機制心衰的代

8、償機制)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 (兒茶酚胺釋放添加兒茶酚胺釋放添加) 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 (心力衰竭的分類心力衰竭的分類) 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 (心力衰竭的發(fā)活力制心力衰竭的發(fā)活力制)SarcomereThick filamentThin filamentMyosinActinTropomyosinTroponinBasic structure of sarcomereTnCTnITnTMyosinTroponi

15、nActinTropomyosinMyocardial filament slidingPathogenesis of heart failure (心力衰竭的發(fā)活力制心力衰竭的發(fā)活力制) Depressed myocardial contractility altered diastolic properties of ventricles asymmetry and asynchronism in ventricular contraction and relaxation1.Depressed myocardial contractility (心肌收縮功能降低心肌收縮功能降低) 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 (心肌代謝妨礙心肌代謝妨礙) 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 (興奮和收縮偶聯(lián)妨礙興奮和收縮偶聯(lián)妨礙) 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 (交感神經(jīng)系統(tǒng)變化交感神經(jīng)系統(tǒng)變化) Norepinephrine depletion Dowmregulation of belta 1-receptors Uncoupling of belta 2-receptors Receptor-operated channels2.Altered diastolic properties of ventricles(舒張功能改動舒張功能改動) 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(心肌收縮舒張不協(xié)調(diào)心肌收縮舒張不協(xié)調(diào)) Hypokinesis or akinesis dyskinesis asynchronismFunctional and metabolic alterations in h

21、eart failure (功能代謝變化功能代謝變化)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(呼吸困難呼吸困難) 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歲。主訴心慌，氣悶，浮腫，腹脹三月余?；颊哂酗L(fēng)濕性心臟病十年病史。近三月來又出現(xiàn)心慌氣悶加重，不能平臥而住院治療。檢查：重病容，半臥位，頸靜脈怒張，呼吸36