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Heart Failure and Intrinsic Myocardial Disease. Heart Failure. I nability of the heart to pump blood at a rate that is adequate for the body’s needs. High mortality - >50% in less than 5 years Contributing cause of death in 300,000 annually, 2,000,000 being treated
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Heart Failure Inability of the heart to pump blood at a rate that is adequate for the body’s needs. High mortality - >50% in less than 5 years Contributing cause of death in 300,000 annually, 2,000,000 being treated Leading discharge diagnosis in hospitalized patients over 65 years of age
Starling’s Law of the Heart • The stroke volume of the heart is a function of the diastolic fiber length and the heart will pump whatever volume of blood is brought to it. • Or the increased preload dilation helps to sustain cardiac performance by enhancing contractility
Principles of cardiac Dysfunction • Failure of the pump itself • An obstruction to flow - overworks the chamber behind the obstruction • Regurgitant flow - increased volume workload • Disorders of cardiac conduction - non uniform and inefficient contractions • Disruption of the continuity of the circulatory system
Congestive Heart Failure • Cardiogenic - myocardial weakness • High output - excessive workload • Thyroid toxicosis • Reduced return - inadequate filling (cardiac tamponade)
Heart Failure • Systolic dysfunction- most, deterioration of myocardial contractile function • Diastolic dysfunction- inability of the chamber to relax, expand or fill during diastole
Left Sided Heart Failure • Ischemic heart disease • Hypertension • Aortic and mitral valve disease • Non ischemic myocardial disease (cardiomyopathies)
Pulmonary edema- left heart failure
Right - Sided Heart Failure • Left heart failure • Cor pulmonale - pure right heart failure due to pulmonary hypertension
Effects of Heart Failure • Dilation of the heart (LHF & RHF) • Pulmonary edema and congestion(LHF) • Pleural effusions (LHF & RHF) • Renal failure (pre-renal azotemia) LHF & RHF • Congestion of liver - “nutmeg” liver (RHF) • Splenic congestion(RHF) • Ascites (RHF) • Dependent edema (RHF)
Causes of CHF • Congenital HD • Ischemic HD • Valvular HD • Cardiomyopathy • Inflammatory disease of the heart • Nutritional, endocrine, metabolic
Cardiac Hypertrophy • Onset of heart failure is preceded by cardiac hypertrophy • Increase rate of protein synthesis, # of sarcomeres, # of mitochondria • Pressure (concentric) hypertrophy • At some point the heart can no longer accommodate the increased demand
Cardiac Hypertrophy • Heart failure preceded by hypertrophy • Pressure overloaded ventricles (HTN or AS) develop concentric hypertrophy- increased thickness and normal to reduced cavity diameter • Volume overloaded ventricles (AR or MR), develop hypertrophy and dilatation • IHD & pulmonary hypertension up to 600gm • HTN, AS, MR or DCM up to 800 gm • AR or HCM up to 1000 gm
Myocardial Disease • Clinical features • Arrhythmias -EKG • Pain • Rapid cardiac enlargement • Rapid onset of CHF • Sudden Death • By definition no significant coronary artery disease, valvular HD, or hypertensive HD
Myocarditis - Infectious • Viral: coxsackie A, B, ECHO, influenza , polio, HIV • interstitial lymphocytes • isolated cell degeneration • Rickettsial- more of a vasculitis • Fungal and protozoan -toxoplasmosis and Chagas disease • Bacterial • Borrelia burgdorferi (Lyme disease)Corynebacterium diphtheriae- toxin
Chaga’s disease toxoplasmosis
“Myocarditis”- Non-Infectious • Hypersensitivity diseases • Radiation • Sarcoidosis, uremia
Cardiomyopathy • Heart disease not due to: • ischemia, hypertension, congenital abnormalities, or valvular heart disease • Idiopathic(meaning not one of the above) • Dilated cardiomyopathy (DCM) • Hypertrophic cardiomyopathy (HCM) • Restrictive cardiomyopathy
Primary Cardiomyopathy • Dilated: cardiac dilation CHF, arrhythmias • Hypertrophic: myocardial hypertrophy with or without outflow obstruction • Restrictive: amyloidosis, endocardial fibroelastosis , endomyocardial fibrosis
Dilated Cardiomyopathy • Progressive hypertrophy, dilation and contractile (systolic)dysfunction • Residual from a myocarditis- some cases have shown viral nucleic acids in the myocytes • Alcohol or other toxicity • Pregnancy-associated • Genetic - familial in some (20%) • Most truly idiopathic
DCM • Heavy >600gms (2 to 3 times normal) • Large , flabby with dilated chambers • Sometimes mural thrombi • Coronaries clear • Hypertrophied fibers, but stretched , large nuclei, and interstitial fibrosis
Clinical Features of DCM • Any age but 20 to 50 most common • Progressive congestive heart failure • End stage have ejection fractions < 25% • 50% die within 2 years, • 25% 5 year survival rate • Die of heart failure, arrhythmia, or embolism
Hypertrophic Cardiomyopathy • Myocardial hypertrophy • Abnormal diastolic filling • Intermittent left ventricular outflow obstruction • Hypercontracting heart • Large heart, asymmetric septal hypertrophy • Myofiber disarray
HCM • Over half are familial, auto. dominant • Any one of 4 genes that encode proteins of the sarcomeres • B-myosin heavy chain (most) • Cardiac troponin T • Alpha-tropomyosin • Myosin-binding protein C
HCM Clinical Features • Reduced chamber size and reduced stroke volume leads to massively hypertrophied left ventricle • DOE • Harsh systolic ejection murmur • Focal ischemia, anginal pain • Atrial fib, emboli, endocarditis & sudden death
Hypertrophic CM Note septal bulging
Secondary Cardiomyopathy • Alcoholic • Metabolic • thyroid, K+ • glycogen storage • nutritional • hemochromatosis
Restrictive CM • Decrease in ventricular compliance resulting in impaired ventricular filling during diastole - contractile function OK • Confused with constrictive pericarditis • Idiopathic or radiation fibrosis, amyloid, sarcoidosis, metastatic tumor • Heart normal size and usually not dilated
2o Cardiomyopathy • Connective tissue diseases: • SLE, PSS, PAN • Neuromuscular disease: MD, etc. • Mucopolysaccharidoses: Hunter’s • Toxic: emetine, arsenic, cobalt • Infiltrative: leukemia • Drugs- Anthracycline (doxorubicin and daunorubicin) dose dependent >500 mg/m2 lipid peroxidation of myocyte membranes
Leutic (Syphilis) Heart Disease • Obliterative endarteritis - plasma cells • Aneurysm of thoracic aorta • Tree barking • Narrowing of ostia of coronary arteries • Severe ASVD at root of aorta • Dilation of aorta valve ring - (aortic insufficency) • Marked LVH - cor bovinum