Diseases Of The Heart Flashcards
Normal histology of the heart
Pericardium
- cellophane-like structure covering the heart
- 2 histologic parts: parietal and visceral (in between is the pericardial cavity filled with 50mL pericardial fluid)
Epicardium
- fibroelastic CT, BV, lymphatics, adipose tissue
- simple sq ep
Myocardium
- cardiac myocyte
- thickest layer
Endocardium
- luminal side of the myocardium
- thickness varies inversely with the thickness of the myocardium
- Subendocardial layer: contains veins, nerves and Purkinje fibers
Often called CONGESTIVE HEART FAILURE
Occurs when the heart is unable to pump blood at a rate sufficient to meet the metabolic demands of the tissues
Heart failure
Classification of heart failure
Right-sided and left-sided heart failure
Right sided vs Left sided heart failure
Right-sided
- most commonly caused by left-sided heart failure
- occur in patients with any disorder affecting the lungs (cor pulmonale)
- pronounced engorgement of the systemic and portal venous system; pulmonary congestion is minimal
- chiefly related to peripheral edema and visceral congestion
- nutmeg liver
Left-sided
- often caused by ischemic heart dse, HTN, aortic & mitral valve dse, 1’ myocardial dse
- consequence of passive congestion (blod backing up in the pulmonary circulation), stasis of the blood in the left-sided chambers, inadequate perfusion of downstream tissues
- congestion in the pulmonary side ➡️ pulmonary edema (long standing, lead ro hemorrhage producing heart failure cells)
- most commonly caused by left-sided heart failure
- occur in patients with any disorder affecting the lungs (cor pulmonale)
- pronounced engorgement of the systemic and portal venous system; pulmonary congestion is minimal
- chiefly related to peripheral edema and visceral congestion
- nutmeg liver
Right-sided heart failure
- often caused by ischemic heart dse, HTN, aortic & mitral valve dse, 1’ myocardial dse
- consequence of passive congestion (blod backing up in the pulmonary circulation), stasis of the blood in the left-sided chambers, inadequate perfusion of downstream tissues
- congestion in the pulmonary side ➡️ pulmonary edema (long standing, lead ro hemorrhage producing heart failure cells)
Left-sided heart failure
Increased weight and thickness of myocardium
Hypertrophy
Enlarged chamber size
Dilatation
Increased cardiac weight or size resulting from hypertrophy and dilatation
Cardiomegaly
Diseases of Pericardium
Effusion
Pericarditis
Neoplasm
- rare
- constrictive pericarditis
- mesothelioma, angiosarcoma
- sarcomaIncrease of pericardial fluid from the normal 50mL
May be serous, pus, blood, fibrinous
Globoid heart in chest radiographs
“Swinging” heart
Rapid accummulation of fluid ➡️ cardiac tamponade
Cause: viral myopericarditis, metastatic malignancy, autoimmune, drug-induced, renal failure, bleeding,TB
Effusion
Can occur 2’ to a variety of cardiac, thoracic, or systemic d/o, metastases from remote neoplasms, or cardiac surgical procedures
Primary- viral origin
Chronic- TB,fungal
Triad: chest pain, pericardial rub, ECG findings
Pericarditis
Type of fluid in Pericarditis may be a clue to an underlying dse:
- ______________ - RF, SLE, scleroderma, tumors, uremia
- ______________ - MI (Dressler ➡️ post MI), uremia, radiation,RF, SLE, open heart surgery
- ______________ - infective, bacterial
- ______________ - malignancy, TB
- ______________ - TB
- Serous
- Fibrinous
- Purulent
- Hemorrhagic
- Caseous
Diseases of the myocardium
Myocarditis
Cardiomyopathies
Ischemic/Hypertensive Heart Dse
Tumors
A diverse group of pathologic entities in which infectious microorganisms/inflam processes cause myocardial injury
Dilated, flabby
Pale patches with hemorrhage (mottled appearance)
All chambers may show dilatation
A diffuse, mononuclear (lymphocytic) infiltrate is most common
Interstitial inflam infiltrate with myocyte necrosis, fibrosis, viral inclusion bodies
- mononuclears (idiopathic, viral)
- neutrophils (bacterial)
- eosinophils (HPS, protozoa)
Myocarditis
Etiology of myocarditis
Infective:
Most- Virus (Coxsackie A)
Trypanosoma, Trichinella
Non-infectious causes
- hypersensitivity myocarditis
- SLE, RHD, Graft rejection, drugs (PCN)
- interstitial infiltrates composed of lympho, mø, many eosino
- idiopathic (giant cell myocarditis)
- widespread inflam cellular infiltrates with giant cells
- fulminant end of myocarditis spectrum, poor prognosis
Heterogenous group of diseases of myocardium assocd w/ mechanical and/or electrical dysfunction that usu exhibit inappropriate ventricular hypertrophy or dilatation due to a variety of causes (freq genetics)
Cardiomyopathies
Heart muscle disease of unknown origin assocd w cardiac dysfunction
Can be genetic or acquired dses of myocardium
Primary cardiomyopathies
Conditions in which the cardiac abnormality results fron another CVD, such as MI
Most common causes include hemochromatosis and amyloidosis
Secondary cardiomyopathies
Classification of 1’ cardiomyopathies accdg to anatomic appearance and abnormal physio
- Dilated cardiomyopathy (DCM)
- Hypertrophic cardiomyopathy (HCM)
- Restrictive cardiomyopathy (RCM)
- Arrhythmogenic cardiomyopathy/ arrhythmogenic right ventricular dysplasia (ARVD)
- Unclassified cardiomyopathies
Chard morph’ly and fxnly by progressive cardiac dilation and contractile (systolic) dysfunction, usu w concomitant hypertrophy
Most common type
Heart is dilated (biventriculat dilatation) and poorly contractile, weak
Thin-walled
Dilated cardiomyopathy
Chard by myocardial hypertrophy, poorly compliant L ventricular myocardium leading to abnormal diastolic filling and intermittent ventricular outflow obstruction
Thick-walled, heavy, hypercontracting
Marked hypertrophy of LV, IVS, and RV; nondilated chamber
Diastolic dysfunction
Most common inherited cardiac dse
Most common cause of sudden cardiac death in young athletes
Myocyte hypertrophy and disarray
Hypertrophic cardiomyopathy
Major abnormality is restriction of ventricular filling, thus an increase in filling pressures
Impaired relaxation and compliance
Stiff/rigid walls but not thickened
Biatrial dilatation due to increased filling pressure; ventricular wall has a rubbery texture
Myocyte hypertrophy, focal and diffuse perimyocytic fibrosis and focal myofiber disarray
Patchy or diffused interstitial fibrosis
Restrictive cardiomyopathy
Dse of myocardihm causing R ventricular failure and rhythm disturbances (ventricular tachycardia or fibrillation)
R ventricular wall is severely thinned due to los sof myocytes, extensive fatty infiltration and fibrosis
R and LV wall thinning
Mutation in plakoglobin (PKP2)
Arrhythmogenic cardiomyopathy
