Heart Flashcards
Rheumatic fever
- Define it
- When does it occur
- What are the 2 main problams
- Acute inflammaiton
- immunologically mediated disease
- Multisystem disease
Occurs few weeks after Phryngitis caused by Group A beta hemolytic streptococcus
- The becteria grows on the tonsils and its antigen is released into the circulation -> B cells produce Ab (NO BACTEREMIA!)
2 problemes:
- Ig cross reacts with the 3 layer of the heart
- Formation of immune complexes -> Vasculitis, glomerulonephritis.
What are the morphological consequences of the problems mentioned before in the Acute RF?
Heart
Heart:
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Aschoff bodies can be found in any of the 3 layers of the heart -> Pancarditis
- Endocardium: Verrucae
- Myocardium: Aschoff bodies
- Pericardium: fibrinous pericarditis
(Aschoff bodies are granulomatous reactions, consisting of a central zone of degenerating, hypereosinophilic extracellular matrix infiltrated by lymphocytes, plasma cells and Anitshschkow cells (/Gaint cells))
What are the morphological consequences of the problems mentioned before in the Acute RF?
in the other organs
Joints:
- due to immune complexes
- Migratory polyarthritis (affects large joints)
Skin:
- Nodules (granulomatous reaction on the skin)
- Erythema marginatum (related to vascular effection)
CNS:
- Syndenham chorea (Chorea-ataxic)
What are the morphological consequences of the chroinc RF?
-
Scarring of the verruca
- vitium (stenosis and/or insufficiency)
- Leaflet thickening - “fish-mouth” / “buttonhole” stenosis
- Aschoff nodules are replaced by fibrous scar
- Othe consequences: Mural thrombi (dilation of the left atrium), R ventricular hypertrophy due to lung changes.
Describe the clinical picture of a patient with acute/chronic RF
Acute??:
- the symptoms occur 2-3 weeks after an episode of streptococcal pharyngitis. The predominant clinical manifestations are arthritis (migratory polyarthritis + fever) and carditis (arrhythmias, CHF).
Chronic:
- vitium with complication such as murmurs, hypertrophy and dilation, CHF, arrhythmias, embolism and an increased risk for infective endocarditis
Describe the diagnosis of RF
Serologic evidence of a previous streptococcal infection, in conjunction with Jones criteria.
The rule is that we have to have 2 or more criteria or 1 Jones criteria (major manifestation) + 2 minor manifestation.
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Major manifestation (Jones criteria):
- Carditis
- Migratory polyarthritis
- Subcutaneous nodules
- Erythema marginatum
- Syndenham chorea
- Minor manifestation: fever, arthralgia, elevated acute phase proteins.
What is Non-bacterial thrombotic endocarditis?
- Deposition of fibrin, platelets and other blood components on cardiac valves.
- Can occur on **normal valve as well.
(no microorganisms)**
Describe the morphology of non-bacterial thrombotic endocarditis
-
Sterile, nondestructive, small (1mm).
- along the lines of closure of the leaflets / cusps.
- Histological appearance: thrombus without inflammation or valve damage.
- Can form Lambl excrescences = strands of fibrous tissue.
What is the pathogenesis (causes) of non-bacterial endocarditis
Typically hypercoagulable states:
- sepsis + DIC, hyperestorgenic states, malignancy (mucinous adenocarcinomas with its procoagulant effect) and also related to endocardial trauma.
When will non-bacterial endocarditis become clinically sagnificant?
- by embolization to the brain, heart or other organs
- can also increase the risk for IE
Describe what is Limban-sacks endocarditis
Sterile vegetations (patients with SLE).
immune complex deposition and thus have associated inflammation
Describe the morphology of Limban-sacks endocarditis
- Small, sterile, granular pink.
- valvulitis fibrinoid necrosis adjacent to the vegetation.
- deformity can occur.
Describe infective endocarditis
- The patient has bacteremia.
- invade the valves where it proliferates, makes necrosis, inflammation and precipitation of platelets and inflammatory cells -> called vegetation.
Vegetation = bacteria, necrotic tissue, cell debris, fibrin, inflammatory cells and platelets.
What are the possible causative agents of infective endocarditis?
Caused by extracellular bacteria (can also be caused by fungi, rickettsiae and chlamydia)
Based on the microbial virulence and whether an underlying cardiac disease is present, we classify IE into….
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Acute endocarditis:
- usually suggests a destructive infection.
- frequently involving a highly virulent organism (mostly s.aureus)
- attacking a previously normal valve.
- Highly resistance to therapy
-
Subacute endocarditis:
- refers to infections by organisms of low virulence (s.viridans)
- colonizing a previously abnormal heart (especially with deformed valves).
- Good chance for recovery after an antibiotic therapy.
Describe the morphology of infective endocarditis
- friable, bulky,potentially destructive vegetations are present on the valves.
- erode the underlying myocardium →ring abscess.
- emboli (virulent) →abscesses develop at the sites of such infarcts (septic infarcts).
The subacute form is milder.
What are the predesposing factors of IE
- rheumatic fever: (lesions on the valves)
- cardiac malformations
- prosthetic valves
- catheterization
- host factors: neutropenia, immunodeficiency, malignancy, immunosuppression, DM, alcohol, intravenous drug abuse
What are the causative agents and the source of the microorganisms of Infective endocarditis?
Causative agents (s.viridans and s.aureus)
-
HACEK
-
Haemophilus, Actinobacillus, Cardiobacterium, Eikenella and Kingella.
- (All are commensals in the oral cavity)
-
Haemophilus, Actinobacillus, Cardiobacterium, Eikenella and Kingella.
Source:
- Dental procedure (as brushing of the teeth or oral surgery)
- Injection of contaminated material
- Portal entry (stomach, intestine)
- Skin lesions
What are the possible complications of IE?
- embolization of the vegetation with development of abscesses at the site of infarct
- perforation of the valve
- ring abscess
- antigens in the circulation -> formation of immune complexes, with resultant: kidney failure, skin eruption, vasculitis, joints disease
What are the clinical features of IE?
- *Non-specific signs!** Diagnosis is based blood culture.
Subacute: fatigue, weight loss, flulike syndrome, sometime fever
Acute: fever, chills, weakness, lassitude.
Due to complications:
- Hematuria, albuminuria, renal failure, septicemia, arrhythmia
What is carcinoid heart disease?
- Morphology
Cardiac manifestation of a systemic syndrome that includes flushing, diarrhea, dermatitis and bronchoconstriction and is caused by bioactive compounds released by carcinoid tumors.
Morphology
- Glistening white intimal plaqulike thickening on the endocardial surface.
What is the pathogenesis of carcinoid heart disease?
Related to APUD cancers which produce vasoactive amines:
- serotonin, kalikrein, bradykinine, histamine, prostaglandins
- (-> neutralized in the pulmonary vessels by the mono-amino-oxidase system).
When the tumor makes liver metastasis, a huge amount of substances reach the right side of the heart before it reaches the lung. (valvular thickening)
(Can occur on the left side a patent foramen ovale or with pulmonary carcinoids)
What is Myxomatous mitral valve?
Valves are “floppy” and prolapse (protrude back into the atrium during systole)
What is the morphology of myxomatous mitral valve?
enlarged leaflets (thick and rubbery)
elongated chordae tendinae
(thin and sometimes rupture)
Histologically: thining of the fibrosa layer (accompined by desposition of myxomatous material)
What is the pahtogenesis of myxomatous mitral valve?
Primary: unknown (probably a CT defect)
Secondary: changes as a respond to chronic hemodynamic forces.
What are the symptoms of myxomatous mitral valve?
Most patients are asymptomatic (discoverd incidentally)
minority of the patients: palpitations, dyspnea, atypical chest pain.
What is calcific valve stenosis?
The valvular counterpart of age-related atherosclerosis.
“Wear and tear” → Calcification
Most commonly → aortic valve stenosis
typically occurs at age 70-80 (normal valve)
age 40-50 (congenitally defected bicuspid valve)
What are the effects of aortic valve stenosis?
Calcific masses on the outflow side of the cusps which mechanically impede valve opening
Consequence: outflow obstruction
- Leads to left ventricular pressure overload -> Concentric hyperthrophy.
The cusps become secondarily fibrosed and thickend.
What are the consequences (clinical features) of aortic valve stenosis?
hypertrophy → ischemia and angina develops
What are the prostetic heart valves and their disadvantages?
Mechanical valve
- require chronic anticoagulant -> risk for hemorrhage
- can cause RBCs hemolysis due to shear stress
- subjected to infection
Bioprosthetic valves
- less durable
- can fail because of matrix deterioration
- can perforate or tear -> valvular insufficiency
- can stiffen after implantation. Together with calcification -> stenosis
- subjected to infection
What is myocarditis?
An inflammatory process in the myocardium that results a myocardial injury
What is the morphology of myocarditis?
Microscopically:
- Interstitial inflammatory infiltrate
- Focal necrosis of myocytes adjacent to inflammatory cells.
What are the 4 different types of myocarditis?
Lymphocytic: most common, if survives the acute -> resolve or heal by fibrosis
Hypersensitivity: interstitial and perivascular infiltrates (lymphocytes, macrophages, eosinophils)
Giant cell: infiltrates composed of giant and plasma cells. focal (or extensive) necrosis
Chagas: infiltrates contains trypansomes + inflammatory cells.
What are the causes of myocarditis?
-
Viral infections: (most common)
- Coxsackieviruses A and B, cytomegalovirus, HIV.
- The injury is caused by an immune response.
-
Nonviral agents:
- Tryposome cruzi, toxoplasma gondii, trichinosis.
- Lyme disease by Borrelia Burgdorferi
-
Noninfectious causes:
- Systemic diseases of immune origin (SLE), drug hypersensitivity reactions.
What are symptomes of myocarditis?
What myocarditis might progress to?
Broad range of clinical spectrum (in between: Fatigue, dyspnea, palpitation)
Might progress to dilated cardiomyopathy
What is cardiomyopathy and the forms of it?
- A group of disease with unknown cardiac failure
- Attributed to an intrinsic myocardial dysfunction
- Diagnosed when coronary disease, valvular disease and hypertension can be excluded.
Comes in 2 forms:
- primary: disease is confined to the heart muscle.
- secondary: part of a generalized multiorgan disorder.
What are the different forms of cardiomyopathies?
- Dilated CM
- Arrhytmogenic right ventricular CM
- Hypertrophic CM
- Restrictive CM
What can be seen in dilated cardiomyopathy?
- Enlargment of the heart - reaching 800gr
- Reduced contractility -> EF < 25%
- Dillation of all chambers
- Additional signs:
- mural thrombosis (stasis)
- mitral insufficiency (dilation)
- hypertrophied muscles with fibrosis
Myocardium Hypertrophies + dilated