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Questions and Answers
Which gender is more frequently affected by the condition described?
Which gender is more frequently affected by the condition described?
Which of the following is a characteristic morphological feature of the condition?
Which of the following is a characteristic morphological feature of the condition?
What is a common clinical feature of the condition discussed?
What is a common clinical feature of the condition discussed?
What type of endocarditis is characterized by microbial infection of heart valves?
What type of endocarditis is characterized by microbial infection of heart valves?
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What is a significant complication of the condition described?
What is a significant complication of the condition described?
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Which factor is suggested as an intrinsic defect in the pathogenesis of the condition?
Which factor is suggested as an intrinsic defect in the pathogenesis of the condition?
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Which type of bacteria is primarily responsible for infective endocarditis?
Which type of bacteria is primarily responsible for infective endocarditis?
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What histological change is associated with the condition outlined?
What histological change is associated with the condition outlined?
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What is the primary characteristic of stenosis in valvular heart disease?
What is the primary characteristic of stenosis in valvular heart disease?
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What is a common feature associated with mitral valve prolapse?
What is a common feature associated with mitral valve prolapse?
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Which of the following risk factors is associated with calcific aortic stenosis?
Which of the following risk factors is associated with calcific aortic stenosis?
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Which outcome resembles the effects of severe calcific aortic stenosis?
Which outcome resembles the effects of severe calcific aortic stenosis?
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What is a primary cause of regurgitation in valvular heart disease?
What is a primary cause of regurgitation in valvular heart disease?
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Which statement is true regarding the manifestation of calcific aortic stenosis in anatomically normal valves?
Which statement is true regarding the manifestation of calcific aortic stenosis in anatomically normal valves?
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Which of the following features is typically observed in both stenosis and insufficiency of heart valves?
Which of the following features is typically observed in both stenosis and insufficiency of heart valves?
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What is the significance of age-related wear and tear in relation to calcific aortic stenosis?
What is the significance of age-related wear and tear in relation to calcific aortic stenosis?
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What is a potential underlying cause of mitral valve prolapse as indicated in the content?
What is a potential underlying cause of mitral valve prolapse as indicated in the content?
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What histological change is noted in the mitral valve associated with the discussed condition?
What histological change is noted in the mitral valve associated with the discussed condition?
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Which of the following is a common clinical finding during auscultation for mitral valve prolapse?
Which of the following is a common clinical finding during auscultation for mitral valve prolapse?
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In which condition can infective endocarditis result, affecting heart valves and endocardium?
In which condition can infective endocarditis result, affecting heart valves and endocardium?
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What characterizes the vegetations formed in infective endocarditis?
What characterizes the vegetations formed in infective endocarditis?
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Which group of bacteria is considered a common cause of infective endocarditis?
Which group of bacteria is considered a common cause of infective endocarditis?
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What is the clinical symptom that often accompanies mitral valve prolapse?
What is the clinical symptom that often accompanies mitral valve prolapse?
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Which statement describes the morphology of the mitral leaflets in mitral valve prolapse?
Which statement describes the morphology of the mitral leaflets in mitral valve prolapse?
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What primarily causes stenosis in valvular heart diseases?
What primarily causes stenosis in valvular heart diseases?
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In which condition does backflow of blood occur due to valve failure?
In which condition does backflow of blood occur due to valve failure?
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What is a common feature of mitral valve prolapse?
What is a common feature of mitral valve prolapse?
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What defines the morphology of calcific aortic stenosis?
What defines the morphology of calcific aortic stenosis?
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At what age do patients with anatomically normal valves typically begin to show symptoms of severe calcific stenosis?
At what age do patients with anatomically normal valves typically begin to show symptoms of severe calcific stenosis?
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What condition arises from the age-related degeneration and arteriosclerosis of heart valves?
What condition arises from the age-related degeneration and arteriosclerosis of heart valves?
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Which factor contributes to the complication of chronic heart failure in severe calcific aortic stenosis?
Which factor contributes to the complication of chronic heart failure in severe calcific aortic stenosis?
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What is a characteristic consequence of left ventricular outflow obstruction caused by severe calcific aortic stenosis?
What is a characteristic consequence of left ventricular outflow obstruction caused by severe calcific aortic stenosis?
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What is the primary consequence of chronic increase in preload?
What is the primary consequence of chronic increase in preload?
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Which of the following conditions is associated with high afterload?
Which of the following conditions is associated with high afterload?
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In the context of the Fick principle, what does 'Q' represent?
In the context of the Fick principle, what does 'Q' represent?
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What does an increase in stroke volume indicate in relation to cardiac performance?
What does an increase in stroke volume indicate in relation to cardiac performance?
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Which of the following methods is used for direct measurement of cardiac output?
Which of the following methods is used for direct measurement of cardiac output?
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How does the Fick principle relate to the function of the lungs?
How does the Fick principle relate to the function of the lungs?
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What is the formula used to calculate cardiac output in the Hamilton dye dilution method?
What is the formula used to calculate cardiac output in the Hamilton dye dilution method?
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In relation to venous return, what is a key factor influencing its efficiency?
In relation to venous return, what is a key factor influencing its efficiency?
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Which factor most directly influences the end diastolic volume (EDV)?
Which factor most directly influences the end diastolic volume (EDV)?
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What is the primary consequence of decreased contractility on stroke volume?
What is the primary consequence of decreased contractility on stroke volume?
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Which variable is used to calculate the ejection fraction (EF)?
Which variable is used to calculate the ejection fraction (EF)?
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In what way does physical training specifically affect stroke volume?
In what way does physical training specifically affect stroke volume?
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What does a high preload indicate regarding the volume of blood in the heart?
What does a high preload indicate regarding the volume of blood in the heart?
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What effect do thyroid hormones have on stroke volume?
What effect do thyroid hormones have on stroke volume?
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Which statement accurately describes the relationship between preload and stroke volume?
Which statement accurately describes the relationship between preload and stroke volume?
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What physiological change occurs when preload remains elevated for an extended period?
What physiological change occurs when preload remains elevated for an extended period?
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Which neural factor increases stroke volume?
Which neural factor increases stroke volume?
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What primarily defines the preload in the context of cardiac function?
What primarily defines the preload in the context of cardiac function?
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What is the primary factor that influences stroke volume during physical activity?
What is the primary factor that influences stroke volume during physical activity?
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Which component of the cardiac output calculation can be directly altered by changes in venous return?
Which component of the cardiac output calculation can be directly altered by changes in venous return?
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What does a significant decrease in ejection fraction typically indicate regarding heart function?
What does a significant decrease in ejection fraction typically indicate regarding heart function?
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What role does preload play in the regulation of stroke volume?
What role does preload play in the regulation of stroke volume?
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Which factor would most likely lead to increased afterload on the heart?
Which factor would most likely lead to increased afterload on the heart?
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Which condition is associated with decreased preload affecting stroke volume?
Which condition is associated with decreased preload affecting stroke volume?
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How does an increase in heart rate potentially affect stroke volume?
How does an increase in heart rate potentially affect stroke volume?
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What is the relationship between stroke volume and cardiac output?
What is the relationship between stroke volume and cardiac output?
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What is cardiac output (COP) defined as?
What is cardiac output (COP) defined as?
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Which factor influences heart rate (HR) by decreasing its value?
Which factor influences heart rate (HR) by decreasing its value?
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What is the primary formula to calculate cardiac output?
What is the primary formula to calculate cardiac output?
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How does physical activity typically affect stroke volume?
How does physical activity typically affect stroke volume?
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What is considered a normal resting heart rate for adults?
What is considered a normal resting heart rate for adults?
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Which of the following factors has a positive chronotropic effect on heart rate?
Which of the following factors has a positive chronotropic effect on heart rate?
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What is the relationship between heart rate and stroke volume when heart rate is very high?
What is the relationship between heart rate and stroke volume when heart rate is very high?
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Which hormones are known to increase heart rate significantly?
Which hormones are known to increase heart rate significantly?
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What does an increase in afterload primarily indicate?
What does an increase in afterload primarily indicate?
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Which method is classified as an indirect method for measuring cardiac output?
Which method is classified as an indirect method for measuring cardiac output?
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What is the correct formula according to the Fick principle for calculating blood flow?
What is the correct formula according to the Fick principle for calculating blood flow?
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Which condition is influenced by high afterload?
Which condition is influenced by high afterload?
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In the Hamilton dye dilution method, what does 'C' represent?
In the Hamilton dye dilution method, what does 'C' represent?
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What effect does chronic increase in preload have on cardiac function?
What effect does chronic increase in preload have on cardiac function?
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According to the Fick principle, what substance is consumed by the lungs to determine blood flow?
According to the Fick principle, what substance is consumed by the lungs to determine blood flow?
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What is the primary significance of venous return in cardiac physiology?
What is the primary significance of venous return in cardiac physiology?
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What primarily determines the end diastolic volume (EDV)?
What primarily determines the end diastolic volume (EDV)?
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Which factor has no direct effect on stroke volume?
Which factor has no direct effect on stroke volume?
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How is ejection fraction (EF) calculated?
How is ejection fraction (EF) calculated?
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What physiological principle relates stroke volume to the initial length of muscle fibers?
What physiological principle relates stroke volume to the initial length of muscle fibers?
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Which effect do catecholamines have on stroke volume?
Which effect do catecholamines have on stroke volume?
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Which condition causes stroke volume to increase during exercise?
Which condition causes stroke volume to increase during exercise?
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What describes the effect of fever on stroke volume?
What describes the effect of fever on stroke volume?
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What is the consequence of prolonged high preload on the heart?
What is the consequence of prolonged high preload on the heart?
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What effect does the sympathetic nervous system have on stroke volume?
What effect does the sympathetic nervous system have on stroke volume?
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What factor is indicative of myocardial contractility?
What factor is indicative of myocardial contractility?
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Study Notes
Valvular Heart Disease (VHD)
- VHD can result in stenosis or insufficiency (regurgitation) or both.
- Stenosis: Failure of a valve to open completely, impeding forward blood flow. Commonly caused by calcification or scarring of the valve cusps.
- Insufficiency (Regurgitation): Failure of a valve to close completely, allowing reversed blood flow (backflow). This is caused by intrinsic valve cusp disease or disruption of supporting structures.
- Valve abnormalities can be congenital or acquired (e.g., bicuspid aortic valve).
- Valve abnormalities lead to abnormal blood flow, causing murmurs.
Pathophysiological Mechanisms of Heart Disease
- Pump Failure: Systolic or diastolic dysfunction; results in decreased cardiac output.
- Flow Obstruction: Lesions prevent valve opening (e.g., calcific aortic stenosis) or increase ventricular chamber pressure.
- Regurgitant Flow: Results in volume overload in affected chambers due to valve lesions.
- Shunted Flow: Results in pressure and volume overload.
- Conduction Disorders: Arrhythmias lead to decreased contraction frequency and reduced effective cardiac output.
- Major Vessel or Heart Rupture: May lead to hypotension, shock, and potential death.
Heart Valve Anatomy and Histology
- Heart valves include aortic, mitral, pulmonary and tricuspid valves.
- Chordae tendineae that consist of collagen and are covered by endothelium.
- Valves have distinct layers.
Etiology of Acquired Heart Valve Disease
- Mitral Valve Disease: Mitral stenosis (post-inflammatory scarring, rheumatic heart disease), mitral regurgitation (abnormalities of leaflets and commissures, post-inflammatory scarring, infective endocarditis, mitral valve prolapse, “fen-phen”-induced valvular fibrosis, rupture of papillary muscle), and more are possible causes
- Aortic Valve Disease: Aortic stenosis (post-inflammatory scarring, rheumatic heart disease, senile calcific aortic stenosis, calcification of congenitally deformed valve), and aortic regurgitation (intrinsic valvular disease, post-inflammatory scarring, infective endocarditis, aortic disease, degenerative aortic dilation, syphilitic aortitis, ankylosing spondylitis, rheumatoid arthritis, Marfan syndrome).
Calcific Aortic Stenosis
- A degenerative valve disease.
- Most common cause of aortic stenosis.
- Age-related wear and tear.
- Age-related arteriosclerosis.
- Risk factors: Male, high LDL, hypertension, and smoking.
- Morphology: Heaped-up calcified masses on the outflow side of the cusps, cuspal calcification and fibrosis.
Clinical Features of Calcific Aortic Stenosis
- Anatomically normal valves → manifestation in 70s and 80s.
- In bicuspid valves → early onset (40-50 years).
- Severe calcific aortic stenosis → left ventricular outflow obstruction, left ventricular pressure increase, leading to concentric left ventricular hypertrophy.
Consequences of Calcific Aortic Stenosis
- Hypertrophy of Myocardium
- Poor Brain Perfusion
- Ischemic Angina
- Syncope
- Systolic Dysfunction
- Diastolic Dysfunction
- Chronic Heart Failure (CHF)
- Cardiac Decompensation
Mitral Valve Prolapse (Myxomatous Mitral Valve)
- One or both mitral leaflets are floppy and balloon back into the left atrium during systole.
- Women are affected more than men.
- Can be primary (idiopathic) or secondary.
- Morphology: Characterized by ballooning or prolapse of mitral leaflets, and enlarged, redundant, rubbery leaflets. Tendinous cords become elongated, thinned, and occasionally ruptured.
Histological appearance of Mitral Valve Prolapse
- Thinning of the fibrosa layer of the valve.
- Extension of the middle spongiosa layer with increased deposition of myxomatous (mucoid) material.
Pathogenesis of Mitral Valve Prolapse
- Largely unknown.
- Underlying intrinsic defect of connective tissue synthesis or remodeling.
- Common features of Marfan syndrome.
Clinical Features of Mitral Valve Prolapse
- Majority asymptomatic.
- Symptoms: Palpitations, dyspnea, or atypical chest pain.
- Auscultation: Midsystolic click with or without an associated regurgitant murmur.
Complications of Mitral Valve Prolapse
- Embolism Risk.
- Sudden Cardiac Death (SCD) Risk
- Infective Endocarditis Risk, Mitral Regurgitation, Congestive Heart Failure (CHF).
Infective Endocarditis (IE)
- Characterized by microbial infection of heart valves or mural endocardium.
- Often with destruction of the underlying cardiac tissues.
- Resulting in bulky, friable vegetations composed of necrotic debris, thrombus and organisms.
- Majorly caused by extracellular bacteria.
Classification of Infective Endocarditis
- Acute Endocarditis: High virulence organisms (e.g., Staphylococcus aureus), destructive lesions, substantial morbidity and mortality
- Subacute Endocarditis: Low virulence organisms (e.g., Streptococcus viridans), insidious onset, protracted course with recovery with antibiotics.
Pathogenesis of Infective Endocarditis
- Causative microorganisms (Streptococcus viridans, Staphylococcus aureus, HACEK group, Gram-negative bacilli, fungi, culture-negative (10%).
- Valvular conditions (RHD, mitral valve prolapse, bicuspid aortic valve, calcific valvular stenosis, prosthetic heart valves).
Host Risk Factors for Infective Endocarditis
- Alcohol or IV drug abuse
- Diabetes Mellitus
- Therapeutic immunosuppression
- Neutropenia
- Immunodeficiency
- Malignancy
- Predisposing condition: Seeding of blood with microbes, dental or surgical procedure bacteremia, injection of contaminated material.
Morphology of Vegetations in Infective Endocarditis
- Friable, bulky, and destructive vegetations on heart valves.
- Made up of fibrin, inflammatory cells, and microorganisms.
- May involve single or multiple valves.
- Commonly found on aortic & mitral valves (commonest).
Complications of Infective Endocarditis
- Erosion into underlying myocardium with abscess formation.
- Acute IE of congenitally bicuspid aortic valve.
- Staph. Aureus.
- Ring abscess
- Systemic emboli, Septic infarcts, mycotic aneurysms.
- presence of virulent organisms
- Subacute IE vegetations have granulation tissue at bases - fibrosis, calcification, chronic inflammatory infiltrate.
Clinical features in IE
- acute IE = rapid onset with fever, chills and weakness
- subacute IE = gradual onset with fatigue, weight loss, flu-like symptoms and splenomegaly
- vegetation patterns in different diseases: Rheumatic heart disease (RHD) , Infective endocarditis (IE), Nonbacterial thrombotic endocarditis (NBTE). Libman-Sacks endocarditis (LSE)
Microemboli Related Features
- Petechiae (small red or purple spots)
- Janeway lesions (painless erythematous lesions, found on palms and soles)
- Nail bed hemorrhages (splinter hemorrhages)
- Retinal hemorrhages (Roth spots)
- Osler nodes (painful fingertip nodules)
Diagnosis of Infective Endocarditis
- Positive blood cultures.
- Echocardiographic findings.
Complications of Infective Endocarditis
- Glomerulonephritis, hematuria, albuminuria, renal failure
- Systemic embolization
- Septicemia
- Arrhythmias
Non-Infected Vegetations (Nonbacterial Thrombotic Endocarditis (NBTE) )
- Characterized by deposition of small sterile thrombi (vegetation) on the leaflets of cardiac valves.
- Sterile valvular lesions usually on previously normal valves.
- Morphology: Sterile, non-destructive, small vegetations, may be single or multiple, bland thrombus without inflammation or valve damage
Morphology of Non-infected Vegetations(NBTE)
- Sterile, non-destructive small vegetations.
- May be single or multiple.
- Bland thrombus without inflammation or valve damage
Pathogenesis of Non-Infected Vegetations (NBTE)
- Symptoms due to embolization to the heart, brain, or other organs.
- Potential nidus of bacterial colonization and IE development.
Libman-Sacks Endocarditis (LSE)
- Sterile vegetations.
- Immune complex deposition.
- Inflammation + fibrinoid necrosis of valve.
- Characteristics: Sterile vegetations, immune-mediated inflammation and fibrinoid necrosis.
- Vegetations locations: valve surface, chordae, atrial and ventricular endocardium.
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Description
This quiz covers key concepts related to Valvular Heart Disease (VHD), including its types, mechanisms, and pathophysiological implications. Understand the differences between stenosis and insufficiency, as well as their causes and effects on blood flow. Test your knowledge on congenital and acquired valve abnormalities and their impact on heart function.
