Valvular Heart Disease Flashcards
(30 cards)
What are the main learning objectives of the course on Valvular Heart Disease?
- Overview of pathological changes affecting cardiac valves
- Describe clinical picture & pathogenesis of Rheumatic Fever (RF)
- Appreciate how acute RF can lead to chronic Rheumatic Heart Disease (RHD)
- Recognise differences in pathological changes of heart valves in acute vs chronic conditions
- Describe how RHD predisposes to Subacute Infective Endocarditis (IE)
- Recognize differences between acute and subacute infective endocarditis
The learning objectives guide the educational focus of the course.
What is the definition of Acute Rheumatic Fever (RF)?
Acute, immunologically mediated, multisystem inflammatory disease occurring weeks after Group A Streptococcal (GAS) pharyngitis.
Occurs in approximately 3% of patients following GAS infection.
What are the clinical features of Rheumatic Fever?
- Pancarditis
- Migratory polyarthritis of large joints
- Subcutaneous nodules
- Erythema marginatum of the skin
- Sydenham chorea
Sydenham chorea is a neurologic disorder characterized by involuntary movements.
What is the pathogenesis of Rheumatic Fever?
Cross-reactivity to group A streptococci with self antigens in the heart, also known as molecular mimicry.
This leads to immunological responses that cause inflammation.
What are the main types of valve pathology?
- Stenosis (Narrowing)
- Regurgitation (Incompetence)
- Functional changes
Stenosis causes obstruction to blood flow, while regurgitation leads to reversed blood flow.
What are the complications of valve pathology?
- Chamber Hypertrophy
- Chamber Dilation
- Atrial Fibrillation (AF)
- Heart failure
- Susceptibility to Infective Endocarditis
These complications arise due to pressure and volume overload.
What is the most common deformity in chronic Rheumatic Heart Disease (RHD)?
Mitral stenosis.
The mitral valve is almost always involved in RHD.
What are the risk factors for Rheumatic Fever?
- Crowded housing conditions
- Cold damp housing
- Socio-economic deprivation
- Barriers to primary healthcare access
- Higher burden of untreated Streptococcal throat infections
These factors contribute to the incidence of RF in certain populations.
What is the difference between acute and subacute infective endocarditis?
- Acute: High virulence organisms (e.g., Staph. aureus)
- Subacute: Low virulence organisms affecting previously damaged valves
Subacute infective endocarditis often follows minor procedures in patients with valve pathologies.
Fill in the blank: The inflammation of all three layers of the heart in Rheumatic Fever is called _______.
Pancarditis.
What morphologic changes occur in Rheumatic Myocarditis?
- Aschoff bodies
- Lymphocytic infiltration
- Abnormal macrophages (Anitschkow cells)
Aschoff bodies are characterized by central necrosis surrounded by inflammatory cells.
What is the significance of verrucae in Rheumatic Endocarditis?
Sterile vegetations that form on the valves, do not embolize.
Unlike the vegetations seen in infective endocarditis, verrucae are sterile.
What is the hallmark of Rheumatic Heart Disease?
Valvular scarring and deformity.
This occurs due to cumulative damage from recurrent Rheumatic Fever.
What is the typical appearance of mitral valve deformities in RHD?
- Fused commissures
- Fibrosed and thickened leaflets
- ‘Button-hole’ or ‘fish-mouth’ appearance
These changes can lead to valve dysfunction.
True or False: Infective Endocarditis is characterized by colonization of heart valves by low virulence organisms only.
False.
Infective Endocarditis can be caused by both high and low virulence organisms.
Fill in the blank: The primary organism associated with acute Infective Endocarditis is _______.
Staphylococcus aureus.
What is the primary concern with contaminated needles shared by IV drug users?
Infective endocarditis due to IV injection reaching the right side of the heart
The tricuspid valve is frequently affected in this setting.
What are the two types of Infective Endocarditis?
Acute Infective Endocarditis and Subacute Infective Endocarditis
Acute involves high virulence organisms; subacute involves low virulence organisms.
Which organisms are associated with Acute Infective Endocarditis?
- Staphylococcus aureus
- Streptococcus pyogenes
- Occasionally fungi
These organisms are considered high virulence.
What organisms are typically involved in Subacute Infective Endocarditis?
- Oral flora including Streptococcus viridans
- Enterococci
- Haemophilus
These are considered low virulence organisms.
What type of patient is likely to have Acute Infective Endocarditis?
Normal valve ± debilitated patient (e.g., IV drug use)
This indicates a high-risk group for acute infection.
What characterizes the infection in Acute Infective Endocarditis?
Destructive, rampant infection with 20-40% fatality
Symptoms include big, bulky, friable vegetations.
What are the clinical features of Subacute Infective Endocarditis?
Low grade infection: fever, heart murmur
Less valvular destruction occurs in the subacute form.
What are septic vegetations?
Big, bulky, friable vegetations containing bacteria, fibrin, and inflammatory cells
Associated with Acute Infective Endocarditis.
